// Copyright 2009 Free Software Foundation, Inc.
// Written by Doug Kwan <dougkwan@google.com> based on the i386 code
// by Ian Lance Taylor <iant@google.com>.
+// This file also contains borrowed and adapted code from
+// bfd/elf32-arm.c.
// This file is part of gold.
#include <limits>
#include <cstdio>
#include <string>
+#include <algorithm>
#include "elfcpp.h"
#include "parameters.h"
#include "target-select.h"
#include "tls.h"
#include "defstd.h"
+#include "gc.h"
namespace
{
template<bool big_endian>
class Output_data_plt_arm;
+template<bool big_endian>
+class Stub_table;
+
+template<bool big_endian>
+class Arm_input_section;
+
+template<bool big_endian>
+class Arm_output_section;
+
+template<bool big_endian>
+class Arm_relobj;
+
+template<bool big_endian>
+class Target_arm;
+
+// For convenience.
+typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
+
+// Maximum branch offsets for ARM, THUMB and THUMB2.
+const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
+const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
+const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
+const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
+const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
+const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
+
// The arm target class.
//
// This is a very simple port of gold for ARM-EABI. It is intended for
//
// R_ARM_NONE
// R_ARM_ABS32
+// R_ARM_ABS32_NOI
+// R_ARM_ABS16
+// R_ARM_ABS12
+// R_ARM_ABS8
+// R_ARM_THM_ABS5
+// R_ARM_BASE_ABS
// R_ARM_REL32
// R_ARM_THM_CALL
// R_ARM_COPY
// R_ARM_RELATIVE
// R_ARM_GOTOFF32
// R_ARM_GOT_BREL
+// R_ARM_GOT_PREL
// R_ARM_PLT32
// R_ARM_CALL
// R_ARM_JUMP24
// R_ARM_TARGET1
// R_ARM_PREL31
+// R_ARM_ABS8
+// R_ARM_MOVW_ABS_NC
+// R_ARM_MOVT_ABS
+// R_ARM_THM_MOVW_ABS_NC
+// R_ARM_THM_MOVT_ABS
+// R_ARM_MOVW_PREL_NC
+// R_ARM_MOVT_PREL
+// R_ARM_THM_MOVW_PREL_NC
+// R_ARM_THM_MOVT_PREL
//
// TODOs:
// - Generate various branch stubs.
// Thumb-2 and BE8.
// There are probably a lot more.
-// Utilities for manipulating integers of up to 32-bits
+// Instruction template class. This class is similar to the insn_sequence
+// struct in bfd/elf32-arm.c.
-namespace utils
+class Insn_template
{
- // Sign extend an n-bit unsigned integer stored in an uint32_t into
- // an int32_t. NO_BITS must be between 1 to 32.
- template<int no_bits>
- static inline int32_t
- sign_extend(uint32_t bits)
+ public:
+ // Types of instruction templates.
+ enum Type
+ {
+ THUMB16_TYPE = 1,
+ THUMB32_TYPE,
+ ARM_TYPE,
+ DATA_TYPE
+ };
+
+ // Factory methods to create instrunction templates in different formats.
+
+ static const Insn_template
+ thumb16_insn(uint32_t data)
+ { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
+
+ // A bit of a hack. A Thumb conditional branch, in which the proper
+ // condition is inserted when we build the stub.
+ static const Insn_template
+ thumb16_bcond_insn(uint32_t data)
+ { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 1); }
+
+ static const Insn_template
+ thumb32_insn(uint32_t data)
+ { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
+
+ static const Insn_template
+ thumb32_b_insn(uint32_t data, int reloc_addend)
{
- gold_assert(no_bits >= 0 && no_bits <= 32);
- if (no_bits == 32)
- return static_cast<int32_t>(bits);
- uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
- bits &= mask;
- uint32_t top_bit = 1U << (no_bits - 1);
- int32_t as_signed = static_cast<int32_t>(bits);
- return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
- }
+ return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
+ reloc_addend);
+ }
- // Detects overflow of an NO_BITS integer stored in a uint32_t.
- template<int no_bits>
- static inline bool
- has_overflow(uint32_t bits)
+ static const Insn_template
+ arm_insn(uint32_t data)
+ { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
+
+ static const Insn_template
+ arm_rel_insn(unsigned data, int reloc_addend)
+ { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
+
+ static const Insn_template
+ data_word(unsigned data, unsigned int r_type, int reloc_addend)
+ { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
+
+ // Accessors. This class is used for read-only objects so no modifiers
+ // are provided.
+
+ uint32_t
+ data() const
+ { return this->data_; }
+
+ // Return the instruction sequence type of this.
+ Type
+ type() const
+ { return this->type_; }
+
+ // Return the ARM relocation type of this.
+ unsigned int
+ r_type() const
+ { return this->r_type_; }
+
+ int32_t
+ reloc_addend() const
+ { return this->reloc_addend_; }
+
+ // Return size of instrunction template in bytes.
+ size_t
+ size() const;
+
+ // Return byte-alignment of instrunction template.
+ unsigned
+ alignment() const;
+
+ private:
+ // We make the constructor private to ensure that only the factory
+ // methods are used.
+ inline
+ Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
+ : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
+ { }
+
+ // Instruction specific data. This is used to store information like
+ // some of the instruction bits.
+ uint32_t data_;
+ // Instruction template type.
+ Type type_;
+ // Relocation type if there is a relocation or R_ARM_NONE otherwise.
+ unsigned int r_type_;
+ // Relocation addend.
+ int32_t reloc_addend_;
+};
+
+// Macro for generating code to stub types. One entry per long/short
+// branch stub
+
+#define DEF_STUBS \
+ DEF_STUB(long_branch_any_any) \
+ DEF_STUB(long_branch_v4t_arm_thumb) \
+ DEF_STUB(long_branch_thumb_only) \
+ DEF_STUB(long_branch_v4t_thumb_thumb) \
+ DEF_STUB(long_branch_v4t_thumb_arm) \
+ DEF_STUB(short_branch_v4t_thumb_arm) \
+ DEF_STUB(long_branch_any_arm_pic) \
+ DEF_STUB(long_branch_any_thumb_pic) \
+ DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
+ DEF_STUB(long_branch_v4t_arm_thumb_pic) \
+ DEF_STUB(long_branch_v4t_thumb_arm_pic) \
+ DEF_STUB(long_branch_thumb_only_pic) \
+ DEF_STUB(a8_veneer_b_cond) \
+ DEF_STUB(a8_veneer_b) \
+ DEF_STUB(a8_veneer_bl) \
+ DEF_STUB(a8_veneer_blx)
+
+// Stub types.
+
+#define DEF_STUB(x) arm_stub_##x,
+typedef enum
{
- gold_assert(no_bits >= 0 && no_bits <= 32);
- if (no_bits == 32)
- return false;
- int32_t max = (1 << (no_bits - 1)) - 1;
- int32_t min = -(1 << (no_bits - 1));
- int32_t as_signed = static_cast<int32_t>(bits);
- return as_signed > max || as_signed < min;
+ arm_stub_none,
+ DEF_STUBS
+
+ // First reloc stub type.
+ arm_stub_reloc_first = arm_stub_long_branch_any_any,
+ // Last reloc stub type.
+ arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
+
+ // First Cortex-A8 stub type.
+ arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
+ // Last Cortex-A8 stub type.
+ arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
+
+ // Last stub type.
+ arm_stub_type_last = arm_stub_a8_veneer_blx
+ } Stub_type;
+#undef DEF_STUB
+
+// Stub template class. Templates are meant to be read-only objects.
+// A stub template for a stub type contains all read-only attributes
+// common to all stubs of the same type.
+
+class Stub_template
+{
+ public:
+ Stub_template(Stub_type, const Insn_template*, size_t);
+
+ ~Stub_template()
+ { }
+
+ // Return stub type.
+ Stub_type
+ type() const
+ { return this->type_; }
+
+ // Return an array of instruction templates.
+ const Insn_template*
+ insns() const
+ { return this->insns_; }
+
+ // Return size of template in number of instructions.
+ size_t
+ insn_count() const
+ { return this->insn_count_; }
+
+ // Return size of template in bytes.
+ size_t
+ size() const
+ { return this->size_; }
+
+ // Return alignment of the stub template.
+ unsigned
+ alignment() const
+ { return this->alignment_; }
+
+ // Return whether entry point is in thumb mode.
+ bool
+ entry_in_thumb_mode() const
+ { return this->entry_in_thumb_mode_; }
+
+ // Return number of relocations in this template.
+ size_t
+ reloc_count() const
+ { return this->relocs_.size(); }
+
+ // Return index of the I-th instruction with relocation.
+ size_t
+ reloc_insn_index(size_t i) const
+ {
+ gold_assert(i < this->relocs_.size());
+ return this->relocs_[i].first;
}
- // Detects overflow of an NO_BITS integer stored in a uint32_t when it
- // fits in the given number of bits as either a signed or unsigned value.
- // For example, has_signed_unsigned_overflow<8> would check
- // -128 <= bits <= 255
- template<int no_bits>
- static inline bool
- has_signed_unsigned_overflow(uint32_t bits)
+ // Return the offset of the I-th instruction with relocation from the
+ // beginning of the stub.
+ section_size_type
+ reloc_offset(size_t i) const
{
- gold_assert(no_bits >= 2 && no_bits <= 32);
- if (no_bits == 32)
- return false;
- int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
- int32_t min = -(1 << (no_bits - 1));
- int32_t as_signed = static_cast<int32_t>(bits);
- return as_signed > max || as_signed < min;
+ gold_assert(i < this->relocs_.size());
+ return this->relocs_[i].second;
}
- // Select bits from A and B using bits in MASK. For each n in [0..31],
- // the n-th bit in the result is chosen from the n-th bits of A and B.
- // A zero selects A and a one selects B.
- static inline uint32_t
- bit_select(uint32_t a, uint32_t b, uint32_t mask)
- { return (a & ~mask) | (b & mask); }
+ private:
+ // This contains information about an instruction template with a relocation
+ // and its offset from start of stub.
+ typedef std::pair<size_t, section_size_type> Reloc;
+
+ // A Stub_template may not be copied. We want to share templates as much
+ // as possible.
+ Stub_template(const Stub_template&);
+ Stub_template& operator=(const Stub_template&);
+
+ // Stub type.
+ Stub_type type_;
+ // Points to an array of Insn_templates.
+ const Insn_template* insns_;
+ // Number of Insn_templates in insns_[].
+ size_t insn_count_;
+ // Size of templated instructions in bytes.
+ size_t size_;
+ // Alignment of templated instructions.
+ unsigned alignment_;
+ // Flag to indicate if entry is in thumb mode.
+ bool entry_in_thumb_mode_;
+ // A table of reloc instruction indices and offsets. We can find these by
+ // looking at the instruction templates but we pre-compute and then stash
+ // them here for speed.
+ std::vector<Reloc> relocs_;
};
-template<bool big_endian>
-class Target_arm : public Sized_target<32, big_endian>
+//
+// A class for code stubs. This is a base class for different type of
+// stubs used in the ARM target.
+//
+
+class Stub
{
+ private:
+ static const section_offset_type invalid_offset =
+ static_cast<section_offset_type>(-1);
+
public:
- typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
- Reloc_section;
+ Stub(const Stub_template* stub_template)
+ : stub_template_(stub_template), offset_(invalid_offset)
+ { }
- Target_arm()
- : Sized_target<32, big_endian>(&arm_info),
- got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
- copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL)
+ virtual
+ ~Stub()
{ }
- // Process the relocations to determine unreferenced sections for
- // garbage collection.
- void
- gc_process_relocs(const General_options& options,
- Symbol_table* symtab,
- Layout* layout,
- Sized_relobj<32, big_endian>* object,
- unsigned int data_shndx,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- bool needs_special_offset_handling,
- size_t local_symbol_count,
- const unsigned char* plocal_symbols);
+ // Return the stub template.
+ const Stub_template*
+ stub_template() const
+ { return this->stub_template_; }
- // Scan the relocations to look for symbol adjustments.
- void
- scan_relocs(const General_options& options,
- Symbol_table* symtab,
- Layout* layout,
- Sized_relobj<32, big_endian>* object,
- unsigned int data_shndx,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- bool needs_special_offset_handling,
- size_t local_symbol_count,
- const unsigned char* plocal_symbols);
+ // Return offset of code stub from beginning of its containing stub table.
+ section_offset_type
+ offset() const
+ {
+ gold_assert(this->offset_ != invalid_offset);
+ return this->offset_;
+ }
- // Finalize the sections.
+ // Set offset of code stub from beginning of its containing stub table.
void
- do_finalize_sections(Layout*);
-
- // Return the value to use for a dynamic symbol which requires special
- // treatment.
- uint64_t
- do_dynsym_value(const Symbol*) const;
+ set_offset(section_offset_type offset)
+ { this->offset_ = offset; }
+
+ // Return the relocation target address of the i-th relocation in the
+ // stub. This must be defined in a child class.
+ Arm_address
+ reloc_target(size_t i)
+ { return this->do_reloc_target(i); }
- // Relocate a section.
+ // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
void
- relocate_section(const Relocate_info<32, big_endian>*,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- bool needs_special_offset_handling,
- unsigned char* view,
- elfcpp::Elf_types<32>::Elf_Addr view_address,
- section_size_type view_size,
- const Reloc_symbol_changes*);
+ write(unsigned char* view, section_size_type view_size, bool big_endian)
+ { this->do_write(view, view_size, big_endian); }
- // Scan the relocs during a relocatable link.
- void
- scan_relocatable_relocs(const General_options& options,
- Symbol_table* symtab,
- Layout* layout,
- Sized_relobj<32, big_endian>* object,
- unsigned int data_shndx,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- bool needs_special_offset_handling,
- size_t local_symbol_count,
- const unsigned char* plocal_symbols,
- Relocatable_relocs*);
+ protected:
+ // This must be defined in the child class.
+ virtual Arm_address
+ do_reloc_target(size_t) = 0;
- // Relocate a section during a relocatable link.
- void
- relocate_for_relocatable(const Relocate_info<32, big_endian>*,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- off_t offset_in_output_section,
- const Relocatable_relocs*,
- unsigned char* view,
- elfcpp::Elf_types<32>::Elf_Addr view_address,
- section_size_type view_size,
- unsigned char* reloc_view,
- section_size_type reloc_view_size);
+ // This must be defined in the child class.
+ virtual void
+ do_write(unsigned char*, section_size_type, bool) = 0;
+
+ private:
+ // Its template.
+ const Stub_template* stub_template_;
+ // Offset within the section of containing this stub.
+ section_offset_type offset_;
+};
- // Return whether SYM is defined by the ABI.
- bool
- do_is_defined_by_abi(Symbol* sym) const
- { return strcmp(sym->name(), "__tls_get_addr") == 0; }
+// Reloc stub class. These are stubs we use to fix up relocation because
+// of limited branch ranges.
- // Return the size of the GOT section.
- section_size_type
- got_size()
+class Reloc_stub : public Stub
+{
+ public:
+ static const unsigned int invalid_index = static_cast<unsigned int>(-1);
+ // We assume we never jump to this address.
+ static const Arm_address invalid_address = static_cast<Arm_address>(-1);
+
+ // Return destination address.
+ Arm_address
+ destination_address() const
{
- gold_assert(this->got_ != NULL);
- return this->got_->data_size();
+ gold_assert(this->destination_address_ != this->invalid_address);
+ return this->destination_address_;
}
- // Map platform-specific reloc types
- static unsigned int
- get_real_reloc_type (unsigned int r_type);
+ // Set destination address.
+ void
+ set_destination_address(Arm_address address)
+ {
+ gold_assert(address != this->invalid_address);
+ this->destination_address_ = address;
+ }
- private:
- // The class which scans relocations.
- class Scan
+ // Reset destination address.
+ void
+ reset_destination_address()
+ { this->destination_address_ = this->invalid_address; }
+
+ // Determine stub type for a branch of a relocation of R_TYPE going
+ // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
+ // the branch target is a thumb instruction. TARGET is used for look
+ // up ARM-specific linker settings.
+ static Stub_type
+ stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
+ Arm_address branch_target, bool target_is_thumb);
+
+ // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
+ // and an addend. Since we treat global and local symbol differently, we
+ // use a Symbol object for a global symbol and a object-index pair for
+ // a local symbol.
+ class Key
{
public:
- Scan()
- : issued_non_pic_error_(false)
+ // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
+ // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
+ // and R_SYM must not be invalid_index.
+ Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
+ unsigned int r_sym, int32_t addend)
+ : stub_type_(stub_type), addend_(addend)
+ {
+ if (symbol != NULL)
+ {
+ this->r_sym_ = Reloc_stub::invalid_index;
+ this->u_.symbol = symbol;
+ }
+ else
+ {
+ gold_assert(relobj != NULL && r_sym != invalid_index);
+ this->r_sym_ = r_sym;
+ this->u_.relobj = relobj;
+ }
+ }
+
+ ~Key()
{ }
- inline void
- local(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_arm* target,
- Sized_relobj<32, big_endian>* object,
- unsigned int data_shndx,
- Output_section* output_section,
- const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
- const elfcpp::Sym<32, big_endian>& lsym);
+ // Accessors: Keys are meant to be read-only object so no modifiers are
+ // provided.
- inline void
- global(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_arm* target,
- Sized_relobj<32, big_endian>* object,
- unsigned int data_shndx,
- Output_section* output_section,
- const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
- Symbol* gsym);
+ // Return stub type.
+ Stub_type
+ stub_type() const
+ { return this->stub_type_; }
- private:
- static void
- unsupported_reloc_local(Sized_relobj<32, big_endian>*,
- unsigned int r_type);
+ // Return the local symbol index or invalid_index.
+ unsigned int
+ r_sym() const
+ { return this->r_sym_; }
+
+ // Return the symbol if there is one.
+ const Symbol*
+ symbol() const
+ { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
+
+ // Return the relobj if there is one.
+ const Relobj*
+ relobj() const
+ { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
+
+ // Whether this equals to another key k.
+ bool
+ eq(const Key& k) const
+ {
+ return ((this->stub_type_ == k.stub_type_)
+ && (this->r_sym_ == k.r_sym_)
+ && ((this->r_sym_ != Reloc_stub::invalid_index)
+ ? (this->u_.relobj == k.u_.relobj)
+ : (this->u_.symbol == k.u_.symbol))
+ && (this->addend_ == k.addend_));
+ }
- static void
- unsupported_reloc_global(Sized_relobj<32, big_endian>*,
- unsigned int r_type, Symbol*);
+ // Return a hash value.
+ size_t
+ hash_value() const
+ {
+ return (this->stub_type_
+ ^ this->r_sym_
+ ^ gold::string_hash<char>(
+ (this->r_sym_ != Reloc_stub::invalid_index)
+ ? this->u_.relobj->name().c_str()
+ : this->u_.symbol->name())
+ ^ this->addend_);
+ }
- void
- check_non_pic(Relobj*, unsigned int r_type);
+ // Functors for STL associative containers.
+ struct hash
+ {
+ size_t
+ operator()(const Key& k) const
+ { return k.hash_value(); }
+ };
- // Almost identical to Symbol::needs_plt_entry except that it also
- // handles STT_ARM_TFUNC.
- static bool
- symbol_needs_plt_entry(const Symbol* sym)
+ struct equal_to
{
- // An undefined symbol from an executable does not need a PLT entry.
- if (sym->is_undefined() && !parameters->options().shared())
- return false;
+ bool
+ operator()(const Key& k1, const Key& k2) const
+ { return k1.eq(k2); }
+ };
- return (!parameters->doing_static_link()
- && (sym->type() == elfcpp::STT_FUNC
- || sym->type() == elfcpp::STT_ARM_TFUNC)
- && (sym->is_from_dynobj()
- || sym->is_undefined()
- || sym->is_preemptible()));
- }
+ // Name of key. This is mainly for debugging.
+ std::string
+ name() const;
- // Whether we have issued an error about a non-PIC compilation.
- bool issued_non_pic_error_;
+ private:
+ // Stub type.
+ Stub_type stub_type_;
+ // If this is a local symbol, this is the index in the defining object.
+ // Otherwise, it is invalid_index for a global symbol.
+ unsigned int r_sym_;
+ // If r_sym_ is invalid index. This points to a global symbol.
+ // Otherwise, this points a relobj. We used the unsized and target
+ // independent Symbol and Relobj classes instead of Sized_symbol<32> and
+ // Arm_relobj. This is done to avoid making the stub class a template
+ // as most of the stub machinery is endianity-neutral. However, it
+ // may require a bit of casting done by users of this class.
+ union
+ {
+ const Symbol* symbol;
+ const Relobj* relobj;
+ } u_;
+ // Addend associated with a reloc.
+ int32_t addend_;
};
- // The class which implements relocation.
- class Relocate
- {
- public:
- Relocate()
- { }
+ protected:
+ // Reloc_stubs are created via a stub factory. So these are protected.
+ Reloc_stub(const Stub_template* stub_template)
+ : Stub(stub_template), destination_address_(invalid_address)
+ { }
- ~Relocate()
- { }
+ ~Reloc_stub()
+ { }
- // Return whether the static relocation needs to be applied.
- inline bool
- should_apply_static_reloc(const Sized_symbol<32>* gsym,
- int ref_flags,
- bool is_32bit,
- Output_section* output_section);
+ friend class Stub_factory;
- // Do a relocation. Return false if the caller should not issue
- // any warnings about this relocation.
- inline bool
- relocate(const Relocate_info<32, big_endian>*, Target_arm*,
- Output_section*, size_t relnum,
- const elfcpp::Rel<32, big_endian>&,
- unsigned int r_type, const Sized_symbol<32>*,
- const Symbol_value<32>*,
- unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
- section_size_type);
+ private:
+ // Return the relocation target address of the i-th relocation in the
+ // stub.
+ Arm_address
+ do_reloc_target(size_t i)
+ {
+ // All reloc stub have only one relocation.
+ gold_assert(i == 0);
+ return this->destination_address_;
+ }
- // Return whether we want to pass flag NON_PIC_REF for this
- // reloc.
- static inline bool
- reloc_is_non_pic (unsigned int r_type)
- {
- switch (r_type)
- {
- case elfcpp::R_ARM_REL32:
- case elfcpp::R_ARM_THM_CALL:
- case elfcpp::R_ARM_CALL:
- case elfcpp::R_ARM_JUMP24:
- case elfcpp::R_ARM_PREL31:
- return true;
- default:
- return false;
- }
- }
- };
+ // A template to implement do_write below.
+ template<bool big_endian>
+ void inline
+ do_fixed_endian_write(unsigned char*, section_size_type);
- // A class which returns the size required for a relocation type,
- // used while scanning relocs during a relocatable link.
- class Relocatable_size_for_reloc
- {
- public:
- unsigned int
- get_size_for_reloc(unsigned int, Relobj*);
- };
+ // Write a stub.
+ void
+ do_write(unsigned char* view, section_size_type view_size, bool big_endian);
- // Get the GOT section, creating it if necessary.
- Output_data_got<32, big_endian>*
- got_section(Symbol_table*, Layout*);
+ // Address of destination.
+ Arm_address destination_address_;
+};
- // Get the GOT PLT section.
- Output_data_space*
- got_plt_section() const
+// Stub factory class.
+
+class Stub_factory
+{
+ public:
+ // Return the unique instance of this class.
+ static const Stub_factory&
+ get_instance()
{
- gold_assert(this->got_plt_ != NULL);
- return this->got_plt_;
+ static Stub_factory singleton;
+ return singleton;
}
- // Create a PLT entry for a global symbol.
- void
- make_plt_entry(Symbol_table*, Layout*, Symbol*);
-
- // Get the PLT section.
- const Output_data_plt_arm<big_endian>*
- plt_section() const
+ // Make a relocation stub.
+ Reloc_stub*
+ make_reloc_stub(Stub_type stub_type) const
{
- gold_assert(this->plt_ != NULL);
- return this->plt_;
+ gold_assert(stub_type >= arm_stub_reloc_first
+ && stub_type <= arm_stub_reloc_last);
+ return new Reloc_stub(this->stub_templates_[stub_type]);
}
- // Get the dynamic reloc section, creating it if necessary.
- Reloc_section*
- rel_dyn_section(Layout*);
+ private:
+ // Constructor and destructor are protected since we only return a single
+ // instance created in Stub_factory::get_instance().
+
+ Stub_factory();
- // Return true if the symbol may need a COPY relocation.
- // References from an executable object to non-function symbols
- // defined in a dynamic object may need a COPY relocation.
+ // A Stub_factory may not be copied since it is a singleton.
+ Stub_factory(const Stub_factory&);
+ Stub_factory& operator=(Stub_factory&);
+
+ // Stub templates. These are initialized in the constructor.
+ const Stub_template* stub_templates_[arm_stub_type_last+1];
+};
+
+// A class to hold stubs for the ARM target.
+
+template<bool big_endian>
+class Stub_table : public Output_data
+{
+ public:
+ Stub_table(Arm_input_section<big_endian>* owner)
+ : Output_data(), addralign_(1), owner_(owner), has_been_changed_(false),
+ reloc_stubs_()
+ { }
+
+ ~Stub_table()
+ { }
+
+ // Owner of this stub table.
+ Arm_input_section<big_endian>*
+ owner() const
+ { return this->owner_; }
+
+ // Whether this stub table is empty.
bool
- may_need_copy_reloc(Symbol* gsym)
- {
- return (gsym->type() != elfcpp::STT_ARM_TFUNC
- && gsym->may_need_copy_reloc());
- }
+ empty() const
+ { return this->reloc_stubs_.empty(); }
- // Add a potential copy relocation.
+ // Whether this has been changed.
+ bool
+ has_been_changed() const
+ { return this->has_been_changed_; }
+
+ // Set the has-been-changed flag.
void
- copy_reloc(Symbol_table* symtab, Layout* layout,
- Sized_relobj<32, big_endian>* object,
- unsigned int shndx, Output_section* output_section,
- Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
+ set_has_been_changed(bool value)
+ { this->has_been_changed_ = value; }
+
+ // Return the current data size.
+ off_t
+ current_data_size() const
+ { return this->current_data_size_for_child(); }
+
+ // Add a STUB with using KEY. Caller is reponsible for avoid adding
+ // if already a STUB with the same key has been added.
+ void
+ add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key);
+
+ // Look up a relocation stub using KEY. Return NULL if there is none.
+ Reloc_stub*
+ find_reloc_stub(const Reloc_stub::Key& key) const
{
- this->copy_relocs_.copy_reloc(symtab, layout,
- symtab->get_sized_symbol<32>(sym),
- object, shndx, output_section, reloc,
- this->rel_dyn_section(layout));
+ typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
+ return (p != this->reloc_stubs_.end()) ? p->second : NULL;
}
- // Information about this specific target which we pass to the
- // general Target structure.
- static const Target::Target_info arm_info;
+ // Relocate stubs in this stub table.
+ void
+ relocate_stubs(const Relocate_info<32, big_endian>*,
+ Target_arm<big_endian>*, Output_section*,
+ unsigned char*, Arm_address, section_size_type);
- // The types of GOT entries needed for this platform.
- enum Got_type
- {
- GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol
- };
+ protected:
+ // Write out section contents.
+ void
+ do_write(Output_file*);
+
+ // Return the required alignment.
+ uint64_t
+ do_addralign() const
+ { return this->addralign_; }
- // The GOT section.
- Output_data_got<32, big_endian>* got_;
- // The PLT section.
- Output_data_plt_arm<big_endian>* plt_;
- // The GOT PLT section.
- Output_data_space* got_plt_;
- // The dynamic reloc section.
- Reloc_section* rel_dyn_;
- // Relocs saved to avoid a COPY reloc.
- Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
- // Space for variables copied with a COPY reloc.
- Output_data_space* dynbss_;
-};
+ // Finalize data size.
+ void
+ set_final_data_size()
+ { this->set_data_size(this->current_data_size_for_child()); }
-template<bool big_endian>
-const Target::Target_info Target_arm<big_endian>::arm_info =
-{
- 32, // size
- big_endian, // is_big_endian
- elfcpp::EM_ARM, // machine_code
- false, // has_make_symbol
- false, // has_resolve
- false, // has_code_fill
- true, // is_default_stack_executable
- '\0', // wrap_char
- "/usr/lib/libc.so.1", // dynamic_linker
- 0x8000, // default_text_segment_address
- 0x1000, // abi_pagesize (overridable by -z max-page-size)
- 0x1000, // common_pagesize (overridable by -z common-page-size)
- elfcpp::SHN_UNDEF, // small_common_shndx
- elfcpp::SHN_UNDEF, // large_common_shndx
- 0, // small_common_section_flags
- 0 // large_common_section_flags
+ // Reset address and file offset.
+ void
+ do_reset_address_and_file_offset();
+
+ private:
+ // Unordered map of stubs.
+ typedef
+ Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
+ Reloc_stub::Key::equal_to>
+ Reloc_stub_map;
+
+ // Address alignment
+ uint64_t addralign_;
+ // Owner of this stub table.
+ Arm_input_section<big_endian>* owner_;
+ // This is set to true during relaxiong if the size of the stub table
+ // has been changed.
+ bool has_been_changed_;
+ // The relocation stubs.
+ Reloc_stub_map reloc_stubs_;
};
-// Arm relocate functions class
-//
+// A class to wrap an ordinary input section containing executable code.
template<bool big_endian>
-class Arm_relocate_functions : public Relocate_functions<32, big_endian>
+class Arm_input_section : public Output_relaxed_input_section
{
public:
- typedef enum
- {
- STATUS_OKAY, // No error during relocation.
- STATUS_OVERFLOW, // Relocation oveflow.
- STATUS_BAD_RELOC // Relocation cannot be applied.
- } Status;
+ Arm_input_section(Relobj* relobj, unsigned int shndx)
+ : Output_relaxed_input_section(relobj, shndx, 1),
+ original_addralign_(1), original_size_(0), stub_table_(NULL)
+ { }
- private:
- typedef Relocate_functions<32, big_endian> Base;
- typedef Arm_relocate_functions<big_endian> This;
+ ~Arm_input_section()
+ { }
- // Get an symbol value of *PSYMVAL with an ADDEND. This is a wrapper
- // to Symbol_value::value(). If HAS_THUMB_BIT is true, that LSB is used
- // to distinguish ARM and THUMB functions and it is treated specially.
- static inline Symbol_value<32>::Value
- arm_symbol_value (const Sized_relobj<32, big_endian> *object,
- const Symbol_value<32>* psymval,
- Symbol_value<32>::Value addend,
- bool has_thumb_bit)
- {
- typedef Symbol_value<32>::Value Valtype;
+ // Initialize.
+ void
+ init();
+
+ // Whether this is a stub table owner.
+ bool
+ is_stub_table_owner() const
+ { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
- if (has_thumb_bit)
- {
- Valtype raw = psymval->value(object, 0);
- Valtype thumb_bit = raw & 1;
- return ((raw & ~((Valtype) 1)) + addend) | thumb_bit;
- }
+ // Return the stub table.
+ Stub_table<big_endian>*
+ stub_table() const
+ { return this->stub_table_; }
+
+ // Set the stub_table.
+ void
+ set_stub_table(Stub_table<big_endian>* stub_table)
+ { this->stub_table_ = stub_table; }
+
+ // Downcast a base pointer to an Arm_input_section pointer. This is
+ // not type-safe but we only use Arm_input_section not the base class.
+ static Arm_input_section<big_endian>*
+ as_arm_input_section(Output_relaxed_input_section* poris)
+ { return static_cast<Arm_input_section<big_endian>*>(poris); }
+
+ protected:
+ // Write data to output file.
+ void
+ do_write(Output_file*);
+
+ // Return required alignment of this.
+ uint64_t
+ do_addralign() const
+ {
+ if (this->is_stub_table_owner())
+ return std::max(this->stub_table_->addralign(),
+ this->original_addralign_);
else
- return psymval->value(object, addend);
+ return this->original_addralign_;
}
- // FIXME: This probably only works for Android on ARM v5te. We should
- // following GNU ld for the general case.
- template<unsigned r_type>
- static inline typename This::Status
- arm_branch_common(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
+ // Finalize data size.
+ void
+ set_final_data_size();
+
+ // Reset address and file offset.
+ void
+ do_reset_address_and_file_offset();
+
+ // Output offset.
+ bool
+ do_output_offset(const Relobj* object, unsigned int shndx,
+ section_offset_type offset,
+ section_offset_type* poutput) const
{
- typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
- Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
-
- bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
- && ((val & 0x0f000000UL) == 0x0a000000UL);
- bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
- bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
- && ((val & 0x0f000000UL) == 0x0b000000UL);
- bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
- bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
-
- if (r_type == elfcpp::R_ARM_CALL)
- {
- if (!insn_is_uncond_bl && !insn_is_blx)
- return This::STATUS_BAD_RELOC;
- }
- else if (r_type == elfcpp::R_ARM_JUMP24)
- {
- if (!insn_is_b && !insn_is_cond_bl)
- return This::STATUS_BAD_RELOC;
- }
- else if (r_type == elfcpp::R_ARM_PLT32)
+ if ((object == this->relobj())
+ && (shndx == this->shndx())
+ && (offset >= 0)
+ && (convert_types<uint64_t, section_offset_type>(offset)
+ <= this->original_size_))
{
- if (!insn_is_any_branch)
- return This::STATUS_BAD_RELOC;
+ *poutput = offset;
+ return true;
}
else
- gold_unreachable();
+ return false;
+ }
- Valtype addend = utils::sign_extend<26>(val << 2);
- Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
- - address);
+ private:
+ // Copying is not allowed.
+ Arm_input_section(const Arm_input_section&);
+ Arm_input_section& operator=(const Arm_input_section&);
+
+ // Address alignment of the original input section.
+ uint64_t original_addralign_;
+ // Section size of the original input section.
+ uint64_t original_size_;
+ // Stub table.
+ Stub_table<big_endian>* stub_table_;
+};
- // If target has thumb bit set, we need to either turn the BL
- // into a BLX (for ARMv5 or above) or generate a stub.
- if (x & 1)
- {
- // Turn BL to BLX.
- if (insn_is_uncond_bl)
- val = (val & 0xffffff) | 0xfa000000 | ((x & 2) << 23);
- else
- return This::STATUS_BAD_RELOC;
- }
- else
- gold_assert(!insn_is_blx);
+// Arm output section class. This is defined mainly to add a number of
+// stub generation methods.
- val = utils::bit_select(val, (x >> 2), 0xffffffUL);
- elfcpp::Swap<32, big_endian>::writeval(wv, val);
- return (utils::has_overflow<26>(x)
- ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
- }
+template<bool big_endian>
+class Arm_output_section : public Output_section
+{
+ public:
+ Arm_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags)
+ : Output_section(name, type, flags)
+ { }
+ ~Arm_output_section()
+ { }
+
+ // Group input sections for stub generation.
+ void
+ group_sections(section_size_type, bool, Target_arm<big_endian>*);
+
+ // Downcast a base pointer to an Arm_output_section pointer. This is
+ // not type-safe but we only use Arm_output_section not the base class.
+ static Arm_output_section<big_endian>*
+ as_arm_output_section(Output_section* os)
+ { return static_cast<Arm_output_section<big_endian>*>(os); }
+
+ private:
+ // For convenience.
+ typedef Output_section::Input_section Input_section;
+ typedef Output_section::Input_section_list Input_section_list;
+
+ // Create a stub group.
+ void create_stub_group(Input_section_list::const_iterator,
+ Input_section_list::const_iterator,
+ Input_section_list::const_iterator,
+ Target_arm<big_endian>*,
+ std::vector<Output_relaxed_input_section*>*);
+};
+
+// Arm_relobj class.
+
+template<bool big_endian>
+class Arm_relobj : public Sized_relobj<32, big_endian>
+{
public:
+ static const Arm_address invalid_address = static_cast<Arm_address>(-1);
- // R_ARM_ABS8: S + A
- static inline typename This::Status
- abs8(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval, bool has_thumb_bit)
+ Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
+ const typename elfcpp::Ehdr<32, big_endian>& ehdr)
+ : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
+ stub_tables_(), local_symbol_is_thumb_function_()
+ { }
+
+ ~Arm_relobj()
+ { }
+
+ // Return the stub table of the SHNDX-th section if there is one.
+ Stub_table<big_endian>*
+ stub_table(unsigned int shndx) const
{
- typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
- typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
- Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
- Reltype addend = utils::sign_extend<8>(val);
- Reltype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit);
- val = utils::bit_select(val, x, 0xffU);
- elfcpp::Swap<8, big_endian>::writeval(wv, val);
- return (utils::has_signed_unsigned_overflow<8>(x)
- ? This::STATUS_OVERFLOW
- : This::STATUS_OKAY);
+ gold_assert(shndx < this->stub_tables_.size());
+ return this->stub_tables_[shndx];
}
- // R_ARM_ABS32: (S + A) | T
- static inline typename This::Status
- abs32(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- bool has_thumb_bit)
+ // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
+ void
+ set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
{
- typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
- Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
- Valtype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit);
- elfcpp::Swap<32, big_endian>::writeval(wv, x);
- return This::STATUS_OKAY;
+ gold_assert(shndx < this->stub_tables_.size());
+ this->stub_tables_[shndx] = stub_table;
}
- // R_ARM_REL32: (S + A) | T - P
- static inline typename This::Status
- rel32(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
+ // Whether a local symbol is a THUMB function. R_SYM is the symbol table
+ // index. This is only valid after do_count_local_symbol is called.
+ bool
+ local_symbol_is_thumb_function(unsigned int r_sym) const
{
- typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
- Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
- Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
- - address);
- elfcpp::Swap<32, big_endian>::writeval(wv, x);
- return This::STATUS_OKAY;
+ gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
+ return this->local_symbol_is_thumb_function_[r_sym];
}
+
+ // Scan all relocation sections for stub generation.
+ void
+ scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
+ const Layout*);
- // R_ARM_THM_CALL: (S + A) | T - P
- static inline typename This::Status
- thm_call(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
+ // Convert regular input section with index SHNDX to a relaxed section.
+ void
+ convert_input_section_to_relaxed_section(unsigned shndx)
{
- // A thumb call consists of two instructions.
- typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
- typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
- Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype hi = elfcpp::Swap<16, big_endian>::readval(wv);
- Valtype lo = elfcpp::Swap<16, big_endian>::readval(wv + 1);
- // Must be a BL instruction. lo == 11111xxxxxxxxxxx.
- gold_assert((lo & 0xf800) == 0xf800);
- Reltype addend = utils::sign_extend<23>(((hi & 0x7ff) << 12)
- | ((lo & 0x7ff) << 1));
- Reltype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
- - address);
+ // The stubs have relocations and we need to process them after writing
+ // out the stubs. So relocation now must follow section write.
+ this->invalidate_section_offset(shndx);
+ this->set_relocs_must_follow_section_writes();
+ }
+
+ // Downcast a base pointer to an Arm_relobj pointer. This is
+ // not type-safe but we only use Arm_relobj not the base class.
+ static Arm_relobj<big_endian>*
+ as_arm_relobj(Relobj* relobj)
+ { return static_cast<Arm_relobj<big_endian>*>(relobj); }
+
+ // Processor-specific flags in ELF file header. This is valid only after
+ // reading symbols.
+ elfcpp::Elf_Word
+ processor_specific_flags() const
+ { return this->processor_specific_flags_; }
+
+ protected:
+ // Post constructor setup.
+ void
+ do_setup()
+ {
+ // Call parent's setup method.
+ Sized_relobj<32, big_endian>::do_setup();
+
+ // Initialize look-up tables.
+ Stub_table_list empty_stub_table_list(this->shnum(), NULL);
+ this->stub_tables_.swap(empty_stub_table_list);
+ }
+
+ // Count the local symbols.
+ void
+ do_count_local_symbols(Stringpool_template<char>*,
+ Stringpool_template<char>*);
+
+ void
+ do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
+ const unsigned char* pshdrs,
+ typename Sized_relobj<32, big_endian>::Views* pivews);
+
+ // Read the symbol information.
+ void
+ do_read_symbols(Read_symbols_data* sd);
+
+ private:
+ // List of stub tables.
+ typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
+ Stub_table_list stub_tables_;
+ // Bit vector to tell if a local symbol is a thumb function or not.
+ // This is only valid after do_count_local_symbol is called.
+ std::vector<bool> local_symbol_is_thumb_function_;
+ // processor-specific flags in ELF file header.
+ elfcpp::Elf_Word processor_specific_flags_;
+};
+
+// Arm_dynobj class.
+
+template<bool big_endian>
+class Arm_dynobj : public Sized_dynobj<32, big_endian>
+{
+ public:
+ Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
+ const elfcpp::Ehdr<32, big_endian>& ehdr)
+ : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
+ processor_specific_flags_(0)
+ { }
+
+ ~Arm_dynobj()
+ { }
+
+ // Downcast a base pointer to an Arm_relobj pointer. This is
+ // not type-safe but we only use Arm_relobj not the base class.
+ static Arm_dynobj<big_endian>*
+ as_arm_dynobj(Dynobj* dynobj)
+ { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
+
+ // Processor-specific flags in ELF file header. This is valid only after
+ // reading symbols.
+ elfcpp::Elf_Word
+ processor_specific_flags() const
+ { return this->processor_specific_flags_; }
+
+ protected:
+ // Read the symbol information.
+ void
+ do_read_symbols(Read_symbols_data* sd);
+
+ private:
+ // processor-specific flags in ELF file header.
+ elfcpp::Elf_Word processor_specific_flags_;
+};
+
+// Functor to read reloc addends during stub generation.
+
+template<int sh_type, bool big_endian>
+struct Stub_addend_reader
+{
+ // Return the addend for a relocation of a particular type. Depending
+ // on whether this is a REL or RELA relocation, read the addend from a
+ // view or from a Reloc object.
+ elfcpp::Elf_types<32>::Elf_Swxword
+ operator()(
+ unsigned int /* r_type */,
+ const unsigned char* /* view */,
+ const typename Reloc_types<sh_type,
+ 32, big_endian>::Reloc& /* reloc */) const;
+};
+
+// Specialized Stub_addend_reader for SHT_REL type relocation sections.
+
+template<bool big_endian>
+struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
+{
+ elfcpp::Elf_types<32>::Elf_Swxword
+ operator()(
+ unsigned int,
+ const unsigned char*,
+ const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
+};
+
+// Specialized Stub_addend_reader for RELA type relocation sections.
+// We currently do not handle RELA type relocation sections but it is trivial
+// to implement the addend reader. This is provided for completeness and to
+// make it easier to add support for RELA relocation sections in the future.
+
+template<bool big_endian>
+struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
+{
+ elfcpp::Elf_types<32>::Elf_Swxword
+ operator()(
+ unsigned int,
+ const unsigned char*,
+ const typename Reloc_types<elfcpp::SHT_RELA, 32,
+ big_endian>::Reloc& reloc) const
+ { return reloc.get_r_addend(); }
+};
+
+// Utilities for manipulating integers of up to 32-bits
+
+namespace utils
+{
+ // Sign extend an n-bit unsigned integer stored in an uint32_t into
+ // an int32_t. NO_BITS must be between 1 to 32.
+ template<int no_bits>
+ static inline int32_t
+ sign_extend(uint32_t bits)
+ {
+ gold_assert(no_bits >= 0 && no_bits <= 32);
+ if (no_bits == 32)
+ return static_cast<int32_t>(bits);
+ uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
+ bits &= mask;
+ uint32_t top_bit = 1U << (no_bits - 1);
+ int32_t as_signed = static_cast<int32_t>(bits);
+ return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
+ }
+
+ // Detects overflow of an NO_BITS integer stored in a uint32_t.
+ template<int no_bits>
+ static inline bool
+ has_overflow(uint32_t bits)
+ {
+ gold_assert(no_bits >= 0 && no_bits <= 32);
+ if (no_bits == 32)
+ return false;
+ int32_t max = (1 << (no_bits - 1)) - 1;
+ int32_t min = -(1 << (no_bits - 1));
+ int32_t as_signed = static_cast<int32_t>(bits);
+ return as_signed > max || as_signed < min;
+ }
+
+ // Detects overflow of an NO_BITS integer stored in a uint32_t when it
+ // fits in the given number of bits as either a signed or unsigned value.
+ // For example, has_signed_unsigned_overflow<8> would check
+ // -128 <= bits <= 255
+ template<int no_bits>
+ static inline bool
+ has_signed_unsigned_overflow(uint32_t bits)
+ {
+ gold_assert(no_bits >= 2 && no_bits <= 32);
+ if (no_bits == 32)
+ return false;
+ int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
+ int32_t min = -(1 << (no_bits - 1));
+ int32_t as_signed = static_cast<int32_t>(bits);
+ return as_signed > max || as_signed < min;
+ }
+
+ // Select bits from A and B using bits in MASK. For each n in [0..31],
+ // the n-th bit in the result is chosen from the n-th bits of A and B.
+ // A zero selects A and a one selects B.
+ static inline uint32_t
+ bit_select(uint32_t a, uint32_t b, uint32_t mask)
+ { return (a & ~mask) | (b & mask); }
+};
+
+template<bool big_endian>
+class Target_arm : public Sized_target<32, big_endian>
+{
+ public:
+ typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
+ Reloc_section;
+
+ // When were are relocating a stub, we pass this as the relocation number.
+ static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
+
+ Target_arm()
+ : Sized_target<32, big_endian>(&arm_info),
+ got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+ copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL), stub_tables_(),
+ stub_factory_(Stub_factory::get_instance()),
+ may_use_blx_(true), should_force_pic_veneer_(false),
+ arm_input_section_map_()
+ { }
+
+ // Whether we can use BLX.
+ bool
+ may_use_blx() const
+ { return this->may_use_blx_; }
+
+ // Set use-BLX flag.
+ void
+ set_may_use_blx(bool value)
+ { this->may_use_blx_ = value; }
+
+ // Whether we force PCI branch veneers.
+ bool
+ should_force_pic_veneer() const
+ { return this->should_force_pic_veneer_; }
+
+ // Set PIC veneer flag.
+ void
+ set_should_force_pic_veneer(bool value)
+ { this->should_force_pic_veneer_ = value; }
+
+ // Whether we use THUMB-2 instructions.
+ bool
+ using_thumb2() const
+ {
+ // FIXME: This should not hard-coded.
+ return false;
+ }
+
+ // Whether we use THUMB/THUMB-2 instructions only.
+ bool
+ using_thumb_only() const
+ {
+ // FIXME: This should not hard-coded.
+ return false;
+ }
+
+ // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
+ bool
+ may_use_arm_nop() const
+ {
+ // FIXME: This should not hard-coded.
+ return false;
+ }
+
+ // Process the relocations to determine unreferenced sections for
+ // garbage collection.
+ void
+ gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Scan the relocations to look for symbol adjustments.
+ void
+ scan_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Finalize the sections.
+ void
+ do_finalize_sections(Layout*, const Input_objects*);
+
+ // Return the value to use for a dynamic symbol which requires special
+ // treatment.
+ uint64_t
+ do_dynsym_value(const Symbol*) const;
+
+ // Relocate a section.
+ void
+ relocate_section(const Relocate_info<32, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ unsigned char* view,
+ Arm_address view_address,
+ section_size_type view_size,
+ const Reloc_symbol_changes*);
+
+ // Scan the relocs during a relocatable link.
+ void
+ scan_relocatable_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs*);
+
+ // Relocate a section during a relocatable link.
+ void
+ relocate_for_relocatable(const Relocate_info<32, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs*,
+ unsigned char* view,
+ Arm_address view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size);
+
+ // Return whether SYM is defined by the ABI.
+ bool
+ do_is_defined_by_abi(Symbol* sym) const
+ { return strcmp(sym->name(), "__tls_get_addr") == 0; }
+
+ // Return the size of the GOT section.
+ section_size_type
+ got_size()
+ {
+ gold_assert(this->got_ != NULL);
+ return this->got_->data_size();
+ }
+
+ // Map platform-specific reloc types
+ static unsigned int
+ get_real_reloc_type (unsigned int r_type);
+
+ //
+ // Methods to support stub-generations.
+ //
+
+ // Return the stub factory
+ const Stub_factory&
+ stub_factory() const
+ { return this->stub_factory_; }
+
+ // Make a new Arm_input_section object.
+ Arm_input_section<big_endian>*
+ new_arm_input_section(Relobj*, unsigned int);
+
+ // Find the Arm_input_section object corresponding to the SHNDX-th input
+ // section of RELOBJ.
+ Arm_input_section<big_endian>*
+ find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
+
+ // Make a new Stub_table
+ Stub_table<big_endian>*
+ new_stub_table(Arm_input_section<big_endian>*);
+
+ // Scan a section for stub generation.
+ void
+ scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
+ const unsigned char*, size_t, Output_section*,
+ bool, const unsigned char*, Arm_address,
+ section_size_type);
+
+ // Relocate a stub.
+ void
+ relocate_stub(Reloc_stub*, const Relocate_info<32, big_endian>*,
+ Output_section*, unsigned char*, Arm_address,
+ section_size_type);
+
+ // Get the default ARM target.
+ static Target_arm<big_endian>*
+ default_target()
+ {
+ gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
+ && parameters->target().is_big_endian() == big_endian);
+ return static_cast<Target_arm<big_endian>*>(
+ parameters->sized_target<32, big_endian>());
+ }
+
+ // Whether relocation type uses LSB to distinguish THUMB addresses.
+ static bool
+ reloc_uses_thumb_bit(unsigned int r_type);
+
+ protected:
+ // Make an ELF object.
+ Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<32, big_endian>& ehdr);
+
+ Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<32, !big_endian>&)
+ { gold_unreachable(); }
+
+ Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<64, false>&)
+ { gold_unreachable(); }
+
+ Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<64, true>&)
+ { gold_unreachable(); }
+
+ // Make an output section.
+ Output_section*
+ do_make_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags)
+ { return new Arm_output_section<big_endian>(name, type, flags); }
+
+ void
+ do_adjust_elf_header(unsigned char* view, int len) const;
+
+ // We only need to generate stubs, and hence perform relaxation if we are
+ // not doing relocatable linking.
+ bool
+ do_may_relax() const
+ { return !parameters->options().relocatable(); }
+
+ bool
+ do_relax(int, const Input_objects*, Symbol_table*, Layout*);
+
+ private:
+ // The class which scans relocations.
+ class Scan
+ {
+ public:
+ Scan()
+ : issued_non_pic_error_(false)
+ { }
+
+ inline void
+ local(Symbol_table* symtab, Layout* layout, Target_arm* target,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
+ const elfcpp::Sym<32, big_endian>& lsym);
+
+ inline void
+ global(Symbol_table* symtab, Layout* layout, Target_arm* target,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
+ Symbol* gsym);
+
+ private:
+ static void
+ unsupported_reloc_local(Sized_relobj<32, big_endian>*,
+ unsigned int r_type);
+
+ static void
+ unsupported_reloc_global(Sized_relobj<32, big_endian>*,
+ unsigned int r_type, Symbol*);
+
+ void
+ check_non_pic(Relobj*, unsigned int r_type);
+
+ // Almost identical to Symbol::needs_plt_entry except that it also
+ // handles STT_ARM_TFUNC.
+ static bool
+ symbol_needs_plt_entry(const Symbol* sym)
+ {
+ // An undefined symbol from an executable does not need a PLT entry.
+ if (sym->is_undefined() && !parameters->options().shared())
+ return false;
+
+ return (!parameters->doing_static_link()
+ && (sym->type() == elfcpp::STT_FUNC
+ || sym->type() == elfcpp::STT_ARM_TFUNC)
+ && (sym->is_from_dynobj()
+ || sym->is_undefined()
+ || sym->is_preemptible()));
+ }
+
+ // Whether we have issued an error about a non-PIC compilation.
+ bool issued_non_pic_error_;
+ };
+
+ // The class which implements relocation.
+ class Relocate
+ {
+ public:
+ Relocate()
+ { }
+
+ ~Relocate()
+ { }
+
+ // Return whether the static relocation needs to be applied.
+ inline bool
+ should_apply_static_reloc(const Sized_symbol<32>* gsym,
+ int ref_flags,
+ bool is_32bit,
+ Output_section* output_section);
+
+ // Do a relocation. Return false if the caller should not issue
+ // any warnings about this relocation.
+ inline bool
+ relocate(const Relocate_info<32, big_endian>*, Target_arm*,
+ Output_section*, size_t relnum,
+ const elfcpp::Rel<32, big_endian>&,
+ unsigned int r_type, const Sized_symbol<32>*,
+ const Symbol_value<32>*,
+ unsigned char*, Arm_address,
+ section_size_type);
+
+ // Return whether we want to pass flag NON_PIC_REF for this
+ // reloc.
+ static inline bool
+ reloc_is_non_pic (unsigned int r_type)
+ {
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_REL32:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_THM_ABS5:
+ case elfcpp::R_ARM_ABS8:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_BASE_ABS:
+ return true;
+ default:
+ return false;
+ }
+ }
+ };
+
+ // A class which returns the size required for a relocation type,
+ // used while scanning relocs during a relocatable link.
+ class Relocatable_size_for_reloc
+ {
+ public:
+ unsigned int
+ get_size_for_reloc(unsigned int, Relobj*);
+ };
+
+ // Get the GOT section, creating it if necessary.
+ Output_data_got<32, big_endian>*
+ got_section(Symbol_table*, Layout*);
+
+ // Get the GOT PLT section.
+ Output_data_space*
+ got_plt_section() const
+ {
+ gold_assert(this->got_plt_ != NULL);
+ return this->got_plt_;
+ }
+
+ // Create a PLT entry for a global symbol.
+ void
+ make_plt_entry(Symbol_table*, Layout*, Symbol*);
+
+ // Get the PLT section.
+ const Output_data_plt_arm<big_endian>*
+ plt_section() const
+ {
+ gold_assert(this->plt_ != NULL);
+ return this->plt_;
+ }
+
+ // Get the dynamic reloc section, creating it if necessary.
+ Reloc_section*
+ rel_dyn_section(Layout*);
+
+ // Return true if the symbol may need a COPY relocation.
+ // References from an executable object to non-function symbols
+ // defined in a dynamic object may need a COPY relocation.
+ bool
+ may_need_copy_reloc(Symbol* gsym)
+ {
+ return (gsym->type() != elfcpp::STT_ARM_TFUNC
+ && gsym->may_need_copy_reloc());
+ }
+
+ // Add a potential copy relocation.
+ void
+ copy_reloc(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int shndx, Output_section* output_section,
+ Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
+ {
+ this->copy_relocs_.copy_reloc(symtab, layout,
+ symtab->get_sized_symbol<32>(sym),
+ object, shndx, output_section, reloc,
+ this->rel_dyn_section(layout));
+ }
+
+ // Whether two EABI versions are compatible.
+ static bool
+ are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
+
+ // Merge processor-specific flags from input object and those in the ELF
+ // header of the output.
+ void
+ merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
+
+ //
+ // Methods to support stub-generations.
+ //
+
+ // Group input sections for stub generation.
+ void
+ group_sections(Layout*, section_size_type, bool);
+
+ // Scan a relocation for stub generation.
+ void
+ scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
+ const Sized_symbol<32>*, unsigned int,
+ const Symbol_value<32>*,
+ elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
+
+ // Scan a relocation section for stub.
+ template<int sh_type>
+ void
+ scan_reloc_section_for_stubs(
+ const Relocate_info<32, big_endian>* relinfo,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ const unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type);
+
+ // Information about this specific target which we pass to the
+ // general Target structure.
+ static const Target::Target_info arm_info;
+
+ // The types of GOT entries needed for this platform.
+ enum Got_type
+ {
+ GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol
+ };
+
+ typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
+
+ // Map input section to Arm_input_section.
+ typedef Unordered_map<Input_section_specifier,
+ Arm_input_section<big_endian>*,
+ Input_section_specifier::hash,
+ Input_section_specifier::equal_to>
+ Arm_input_section_map;
+
+ // The GOT section.
+ Output_data_got<32, big_endian>* got_;
+ // The PLT section.
+ Output_data_plt_arm<big_endian>* plt_;
+ // The GOT PLT section.
+ Output_data_space* got_plt_;
+ // The dynamic reloc section.
+ Reloc_section* rel_dyn_;
+ // Relocs saved to avoid a COPY reloc.
+ Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
+ // Space for variables copied with a COPY reloc.
+ Output_data_space* dynbss_;
+ // Vector of Stub_tables created.
+ Stub_table_list stub_tables_;
+ // Stub factory.
+ const Stub_factory &stub_factory_;
+ // Whether we can use BLX.
+ bool may_use_blx_;
+ // Whether we force PIC branch veneers.
+ bool should_force_pic_veneer_;
+ // Map for locating Arm_input_sections.
+ Arm_input_section_map arm_input_section_map_;
+};
+
+template<bool big_endian>
+const Target::Target_info Target_arm<big_endian>::arm_info =
+{
+ 32, // size
+ big_endian, // is_big_endian
+ elfcpp::EM_ARM, // machine_code
+ false, // has_make_symbol
+ false, // has_resolve
+ false, // has_code_fill
+ true, // is_default_stack_executable
+ '\0', // wrap_char
+ "/usr/lib/libc.so.1", // dynamic_linker
+ 0x8000, // default_text_segment_address
+ 0x1000, // abi_pagesize (overridable by -z max-page-size)
+ 0x1000, // common_pagesize (overridable by -z common-page-size)
+ elfcpp::SHN_UNDEF, // small_common_shndx
+ elfcpp::SHN_UNDEF, // large_common_shndx
+ 0, // small_common_section_flags
+ 0 // large_common_section_flags
+};
+
+// Arm relocate functions class
+//
+
+template<bool big_endian>
+class Arm_relocate_functions : public Relocate_functions<32, big_endian>
+{
+ public:
+ typedef enum
+ {
+ STATUS_OKAY, // No error during relocation.
+ STATUS_OVERFLOW, // Relocation oveflow.
+ STATUS_BAD_RELOC // Relocation cannot be applied.
+ } Status;
+
+ private:
+ typedef Relocate_functions<32, big_endian> Base;
+ typedef Arm_relocate_functions<big_endian> This;
+
+ // Encoding of imm16 argument for movt and movw ARM instructions
+ // from ARM ARM:
+ //
+ // imm16 := imm4 | imm12
+ //
+ // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
+ // +-------+---------------+-------+-------+-----------------------+
+ // | | |imm4 | |imm12 |
+ // +-------+---------------+-------+-------+-----------------------+
+
+ // Extract the relocation addend from VAL based on the ARM
+ // instruction encoding described above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ extract_arm_movw_movt_addend(
+ typename elfcpp::Swap<32, big_endian>::Valtype val)
+ {
+ // According to the Elf ABI for ARM Architecture the immediate
+ // field is sign-extended to form the addend.
+ return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
+ }
+
+ // Insert X into VAL based on the ARM instruction encoding described
+ // above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ insert_val_arm_movw_movt(
+ typename elfcpp::Swap<32, big_endian>::Valtype val,
+ typename elfcpp::Swap<32, big_endian>::Valtype x)
+ {
+ val &= 0xfff0f000;
+ val |= x & 0x0fff;
+ val |= (x & 0xf000) << 4;
+ return val;
+ }
+
+ // Encoding of imm16 argument for movt and movw Thumb2 instructions
+ // from ARM ARM:
+ //
+ // imm16 := imm4 | i | imm3 | imm8
+ //
+ // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
+ // +---------+-+-----------+-------++-+-----+-------+---------------+
+ // | |i| |imm4 || |imm3 | |imm8 |
+ // +---------+-+-----------+-------++-+-----+-------+---------------+
+
+ // Extract the relocation addend from VAL based on the Thumb2
+ // instruction encoding described above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ extract_thumb_movw_movt_addend(
+ typename elfcpp::Swap<32, big_endian>::Valtype val)
+ {
+ // According to the Elf ABI for ARM Architecture the immediate
+ // field is sign-extended to form the addend.
+ return utils::sign_extend<16>(((val >> 4) & 0xf000)
+ | ((val >> 15) & 0x0800)
+ | ((val >> 4) & 0x0700)
+ | (val & 0x00ff));
+ }
+
+ // Insert X into VAL based on the Thumb2 instruction encoding
+ // described above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ insert_val_thumb_movw_movt(
+ typename elfcpp::Swap<32, big_endian>::Valtype val,
+ typename elfcpp::Swap<32, big_endian>::Valtype x)
+ {
+ val &= 0xfbf08f00;
+ val |= (x & 0xf000) << 4;
+ val |= (x & 0x0800) << 15;
+ val |= (x & 0x0700) << 4;
+ val |= (x & 0x00ff);
+ return val;
+ }
+
+ // Handle ARM long branches.
+ static typename This::Status
+ arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
+ unsigned char *, const Sized_symbol<32>*,
+ const Arm_relobj<big_endian>*, unsigned int,
+ const Symbol_value<32>*, Arm_address, Arm_address, bool);
+
+ public:
+
+ // R_ARM_ABS8: S + A
+ static inline typename This::Status
+ abs8(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
+ Reltype addend = utils::sign_extend<8>(val);
+ Reltype x = psymval->value(object, addend);
+ val = utils::bit_select(val, x, 0xffU);
+ elfcpp::Swap<8, big_endian>::writeval(wv, val);
+ return (utils::has_signed_unsigned_overflow<8>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_THM_ABS5: S + A
+ static inline typename This::Status
+ thm_abs5(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
+ Reltype addend = (val & 0x7e0U) >> 6;
+ Reltype x = psymval->value(object, addend);
+ val = utils::bit_select(val, x << 6, 0x7e0U);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<5>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_ABS12: S + A
+ static inline typename This::Status
+ abs12(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Reltype addend = val & 0x0fffU;
+ Reltype x = psymval->value(object, addend);
+ val = utils::bit_select(val, x, 0x0fffU);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<12>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_ABS16: S + A
+ static inline typename This::Status
+ abs16(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
+ Reltype addend = utils::sign_extend<16>(val);
+ Reltype x = psymval->value(object, addend);
+ val = utils::bit_select(val, x, 0xffffU);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val);
+ return (utils::has_signed_unsigned_overflow<16>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_ABS32: (S + A) | T
+ static inline typename This::Status
+ abs32(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype x = psymval->value(object, addend) | thumb_bit;
+ elfcpp::Swap<32, big_endian>::writeval(wv, x);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_REL32: (S + A) | T - P
+ static inline typename This::Status
+ rel32(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
+ elfcpp::Swap<32, big_endian>::writeval(wv, x);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_CALL: (S + A) | T - P
+ static inline typename This::Status
+ thm_call(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit)
+ {
+ // A thumb call consists of two instructions.
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype hi = elfcpp::Swap<16, big_endian>::readval(wv);
+ Valtype lo = elfcpp::Swap<16, big_endian>::readval(wv + 1);
+ // Must be a BL instruction. lo == 11111xxxxxxxxxxx.
+ gold_assert((lo & 0xf800) == 0xf800);
+ Reltype addend = utils::sign_extend<23>(((hi & 0x7ff) << 12)
+ | ((lo & 0x7ff) << 1));
+ Reltype x = (psymval->value(object, addend) | thumb_bit) - address;
+
+ // If target has no thumb bit set, we need to either turn the BL
+ // into a BLX (for ARMv5 or above) or generate a stub.
+ if ((x & 1) == 0)
+ {
+ // This only works for ARMv5 and above with interworking enabled.
+ lo &= 0xefff;
+ }
+ hi = utils::bit_select(hi, (x >> 12), 0x7ffU);
+ lo = utils::bit_select(lo, (x >> 1), 0x7ffU);
+ elfcpp::Swap<16, big_endian>::writeval(wv, hi);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, lo);
+ return (utils::has_overflow<23>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_BASE_PREL: B(S) + A - P
+ static inline typename This::Status
+ base_prel(unsigned char* view,
+ Arm_address origin,
+ Arm_address address)
+ {
+ Base::rel32(view, origin - address);
+ return STATUS_OKAY;
+ }
+
+ // R_ARM_BASE_ABS: B(S) + A
+ static inline typename This::Status
+ base_abs(unsigned char* view,
+ Arm_address origin)
+ {
+ Base::rel32(view, origin);
+ return STATUS_OKAY;
+ }
+
+ // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
+ static inline typename This::Status
+ got_brel(unsigned char* view,
+ typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
+ {
+ Base::rel32(view, got_offset);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_GOT_PREL: GOT(S) + A – P
+ static inline typename This::Status
+ got_prel(unsigned char* view,
+ typename elfcpp::Swap<32, big_endian>::Valtype got_offset,
+ Arm_address address)
+ {
+ Base::rel32(view, got_offset - address);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_PLT32: (S + A) | T - P
+ static inline typename This::Status
+ plt32(const Relocate_info<32, big_endian>* relinfo,
+ unsigned char *view,
+ const Sized_symbol<32>* gsym,
+ const Arm_relobj<big_endian>* object,
+ unsigned int r_sym,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit,
+ bool is_weakly_undefined_without_plt)
+ {
+ return arm_branch_common(elfcpp::R_ARM_PLT32, relinfo, view, gsym,
+ object, r_sym, psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
+ }
+
+ // R_ARM_XPC25: (S + A) | T - P
+ static inline typename This::Status
+ xpc25(const Relocate_info<32, big_endian>* relinfo,
+ unsigned char *view,
+ const Sized_symbol<32>* gsym,
+ const Arm_relobj<big_endian>* object,
+ unsigned int r_sym,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit,
+ bool is_weakly_undefined_without_plt)
+ {
+ return arm_branch_common(elfcpp::R_ARM_XPC25, relinfo, view, gsym,
+ object, r_sym, psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
+ }
+
+ // R_ARM_CALL: (S + A) | T - P
+ static inline typename This::Status
+ call(const Relocate_info<32, big_endian>* relinfo,
+ unsigned char *view,
+ const Sized_symbol<32>* gsym,
+ const Arm_relobj<big_endian>* object,
+ unsigned int r_sym,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit,
+ bool is_weakly_undefined_without_plt)
+ {
+ return arm_branch_common(elfcpp::R_ARM_CALL, relinfo, view, gsym,
+ object, r_sym, psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
+ }
+
+ // R_ARM_JUMP24: (S + A) | T - P
+ static inline typename This::Status
+ jump24(const Relocate_info<32, big_endian>* relinfo,
+ unsigned char *view,
+ const Sized_symbol<32>* gsym,
+ const Arm_relobj<big_endian>* object,
+ unsigned int r_sym,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit,
+ bool is_weakly_undefined_without_plt)
+ {
+ return arm_branch_common(elfcpp::R_ARM_JUMP24, relinfo, view, gsym,
+ object, r_sym, psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
+ }
+
+ // R_ARM_PREL: (S + A) | T - P
+ static inline typename This::Status
+ prel31(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = utils::sign_extend<31>(val);
+ Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
+ val = utils::bit_select(val, x, 0x7fffffffU);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<31>(x) ?
+ This::STATUS_OVERFLOW : This::STATUS_OKAY);
+ }
+
+ // R_ARM_MOVW_ABS_NC: (S + A) | T
+ static inline typename This::Status
+ movw_abs_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = psymval->value(object, addend) | thumb_bit;
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_MOVT_ABS: S + A
+ static inline typename This::Status
+ movt_abs(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = psymval->value(object, addend) >> 16;
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVW_ABS_NC: S + A | T
+ static inline typename This::Status
+ thm_movw_abs_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1));
+ Reltype addend = extract_thumb_movw_movt_addend(val);
+ Reltype x = psymval->value(object, addend) | thumb_bit;
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVT_ABS: S + A
+ static inline typename This::Status
+ thm_movt_abs(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1));
+ Reltype addend = This::extract_thumb_movw_movt_addend(val);
+ Reltype x = psymval->value(object, addend) >> 16;
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_MOVW_PREL_NC: (S + A) | T - P
+ static inline typename This::Status
+ movw_prel_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_MOVT_PREL: S + A - P
+ static inline typename This::Status
+ movt_prel(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = (psymval->value(object, addend) - address) >> 16;
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
+ static inline typename This::Status
+ thm_movw_prel_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1);
+ Reltype addend = This::extract_thumb_movw_movt_addend(val);
+ Reltype x = (psymval->value(object, addend) | thumb_bit) - address;
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVT_PREL: S + A - P
+ static inline typename This::Status
+ thm_movt_prel(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ Arm_address address)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1);
+ Reltype addend = This::extract_thumb_movw_movt_addend(val);
+ Reltype x = (psymval->value(object, addend) - address) >> 16;
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+};
+
+// Relocate ARM long branches. This handles relocation types
+// R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
+// If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
+// undefined and we do not use PLT in this relocation. In such a case,
+// the branch is converted into an NOP.
+
+template<bool big_endian>
+typename Arm_relocate_functions<big_endian>::Status
+Arm_relocate_functions<big_endian>::arm_branch_common(
+ unsigned int r_type,
+ const Relocate_info<32, big_endian>* relinfo,
+ unsigned char *view,
+ const Sized_symbol<32>* gsym,
+ const Arm_relobj<big_endian>* object,
+ unsigned int r_sym,
+ const Symbol_value<32>* psymval,
+ Arm_address address,
+ Arm_address thumb_bit,
+ bool is_weakly_undefined_without_plt)
+{
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+
+ bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
+ && ((val & 0x0f000000UL) == 0x0a000000UL);
+ bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
+ bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
+ && ((val & 0x0f000000UL) == 0x0b000000UL);
+ bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
+ bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
+
+ // Check that the instruction is valid.
+ if (r_type == elfcpp::R_ARM_CALL)
+ {
+ if (!insn_is_uncond_bl && !insn_is_blx)
+ return This::STATUS_BAD_RELOC;
+ }
+ else if (r_type == elfcpp::R_ARM_JUMP24)
+ {
+ if (!insn_is_b && !insn_is_cond_bl)
+ return This::STATUS_BAD_RELOC;
+ }
+ else if (r_type == elfcpp::R_ARM_PLT32)
+ {
+ if (!insn_is_any_branch)
+ return This::STATUS_BAD_RELOC;
+ }
+ else if (r_type == elfcpp::R_ARM_XPC25)
+ {
+ // FIXME: AAELF document IH0044C does not say much about it other
+ // than it being obsolete.
+ if (!insn_is_any_branch)
+ return This::STATUS_BAD_RELOC;
+ }
+ else
+ gold_unreachable();
+
+ // A branch to an undefined weak symbol is turned into a jump to
+ // the next instruction unless a PLT entry will be created.
+ // Do the same for local undefined symbols.
+ // The jump to the next instruction is optimized as a NOP depending
+ // on the architecture.
+ const Target_arm<big_endian>* arm_target =
+ Target_arm<big_endian>::default_target();
+ if (is_weakly_undefined_without_plt)
+ {
+ Valtype cond = val & 0xf0000000U;
+ if (arm_target->may_use_arm_nop())
+ val = cond | 0x0320f000;
+ else
+ val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ Valtype addend = utils::sign_extend<26>(val << 2);
+ Valtype branch_target = psymval->value(object, addend);
+ int32_t branch_offset = branch_target - address;
+
+ // We need a stub if the branch offset is too large or if we need
+ // to switch mode.
+ bool may_use_blx = arm_target->may_use_blx();
+ Reloc_stub* stub = NULL;
+ if ((branch_offset > ARM_MAX_FWD_BRANCH_OFFSET)
+ || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
+ || ((thumb_bit != 0) && !(may_use_blx && r_type == elfcpp::R_ARM_CALL)))
+ {
+ Stub_type stub_type =
+ Reloc_stub::stub_type_for_reloc(r_type, address, branch_target,
+ (thumb_bit != 0));
+ if (stub_type != arm_stub_none)
+ {
+ Stub_table<big_endian>* stub_table =
+ object->stub_table(relinfo->data_shndx);
+ gold_assert(stub_table != NULL);
+
+ Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
+ stub = stub_table->find_reloc_stub(stub_key);
+ gold_assert(stub != NULL);
+ thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
+ branch_target = stub_table->address() + stub->offset() + addend;
+ branch_offset = branch_target - address;
+ gold_assert((branch_offset <= ARM_MAX_FWD_BRANCH_OFFSET)
+ && (branch_offset >= ARM_MAX_BWD_BRANCH_OFFSET));
+ }
+ }
+
+ // At this point, if we still need to switch mode, the instruction
+ // must either be a BLX or a BL that can be converted to a BLX.
+ if (thumb_bit != 0)
+ {
+ // Turn BL to BLX.
+ gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
+ val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
+ }
+
+ val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<26>(branch_offset)
+ ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
+}
+
+// Get the GOT section, creating it if necessary.
+
+template<bool big_endian>
+Output_data_got<32, big_endian>*
+Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
+{
+ if (this->got_ == NULL)
+ {
+ gold_assert(symtab != NULL && layout != NULL);
+
+ this->got_ = new Output_data_got<32, big_endian>();
+
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_, false);
+ os->set_is_relro();
+
+ // The old GNU linker creates a .got.plt section. We just
+ // create another set of data in the .got section. Note that we
+ // always create a PLT if we create a GOT, although the PLT
+ // might be empty.
+ this->got_plt_ = new Output_data_space(4, "** GOT PLT");
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_, false);
+ os->set_is_relro();
+
+ // The first three entries are reserved.
+ this->got_plt_->set_current_data_size(3 * 4);
+
+ // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
+ symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
+ this->got_plt_,
+ 0, 0, elfcpp::STT_OBJECT,
+ elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0,
+ false, false);
+ }
+ return this->got_;
+}
+
+// Get the dynamic reloc section, creating it if necessary.
+
+template<bool big_endian>
+typename Target_arm<big_endian>::Reloc_section*
+Target_arm<big_endian>::rel_dyn_section(Layout* layout)
+{
+ if (this->rel_dyn_ == NULL)
+ {
+ gold_assert(layout != NULL);
+ this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
+ layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
+ elfcpp::SHF_ALLOC, this->rel_dyn_, true);
+ }
+ return this->rel_dyn_;
+}
+
+// Insn_template methods.
+
+// Return byte size of an instruction template.
+
+size_t
+Insn_template::size() const
+{
+ switch (this->type())
+ {
+ case THUMB16_TYPE:
+ return 2;
+ case ARM_TYPE:
+ case THUMB32_TYPE:
+ case DATA_TYPE:
+ return 4;
+ default:
+ gold_unreachable();
+ }
+}
+
+// Return alignment of an instruction template.
+
+unsigned
+Insn_template::alignment() const
+{
+ switch (this->type())
+ {
+ case THUMB16_TYPE:
+ case THUMB32_TYPE:
+ return 2;
+ case ARM_TYPE:
+ case DATA_TYPE:
+ return 4;
+ default:
+ gold_unreachable();
+ }
+}
+
+// Stub_template methods.
+
+Stub_template::Stub_template(
+ Stub_type type, const Insn_template* insns,
+ size_t insn_count)
+ : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
+ entry_in_thumb_mode_(false), relocs_()
+{
+ off_t offset = 0;
+
+ // Compute byte size and alignment of stub template.
+ for (size_t i = 0; i < insn_count; i++)
+ {
+ unsigned insn_alignment = insns[i].alignment();
+ size_t insn_size = insns[i].size();
+ gold_assert((offset & (insn_alignment - 1)) == 0);
+ this->alignment_ = std::max(this->alignment_, insn_alignment);
+ switch (insns[i].type())
+ {
+ case Insn_template::THUMB16_TYPE:
+ if (i == 0)
+ this->entry_in_thumb_mode_ = true;
+ break;
+
+ case Insn_template::THUMB32_TYPE:
+ if (insns[i].r_type() != elfcpp::R_ARM_NONE)
+ this->relocs_.push_back(Reloc(i, offset));
+ if (i == 0)
+ this->entry_in_thumb_mode_ = true;
+ break;
+
+ case Insn_template::ARM_TYPE:
+ // Handle cases where the target is encoded within the
+ // instruction.
+ if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
+ this->relocs_.push_back(Reloc(i, offset));
+ break;
+
+ case Insn_template::DATA_TYPE:
+ // Entry point cannot be data.
+ gold_assert(i != 0);
+ this->relocs_.push_back(Reloc(i, offset));
+ break;
+
+ default:
+ gold_unreachable();
+ }
+ offset += insn_size;
+ }
+ this->size_ = offset;
+}
+
+// Reloc_stub::Key methods.
+
+// Dump a Key as a string for debugging.
+
+std::string
+Reloc_stub::Key::name() const
+{
+ if (this->r_sym_ == invalid_index)
+ {
+ // Global symbol key name
+ // <stub-type>:<symbol name>:<addend>.
+ const std::string sym_name = this->u_.symbol->name();
+ // We need to print two hex number and two colons. So just add 100 bytes
+ // to the symbol name size.
+ size_t len = sym_name.size() + 100;
+ char* buffer = new char[len];
+ int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
+ sym_name.c_str(), this->addend_);
+ gold_assert(c > 0 && c < static_cast<int>(len));
+ delete[] buffer;
+ return std::string(buffer);
+ }
+ else
+ {
+ // local symbol key name
+ // <stub-type>:<object>:<r_sym>:<addend>.
+ const size_t len = 200;
+ char buffer[len];
+ int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
+ this->u_.relobj, this->r_sym_, this->addend_);
+ gold_assert(c > 0 && c < static_cast<int>(len));
+ return std::string(buffer);
+ }
+}
+
+// Reloc_stub methods.
+
+// Determine the type of stub needed, if any, for a relocation of R_TYPE at
+// LOCATION to DESTINATION.
+// This code is based on the arm_type_of_stub function in
+// bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub
+// class simple.
+
+Stub_type
+Reloc_stub::stub_type_for_reloc(
+ unsigned int r_type,
+ Arm_address location,
+ Arm_address destination,
+ bool target_is_thumb)
+{
+ Stub_type stub_type = arm_stub_none;
+
+ // This is a bit ugly but we want to avoid using a templated class for
+ // big and little endianities.
+ bool may_use_blx;
+ bool should_force_pic_veneer;
+ bool thumb2;
+ bool thumb_only;
+ if (parameters->target().is_big_endian())
+ {
+ const Target_arm<true>* big_endian_target =
+ Target_arm<true>::default_target();
+ may_use_blx = big_endian_target->may_use_blx();
+ should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
+ thumb2 = big_endian_target->using_thumb2();
+ thumb_only = big_endian_target->using_thumb_only();
+ }
+ else
+ {
+ const Target_arm<false>* little_endian_target =
+ Target_arm<false>::default_target();
+ may_use_blx = little_endian_target->may_use_blx();
+ should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
+ thumb2 = little_endian_target->using_thumb2();
+ thumb_only = little_endian_target->using_thumb_only();
+ }
+
+ int64_t branch_offset = (int64_t)destination - location;
+
+ if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
+ {
+ // Handle cases where:
+ // - this call goes too far (different Thumb/Thumb2 max
+ // distance)
+ // - it's a Thumb->Arm call and blx is not available, or it's a
+ // Thumb->Arm branch (not bl). A stub is needed in this case.
+ if ((!thumb2
+ && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
+ || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
+ || (thumb2
+ && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
+ || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
+ || ((!target_is_thumb)
+ && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
+ || (r_type == elfcpp::R_ARM_THM_JUMP24))))
+ {
+ if (target_is_thumb)
+ {
+ // Thumb to thumb.
+ if (!thumb_only)
+ {
+ stub_type = (parameters->options().shared() | should_force_pic_veneer)
+ // PIC stubs.
+ ? ((may_use_blx
+ && (r_type == elfcpp::R_ARM_THM_CALL))
+ // V5T and above. Stub starts with ARM code, so
+ // we must be able to switch mode before
+ // reaching it, which is only possible for 'bl'
+ // (ie R_ARM_THM_CALL relocation).
+ ? arm_stub_long_branch_any_thumb_pic
+ // On V4T, use Thumb code only.
+ : arm_stub_long_branch_v4t_thumb_thumb_pic)
+
+ // non-PIC stubs.
+ : ((may_use_blx
+ && (r_type == elfcpp::R_ARM_THM_CALL))
+ ? arm_stub_long_branch_any_any // V5T and above.
+ : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
+ }
+ else
+ {
+ stub_type = (parameters->options().shared() | should_force_pic_veneer)
+ ? arm_stub_long_branch_thumb_only_pic // PIC stub.
+ : arm_stub_long_branch_thumb_only; // non-PIC stub.
+ }
+ }
+ else
+ {
+ // Thumb to arm.
+
+ // FIXME: We should check that the input section is from an
+ // object that has interwork enabled.
+
+ stub_type = (parameters->options().shared()
+ || should_force_pic_veneer)
+ // PIC stubs.
+ ? ((may_use_blx
+ && (r_type == elfcpp::R_ARM_THM_CALL))
+ ? arm_stub_long_branch_any_arm_pic // V5T and above.
+ : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
+
+ // non-PIC stubs.
+ : ((may_use_blx
+ && (r_type == elfcpp::R_ARM_THM_CALL))
+ ? arm_stub_long_branch_any_any // V5T and above.
+ : arm_stub_long_branch_v4t_thumb_arm); // V4T.
+
+ // Handle v4t short branches.
+ if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
+ && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
+ && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
+ stub_type = arm_stub_short_branch_v4t_thumb_arm;
+ }
+ }
+ }
+ else if (r_type == elfcpp::R_ARM_CALL
+ || r_type == elfcpp::R_ARM_JUMP24
+ || r_type == elfcpp::R_ARM_PLT32)
+ {
+ if (target_is_thumb)
+ {
+ // Arm to thumb.
+
+ // FIXME: We should check that the input section is from an
+ // object that has interwork enabled.
+
+ // We have an extra 2-bytes reach because of
+ // the mode change (bit 24 (H) of BLX encoding).
+ if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
+ || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
+ || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
+ || (r_type == elfcpp::R_ARM_JUMP24)
+ || (r_type == elfcpp::R_ARM_PLT32))
+ {
+ stub_type = (parameters->options().shared()
+ || should_force_pic_veneer)
+ // PIC stubs.
+ ? (may_use_blx
+ ? arm_stub_long_branch_any_thumb_pic// V5T and above.
+ : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
+
+ // non-PIC stubs.
+ : (may_use_blx
+ ? arm_stub_long_branch_any_any // V5T and above.
+ : arm_stub_long_branch_v4t_arm_thumb); // V4T.
+ }
+ }
+ else
+ {
+ // Arm to arm.
+ if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
+ || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
+ {
+ stub_type = (parameters->options().shared()
+ || should_force_pic_veneer)
+ ? arm_stub_long_branch_any_arm_pic // PIC stubs.
+ : arm_stub_long_branch_any_any; /// non-PIC.
+ }
+ }
+ }
+
+ return stub_type;
+}
+
+// Template to implement do_write for a specific target endianity.
+
+template<bool big_endian>
+void inline
+Reloc_stub::do_fixed_endian_write(unsigned char* view,
+ section_size_type view_size)
+{
+ const Stub_template* stub_template = this->stub_template();
+ const Insn_template* insns = stub_template->insns();
+
+ // FIXME: We do not handle BE8 encoding yet.
+ unsigned char* pov = view;
+ for (size_t i = 0; i < stub_template->insn_count(); i++)
+ {
+ switch (insns[i].type())
+ {
+ case Insn_template::THUMB16_TYPE:
+ // Non-zero reloc addends are only used in Cortex-A8 stubs.
+ gold_assert(insns[i].reloc_addend() == 0);
+ elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
+ break;
+ case Insn_template::THUMB32_TYPE:
+ {
+ uint32_t hi = (insns[i].data() >> 16) & 0xffff;
+ uint32_t lo = insns[i].data() & 0xffff;
+ elfcpp::Swap<16, big_endian>::writeval(pov, hi);
+ elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
+ }
+ break;
+ case Insn_template::ARM_TYPE:
+ case Insn_template::DATA_TYPE:
+ elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
+ break;
+ default:
+ gold_unreachable();
+ }
+ pov += insns[i].size();
+ }
+ gold_assert(static_cast<section_size_type>(pov - view) == view_size);
+}
+
+// Write a reloc stub to VIEW with endianity specified by BIG_ENDIAN.
+
+void
+Reloc_stub::do_write(unsigned char* view, section_size_type view_size,
+ bool big_endian)
+{
+ if (big_endian)
+ this->do_fixed_endian_write<true>(view, view_size);
+ else
+ this->do_fixed_endian_write<false>(view, view_size);
+}
+
+// Stub_factory methods.
+
+Stub_factory::Stub_factory()
+{
+ // The instruction template sequences are declared as static
+ // objects and initialized first time the constructor runs.
+
+ // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
+ // to reach the stub if necessary.
+ static const Insn_template elf32_arm_stub_long_branch_any_any[] =
+ {
+ Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
+ Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
+ // dcd R_ARM_ABS32(X)
+ };
+
+ // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
+ // available.
+ static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
+ {
+ Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
+ Insn_template::arm_insn(0xe12fff1c), // bx ip
+ Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
+ // dcd R_ARM_ABS32(X)
+ };
+
+ // Thumb -> Thumb long branch stub. Used on M-profile architectures.
+ static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
+ {
+ Insn_template::thumb16_insn(0xb401), // push {r0}
+ Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
+ Insn_template::thumb16_insn(0x4684), // mov ip, r0
+ Insn_template::thumb16_insn(0xbc01), // pop {r0}
+ Insn_template::thumb16_insn(0x4760), // bx ip
+ Insn_template::thumb16_insn(0xbf00), // nop
+ Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
+ // dcd R_ARM_ABS32(X)
+ };
+
+ // V4T Thumb -> Thumb long branch stub. Using the stack is not
+ // allowed.
+ static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
+ {
+ Insn_template::thumb16_insn(0x4778), // bx pc
+ Insn_template::thumb16_insn(0x46c0), // nop
+ Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
+ Insn_template::arm_insn(0xe12fff1c), // bx ip
+ Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
+ // dcd R_ARM_ABS32(X)
+ };
+
+ // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
+ // available.
+ static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
+ {
+ Insn_template::thumb16_insn(0x4778), // bx pc
+ Insn_template::thumb16_insn(0x46c0), // nop
+ Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
+ Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
+ // dcd R_ARM_ABS32(X)
+ };
+
+ // V4T Thumb -> ARM short branch stub. Shorter variant of the above
+ // one, when the destination is close enough.
+ static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
+ {
+ Insn_template::thumb16_insn(0x4778), // bx pc
+ Insn_template::thumb16_insn(0x46c0), // nop
+ Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
+ };
+
+ // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
+ // blx to reach the stub if necessary.
+ static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
+ {
+ Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
+ Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
+ Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
+ // dcd R_ARM_REL32(X-4)
+ };
+
+ // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
+ // blx to reach the stub if necessary. We can not add into pc;
+ // it is not guaranteed to mode switch (different in ARMv6 and
+ // ARMv7).
+ static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
+ {
+ Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
+ Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
+ Insn_template::arm_insn(0xe12fff1c), // bx ip
+ Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
+ // dcd R_ARM_REL32(X)
+ };
+
+ // V4T ARM -> ARM long branch stub, PIC.
+ static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
+ {
+ Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
+ Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
+ Insn_template::arm_insn(0xe12fff1c), // bx ip
+ Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
+ // dcd R_ARM_REL32(X)
+ };
+
+ // V4T Thumb -> ARM long branch stub, PIC.
+ static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
+ {
+ Insn_template::thumb16_insn(0x4778), // bx pc
+ Insn_template::thumb16_insn(0x46c0), // nop
+ Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
+ Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
+ Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
+ // dcd R_ARM_REL32(X)
+ };
+
+ // Thumb -> Thumb long branch stub, PIC. Used on M-profile
+ // architectures.
+ static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
+ {
+ Insn_template::thumb16_insn(0xb401), // push {r0}
+ Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
+ Insn_template::thumb16_insn(0x46fc), // mov ip, pc
+ Insn_template::thumb16_insn(0x4484), // add ip, r0
+ Insn_template::thumb16_insn(0xbc01), // pop {r0}
+ Insn_template::thumb16_insn(0x4760), // bx ip
+ Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
+ // dcd R_ARM_REL32(X)
+ };
+
+ // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
+ // allowed.
+ static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
+ {
+ Insn_template::thumb16_insn(0x4778), // bx pc
+ Insn_template::thumb16_insn(0x46c0), // nop
+ Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
+ Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
+ Insn_template::arm_insn(0xe12fff1c), // bx ip
+ Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
+ // dcd R_ARM_REL32(X)
+ };
+
+ // Cortex-A8 erratum-workaround stubs.
+
+ // Stub used for conditional branches (which may be beyond +/-1MB away,
+ // so we can't use a conditional branch to reach this stub).
+
+ // original code:
+ //
+ // b<cond> X
+ // after:
+ //
+ static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
+ {
+ Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
+ Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
+ Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
+ // b.w X
+ };
+
+ // Stub used for b.w and bl.w instructions.
+
+ static const Insn_template elf32_arm_stub_a8_veneer_b[] =
+ {
+ Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
+ };
+
+ static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
+ {
+ Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
+ };
+
+ // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
+ // instruction (which switches to ARM mode) to point to this stub. Jump to
+ // the real destination using an ARM-mode branch.
+ const Insn_template elf32_arm_stub_a8_veneer_blx[] =
+ {
+ Insn_template::arm_rel_insn(0xea000000, -8) // b dest
+ };
+
+ // Fill in the stub template look-up table. Stub templates are constructed
+ // per instance of Stub_factory for fast look-up without locking
+ // in a thread-enabled environment.
+
+ this->stub_templates_[arm_stub_none] =
+ new Stub_template(arm_stub_none, NULL, 0);
+
+#define DEF_STUB(x) \
+ do \
+ { \
+ size_t array_size \
+ = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
+ Stub_type type = arm_stub_##x; \
+ this->stub_templates_[type] = \
+ new Stub_template(type, elf32_arm_stub_##x, array_size); \
+ } \
+ while (0);
+
+ DEF_STUBS
+#undef DEF_STUB
+}
+
+// Stub_table methods.
+
+// Add a STUB with using KEY. Caller is reponsible for avoid adding
+// if already a STUB with the same key has been added.
+
+template<bool big_endian>
+void
+Stub_table<big_endian>::add_reloc_stub(
+ Reloc_stub* stub,
+ const Reloc_stub::Key& key)
+{
+ const Stub_template* stub_template = stub->stub_template();
+ gold_assert(stub_template->type() == key.stub_type());
+ this->reloc_stubs_[key] = stub;
+ if (this->addralign_ < stub_template->alignment())
+ this->addralign_ = stub_template->alignment();
+ this->has_been_changed_ = true;
+}
+
+template<bool big_endian>
+void
+Stub_table<big_endian>::relocate_stubs(
+ const Relocate_info<32, big_endian>* relinfo,
+ Target_arm<big_endian>* arm_target,
+ Output_section* output_section,
+ unsigned char* view,
+ Arm_address address,
+ section_size_type view_size)
+{
+ // If we are passed a view bigger than the stub table's. we need to
+ // adjust the view.
+ gold_assert(address == this->address()
+ && (view_size
+ == static_cast<section_size_type>(this->data_size())));
+
+ for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
+ p != this->reloc_stubs_.end();
+ ++p)
+ {
+ Reloc_stub* stub = p->second;
+ const Stub_template* stub_template = stub->stub_template();
+ if (stub_template->reloc_count() != 0)
+ {
+ // Adjust view to cover the stub only.
+ section_size_type offset = stub->offset();
+ section_size_type stub_size = stub_template->size();
+ gold_assert(offset + stub_size <= view_size);
+
+ arm_target->relocate_stub(stub, relinfo, output_section,
+ view + offset, address + offset,
+ stub_size);
+ }
+ }
+}
+
+// Reset address and file offset.
+
+template<bool big_endian>
+void
+Stub_table<big_endian>::do_reset_address_and_file_offset()
+{
+ off_t off = 0;
+ uint64_t max_addralign = 1;
+ for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
+ p != this->reloc_stubs_.end();
+ ++p)
+ {
+ Reloc_stub* stub = p->second;
+ const Stub_template* stub_template = stub->stub_template();
+ uint64_t stub_addralign = stub_template->alignment();
+ max_addralign = std::max(max_addralign, stub_addralign);
+ off = align_address(off, stub_addralign);
+ stub->set_offset(off);
+ stub->reset_destination_address();
+ off += stub_template->size();
+ }
+
+ this->addralign_ = max_addralign;
+ this->set_current_data_size_for_child(off);
+}
+
+// Write out the stubs to file.
+
+template<bool big_endian>
+void
+Stub_table<big_endian>::do_write(Output_file* of)
+{
+ off_t offset = this->offset();
+ const section_size_type oview_size =
+ convert_to_section_size_type(this->data_size());
+ unsigned char* const oview = of->get_output_view(offset, oview_size);
+
+ for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
+ p != this->reloc_stubs_.end();
+ ++p)
+ {
+ Reloc_stub* stub = p->second;
+ Arm_address address = this->address() + stub->offset();
+ gold_assert(address
+ == align_address(address,
+ stub->stub_template()->alignment()));
+ stub->write(oview + stub->offset(), stub->stub_template()->size(),
+ big_endian);
+ }
+ of->write_output_view(this->offset(), oview_size, oview);
+}
+
+// Arm_input_section methods.
+
+// Initialize an Arm_input_section.
+
+template<bool big_endian>
+void
+Arm_input_section<big_endian>::init()
+{
+ Relobj* relobj = this->relobj();
+ unsigned int shndx = this->shndx();
+
+ // Cache these to speed up size and alignment queries. It is too slow
+ // to call section_addraglin and section_size every time.
+ this->original_addralign_ = relobj->section_addralign(shndx);
+ this->original_size_ = relobj->section_size(shndx);
+
+ // We want to make this look like the original input section after
+ // output sections are finalized.
+ Output_section* os = relobj->output_section(shndx);
+ off_t offset = relobj->output_section_offset(shndx);
+ gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
+ this->set_address(os->address() + offset);
+ this->set_file_offset(os->offset() + offset);
+
+ this->set_current_data_size(this->original_size_);
+ this->finalize_data_size();
+}
+
+template<bool big_endian>
+void
+Arm_input_section<big_endian>::do_write(Output_file* of)
+{
+ // We have to write out the original section content.
+ section_size_type section_size;
+ const unsigned char* section_contents =
+ this->relobj()->section_contents(this->shndx(), §ion_size, false);
+ of->write(this->offset(), section_contents, section_size);
+
+ // If this owns a stub table and it is not empty, write it.
+ if (this->is_stub_table_owner() && !this->stub_table_->empty())
+ this->stub_table_->write(of);
+}
+
+// Finalize data size.
+
+template<bool big_endian>
+void
+Arm_input_section<big_endian>::set_final_data_size()
+{
+ // If this owns a stub table, finalize its data size as well.
+ if (this->is_stub_table_owner())
+ {
+ uint64_t address = this->address();
+
+ // The stub table comes after the original section contents.
+ address += this->original_size_;
+ address = align_address(address, this->stub_table_->addralign());
+ off_t offset = this->offset() + (address - this->address());
+ this->stub_table_->set_address_and_file_offset(address, offset);
+ address += this->stub_table_->data_size();
+ gold_assert(address == this->address() + this->current_data_size());
+ }
+
+ this->set_data_size(this->current_data_size());
+}
+
+// Reset address and file offset.
+
+template<bool big_endian>
+void
+Arm_input_section<big_endian>::do_reset_address_and_file_offset()
+{
+ // Size of the original input section contents.
+ off_t off = convert_types<off_t, uint64_t>(this->original_size_);
+
+ // If this is a stub table owner, account for the stub table size.
+ if (this->is_stub_table_owner())
+ {
+ Stub_table<big_endian>* stub_table = this->stub_table_;
+
+ // Reset the stub table's address and file offset. The
+ // current data size for child will be updated after that.
+ stub_table_->reset_address_and_file_offset();
+ off = align_address(off, stub_table_->addralign());
+ off += stub_table->current_data_size();
+ }
+
+ this->set_current_data_size(off);
+}
+
+// Arm_output_section methods.
+
+// Create a stub group for input sections from BEGIN to END. OWNER
+// points to the input section to be the owner a new stub table.
+
+template<bool big_endian>
+void
+Arm_output_section<big_endian>::create_stub_group(
+ Input_section_list::const_iterator begin,
+ Input_section_list::const_iterator end,
+ Input_section_list::const_iterator owner,
+ Target_arm<big_endian>* target,
+ std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
+{
+ // Currently we convert ordinary input sections into relaxed sections only
+ // at this point but we may want to support creating relaxed input section
+ // very early. So we check here to see if owner is already a relaxed
+ // section.
+
+ Arm_input_section<big_endian>* arm_input_section;
+ if (owner->is_relaxed_input_section())
+ {
+ arm_input_section =
+ Arm_input_section<big_endian>::as_arm_input_section(
+ owner->relaxed_input_section());
+ }
+ else
+ {
+ gold_assert(owner->is_input_section());
+ // Create a new relaxed input section.
+ arm_input_section =
+ target->new_arm_input_section(owner->relobj(), owner->shndx());
+ new_relaxed_sections->push_back(arm_input_section);
+ }
+
+ // Create a stub table.
+ Stub_table<big_endian>* stub_table =
+ target->new_stub_table(arm_input_section);
+
+ arm_input_section->set_stub_table(stub_table);
+
+ Input_section_list::const_iterator p = begin;
+ Input_section_list::const_iterator prev_p;
+
+ // Look for input sections or relaxed input sections in [begin ... end].
+ do
+ {
+ if (p->is_input_section() || p->is_relaxed_input_section())
+ {
+ // The stub table information for input sections live
+ // in their objects.
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
+ arm_relobj->set_stub_table(p->shndx(), stub_table);
+ }
+ prev_p = p++;
+ }
+ while (prev_p != end);
+}
+
+// Group input sections for stub generation. GROUP_SIZE is roughly the limit
+// of stub groups. We grow a stub group by adding input section until the
+// size is just below GROUP_SIZE. The last input section will be converted
+// into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
+// input section after the stub table, effectively double the group size.
+//
+// This is similar to the group_sections() function in elf32-arm.c but is
+// implemented differently.
+
+template<bool big_endian>
+void
+Arm_output_section<big_endian>::group_sections(
+ section_size_type group_size,
+ bool stubs_always_after_branch,
+ Target_arm<big_endian>* target)
+{
+ // We only care about sections containing code.
+ if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
+ return;
+
+ // States for grouping.
+ typedef enum
+ {
+ // No group is being built.
+ NO_GROUP,
+ // A group is being built but the stub table is not found yet.
+ // We keep group a stub group until the size is just under GROUP_SIZE.
+ // The last input section in the group will be used as the stub table.
+ FINDING_STUB_SECTION,
+ // A group is being built and we have already found a stub table.
+ // We enter this state to grow a stub group by adding input section
+ // after the stub table. This effectively doubles the group size.
+ HAS_STUB_SECTION
+ } State;
+
+ // Any newly created relaxed sections are stored here.
+ std::vector<Output_relaxed_input_section*> new_relaxed_sections;
+
+ State state = NO_GROUP;
+ section_size_type off = 0;
+ section_size_type group_begin_offset = 0;
+ section_size_type group_end_offset = 0;
+ section_size_type stub_table_end_offset = 0;
+ Input_section_list::const_iterator group_begin =
+ this->input_sections().end();
+ Input_section_list::const_iterator stub_table =
+ this->input_sections().end();
+ Input_section_list::const_iterator group_end = this->input_sections().end();
+ for (Input_section_list::const_iterator p = this->input_sections().begin();
+ p != this->input_sections().end();
+ ++p)
+ {
+ section_size_type section_begin_offset =
+ align_address(off, p->addralign());
+ section_size_type section_end_offset =
+ section_begin_offset + p->data_size();
+
+ // Check to see if we should group the previously seens sections.
+ switch (state)
+ {
+ case NO_GROUP:
+ break;
+
+ case FINDING_STUB_SECTION:
+ // Adding this section makes the group larger than GROUP_SIZE.
+ if (section_end_offset - group_begin_offset >= group_size)
+ {
+ if (stubs_always_after_branch)
+ {
+ gold_assert(group_end != this->input_sections().end());
+ this->create_stub_group(group_begin, group_end, group_end,
+ target, &new_relaxed_sections);
+ state = NO_GROUP;
+ }
+ else
+ {
+ // But wait, there's more! Input sections up to
+ // stub_group_size bytes after the stub table can be
+ // handled by it too.
+ state = HAS_STUB_SECTION;
+ stub_table = group_end;
+ stub_table_end_offset = group_end_offset;
+ }
+ }
+ break;
+
+ case HAS_STUB_SECTION:
+ // Adding this section makes the post stub-section group larger
+ // than GROUP_SIZE.
+ if (section_end_offset - stub_table_end_offset >= group_size)
+ {
+ gold_assert(group_end != this->input_sections().end());
+ this->create_stub_group(group_begin, group_end, stub_table,
+ target, &new_relaxed_sections);
+ state = NO_GROUP;
+ }
+ break;
+
+ default:
+ gold_unreachable();
+ }
+
+ // If we see an input section and currently there is no group, start
+ // a new one. Skip any empty sections.
+ if ((p->is_input_section() || p->is_relaxed_input_section())
+ && (p->relobj()->section_size(p->shndx()) != 0))
+ {
+ if (state == NO_GROUP)
+ {
+ state = FINDING_STUB_SECTION;
+ group_begin = p;
+ group_begin_offset = section_begin_offset;
+ }
+
+ // Keep track of the last input section seen.
+ group_end = p;
+ group_end_offset = section_end_offset;
+ }
+
+ off = section_end_offset;
+ }
+
+ // Create a stub group for any ungrouped sections.
+ if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
+ {
+ gold_assert(group_end != this->input_sections().end());
+ this->create_stub_group(group_begin, group_end,
+ (state == FINDING_STUB_SECTION
+ ? group_end
+ : stub_table),
+ target, &new_relaxed_sections);
+ }
+
+ // Convert input section into relaxed input section in a batch.
+ if (!new_relaxed_sections.empty())
+ this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
+
+ // Update the section offsets
+ for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
+ {
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(
+ new_relaxed_sections[i]->relobj());
+ unsigned int shndx = new_relaxed_sections[i]->shndx();
+ // Tell Arm_relobj that this input section is converted.
+ arm_relobj->convert_input_section_to_relaxed_section(shndx);
+ }
+}
+
+// Arm_relobj methods.
+
+// Scan relocations for stub generation.
+
+template<bool big_endian>
+void
+Arm_relobj<big_endian>::scan_sections_for_stubs(
+ Target_arm<big_endian>* arm_target,
+ const Symbol_table* symtab,
+ const Layout* layout)
+{
+ unsigned int shnum = this->shnum();
+ const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
+
+ // Read the section headers.
+ const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
+ shnum * shdr_size,
+ true, true);
- // If target has no thumb bit set, we need to either turn the BL
- // into a BLX (for ARMv5 or above) or generate a stub.
- if ((x & 1) == 0)
- {
- // This only works for ARMv5 and above with interworking enabled.
- lo &= 0xefff;
- }
- hi = utils::bit_select(hi, (x >> 12), 0x7ffU);
- lo = utils::bit_select(lo, (x >> 1), 0x7ffU);
- elfcpp::Swap<16, big_endian>::writeval(wv, hi);
- elfcpp::Swap<16, big_endian>::writeval(wv + 1, lo);
- return (utils::has_overflow<23>(x)
- ? This::STATUS_OVERFLOW
- : This::STATUS_OKAY);
- }
+ // To speed up processing, we set up hash tables for fast lookup of
+ // input offsets to output addresses.
+ this->initialize_input_to_output_maps();
- // R_ARM_BASE_PREL: B(S) + A - P
- static inline typename This::Status
- base_prel(unsigned char* view,
- elfcpp::Elf_types<32>::Elf_Addr origin,
- elfcpp::Elf_types<32>::Elf_Addr address)
- {
- Base::rel32(view, origin - address);
- return STATUS_OKAY;
- }
+ const Relobj::Output_sections& out_sections(this->output_sections());
- // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
- static inline typename This::Status
- got_brel(unsigned char* view,
- typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
- {
- Base::rel32(view, got_offset);
- return This::STATUS_OKAY;
- }
+ Relocate_info<32, big_endian> relinfo;
+ relinfo.symtab = symtab;
+ relinfo.layout = layout;
+ relinfo.object = this;
- // R_ARM_PLT32: (S + A) | T - P
- static inline typename This::Status
- plt32(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
- {
- return arm_branch_common<elfcpp::R_ARM_PLT32>(view, object, psymval,
- address, has_thumb_bit);
- }
+ const unsigned char* p = pshdrs + shdr_size;
+ for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
+ {
+ typename elfcpp::Shdr<32, big_endian> shdr(p);
- // R_ARM_CALL: (S + A) | T - P
- static inline typename This::Status
- call(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
- {
- return arm_branch_common<elfcpp::R_ARM_CALL>(view, object, psymval,
- address, has_thumb_bit);
- }
+ unsigned int sh_type = shdr.get_sh_type();
+ if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
+ continue;
- // R_ARM_JUMP24: (S + A) | T - P
- static inline typename This::Status
- jump24(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
- {
- return arm_branch_common<elfcpp::R_ARM_JUMP24>(view, object, psymval,
- address, has_thumb_bit);
- }
+ off_t sh_size = shdr.get_sh_size();
+ if (sh_size == 0)
+ continue;
- // R_ARM_PREL: (S + A) | T - P
- static inline typename This::Status
- prel31(unsigned char *view,
- const Sized_relobj<32, big_endian>* object,
- const Symbol_value<32>* psymval,
- elfcpp::Elf_types<32>::Elf_Addr address,
- bool has_thumb_bit)
- {
- typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
- Valtype* wv = reinterpret_cast<Valtype*>(view);
- Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
- Valtype addend = utils::sign_extend<31>(val);
- Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
- - address);
- val = utils::bit_select(val, x, 0x7fffffffU);
- elfcpp::Swap<32, big_endian>::writeval(wv, val);
- return (utils::has_overflow<31>(x) ?
- This::STATUS_OVERFLOW : This::STATUS_OKAY);
- }
-};
+ unsigned int index = this->adjust_shndx(shdr.get_sh_info());
+ if (index >= this->shnum())
+ {
+ // Ignore reloc section with bad info. This error will be
+ // reported in the final link.
+ continue;
+ }
-// Get the GOT section, creating it if necessary.
+ Output_section* os = out_sections[index];
+ if (os == NULL)
+ {
+ // This relocation section is against a section which we
+ // discarded.
+ continue;
+ }
+ Arm_address output_offset = this->get_output_section_offset(index);
+
+ if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
+ {
+ // Ignore reloc section with unexpected symbol table. The
+ // error will be reported in the final link.
+ continue;
+ }
+
+ const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
+ sh_size, true, false);
+
+ unsigned int reloc_size;
+ if (sh_type == elfcpp::SHT_REL)
+ reloc_size = elfcpp::Elf_sizes<32>::rel_size;
+ else
+ reloc_size = elfcpp::Elf_sizes<32>::rela_size;
+
+ if (reloc_size != shdr.get_sh_entsize())
+ {
+ // Ignore reloc section with unexpected entsize. The error
+ // will be reported in the final link.
+ continue;
+ }
+
+ size_t reloc_count = sh_size / reloc_size;
+ if (static_cast<off_t>(reloc_count * reloc_size) != sh_size)
+ {
+ // Ignore reloc section with uneven size. The error will be
+ // reported in the final link.
+ continue;
+ }
+
+ gold_assert(output_offset != invalid_address
+ || this->relocs_must_follow_section_writes());
+
+ // Get the section contents. This does work for the case in which
+ // we modify the contents of an input section. We need to pass the
+ // output view under such circumstances.
+ section_size_type input_view_size = 0;
+ const unsigned char* input_view =
+ this->section_contents(index, &input_view_size, false);
+
+ relinfo.reloc_shndx = i;
+ relinfo.data_shndx = index;
+ arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
+ reloc_count, os,
+ output_offset == invalid_address,
+ input_view,
+ os->address(),
+ input_view_size);
+ }
+
+ // After we've done the relocations, we release the hash tables,
+ // since we no longer need them.
+ this->free_input_to_output_maps();
+}
+
+// Count the local symbols. The ARM backend needs to know if a symbol
+// is a THUMB function or not. For global symbols, it is easy because
+// the Symbol object keeps the ELF symbol type. For local symbol it is
+// harder because we cannot access this information. So we override the
+// do_count_local_symbol in parent and scan local symbols to mark
+// THUMB functions. This is not the most efficient way but I do not want to
+// slow down other ports by calling a per symbol targer hook inside
+// Sized_relobj<size, big_endian>::do_count_local_symbols.
template<bool big_endian>
-Output_data_got<32, big_endian>*
-Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
+void
+Arm_relobj<big_endian>::do_count_local_symbols(
+ Stringpool_template<char>* pool,
+ Stringpool_template<char>* dynpool)
{
- if (this->got_ == NULL)
+ // We need to fix-up the values of any local symbols whose type are
+ // STT_ARM_TFUNC.
+
+ // Ask parent to count the local symbols.
+ Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
+ const unsigned int loccount = this->local_symbol_count();
+ if (loccount == 0)
+ return;
+
+ // Intialize the thumb function bit-vector.
+ std::vector<bool> empty_vector(loccount, false);
+ this->local_symbol_is_thumb_function_.swap(empty_vector);
+
+ // Read the symbol table section header.
+ const unsigned int symtab_shndx = this->symtab_shndx();
+ elfcpp::Shdr<32, big_endian>
+ symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
+ gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
+
+ // Read the local symbols.
+ const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
+ gold_assert(loccount == symtabshdr.get_sh_info());
+ off_t locsize = loccount * sym_size;
+ const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
+ locsize, true, true);
+
+ // Loop over the local symbols and mark any local symbols pointing
+ // to THUMB functions.
+
+ // Skip the first dummy symbol.
+ psyms += sym_size;
+ typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
+ this->local_values();
+ for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
{
- gold_assert(symtab != NULL && layout != NULL);
+ elfcpp::Sym<32, big_endian> sym(psyms);
+ elfcpp::STT st_type = sym.get_st_type();
+ Symbol_value<32>& lv((*plocal_values)[i]);
+ Arm_address input_value = lv.input_value();
- this->got_ = new Output_data_got<32, big_endian>();
+ if (st_type == elfcpp::STT_ARM_TFUNC
+ || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
+ {
+ // This is a THUMB function. Mark this and canonicalize the
+ // symbol value by setting LSB.
+ this->local_symbol_is_thumb_function_[i] = true;
+ if ((input_value & 1) == 0)
+ lv.set_input_value(input_value | 1);
+ }
+ }
+}
- Output_section* os;
- os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- (elfcpp::SHF_ALLOC
- | elfcpp::SHF_WRITE),
- this->got_);
- os->set_is_relro();
+// Relocate sections.
+template<bool big_endian>
+void
+Arm_relobj<big_endian>::do_relocate_sections(
+ const Symbol_table* symtab,
+ const Layout* layout,
+ const unsigned char* pshdrs,
+ typename Sized_relobj<32, big_endian>::Views* pviews)
+{
+ // Call parent to relocate sections.
+ Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
+ pviews);
- // The old GNU linker creates a .got.plt section. We just
- // create another set of data in the .got section. Note that we
- // always create a PLT if we create a GOT, although the PLT
- // might be empty.
- this->got_plt_ = new Output_data_space(4, "** GOT PLT");
- os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- (elfcpp::SHF_ALLOC
- | elfcpp::SHF_WRITE),
- this->got_plt_);
- os->set_is_relro();
+ // We do not generate stubs if doing a relocatable link.
+ if (parameters->options().relocatable())
+ return;
- // The first three entries are reserved.
- this->got_plt_->set_current_data_size(3 * 4);
+ // Relocate stub tables.
+ unsigned int shnum = this->shnum();
- // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
- symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
- this->got_plt_,
- 0, 0, elfcpp::STT_OBJECT,
- elfcpp::STB_LOCAL,
- elfcpp::STV_HIDDEN, 0,
- false, false);
+ Target_arm<big_endian>* arm_target =
+ Target_arm<big_endian>::default_target();
+
+ Relocate_info<32, big_endian> relinfo;
+ relinfo.symtab = symtab;
+ relinfo.layout = layout;
+ relinfo.object = this;
+
+ for (unsigned int i = 1; i < shnum; ++i)
+ {
+ Arm_input_section<big_endian>* arm_input_section =
+ arm_target->find_arm_input_section(this, i);
+
+ if (arm_input_section == NULL
+ || !arm_input_section->is_stub_table_owner()
+ || arm_input_section->stub_table()->empty())
+ continue;
+
+ // We cannot discard a section if it owns a stub table.
+ Output_section* os = this->output_section(i);
+ gold_assert(os != NULL);
+
+ relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
+ relinfo.reloc_shdr = NULL;
+ relinfo.data_shndx = i;
+ relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
+
+ gold_assert((*pviews)[i].view != NULL);
+
+ // We are passed the output section view. Adjust it to cover the
+ // stub table only.
+ Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
+ gold_assert((stub_table->address() >= (*pviews)[i].address)
+ && ((stub_table->address() + stub_table->data_size())
+ <= (*pviews)[i].address + (*pviews)[i].view_size));
+
+ off_t offset = stub_table->address() - (*pviews)[i].address;
+ unsigned char* view = (*pviews)[i].view + offset;
+ Arm_address address = stub_table->address();
+ section_size_type view_size = stub_table->data_size();
+
+ stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
+ view_size);
}
- return this->got_;
}
-// Get the dynamic reloc section, creating it if necessary.
+// Read the symbol information.
template<bool big_endian>
-typename Target_arm<big_endian>::Reloc_section*
-Target_arm<big_endian>::rel_dyn_section(Layout* layout)
+void
+Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
{
- if (this->rel_dyn_ == NULL)
+ // Call parent class to read symbol information.
+ Sized_relobj<32, big_endian>::do_read_symbols(sd);
+
+ // Read processor-specific flags in ELF file header.
+ const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
+ elfcpp::Elf_sizes<32>::ehdr_size,
+ true, false);
+ elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
+ this->processor_specific_flags_ = ehdr.get_e_flags();
+}
+
+// Arm_dynobj methods.
+
+// Read the symbol information.
+
+template<bool big_endian>
+void
+Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
+{
+ // Call parent class to read symbol information.
+ Sized_dynobj<32, big_endian>::do_read_symbols(sd);
+
+ // Read processor-specific flags in ELF file header.
+ const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
+ elfcpp::Elf_sizes<32>::ehdr_size,
+ true, false);
+ elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
+ this->processor_specific_flags_ = ehdr.get_e_flags();
+}
+
+// Stub_addend_reader methods.
+
+// Read the addend of a REL relocation of type R_TYPE at VIEW.
+
+template<bool big_endian>
+elfcpp::Elf_types<32>::Elf_Swxword
+Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
+ unsigned int r_type,
+ const unsigned char* view,
+ const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
+{
+ switch (r_type)
{
- gold_assert(layout != NULL);
- this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
- layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
- elfcpp::SHF_ALLOC, this->rel_dyn_);
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_PLT32:
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ const Valtype* wv = reinterpret_cast<const Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ return utils::sign_extend<26>(val << 2);
+ }
+
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_THM_JUMP24:
+ case elfcpp::R_ARM_THM_XPC22:
+ {
+ // Fetch the addend. We use the Thumb-2 encoding (backwards
+ // compatible with Thumb-1) involving the J1 and J2 bits.
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ const Valtype* wv = reinterpret_cast<const Valtype*>(view);
+ Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
+ Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
+
+ uint32_t s = (upper_insn & (1 << 10)) >> 10;
+ uint32_t upper = upper_insn & 0x3ff;
+ uint32_t lower = lower_insn & 0x7ff;
+ uint32_t j1 = (lower_insn & (1 << 13)) >> 13;
+ uint32_t j2 = (lower_insn & (1 << 11)) >> 11;
+ uint32_t i1 = j1 ^ s ? 0 : 1;
+ uint32_t i2 = j2 ^ s ? 0 : 1;
+
+ return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
+ | (upper << 12) | (lower << 1));
+ }
+
+ case elfcpp::R_ARM_THM_JUMP19:
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ const Valtype* wv = reinterpret_cast<const Valtype*>(view);
+ Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
+ Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
+
+ // Reconstruct the top three bits and squish the two 11 bit pieces
+ // together.
+ uint32_t S = (upper_insn & 0x0400) >> 10;
+ uint32_t J1 = (lower_insn & 0x2000) >> 13;
+ uint32_t J2 = (lower_insn & 0x0800) >> 11;
+ uint32_t upper =
+ (S << 8) | (J2 << 7) | (J1 << 6) | (upper_insn & 0x003f);
+ uint32_t lower = (lower_insn & 0x07ff);
+ return utils::sign_extend<23>((upper << 12) | (lower << 1));
+ }
+
+ default:
+ gold_unreachable();
}
- return this->rel_dyn_;
}
// A class to handle the PLT data.
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
- elfcpp::SHF_ALLOC, this->rel_);
+ elfcpp::SHF_ALLOC, this->rel_, true);
}
template<bool big_endian>
got_size);
unsigned char* pov = oview;
- elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
- elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
+ Arm_address plt_address = this->address();
+ Arm_address got_address = this->got_plt_->address();
// Write first PLT entry. All but the last word are constants.
const size_t num_first_plt_words = (sizeof(first_plt_entry)
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
- this->plt_);
+ this->plt_, false);
}
this->plt_->add_entry(gsym);
}
case elfcpp::R_ARM_GLOB_DAT:
case elfcpp::R_ARM_JUMP_SLOT:
case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
case elfcpp::R_ARM_PC24:
// FIXME: The following 3 types are not supported by Android's dynamic
// linker.
template<bool big_endian>
inline void
-Target_arm<big_endian>::Scan::local(const General_options&,
- Symbol_table* symtab,
+Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
Layout* layout,
Target_arm* target,
Sized_relobj<32, big_endian>* object,
case elfcpp::R_ARM_NONE:
break;
- case elfcpp::R_ARM_ABS8:
- if (parameters->options().output_is_position_independent())
- {
- // FIXME: Create a dynamic relocation for this location.
- gold_error(_("%s: gold bug: need dynamic ABS8 reloc"),
- object->name().c_str());
- }
- break;
-
case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
// If building a shared library (or a position-independent
// executable), we need to create a dynamic relocation for
// this location. The relocation applied at link time will
case elfcpp::R_ARM_PREL31:
case elfcpp::R_ARM_JUMP24:
case elfcpp::R_ARM_PLT32:
+ case elfcpp::R_ARM_THM_ABS5:
+ case elfcpp::R_ARM_ABS8:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_BASE_ABS:
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVT_ABS:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_MOVT_PREL:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVT_PREL:
break;
case elfcpp::R_ARM_GOTOFF32:
break;
case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
{
// The symbol requires a GOT entry.
Output_data_got<32, big_endian>* got =
template<bool big_endian>
inline void
-Target_arm<big_endian>::Scan::global(const General_options&,
- Symbol_table* symtab,
+Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
Layout* layout,
Target_arm* target,
Sized_relobj<32, big_endian>* object,
case elfcpp::R_ARM_NONE:
break;
- case elfcpp::R_ARM_ABS8:
- // Make a dynamic relocation if necessary.
- if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
- {
- // FIXME: Create a dynamic relocation for this location.
- gold_error(_("%s: gold bug: need dynamic ABS8 reloc for %s"),
- object->name().c_str(), gsym->demangled_name().c_str());
- }
- break;
-
case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
{
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
}
break;
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVT_ABS:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_MOVT_PREL:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVT_PREL:
+ break;
+
+ case elfcpp::R_ARM_THM_ABS5:
+ case elfcpp::R_ARM_ABS8:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_BASE_ABS:
+ {
+ // No dynamic relocs of this kinds.
+ // Report the error in case of PIC.
+ int flags = Symbol::NON_PIC_REF;
+ if (gsym->type() == elfcpp::STT_FUNC
+ || gsym->type() == elfcpp::STT_ARM_TFUNC)
+ flags |= Symbol::FUNCTION_CALL;
+ if (gsym->needs_dynamic_reloc(flags))
+ check_non_pic(object, r_type);
+ }
+ break;
+
case elfcpp::R_ARM_REL32:
case elfcpp::R_ARM_PREL31:
{
break;
case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
{
// The symbol requires a GOT entry.
Output_data_got<32, big_endian>* got =
template<bool big_endian>
void
-Target_arm<big_endian>::gc_process_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, big_endian>* object,
unsigned int data_shndx,
typedef typename Target_arm<big_endian>::Scan Scan;
gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>(
- options,
symtab,
layout,
this,
template<bool big_endian>
void
-Target_arm<big_endian>::scan_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, big_endian>* object,
unsigned int data_shndx,
}
gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
- options,
symtab,
layout,
this,
template<bool big_endian>
void
-Target_arm<big_endian>::do_finalize_sections(Layout* layout)
+Target_arm<big_endian>::do_finalize_sections(
+ Layout* layout,
+ const Input_objects* input_objects)
{
+ // Merge processor-specific flags.
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(*p);
+ this->merge_processor_specific_flags(
+ arm_relobj->name(),
+ arm_relobj->processor_specific_flags());
+ }
+
+ for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
+ p != input_objects->dynobj_end();
+ ++p)
+ {
+ Arm_dynobj<big_endian>* arm_dynobj =
+ Arm_dynobj<big_endian>::as_arm_dynobj(*p);
+ this->merge_processor_specific_flags(
+ arm_dynobj->name(),
+ arm_dynobj->processor_specific_flags());
+ }
+
// Fill in some more dynamic tags.
Output_data_dynamic* const odyn = layout->dynamic_data();
if (odyn != NULL)
{
- if (this->got_plt_ != NULL)
+ if (this->got_plt_ != NULL
+ && this->got_plt_->output_section() != NULL)
odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
- if (this->plt_ != NULL)
+ if (this->plt_ != NULL
+ && this->plt_->output_section() != NULL)
{
const Output_data* od = this->plt_->rel_plt();
odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
}
- if (this->rel_dyn_ != NULL)
+ if (this->rel_dyn_ != NULL
+ && this->rel_dyn_->output_section() != NULL)
{
const Output_data* od = this->rel_dyn_;
odyn->add_section_address(elfcpp::DT_REL, od);
== NULL);
Output_segment* exidx_segment =
layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
- exidx_segment->add_output_section(exidx_section, elfcpp::PF_R);
+ exidx_segment->add_output_section(exidx_section, elfcpp::PF_R,
+ false);
}
}
}
const Sized_symbol<32>* gsym,
const Symbol_value<32>* psymval,
unsigned char* view,
- elfcpp::Elf_types<32>::Elf_Addr address,
+ Arm_address address,
section_size_type /* view_size */ )
{
typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
r_type = get_real_reloc_type(r_type);
- // If this the symbol may be a Thumb function, set thumb bit to 1.
- bool has_thumb_bit = ((gsym != NULL)
- && (gsym->type() == elfcpp::STT_FUNC
- || gsym->type() == elfcpp::STT_ARM_TFUNC));
+ const Arm_relobj<big_endian>* object =
+ Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
- // Pick the value to use for symbols defined in shared objects.
+ // If the final branch target of a relocation is THUMB instruction, this
+ // is 1. Otherwise it is 0.
+ Arm_address thumb_bit = 0;
Symbol_value<32> symval;
- if (gsym != NULL
- && gsym->use_plt_offset(reloc_is_non_pic(r_type)))
+ bool is_weakly_undefined_without_plt = false;
+ if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
{
- symval.set_output_value(target->plt_section()->address()
- + gsym->plt_offset());
- psymval = &symval;
- has_thumb_bit = 0;
+ if (gsym != NULL)
+ {
+ // This is a global symbol. Determine if we use PLT and if the
+ // final target is THUMB.
+ if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
+ {
+ // This uses a PLT, change the symbol value.
+ symval.set_output_value(target->plt_section()->address()
+ + gsym->plt_offset());
+ psymval = &symval;
+ }
+ else if (gsym->is_weak_undefined())
+ {
+ // This is a weakly undefined symbol and we do not use PLT
+ // for this relocation. A branch targeting this symbol will
+ // be converted into an NOP.
+ is_weakly_undefined_without_plt = true;
+ }
+ else
+ {
+ // Set thumb bit if symbol:
+ // -Has type STT_ARM_TFUNC or
+ // -Has type STT_FUNC, is defined and with LSB in value set.
+ thumb_bit =
+ (((gsym->type() == elfcpp::STT_ARM_TFUNC)
+ || (gsym->type() == elfcpp::STT_FUNC
+ && !gsym->is_undefined()
+ && ((psymval->value(object, 0) & 1) != 0)))
+ ? 1
+ : 0);
+ }
+ }
+ else
+ {
+ // This is a local symbol. Determine if the final target is THUMB.
+ // We saved this information when all the local symbols were read.
+ elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
+ thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
+ }
+ }
+ else
+ {
+ // This is a fake relocation synthesized for a stub. It does not have
+ // a real symbol. We just look at the LSB of the symbol value to
+ // determine if the target is THUMB or not.
+ thumb_bit = ((psymval->value(object, 0) & 1) != 0);
}
- const Sized_relobj<32, big_endian>* object = relinfo->object;
-
+ // Strip LSB if this points to a THUMB target.
+ if (thumb_bit != 0
+ && Target_arm<big_endian>::reloc_uses_thumb_bit(r_type)
+ && ((psymval->value(object, 0) & 1) != 0))
+ {
+ Arm_address stripped_value =
+ psymval->value(object, 0) & ~static_cast<Arm_address>(1);
+ symval.set_output_value(stripped_value);
+ psymval = &symval;
+ }
+
// Get the GOT offset if needed.
// The GOT pointer points to the end of the GOT section.
// We need to subtract the size of the GOT section to get
switch (r_type)
{
case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
break;
}
+ // To look up relocation stubs, we need to pass the symbol table index of
+ // a local symbol.
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
+
typename Arm_relocate_functions::Status reloc_status =
Arm_relocate_functions::STATUS_OKAY;
switch (r_type)
case elfcpp::R_ARM_ABS8:
if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
output_section))
- reloc_status = Arm_relocate_functions::abs8(view, object, psymval,
- has_thumb_bit);
+ reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
+ break;
+
+ case elfcpp::R_ARM_ABS12:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
+ reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
+ break;
+
+ case elfcpp::R_ARM_ABS16:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
+ reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
+ break;
+
+ case elfcpp::R_ARM_ABS32:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
+ thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_ABS32_NOI:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ // No thumb bit for this relocation: (S + A)
+ reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
+ false);
+ break;
+
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::movw_abs_nc(view, object,
+ psymval,
+ thumb_bit);
+ else
+ gold_error(_("relocation R_ARM_MOVW_ABS_NC cannot be used when making"
+ "a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_MOVT_ABS:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::movt_abs(view, object, psymval);
+ else
+ gold_error(_("relocation R_ARM_MOVT_ABS cannot be used when making"
+ "a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::thm_movw_abs_nc(view, object,
+ psymval,
+ thumb_bit);
+ else
+ gold_error(_("relocation R_ARM_THM_MOVW_ABS_NC cannot be used when"
+ "making a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::thm_movt_abs(view, object,
+ psymval);
+ else
+ gold_error(_("relocation R_ARM_THM_MOVT_ABS cannot be used when"
+ "making a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ reloc_status = Arm_relocate_functions::movw_prel_nc(view, object,
+ psymval, address,
+ thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_MOVT_PREL:
+ reloc_status = Arm_relocate_functions::movt_prel(view, object,
+ psymval, address);
break;
- case elfcpp::R_ARM_ABS32:
- if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
- output_section))
- reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
- has_thumb_bit);
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ reloc_status = Arm_relocate_functions::thm_movw_prel_nc(view, object,
+ psymval, address,
+ thumb_bit);
break;
+ case elfcpp::R_ARM_THM_MOVT_PREL:
+ reloc_status = Arm_relocate_functions::thm_movt_prel(view, object,
+ psymval, address);
+ break;
+
case elfcpp::R_ARM_REL32:
reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
- address, has_thumb_bit);
+ address, thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_THM_ABS5:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
+ reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
break;
case elfcpp::R_ARM_THM_CALL:
reloc_status = Arm_relocate_functions::thm_call(view, object, psymval,
- address, has_thumb_bit);
+ address, thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_XPC25:
+ reloc_status =
+ Arm_relocate_functions::xpc25(relinfo, view, gsym, object, r_sym,
+ psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
break;
case elfcpp::R_ARM_GOTOFF32:
{
- elfcpp::Elf_types<32>::Elf_Addr got_origin;
+ Arm_address got_origin;
got_origin = target->got_plt_section()->address();
reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
- got_origin, has_thumb_bit);
+ got_origin, thumb_bit);
}
break;
}
break;
+ case elfcpp::R_ARM_BASE_ABS:
+ {
+ if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ break;
+
+ uint32_t origin;
+ // Get the addressing origin of the output segment defining
+ // the symbol gsym (AAELF 4.6.1.2 Relocation types).
+ if (gsym == NULL)
+ // R_ARM_BASE_ABS with the NULL symbol will give the
+ // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
+ // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
+ origin = target->got_plt_section()->address();
+ else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
+ origin = gsym->output_segment()->vaddr();
+ else if (gsym->source () == Symbol::IN_OUTPUT_DATA)
+ origin = gsym->output_data()->address();
+ else
+ {
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("cannot find origin of R_ARM_BASE_ABS"));
+ return true;
+ }
+
+ reloc_status = Arm_relocate_functions::base_abs(view, origin);
+ }
+ break;
+
case elfcpp::R_ARM_GOT_BREL:
gold_assert(have_got_offset);
reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
break;
+ case elfcpp::R_ARM_GOT_PREL:
+ gold_assert(have_got_offset);
+ // Get the address origin for GOT PLT, which is allocated right
+ // after the GOT section, to calculate an absolute address of
+ // the symbol GOT entry (got_origin + got_offset).
+ Arm_address got_origin;
+ got_origin = target->got_plt_section()->address();
+ reloc_status = Arm_relocate_functions::got_prel(view,
+ got_origin + got_offset,
+ address);
+ break;
+
case elfcpp::R_ARM_PLT32:
gold_assert(gsym == NULL
|| gsym->has_plt_offset()
|| (gsym->is_defined()
&& !gsym->is_from_dynobj()
&& !gsym->is_preemptible()));
- reloc_status = Arm_relocate_functions::plt32(view, object, psymval,
- address, has_thumb_bit);
+ reloc_status =
+ Arm_relocate_functions::plt32(relinfo, view, gsym, object, r_sym,
+ psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
break;
case elfcpp::R_ARM_CALL:
- reloc_status = Arm_relocate_functions::call(view, object, psymval,
- address, has_thumb_bit);
+ reloc_status =
+ Arm_relocate_functions::call(relinfo, view, gsym, object, r_sym,
+ psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
break;
case elfcpp::R_ARM_JUMP24:
- reloc_status = Arm_relocate_functions::jump24(view, object, psymval,
- address, has_thumb_bit);
+ reloc_status =
+ Arm_relocate_functions::jump24(relinfo, view, gsym, object, r_sym,
+ psymval, address, thumb_bit,
+ is_weakly_undefined_without_plt);
break;
case elfcpp::R_ARM_PREL31:
reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
- address, has_thumb_bit);
+ address, thumb_bit);
break;
case elfcpp::R_ARM_TARGET1:
Output_section* output_section,
bool needs_special_offset_handling,
unsigned char* view,
- elfcpp::Elf_types<32>::Elf_Addr address,
+ Arm_address address,
section_size_type view_size,
const Reloc_symbol_changes* reloc_symbol_changes)
{
typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
gold_assert(sh_type == elfcpp::SHT_REL);
+ Arm_input_section<big_endian>* arm_input_section =
+ this->find_arm_input_section(relinfo->object, relinfo->data_shndx);
+
+ // This is an ARM input section and the view covers the whole output
+ // section.
+ if (arm_input_section != NULL)
+ {
+ gold_assert(needs_special_offset_handling);
+ Arm_address section_address = arm_input_section->address();
+ section_size_type section_size = arm_input_section->data_size();
+
+ gold_assert((arm_input_section->address() >= address)
+ && ((arm_input_section->address()
+ + arm_input_section->data_size())
+ <= (address + view_size)));
+
+ off_t offset = section_address - address;
+ view += offset;
+ address += offset;
+ view_size = section_size;
+ }
+
gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
Arm_relocate>(
relinfo,
case elfcpp::R_ARM_ABS8:
return 1;
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_THM_ABS5:
+ return 2;
+
case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_BASE_ABS:
case elfcpp::R_ARM_REL32:
case elfcpp::R_ARM_THM_CALL:
case elfcpp::R_ARM_GOTOFF32:
case elfcpp::R_ARM_BASE_PREL:
case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
case elfcpp::R_ARM_PLT32:
case elfcpp::R_ARM_CALL:
case elfcpp::R_ARM_JUMP24:
case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVT_ABS:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_MOVT_PREL:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVT_PREL:
return 4;
case elfcpp::R_ARM_TARGET1:
template<bool big_endian>
void
Target_arm<big_endian>::scan_relocatable_relocs(
- const General_options& options,
Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, big_endian>* object,
gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
Scan_relocatable_relocs>(
- options,
symtab,
layout,
object,
off_t offset_in_output_section,
const Relocatable_relocs* rr,
unsigned char* view,
- elfcpp::Elf_types<32>::Elf_Addr view_address,
+ Arm_address view_address,
section_size_type view_size,
unsigned char* reloc_view,
section_size_type reloc_view_size)
}
}
+// Whether if two EABI versions V1 and V2 are compatible.
+
+template<bool big_endian>
+bool
+Target_arm<big_endian>::are_eabi_versions_compatible(
+ elfcpp::Elf_Word v1,
+ elfcpp::Elf_Word v2)
+{
+ // v4 and v5 are the same spec before and after it was released,
+ // so allow mixing them.
+ if ((v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
+ || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
+ return true;
+
+ return v1 == v2;
+}
+
+// Combine FLAGS from an input object called NAME and the processor-specific
+// flags in the ELF header of the output. Much of this is adapted from the
+// processor-specific flags merging code in elf32_arm_merge_private_bfd_data
+// in bfd/elf32-arm.c.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::merge_processor_specific_flags(
+ const std::string& name,
+ elfcpp::Elf_Word flags)
+{
+ if (this->are_processor_specific_flags_set())
+ {
+ elfcpp::Elf_Word out_flags = this->processor_specific_flags();
+
+ // Nothing to merge if flags equal to those in output.
+ if (flags == out_flags)
+ return;
+
+ // Complain about various flag mismatches.
+ elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
+ elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
+ if (!this->are_eabi_versions_compatible(version1, version2))
+ gold_error(_("Source object %s has EABI version %d but output has "
+ "EABI version %d."),
+ name.c_str(),
+ (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
+ (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
+ }
+ else
+ {
+ // If the input is the default architecture and had the default
+ // flags then do not bother setting the flags for the output
+ // architecture, instead allow future merges to do this. If no
+ // future merges ever set these flags then they will retain their
+ // uninitialised values, which surprise surprise, correspond
+ // to the default values.
+ if (flags == 0)
+ return;
+
+ // This is the first time, just copy the flags.
+ // We only copy the EABI version for now.
+ this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
+ }
+}
+
+// Adjust ELF file header.
+template<bool big_endian>
+void
+Target_arm<big_endian>::do_adjust_elf_header(
+ unsigned char* view,
+ int len) const
+{
+ gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
+
+ elfcpp::Ehdr<32, big_endian> ehdr(view);
+ unsigned char e_ident[elfcpp::EI_NIDENT];
+ memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
+
+ if (elfcpp::arm_eabi_version(this->processor_specific_flags())
+ == elfcpp::EF_ARM_EABI_UNKNOWN)
+ e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
+ else
+ e_ident[elfcpp::EI_OSABI] = 0;
+ e_ident[elfcpp::EI_ABIVERSION] = 0;
+
+ // FIXME: Do EF_ARM_BE8 adjustment.
+
+ elfcpp::Ehdr_write<32, big_endian> oehdr(view);
+ oehdr.put_e_ident(e_ident);
+}
+
+// do_make_elf_object to override the same function in the base class.
+// We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
+// to store ARM specific information. Hence we need to have our own
+// ELF object creation.
+
+template<bool big_endian>
+Object*
+Target_arm<big_endian>::do_make_elf_object(
+ const std::string& name,
+ Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
+{
+ int et = ehdr.get_e_type();
+ if (et == elfcpp::ET_REL)
+ {
+ Arm_relobj<big_endian>* obj =
+ new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
+ obj->setup();
+ return obj;
+ }
+ else if (et == elfcpp::ET_DYN)
+ {
+ Sized_dynobj<32, big_endian>* obj =
+ new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
+ obj->setup();
+ return obj;
+ }
+ else
+ {
+ gold_error(_("%s: unsupported ELF file type %d"),
+ name.c_str(), et);
+ return NULL;
+ }
+}
+
+// Return whether a relocation type used the LSB to distinguish THUMB
+// addresses.
+template<bool big_endian>
+bool
+Target_arm<big_endian>::reloc_uses_thumb_bit(unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_PC24:
+ case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_REL32:
+ case elfcpp::R_ARM_SBREL32:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_GLOB_DAT:
+ case elfcpp::R_ARM_JUMP_SLOT:
+ case elfcpp::R_ARM_GOTOFF32:
+ case elfcpp::R_ARM_PLT32:
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_THM_JUMP24:
+ case elfcpp::R_ARM_SBREL31:
+ case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_JUMP19:
+ case elfcpp::R_ARM_THM_ALU_PREL_11_0:
+ case elfcpp::R_ARM_ALU_PC_G0_NC:
+ case elfcpp::R_ARM_ALU_PC_G0:
+ case elfcpp::R_ARM_ALU_PC_G1_NC:
+ case elfcpp::R_ARM_ALU_PC_G1:
+ case elfcpp::R_ARM_ALU_PC_G2:
+ case elfcpp::R_ARM_ALU_SB_G0_NC:
+ case elfcpp::R_ARM_ALU_SB_G0:
+ case elfcpp::R_ARM_ALU_SB_G1_NC:
+ case elfcpp::R_ARM_ALU_SB_G1:
+ case elfcpp::R_ARM_ALU_SB_G2:
+ case elfcpp::R_ARM_MOVW_BREL_NC:
+ case elfcpp::R_ARM_MOVW_BREL:
+ case elfcpp::R_ARM_THM_MOVW_BREL_NC:
+ case elfcpp::R_ARM_THM_MOVW_BREL:
+ return true;
+ default:
+ return false;
+ }
+}
+
+// Stub-generation methods for Target_arm.
+
+// Make a new Arm_input_section object.
+
+template<bool big_endian>
+Arm_input_section<big_endian>*
+Target_arm<big_endian>::new_arm_input_section(
+ Relobj* relobj,
+ unsigned int shndx)
+{
+ Input_section_specifier iss(relobj, shndx);
+
+ Arm_input_section<big_endian>* arm_input_section =
+ new Arm_input_section<big_endian>(relobj, shndx);
+ arm_input_section->init();
+
+ // Register new Arm_input_section in map for look-up.
+ std::pair<typename Arm_input_section_map::iterator, bool> ins =
+ this->arm_input_section_map_.insert(std::make_pair(iss, arm_input_section));
+
+ // Make sure that it we have not created another Arm_input_section
+ // for this input section already.
+ gold_assert(ins.second);
+
+ return arm_input_section;
+}
+
+// Find the Arm_input_section object corresponding to the SHNDX-th input
+// section of RELOBJ.
+
+template<bool big_endian>
+Arm_input_section<big_endian>*
+Target_arm<big_endian>::find_arm_input_section(
+ Relobj* relobj,
+ unsigned int shndx) const
+{
+ Input_section_specifier iss(relobj, shndx);
+ typename Arm_input_section_map::const_iterator p =
+ this->arm_input_section_map_.find(iss);
+ return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
+}
+
+// Make a new stub table.
+
+template<bool big_endian>
+Stub_table<big_endian>*
+Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
+{
+ Stub_table<big_endian>* stub_table =
+ new Stub_table<big_endian>(owner);
+ this->stub_tables_.push_back(stub_table);
+
+ stub_table->set_address(owner->address() + owner->data_size());
+ stub_table->set_file_offset(owner->offset() + owner->data_size());
+ stub_table->finalize_data_size();
+
+ return stub_table;
+}
+
+// Scan a relocation for stub generation.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::scan_reloc_for_stub(
+ const Relocate_info<32, big_endian>* relinfo,
+ unsigned int r_type,
+ const Sized_symbol<32>* gsym,
+ unsigned int r_sym,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Swxword addend,
+ Arm_address address)
+{
+ typedef typename Target_arm<big_endian>::Relocate Relocate;
+
+ const Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
+
+ bool target_is_thumb;
+ Symbol_value<32> symval;
+ if (gsym != NULL)
+ {
+ // This is a global symbol. Determine if we use PLT and if the
+ // final target is THUMB.
+ if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
+ {
+ // This uses a PLT, change the symbol value.
+ symval.set_output_value(this->plt_section()->address()
+ + gsym->plt_offset());
+ psymval = &symval;
+ target_is_thumb = false;
+ }
+ else if (gsym->is_undefined())
+ // There is no need to generate a stub symbol is undefined.
+ return;
+ else
+ {
+ target_is_thumb =
+ ((gsym->type() == elfcpp::STT_ARM_TFUNC)
+ || (gsym->type() == elfcpp::STT_FUNC
+ && !gsym->is_undefined()
+ && ((psymval->value(arm_relobj, 0) & 1) != 0)));
+ }
+ }
+ else
+ {
+ // This is a local symbol. Determine if the final target is THUMB.
+ target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
+ }
+
+ // Strip LSB if this points to a THUMB target.
+ if (target_is_thumb
+ && Target_arm<big_endian>::reloc_uses_thumb_bit(r_type)
+ && ((psymval->value(arm_relobj, 0) & 1) != 0))
+ {
+ Arm_address stripped_value =
+ psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
+ symval.set_output_value(stripped_value);
+ psymval = &symval;
+ }
+
+ // Get the symbol value.
+ Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
+
+ // Owing to pipelining, the PC relative branches below actually skip
+ // two instructions when the branch offset is 0.
+ Arm_address destination;
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_PLT32:
+ // ARM branches.
+ destination = value + addend + 8;
+ break;
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_THM_XPC22:
+ case elfcpp::R_ARM_THM_JUMP24:
+ case elfcpp::R_ARM_THM_JUMP19:
+ // THUMB branches.
+ destination = value + addend + 4;
+ break;
+ default:
+ gold_unreachable();
+ }
+
+ Stub_type stub_type =
+ Reloc_stub::stub_type_for_reloc(r_type, address, destination,
+ target_is_thumb);
+
+ // This reloc does not need a stub.
+ if (stub_type == arm_stub_none)
+ return;
+
+ // Try looking up an existing stub from a stub table.
+ Stub_table<big_endian>* stub_table =
+ arm_relobj->stub_table(relinfo->data_shndx);
+ gold_assert(stub_table != NULL);
+
+ // Locate stub by destination.
+ Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
+
+ // Create a stub if there is not one already
+ Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
+ if (stub == NULL)
+ {
+ // create a new stub and add it to stub table.
+ stub = this->stub_factory().make_reloc_stub(stub_type);
+ stub_table->add_reloc_stub(stub, stub_key);
+ }
+
+ // Record the destination address.
+ stub->set_destination_address(destination
+ | (target_is_thumb ? 1 : 0));
+}
+
+// This function scans a relocation sections for stub generation.
+// The template parameter Relocate must be a class type which provides
+// a single function, relocate(), which implements the machine
+// specific part of a relocation.
+
+// BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
+// SHT_REL or SHT_RELA.
+
+// PRELOCS points to the relocation data. RELOC_COUNT is the number
+// of relocs. OUTPUT_SECTION is the output section.
+// NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
+// mapped to output offsets.
+
+// VIEW is the section data, VIEW_ADDRESS is its memory address, and
+// VIEW_SIZE is the size. These refer to the input section, unless
+// NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
+// the output section.
+
+template<bool big_endian>
+template<int sh_type>
+void inline
+Target_arm<big_endian>::scan_reloc_section_for_stubs(
+ const Relocate_info<32, big_endian>* relinfo,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ const unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type)
+{
+ typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
+ const int reloc_size =
+ Reloc_types<sh_type, 32, big_endian>::reloc_size;
+
+ Arm_relobj<big_endian>* arm_object =
+ Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
+ unsigned int local_count = arm_object->local_symbol_count();
+
+ Comdat_behavior comdat_behavior = CB_UNDETERMINED;
+
+ for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
+ {
+ Reltype reloc(prelocs);
+
+ typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
+ unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
+
+ r_type = this->get_real_reloc_type(r_type);
+
+ // Only a few relocation types need stubs.
+ if ((r_type != elfcpp::R_ARM_CALL)
+ && (r_type != elfcpp::R_ARM_JUMP24)
+ && (r_type != elfcpp::R_ARM_PLT32)
+ && (r_type != elfcpp::R_ARM_THM_CALL)
+ && (r_type != elfcpp::R_ARM_THM_XPC22)
+ && (r_type != elfcpp::R_ARM_THM_JUMP24)
+ && (r_type != elfcpp::R_ARM_THM_JUMP19))
+ continue;
+
+ section_offset_type offset =
+ convert_to_section_size_type(reloc.get_r_offset());
+
+ if (needs_special_offset_handling)
+ {
+ offset = output_section->output_offset(relinfo->object,
+ relinfo->data_shndx,
+ offset);
+ if (offset == -1)
+ continue;
+ }
+
+ // Get the addend.
+ Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
+ elfcpp::Elf_types<32>::Elf_Swxword addend =
+ stub_addend_reader(r_type, view + offset, reloc);
+
+ const Sized_symbol<32>* sym;
+
+ Symbol_value<32> symval;
+ const Symbol_value<32> *psymval;
+ if (r_sym < local_count)
+ {
+ sym = NULL;
+ psymval = arm_object->local_symbol(r_sym);
+
+ // If the local symbol belongs to a section we are discarding,
+ // and that section is a debug section, try to find the
+ // corresponding kept section and map this symbol to its
+ // counterpart in the kept section. The symbol must not
+ // correspond to a section we are folding.
+ bool is_ordinary;
+ unsigned int shndx = psymval->input_shndx(&is_ordinary);
+ if (is_ordinary
+ && shndx != elfcpp::SHN_UNDEF
+ && !arm_object->is_section_included(shndx)
+ && !(relinfo->symtab->is_section_folded(arm_object, shndx)))
+ {
+ if (comdat_behavior == CB_UNDETERMINED)
+ {
+ std::string name =
+ arm_object->section_name(relinfo->data_shndx);
+ comdat_behavior = get_comdat_behavior(name.c_str());
+ }
+ if (comdat_behavior == CB_PRETEND)
+ {
+ bool found;
+ typename elfcpp::Elf_types<32>::Elf_Addr value =
+ arm_object->map_to_kept_section(shndx, &found);
+ if (found)
+ symval.set_output_value(value + psymval->input_value());
+ else
+ symval.set_output_value(0);
+ }
+ else
+ {
+ symval.set_output_value(0);
+ }
+ symval.set_no_output_symtab_entry();
+ psymval = &symval;
+ }
+ }
+ else
+ {
+ const Symbol* gsym = arm_object->global_symbol(r_sym);
+ gold_assert(gsym != NULL);
+ if (gsym->is_forwarder())
+ gsym = relinfo->symtab->resolve_forwards(gsym);
+
+ sym = static_cast<const Sized_symbol<32>*>(gsym);
+ if (sym->has_symtab_index())
+ symval.set_output_symtab_index(sym->symtab_index());
+ else
+ symval.set_no_output_symtab_entry();
+
+ // We need to compute the would-be final value of this global
+ // symbol.
+ const Symbol_table* symtab = relinfo->symtab;
+ const Sized_symbol<32>* sized_symbol =
+ symtab->get_sized_symbol<32>(gsym);
+ Symbol_table::Compute_final_value_status status;
+ Arm_address value =
+ symtab->compute_final_value<32>(sized_symbol, &status);
+
+ // Skip this if the symbol has not output section.
+ if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
+ continue;
+
+ symval.set_output_value(value);
+ psymval = &symval;
+ }
+
+ // If symbol is a section symbol, we don't know the actual type of
+ // destination. Give up.
+ if (psymval->is_section_symbol())
+ continue;
+
+ this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
+ addend, view_address + offset);
+ }
+}
+
+// Scan an input section for stub generation.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::scan_section_for_stubs(
+ const Relocate_info<32, big_endian>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ const unsigned char* view,
+ Arm_address view_address,
+ section_size_type view_size)
+{
+ if (sh_type == elfcpp::SHT_REL)
+ this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ view,
+ view_address,
+ view_size);
+ else if (sh_type == elfcpp::SHT_RELA)
+ // We do not support RELA type relocations yet. This is provided for
+ // completeness.
+ this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ view,
+ view_address,
+ view_size);
+ else
+ gold_unreachable();
+}
+
+// Group input sections for stub generation.
+//
+// We goup input sections in an output sections so that the total size,
+// including any padding space due to alignment is smaller than GROUP_SIZE
+// unless the only input section in group is bigger than GROUP_SIZE already.
+// Then an ARM stub table is created to follow the last input section
+// in group. For each group an ARM stub table is created an is placed
+// after the last group. If STUB_ALWATS_AFTER_BRANCH is false, we further
+// extend the group after the stub table.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::group_sections(
+ Layout* layout,
+ section_size_type group_size,
+ bool stubs_always_after_branch)
+{
+ // Group input sections and insert stub table
+ Layout::Section_list section_list;
+ layout->get_allocated_sections(§ion_list);
+ for (Layout::Section_list::const_iterator p = section_list.begin();
+ p != section_list.end();
+ ++p)
+ {
+ Arm_output_section<big_endian>* output_section =
+ Arm_output_section<big_endian>::as_arm_output_section(*p);
+ output_section->group_sections(group_size, stubs_always_after_branch,
+ this);
+ }
+}
+
+// Relaxation hook. This is where we do stub generation.
+
+template<bool big_endian>
+bool
+Target_arm<big_endian>::do_relax(
+ int pass,
+ const Input_objects* input_objects,
+ Symbol_table* symtab,
+ Layout* layout)
+{
+ // No need to generate stubs if this is a relocatable link.
+ gold_assert(!parameters->options().relocatable());
+
+ // If this is the first pass, we need to group input sections into
+ // stub groups.
+ if (pass == 1)
+ {
+ // Determine the stub group size. The group size is the absolute
+ // value of the parameter --stub-group-size. If --stub-group-size
+ // is passed a negative value, we restict stubs to be always after
+ // the stubbed branches.
+ int32_t stub_group_size_param =
+ parameters->options().stub_group_size();
+ bool stubs_always_after_branch = stub_group_size_param < 0;
+ section_size_type stub_group_size = abs(stub_group_size_param);
+
+ if (stub_group_size == 1)
+ {
+ // Default value.
+ // Thumb branch range is +-4MB has to be used as the default
+ // maximum size (a given section can contain both ARM and Thumb
+ // code, so the worst case has to be taken into account).
+ //
+ // This value is 24K less than that, which allows for 2025
+ // 12-byte stubs. If we exceed that, then we will fail to link.
+ // The user will have to relink with an explicit group size
+ // option.
+ stub_group_size = 4170000;
+ }
+
+ group_sections(layout, stub_group_size, stubs_always_after_branch);
+ }
+
+ // clear changed flags for all stub_tables
+ typedef typename Stub_table_list::iterator Stub_table_iterator;
+ for (Stub_table_iterator sp = this->stub_tables_.begin();
+ sp != this->stub_tables_.end();
+ ++sp)
+ (*sp)->set_has_been_changed(false);
+
+ // scan relocs for stubs
+ for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
+ op != input_objects->relobj_end();
+ ++op)
+ {
+ Arm_relobj<big_endian>* arm_relobj =
+ Arm_relobj<big_endian>::as_arm_relobj(*op);
+ arm_relobj->scan_sections_for_stubs(this, symtab, layout);
+ }
+
+ bool any_stub_table_changed = false;
+ for (Stub_table_iterator sp = this->stub_tables_.begin();
+ (sp != this->stub_tables_.end()) && !any_stub_table_changed;
+ ++sp)
+ {
+ if ((*sp)->has_been_changed())
+ any_stub_table_changed = true;
+ }
+
+ return any_stub_table_changed;
+}
+
+// Relocate a stub.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::relocate_stub(
+ Reloc_stub* stub,
+ const Relocate_info<32, big_endian>* relinfo,
+ Output_section* output_section,
+ unsigned char* view,
+ Arm_address address,
+ section_size_type view_size)
+{
+ Relocate relocate;
+ const Stub_template* stub_template = stub->stub_template();
+ for (size_t i = 0; i < stub_template->reloc_count(); i++)
+ {
+ size_t reloc_insn_index = stub_template->reloc_insn_index(i);
+ const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
+
+ unsigned int r_type = insn->r_type();
+ section_size_type reloc_offset = stub_template->reloc_offset(i);
+ section_size_type reloc_size = insn->size();
+ gold_assert(reloc_offset + reloc_size <= view_size);
+
+ // This is the address of the stub destination.
+ Arm_address target = stub->reloc_target(i);
+ Symbol_value<32> symval;
+ symval.set_output_value(target);
+
+ // Synthesize a fake reloc just in case. We don't have a symbol so
+ // we use 0.
+ unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
+ memset(reloc_buffer, 0, sizeof(reloc_buffer));
+ elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
+ reloc_write.put_r_offset(reloc_offset);
+ reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
+ elfcpp::Rel<32, big_endian> rel(reloc_buffer);
+
+ relocate.relocate(relinfo, this, output_section,
+ this->fake_relnum_for_stubs, rel, r_type,
+ NULL, &symval, view + reloc_offset,
+ address + reloc_offset, reloc_size);
+ }
+}
+
// The selector for arm object files.
template<bool big_endian>
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