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authorJim Kingdon <jkingdon@engr.sgi.com>1993-07-15 17:38:59 +0000
committerJim Kingdon <jkingdon@engr.sgi.com>1993-07-15 17:38:59 +0000
commit5ac7f56ee841f67ede27213a2e17f6109b049eb0 (patch)
tree9b28c504cb47db1049ca659210c8fd5407ff0504 /gdb/hppa-tdep.c
parent0568df2acfe3796fe7248fe2742051b375f1757a (diff)
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* hppa-tdep.c (pc_in_linker_stub): New function.
(find_proc_framesize): Return 0 for linker stubs. (rp_saved): Tell the caller where rp is saved. (frame_chain_valid): Return 1 for linker stubs. (frame_saved_pc): Use return value from rp_saved.
Diffstat (limited to 'gdb/hppa-tdep.c')
-rw-r--r--gdb/hppa-tdep.c109
1 files changed, 98 insertions, 11 deletions
diff --git a/gdb/hppa-tdep.c b/gdb/hppa-tdep.c
index c4a8580..d72e831 100644
--- a/gdb/hppa-tdep.c
+++ b/gdb/hppa-tdep.c
@@ -296,6 +296,62 @@ find_unwind_entry(pc)
return NULL;
}
+/* Called when no unwind descriptor was found for PC. Returns 1 if it
+ appears that PC is in a linker stub. */
+static int pc_in_linker_stub PARAMS ((CORE_ADDR));
+
+static int
+pc_in_linker_stub (pc)
+ CORE_ADDR pc;
+{
+
+ int found_magic_instruction = 0;
+ int i;
+
+ /* Maximum known linker stub size is 4 instructions. Search forward
+ from the given PC, then backward. */
+ for (i = 0; i < 4; i++)
+ {
+ /* If we hit something with an unwind, stop searching this direction.
+
+ if (find_unwind_entry (pc + i * 4) != 0)
+ break;
+
+ /* Check for ldsid (rp),r1 which is the magic instruction for a
+ return from a cross-space function call. */
+ if (read_memory_integer (pc + i * 4, 4) == 0x004010a1)
+ {
+ found_magic_instruction = 1;
+ break;
+ }
+ /* Add code to handle long call/branch and argument relocation stubs
+ here. */
+ }
+
+ if (found_magic_instruction != 0)
+ return 1;
+
+ /* Now look backward. */
+ for (i = 0; i < 4; i++)
+ {
+ /* If we hit something with an unwind, stop searching this direction.
+
+ if (find_unwind_entry (pc - i * 4) != 0)
+ break;
+
+ /* Check for ldsid (rp),r1 which is the magic instruction for a
+ return from a cross-space function call. */
+ if (read_memory_integer (pc - i * 4, 4) == 0x004010a1)
+ {
+ found_magic_instruction = 1;
+ break;
+ }
+ /* Add code to handle long call/branch and argument relocation stubs
+ here. */
+ }
+ return found_magic_instruction;
+}
+
static int
find_return_regnum(pc)
CORE_ADDR pc;
@@ -313,6 +369,7 @@ find_return_regnum(pc)
return RP_REGNUM;
}
+/* Return size of frame, or -1 if we should use a frame pointer. */
int
find_proc_framesize(pc)
CORE_ADDR pc;
@@ -325,7 +382,13 @@ find_proc_framesize(pc)
u = find_unwind_entry (pc);
if (!u)
- return -1;
+ {
+ if (pc_in_linker_stub (pc))
+ /* Linker stubs have a zero size frame. */
+ return 0;
+ else
+ return -1;
+ }
if (u->Save_SP)
/* If this bit is set, it means there is a frame pointer and we should
@@ -335,18 +398,28 @@ find_proc_framesize(pc)
return u->Total_frame_size << 3;
}
-int
-rp_saved(pc)
+/* Return offset from sp at which rp is saved, or 0 if not saved. */
+static int rp_saved PARAMS ((CORE_ADDR));
+
+static int
+rp_saved (pc)
+ CORE_ADDR pc;
{
struct unwind_table_entry *u;
u = find_unwind_entry (pc);
if (!u)
- return 0;
+ {
+ if (pc_in_linker_stub (pc))
+ /* This is the so-called RP'. */
+ return -24;
+ else
+ return 0;
+ }
if (u->Save_RP)
- return 1;
+ return -20;
else
return 0;
}
@@ -396,10 +469,15 @@ frame_saved_pc (frame)
return read_register (ret_regnum) & ~0x3;
}
- else if (rp_saved (pc))
- return read_memory_integer (frame->frame - 20, 4) & ~0x3;
else
- return read_register (RP_REGNUM) & ~0x3;
+ {
+ int rp_offset = rp_saved (pc);
+
+ if (rp_offset == 0)
+ return read_register (RP_REGNUM) & ~0x3;
+ else
+ return read_memory_integer (frame->frame - rp_offset, 4) & ~0x3;
+ }
}
/* We need to correct the PC and the FP for the outermost frame when we are
@@ -470,10 +548,19 @@ frame_chain_valid (chain, thisframe)
u = find_unwind_entry (thisframe->pc);
- if (u && (u->Save_SP || u->Total_frame_size))
- return 1;
- else
+ if (u == NULL)
+ /* FIXME, we should probably fall back to some other technique,
+ if we want to deal gracefully with stripped executables or others
+ without unwind info. */
return 0;
+
+ if (u->Save_SP || u->Total_frame_size)
+ return 1;
+
+ if (pc_in_linker_stub (thisframe->pc))
+ return 1;
+
+ return 0;
}
else
{