// Include the debug info compression header:
// "ZLIB" followed by 8 bytes representing the uncompressed size of the section,
// useful for consumers to preallocate a buffer to decompress into.
-static void
+static bool
prependCompressionHeader(uint64_t Size,
SmallVectorImpl<char> &CompressedContents) {
static const StringRef Magic = "ZLIB";
+ if (Size <= Magic.size() + sizeof(Size) + CompressedContents.size())
+ return false;
if (sys::IsLittleEndianHost)
Size = sys::SwapByteOrder(Size);
CompressedContents.insert(CompressedContents.begin(),
std::copy(reinterpret_cast<char *>(&Size),
reinterpret_cast<char *>(&Size + 1),
CompressedContents.begin() + Magic.size());
+ return true;
}
// Return a single fragment containing the compressed contents of the whole
if (Success != zlib::StatusOK)
return nullptr;
- prependCompressionHeader(UncompressedData.size(), CompressedContents);
+ if (!prependCompressionHeader(UncompressedData.size(), CompressedContents))
+ return nullptr;
return CompressedFragment;
}
// RUN: llvm-mc -filetype=obj -compress-debug-sections -triple x86_64-pc-linux-gnu < %s -o %t
// RUN: llvm-objdump -s %t | FileCheck %s
-// RUN: llvm-dwarfdump -debug-dump=abbrev %t | FileCheck --check-prefix=ABBREV %s
+// RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck --check-prefix=INFO %s
// RUN: llvm-mc -filetype=obj -compress-debug-sections -triple i386-pc-linux-gnu < %s \
// RUN: | llvm-readobj -symbols - | FileCheck --check-prefix=386-SYMBOLS %s
// CHECK-NOT: ZLIB
// CHECK: Contents of
-// CHECK: Contents of section .zdebug_abbrev:
-// CHECK-NEXT: ZLIB
+// Don't compress small sections, such as this simple debug_abbrev example
+// CHECK: Contents of section .debug_abbrev:
+// CHECK-NOT: ZLIB
+// CHECK-NOT: Contents of
+
+// CHECK: Contents of section .debug_info:
// FIXME: Handle compressing alignment fragments to support compressing debug_frame
// CHECK: Contents of section .debug_frame:
// CHECK: Contents of
// Decompress one valid dwarf section just to check that this roundtrips
-// ABBREV: Abbrev table for offset: 0x00000000
-// ABBREV: [1] DW_TAG_compile_unit DW_CHILDREN_no
+// INFO: 0x00000000: Compile Unit: length = 0x0000000c version = 0x0004 abbr_offset = 0x0000 addr_size = 0x08 (next unit at 0x00000010)
// In x86 32 bit named symbols are used for temporary symbols in merge
// sections, so make sure we handle symbols inside compressed sections
.byte 14 # DW_FORM_strp
.byte 0 # EOM(1)
.byte 0 # EOM(2)
+
+ .section .debug_info,"",@progbits
+ .long 12 # Length of Unit
+ .short 4 # DWARF version number
+ .long .Lsection_abbrev # Offset Into Abbrev. Section
+ .byte 8 # Address Size (in bytes)
+ .byte 1 # Abbrev [1] DW_TAG_compile_unit
+ .long .Linfo_string0 # DW_AT_comp_dir
+
.text
foo:
.cfi_startproc
.file 1 "Driver.ii"
+# pad out the line table to make sure it's big enough to warrant compression
.loc 1 2 0
nop
+ .loc 1 3 0
+ nop
+ .loc 1 4 0
+ nop
+ .loc 1 5 0
+ nop
+ .loc 1 6 0
+ nop
+ .loc 1 7 0
+ nop
+ .loc 1 8 0
+ nop
.cfi_endproc
.cfi_sections .debug_frame
.section .debug_str,"MS",@progbits,1
.Linfo_string0:
- .asciz "foo"
-
- .section .debug_info,"",@progbits
- .long 40 # Length of Unit
- .short 4 # DWARF version number
- .long .Lsection_abbrev # Offset Into Abbrev. Section
- .byte 4 # Address Size (in bytes)
- .byte 1 # Abbrev [1] DW_TAG_compile_unit
- .long .Linfo_string0 # DW_AT_comp_dir
+ .asciz "compress this "