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authorMark Kettenis <kettenis@gnu.org>2003-08-10 12:15:16 +0000
committerMark Kettenis <kettenis@gnu.org>2003-08-10 12:15:16 +0000
commit26604a3475bfc050d2bde39be82007de6d728678 (patch)
tree252d0d367dd901a9018abbf5ec405a833beceff7 /gdb
parent55ed75018d50a88fb3696745b64d7b44b20711a0 (diff)
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Based on a patch from Michael Elizabeth Chastain (mec@shout.net):
* i386-tdep.c (i386_analyze_frame_setup): Recognize more instructions that GCC likes to mingle into the prologue. Fixes gdb/1253 and gdb/1255.
Diffstat (limited to 'gdb')
-rw-r--r--gdb/ChangeLog7
-rw-r--r--gdb/i386-tdep.c47
2 files changed, 49 insertions, 5 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 59a5739..9ee048b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2003-08-10 Mark Kettenis <kettenis@gnu.org>
+
+ Based on a patch from Michael Elizabeth Chastain (mec@shout.net):
+ * i386-tdep.c (i386_analyze_frame_setup): Recognize more
+ instructions that GCC likes to mingle into the prologue. Fixes
+ gdb/1253 and gdb/1255.
+
2003-08-09 Andrew Cagney <cagney@redhat.com>
Fix GDB PR cli/926.
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 328dff2..6a54be5 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -439,6 +439,7 @@ i386_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR current_pc,
struct i386_frame_cache *cache)
{
unsigned char op;
+ int skip = 0;
if (current_pc <= pc)
return current_pc;
@@ -456,25 +457,61 @@ i386_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR current_pc,
if (current_pc <= pc + 1)
return current_pc;
- /* Check for `movl %esp, %ebp' -- can be written in two ways. */
op = read_memory_unsigned_integer (pc + 1, 1);
+
+ /* Check for some special instructions that might be migrated
+ by GCC into the prologue. We check for
+
+ xorl %ebx, %ebx
+ xorl %ecx, %ecx
+ xorl %edx, %edx
+
+ and the equivalent
+
+ subl %ebx, %ebx
+ subl %ecx, %ecx
+ subl %edx, %edx
+
+ Make sure we only skip these instructions if we later see the
+ `movl %esp, %ebp' that actually sets up the frame. */
+ while (op == 0x29 || op == 0x31)
+ {
+ op = read_memory_unsigned_integer (pc + skip + 2, 1);
+ switch (op)
+ {
+ case 0xdb: /* %ebx */
+ case 0xc9: /* %ecx */
+ case 0xd2: /* %edx */
+ skip += 2;
+ break;
+ default:
+ return pc + 1;
+ }
+
+ op = read_memory_unsigned_integer (pc + skip + 1, 1);
+ }
+
+ /* Check for `movl %esp, %ebp' -- can be written in two ways. */
switch (op)
{
case 0x8b:
- if (read_memory_unsigned_integer (pc + 2, 1) != 0xec)
+ if (read_memory_unsigned_integer (pc + skip + 2, 1) != 0xec)
return pc + 1;
break;
case 0x89:
- if (read_memory_unsigned_integer (pc + 2, 1) != 0xe5)
+ if (read_memory_unsigned_integer (pc + skip + 2, 1) != 0xe5)
return pc + 1;
break;
default:
return pc + 1;
}
- /* OK, we actually have a frame. We just don't know how large it is
- yet. Set its size to zero. We'll adjust it if necessary. */
+ /* OK, we actually have a frame. We just don't know how large
+ it is yet. Set its size to zero. We'll adjust it if
+ necessary. We also now commit to skipping the special
+ instructions mentioned before. */
cache->locals = 0;
+ pc += skip;
/* If that's all, return now. */
if (current_pc <= pc + 3)