* NEWS: Add note on new "set stack-cache" option.
* corefile.c (read_stack): New function.
* dcache.c (dcache_struct): New member ptid.
(dcache_enable_p): Mark as obsolete.
(show_dcache_enabled_p): Flag option as deprecated.
(dcache_invalidate): Update ptid.
(dcache_invalidate_line): New function.
(dcache_read_line): No longer check cacheable attribute, stack
accesses get cached despite attribute.
(dcache_init): Set ptid.
(dcache_xfer_memory): Flush cache if from different ptid than before.
Update cache after write.
(dcache_update): New function.
(dcache_info): Report ptid.
(_initialize_dcache): Update text for `remotecache' to indicate it
is obsolete.
* dcache.h (dcache_update): Declare.
* dwarf2loc.c (dwarf2_evaluate_loc_desc): Mark values on stack with
set_value_stack.
* frame-unwind.c (frame_unwind_got_memory): Ditto.
* gdbcore.h (read_stack): Declare.
* memattr.c (mem_enable_command): Call target_dcache_invalidate
instead of dcache_invalidate.
(mem_disable_command, mem_delete_command): Ditto.
* target.c (stack_cache_enabled_p_1): New static global.
(stack_cache_enabled_p): New static global.
(set_stack_cache_enabled_p): New function.
(show_stack_cache_enabled_p): New function.
(target_dcache): Make static.
(target_dcache_invalidate): New function.
(target_load, target_resume): Call target_dcache_invalidate
instead of dcache_invalidate.
(memory_xfer_partial): New arg object, all callers updated.
Check for existing inferior before calling dcache routines.
When writing non-TARGET_OBJECT_STACK_MEMORY, notify dcache.
(target_xfer_partial): Call memory_xfer_partial for
TARGET_OBJECT_STACK_MEMORY.
(target_read_stack): New function.
(initialize_targets): Install new option `stack-cache'.
* target.h: Remove #include of dcache.h.
(enum target_object): New value TARGET_OBJECT_STACK_MEMORY.
(target_dcache): Delete.
(target_dcache_invalidate): Declare.
(target_read_stack): Declare.
* top.c (prepare_execute_command): New function.
(execute_command): Call prepare_execute_command
instead of free_all_values.
* top.h (prepare_execute_command): Declare.
* valops.c (get_value_at): New function.
(value_at): Guts moved to get_value_at.
(value_at_lazy): Similarly.
(value_fetch_lazy): Call read_stack for stack values.
* value.c (struct value): New member `stack'.
(value_stack, set_value_stack): New functions.
* value.h (value_stack, set_value_stack): Declare.
* mi/mi-main.c (mi_cmd_execute): Call prepare_execute_command
instead of free_all_values.
doc/
* gdb.texinfo (Caching Data of Remote Targets): Update text.
Mark `set/show remotecache' options as obsolete.
Document new `set/show stack-cache' option.
Update text for `info dcache'.
+2009-08-31 Jacob Potter <jdpotter@google.com>
+ Doug Evans <dje@google.com>
+
+ Implement TARGET_OBJECT_STACK_MEMORY.
+ * NEWS: Add note on new "set stack-cache" option.
+ * corefile.c (read_stack): New function.
+ * dcache.c (dcache_struct): New member ptid.
+ (dcache_enable_p): Mark as obsolete.
+ (show_dcache_enabled_p): Flag option as deprecated.
+ (dcache_invalidate): Update ptid.
+ (dcache_invalidate_line): New function.
+ (dcache_read_line): No longer check cacheable attribute, stack
+ accesses get cached despite attribute.
+ (dcache_init): Set ptid.
+ (dcache_xfer_memory): Flush cache if from different ptid than before.
+ Update cache after write.
+ (dcache_update): New function.
+ (dcache_info): Report ptid.
+ (_initialize_dcache): Update text for `remotecache' to indicate it
+ is obsolete.
+ * dcache.h (dcache_update): Declare.
+ * dwarf2loc.c (dwarf2_evaluate_loc_desc): Mark values on stack with
+ set_value_stack.
+ * frame-unwind.c (frame_unwind_got_memory): Ditto.
+ * gdbcore.h (read_stack): Declare.
+ * memattr.c (mem_enable_command): Call target_dcache_invalidate
+ instead of dcache_invalidate.
+ (mem_disable_command, mem_delete_command): Ditto.
+ * target.c (stack_cache_enabled_p_1): New static global.
+ (stack_cache_enabled_p): New static global.
+ (set_stack_cache_enabled_p): New function.
+ (show_stack_cache_enabled_p): New function.
+ (target_dcache): Make static.
+ (target_dcache_invalidate): New function.
+ (target_load, target_resume): Call target_dcache_invalidate
+ instead of dcache_invalidate.
+ (memory_xfer_partial): New arg object, all callers updated.
+ Check for existing inferior before calling dcache routines.
+ When writing non-TARGET_OBJECT_STACK_MEMORY, notify dcache.
+ (target_xfer_partial): Call memory_xfer_partial for
+ TARGET_OBJECT_STACK_MEMORY.
+ (target_read_stack): New function.
+ (initialize_targets): Install new option `stack-cache'.
+ * target.h: Remove #include of dcache.h.
+ (enum target_object): New value TARGET_OBJECT_STACK_MEMORY.
+ (target_dcache): Delete.
+ (target_dcache_invalidate): Declare.
+ (target_read_stack): Declare.
+ * top.c (prepare_execute_command): New function.
+ (execute_command): Call prepare_execute_command
+ instead of free_all_values.
+ * top.h (prepare_execute_command): Declare.
+ * valops.c (get_value_at): New function.
+ (value_at): Guts moved to get_value_at.
+ (value_at_lazy): Similarly.
+ (value_fetch_lazy): Call read_stack for stack values.
+ * value.c (struct value): New member `stack'.
+ (value_stack, set_value_stack): New functions.
+ * value.h (value_stack, set_value_stack): Declare.
+ * mi/mi-main.c (mi_cmd_execute): Call prepare_execute_command
+ instead of free_all_values.
+
2009-08-29 Hui Zhu <teawater@gmail.com>
* i386-tdep.c (i386_process_record): Fix the error of string
Allow GDB to resume all threads of all processes or only threads of
the current process.
+set stack-cache
+show stack-cache
+ Use more aggressive caching for accesses to the stack. This improves
+ performance of remote debugging (particularly backtraces) without
+ affecting correctness.
+
* Removed commands
info forks
}
/* Same as target_read_memory, but report an error if can't read. */
+
void
read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
{
memory_error (status, memaddr);
}
+/* Same as target_read_stack, but report an error if can't read. */
+
+void
+read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
+{
+ int status;
+ status = target_read_stack (memaddr, myaddr, len);
+ if (status != 0)
+ memory_error (status, memaddr);
+}
+
/* Argument / return result struct for use with
do_captured_read_memory_integer(). MEMADDR and LEN are filled in
by gdb_read_memory_integer(). RESULT is the contents that were
#include "gdb_string.h"
#include "gdbcore.h"
#include "target.h"
+#include "inferior.h"
#include "splay-tree.h"
/* The data cache could lead to incorrect results because it doesn't
/* The number of in-use lines in the cache. */
int size;
+
+ /* The ptid of last inferior to use cache or null_ptid. */
+ ptid_t ptid;
};
static struct dcache_block *dcache_hit (DCACHE *dcache, CORE_ADDR addr);
void _initialize_dcache (void);
-static int dcache_enabled_p = 0;
+static int dcache_enabled_p = 0; /* OBSOLETE */
static void
show_dcache_enabled_p (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
- fprintf_filtered (file, _("Cache use for remote targets is %s.\n"), value);
+ fprintf_filtered (file, _("Deprecated remotecache flag is %s.\n"), value);
}
-
static DCACHE *last_cache; /* Used by info dcache */
/* Free all the data cache blocks, thus discarding all cached data. */
dcache->oldest = NULL;
dcache->newest = NULL;
dcache->size = 0;
+ dcache->ptid = null_ptid;
+}
+
+/* Invalidate the line associated with ADDR. */
+
+static void
+dcache_invalidate_line (DCACHE *dcache, CORE_ADDR addr)
+{
+ struct dcache_block *db = dcache_hit (dcache, addr);
+
+ if (db)
+ {
+ splay_tree_remove (dcache->tree, (splay_tree_key) db->addr);
+ db->newer = dcache->freelist;
+ dcache->freelist = db;
+ --dcache->size;
+ }
}
/* If addr is present in the dcache, return the address of the block
else
reg_len = region->hi - memaddr;
- /* Skip non-cacheable/non-readable regions. */
- if (!region->attrib.cache || region->attrib.mode == MEM_WO)
+ /* Skip non-readable regions. The cache attribute can be ignored,
+ since we may be loading this for a stack access. */
+ if (region->attrib.mode == MEM_WO)
{
memaddr += reg_len;
myaddr += reg_len;
an area of memory which wasn't present in the cache doesn't cause
it to be loaded in.
- Always return 1 to simplify dcache_xfer_memory. */
+ Always return 1 (meaning success) to simplify dcache_xfer_memory. */
static int
dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, gdb_byte *ptr)
dcache->newest = NULL;
dcache->freelist = NULL;
dcache->size = 0;
+ dcache->ptid = null_ptid;
last_cache = dcache;
return dcache;
to or from debugger address MYADDR. Write to inferior if SHOULD_WRITE is
nonzero.
- Returns length of data written or read; 0 for error. */
+ The meaning of the result is the same as for target_write. */
int
dcache_xfer_memory (struct target_ops *ops, DCACHE *dcache,
int (*xfunc) (DCACHE *dcache, CORE_ADDR addr, gdb_byte *ptr);
xfunc = should_write ? dcache_poke_byte : dcache_peek_byte;
+ /* If this is a different inferior from what we've recorded,
+ flush the cache. */
+
+ if (! ptid_equal (inferior_ptid, dcache->ptid))
+ {
+ dcache_invalidate (dcache);
+ dcache->ptid = inferior_ptid;
+ }
+
/* Do write-through first, so that if it fails, we don't write to
the cache at all. */
{
res = target_write (ops, TARGET_OBJECT_RAW_MEMORY,
NULL, myaddr, memaddr, len);
- if (res < len)
- return 0;
+ if (res <= 0)
+ return res;
+ /* Update LEN to what was actually written. */
+ len = res;
}
for (i = 0; i < len; i++)
{
if (!xfunc (dcache, memaddr + i, myaddr + i))
- return 0;
+ {
+ /* That failed. Discard its cache line so we don't have a
+ partially read line. */
+ dcache_invalidate_line (dcache, memaddr + i);
+ /* If we're writing, we still wrote LEN bytes. */
+ if (should_write)
+ return len;
+ else
+ return i;
+ }
}
return len;
"logically" connected but not actually a single call to one of the
memory transfer functions. */
+/* Just update any cache lines which are already present. This is called
+ by memory_xfer_partial in cases where the access would otherwise not go
+ through the cache. */
+
+void
+dcache_update (DCACHE *dcache, CORE_ADDR memaddr, gdb_byte *myaddr, int len)
+{
+ int i;
+ for (i = 0; i < len; i++)
+ dcache_poke_byte (dcache, memaddr + i, myaddr + i);
+}
+
static void
dcache_print_line (int index)
{
printf_filtered (_("Dcache line width %d, maximum size %d\n"),
LINE_SIZE, DCACHE_SIZE);
- if (!last_cache)
+ if (!last_cache || ptid_equal (last_cache->ptid, null_ptid))
{
printf_filtered (_("No data cache available.\n"));
return;
}
+ printf_filtered (_("Contains data for %s\n"),
+ target_pid_to_str (last_cache->ptid));
+
refcount = 0;
n = splay_tree_min (last_cache->tree);
&dcache_enabled_p, _("\
Set cache use for remote targets."), _("\
Show cache use for remote targets."), _("\
-When on, use data caching for remote targets. For many remote targets\n\
-this option can offer better throughput for reading target memory.\n\
-Unfortunately, gdb does not currently know anything about volatile\n\
-registers and thus data caching will produce incorrect results with\n\
-volatile registers are in use. By default, this option is off."),
+This used to enable the data cache for remote targets. The cache\n\
+functionality is now controlled by the memory region system and the\n\
+\"stack-cache\" flag; \"remotecache\" now does nothing and\n\
+exists only for compatibility reasons."),
NULL,
show_dcache_enabled_p,
&setlist, &showlist);
int dcache_xfer_memory (struct target_ops *ops, DCACHE *cache, CORE_ADDR mem,
gdb_byte *my, int len, int should_write);
+void dcache_update (DCACHE *dcache, CORE_ADDR memaddr, gdb_byte *myaddr,
+ int len);
+
#endif /* DCACHE_H */
+2009-08-31 Jacob Potter <jdpotter@google.com>
+ Doug Evans <dje@google.com>
+
+ * gdb.texinfo (Caching Data of Remote Targets): Update text.
+ Mark `set/show remotecache' options as obsolete.
+ Document new `set/show stack-cache' option.
+ Update text for `info dcache'.
+
2009-08-27 Doug Evans <dje@google.com>
* gdb.texinfo (Symbols): Delete `set print symbol-loading'.
@section Caching Data of Remote Targets
@cindex caching data of remote targets
-@value{GDBN} can cache data exchanged between the debugger and a
+@value{GDBN} caches data exchanged between the debugger and a
remote target (@pxref{Remote Debugging}). Such caching generally improves
performance, because it reduces the overhead of the remote protocol by
-bundling memory reads and writes into large chunks. Unfortunately,
-@value{GDBN} does not currently know anything about volatile
-registers, and thus data caching will produce incorrect results when
-volatile registers are in use.
+bundling memory reads and writes into large chunks. Unfortunately, simply
+caching everything would lead to incorrect results, since @value{GDBN}
+does not necessarily know anything about volatile values, memory-mapped I/O
+addresses, etc. Therefore, by default, @value{GDBN} only caches data
+known to be on the stack. Other regions of memory can be explicitly marked
+cacheable; see @pxref{Memory Region Attributes}.
@table @code
@kindex set remotecache
@item set remotecache on
@itemx set remotecache off
-Set caching state for remote targets. When @code{ON}, use data
-caching. By default, this option is @code{OFF}.
+This option no longer does anything; it exists for compatibility
+with old scripts.
@kindex show remotecache
@item show remotecache
-Show the current state of data caching for remote targets.
+Show the current state of the obsolete remotecache flag.
+
+@kindex set stack-cache
+@item set stack-cache on
+@itemx set stack-cache off
+Enable or disable caching of stack accesses. When @code{ON}, use
+caching. By default, this option is @code{ON}.
+
+@kindex show stack-cache
+@item show stack-cache
+Show the current state of data caching for memory accesses.
@kindex info dcache
-@item info dcache
+@item info dcache @r{[}line@r{]}
Print the information about the data cache performance. The
-information displayed includes: the dcache width and depth; and for
-each cache line, how many times it was referenced, and its data and
-state (invalid, dirty, valid). This command is useful for debugging
-the data cache operation.
+information displayed includes the dcache width and depth, and for
+each cache line, its number, address, and how many times it was
+referenced. This command is useful for debugging the data cache
+operation.
+
+If a line number is specified, the contents of that line will be
+printed in hex.
@end table
@node Searching Memory
retval = allocate_value (SYMBOL_TYPE (var));
VALUE_LVAL (retval) = lval_memory;
set_value_lazy (retval, 1);
+ set_value_stack (retval, 1);
set_value_address (retval, address);
}
frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr)
{
struct gdbarch *gdbarch = frame_unwind_arch (frame);
+ struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr);
- return value_at_lazy (register_type (gdbarch, regnum), addr);
+ set_value_stack (v, 1);
+ return v;
}
/* Return a value which indicates that FRAME's saved version of
extern void read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
+/* Like target_read_stack, but report an error if can't read. */
+
+extern void read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
+
/* Read an integer from debugged memory, given address and number of
bytes. */
require_user_regions (from_tty);
- dcache_invalidate (target_dcache);
+ target_dcache_invalidate ();
if (p == 0)
{
require_user_regions (from_tty);
- dcache_invalidate (target_dcache);
+ target_dcache_invalidate ();
if (p == 0)
{
require_user_regions (from_tty);
- dcache_invalidate (target_dcache);
+ target_dcache_invalidate ();
if (p == 0)
{
struct cleanup *cleanup;
int i;
- free_all_values ();
+ prepare_execute_command ();
+
cleanup = make_cleanup (null_cleanup, NULL);
if (parse->frame != -1 && parse->thread == -1)
static void setup_target_debug (void);
-DCACHE *target_dcache;
+/* The option sets this. */
+static int stack_cache_enabled_p_1 = 1;
+/* And set_stack_cache_enabled_p updates this.
+ The reason for the separation is so that we don't flush the cache for
+ on->on transitions. */
+static int stack_cache_enabled_p = 1;
+
+/* This is called *after* the stack-cache has been set.
+ Flush the cache for off->on and on->off transitions.
+ There's no real need to flush the cache for on->off transitions,
+ except cleanliness. */
+
+static void
+set_stack_cache_enabled_p (char *args, int from_tty,
+ struct cmd_list_element *c)
+{
+ if (stack_cache_enabled_p != stack_cache_enabled_p_1)
+ target_dcache_invalidate ();
+
+ stack_cache_enabled_p = stack_cache_enabled_p_1;
+}
+
+static void
+show_stack_cache_enabled_p (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Cache use for stack accesses is %s.\n"), value);
+}
+
+/* Cache of memory operations, to speed up remote access. */
+static DCACHE *target_dcache;
+
+/* Invalidate the target dcache. */
+
+void
+target_dcache_invalidate (void)
+{
+ dcache_invalidate (target_dcache);
+}
/* The user just typed 'target' without the name of a target. */
void
target_load (char *arg, int from_tty)
{
- dcache_invalidate (target_dcache);
+ target_dcache_invalidate ();
(*current_target.to_load) (arg, from_tty);
}
value are just as for target_xfer_partial. */
static LONGEST
-memory_xfer_partial (struct target_ops *ops, void *readbuf, const void *writebuf,
- ULONGEST memaddr, LONGEST len)
+memory_xfer_partial (struct target_ops *ops, enum target_object object,
+ void *readbuf, const void *writebuf, ULONGEST memaddr,
+ LONGEST len)
{
LONGEST res;
int reg_len;
struct mem_region *region;
+ struct inferior *inf;
/* Zero length requests are ok and require no work. */
if (len == 0)
return -1;
}
- if (region->attrib.cache)
+ inf = find_inferior_pid (ptid_get_pid (inferior_ptid));
+
+ if (inf != NULL
+ && (region->attrib.cache
+ || (stack_cache_enabled_p && object == TARGET_OBJECT_STACK_MEMORY)))
{
if (readbuf != NULL)
res = dcache_xfer_memory (ops, target_dcache, memaddr, readbuf,
}
}
+ /* Make sure the cache gets updated no matter what - if we are writing
+ to the stack, even if this write is not tagged as such, we still need
+ to update the cache. */
+
+ if (inf != NULL
+ && readbuf == NULL
+ && !region->attrib.cache
+ && stack_cache_enabled_p
+ && object != TARGET_OBJECT_STACK_MEMORY)
+ {
+ dcache_update (target_dcache, memaddr, (void *) writebuf, reg_len);
+ }
+
/* If none of those methods found the memory we wanted, fall back
to a target partial transfer. Normally a single call to
to_xfer_partial is enough; if it doesn't recognize an object
/* If this is a memory transfer, let the memory-specific code
have a look at it instead. Memory transfers are more
complicated. */
- if (object == TARGET_OBJECT_MEMORY)
- retval = memory_xfer_partial (ops, readbuf, writebuf, offset, len);
+ if (object == TARGET_OBJECT_MEMORY || object == TARGET_OBJECT_STACK_MEMORY)
+ retval = memory_xfer_partial (ops, object, readbuf,
+ writebuf, offset, len);
else
{
enum target_object raw_object = object;
return EIO;
}
+/* Like target_read_memory, but specify explicitly that this is a read from
+ the target's stack. This may trigger different cache behavior. */
+
+int
+target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
+{
+ /* Dispatch to the topmost target, not the flattened current_target.
+ Memory accesses check target->to_has_(all_)memory, and the
+ flattened target doesn't inherit those. */
+
+ if (target_read (current_target.beneath, TARGET_OBJECT_STACK_MEMORY, NULL,
+ myaddr, memaddr, len) == len)
+ return 0;
+ else
+ return EIO;
+}
+
int
target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, int len)
{
{
struct target_ops *t;
- dcache_invalidate (target_dcache);
+ target_dcache_invalidate ();
for (t = current_target.beneath; t != NULL; t = t->beneath)
{
&setlist,
&showlist);
+ add_setshow_boolean_cmd ("stack-cache", class_support,
+ &stack_cache_enabled_p, _("\
+Set cache use for stack access."), _("\
+Show cache use for stack access."), _("\
+When on, use the data cache for all stack access, regardless of any\n\
+configured memory regions. This improves remote performance significantly.\n\
+By default, caching for stack access is on."),
+ set_stack_cache_enabled_p,
+ show_stack_cache_enabled_p,
+ &setlist, &showlist);
+
target_dcache = dcache_init ();
}
#include "bfd.h"
#include "symtab.h"
-#include "dcache.h"
#include "memattr.h"
#include "vec.h"
#include "gdb_signals.h"
Target implementations of to_xfer_partial never need to handle
this object, and most callers should not use it. */
TARGET_OBJECT_RAW_MEMORY,
+ /* Memory known to be part of the target's stack. This is cached even
+ if it is not in a region marked as such, since it is known to be
+ "normal" RAM. */
+ TARGET_OBJECT_STACK_MEMORY,
/* Kernel Unwind Table. See "ia64-tdep.c". */
TARGET_OBJECT_UNWIND_TABLE,
/* Transfer auxilliary vector. */
#define target_supports_multi_process() \
(*current_target.to_supports_multi_process) ()
-extern DCACHE *target_dcache;
+/* Invalidate all target dcaches. */
+extern void target_dcache_invalidate (void);
extern int target_read_string (CORE_ADDR, char **, int, int *);
extern int target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
+extern int target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
+
extern int target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr,
int len);
}
#endif
+void
+prepare_execute_command (void)
+{
+ free_all_values ();
+
+ /* With multiple threads running while the one we're examining is stopped,
+ the dcache can get stale without us being able to detect it.
+ For the duration of the command, though, use the dcache to help
+ things like backtrace. */
+ if (non_stop)
+ target_dcache_invalidate ();
+}
+
/* Execute the line P as a command, in the current user context.
Pass FROM_TTY as second argument to the defining function. */
#endif
}
}
-
- free_all_values ();
+
+ prepare_execute_command ();
/* Force cleanup of any alloca areas if using C alloca instead of
a builtin alloca. */
extern int quit_cover (void *);
extern void execute_command (char *, int);
+/* Prepare for execution of a command.
+ Call this before every command, CLI or MI. */
+extern void prepare_execute_command (void);
+
/* This function returns a pointer to the string that is used
by gdb for its command prompt. */
extern char *get_prompt (void);
return val;
}
+/* Helper function for value_at, value_at_lazy, and value_at_lazy_stack. */
+
+static struct value *
+get_value_at (struct type *type, CORE_ADDR addr, int lazy)
+{
+ struct value *val;
+
+ if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
+ error (_("Attempt to dereference a generic pointer."));
+
+ if (lazy)
+ {
+ val = allocate_value_lazy (type);
+ }
+ else
+ {
+ val = allocate_value (type);
+ read_memory (addr, value_contents_all_raw (val), TYPE_LENGTH (type));
+ }
+
+ VALUE_LVAL (val) = lval_memory;
+ set_value_address (val, addr);
+
+ return val;
+}
+
/* Return a value with type TYPE located at ADDR.
Call value_at only if the data needs to be fetched immediately;
struct value *
value_at (struct type *type, CORE_ADDR addr)
{
- struct value *val;
-
- if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
- error (_("Attempt to dereference a generic pointer."));
-
- val = allocate_value (type);
-
- read_memory (addr, value_contents_all_raw (val), TYPE_LENGTH (type));
-
- VALUE_LVAL (val) = lval_memory;
- set_value_address (val, addr);
-
- return val;
+ return get_value_at (type, addr, 0);
}
/* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
struct value *
value_at_lazy (struct type *type, CORE_ADDR addr)
{
- struct value *val;
-
- if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
- error (_("Attempt to dereference a generic pointer."));
-
- val = allocate_value_lazy (type);
-
- VALUE_LVAL (val) = lval_memory;
- set_value_address (val, addr);
-
- return val;
+ return get_value_at (type, addr, 1);
}
/* Called only from the value_contents and value_contents_all()
int length = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
if (length)
- read_memory (addr, value_contents_all_raw (val), length);
+ {
+ if (value_stack (val))
+ read_stack (addr, value_contents_all_raw (val), length);
+ else
+ read_memory (addr, value_contents_all_raw (val), length);
+ }
}
else if (VALUE_LVAL (val) == lval_register)
{
/* If value is a variable, is it initialized or not. */
int initialized;
+ /* If value is from the stack. If this is set, read_stack will be
+ used instead of read_memory to enable extra caching. */
+ int stack;
+
/* Actual contents of the value. Target byte-order. NULL or not
valid if lazy is nonzero. */
gdb_byte *contents;
value->lazy = val;
}
+int
+value_stack (struct value *value)
+{
+ return value->stack;
+}
+
+void
+set_value_stack (struct value *value, int val)
+{
+ value->stack = val;
+}
+
const gdb_byte *
value_contents (struct value *value)
{
extern int value_lazy (struct value *);
extern void set_value_lazy (struct value *value, int val);
+extern int value_stack (struct value *);
+extern void set_value_stack (struct value *value, int val);
+
/* value_contents() and value_contents_raw() both return the address
of the gdb buffer used to hold a copy of the contents of the lval.
value_contents() is used when the contents of the buffer are needed
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