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| author | Mark Kettenis <kettenis@gnu.org> | 2003-08-10 12:15:16 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@gnu.org> | 2003-08-10 12:15:16 +0000 |
| commit | 26604a3475bfc050d2bde39be82007de6d728678 (patch) | |
| tree | 252d0d367dd901a9018abbf5ec405a833beceff7 | |
| parent | 55ed75018d50a88fb3696745b64d7b44b20711a0 (diff) | |
| download | gdb-26604a3475bfc050d2bde39be82007de6d728678.zip gdb-26604a3475bfc050d2bde39be82007de6d728678.tar.gz gdb-26604a3475bfc050d2bde39be82007de6d728678.tar.bz2 | |
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.
| -rw-r--r-- | gdb/ChangeLog | 7 | ||||
| -rw-r--r-- | gdb/i386-tdep.c | 47 |
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) |