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authorMichael Snyder <msnyder@vmware.com>1996-11-05 19:06:11 +0000
committerMichael Snyder <msnyder@vmware.com>1996-11-05 19:06:11 +0000
commite1703d1f535a7320b1043c8330f17728087e4afd (patch)
tree5aa3a8845ad9a8f22425cd9a7baff2e79c88d597 /gdb/m32r-tdep.c
parent733861650ab16a4ddb33289d0f30d3894a61559f (diff)
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Tue Nov 5 10:21:02 1996 Michael Snyder <msnyder@cleaver.cygnus.com>
* m32r-tdep.c: Improved frame_chain and fn prologue analysis. * config/tm-m32r.h: Add framesize and register to extra_frame_info.
Diffstat (limited to 'gdb/m32r-tdep.c')
-rw-r--r--gdb/m32r-tdep.c56
1 files changed, 29 insertions, 27 deletions
diff --git a/gdb/m32r-tdep.c b/gdb/m32r-tdep.c
index 98fca39..1e6ec8d 100644
--- a/gdb/m32r-tdep.c
+++ b/gdb/m32r-tdep.c
@@ -93,9 +93,6 @@ m32r_scan_prologue (fi, fsr)
/* this code essentially duplicates skip_prologue,
but we need the start address below. */
- if (fsr)
- memset (fsr->regs, '\000', sizeof fsr->regs);
-
if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
{
sal = find_pc_line (prologue_start, 0);
@@ -109,7 +106,7 @@ m32r_scan_prologue (fi, fsr)
prologue_end = sal.end; /* (probably means no prologue) */
}
else
- prologue_end = prologue_start + 48; /* We're in the boondocks: allow for */
+ prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */
/* 16 pushes, an add, and "mv fp,sp" */
prologue_end = min (prologue_end, fi->pc);
@@ -149,15 +146,20 @@ m32r_scan_prologue (fi, fsr)
insn &= 0x00ffffff; /* positive */
framesize += insn;
}
- else if (insn == 0x1d8f) /* mv fp, sp */
- break; /* end of stack adjustments */
+ else if (insn == 0x1d8f) { /* mv fp, sp */
+ fi->using_frame_pointer = 1; /* fp is now valid */
+ break; /* end of stack adjustments */
+ }
+ else
+ break; /* anything else isn't prologue */
}
return framesize;
}
/* This function actually figures out the frame address for a given pc and
- sp. This is tricky on the v850 because we only use an explicit frame
- pointer when using alloca(). The only reliable way to get this info is to
+ sp. This is tricky on the m32r because we sometimes don't use an explicit
+ frame pointer, and the previous stack pointer isn't necessarily recorded
+ on the stack. The only reliable way to get this info is to
examine the prologue.
*/
@@ -166,23 +168,31 @@ m32r_init_extra_frame_info (fi)
struct frame_info *fi;
{
int reg;
- int framesize;
if (fi->next)
fi->pc = FRAME_SAVED_PC (fi->next);
- framesize = m32r_scan_prologue (fi, &fi->fsr);
+ memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
+ fi->using_frame_pointer = 0;
+ fi->framesize = m32r_scan_prologue (fi, &fi->fsr);
#if 0
if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL))
fi->frame = dummy_frame_stack->sp;
else
#endif
if (!fi->next)
- fi->frame = read_register (SP_REGNUM);
+ if (fi->using_frame_pointer)
+ fi->frame = read_register (FP_REGNUM);
+ else
+ fi->frame = read_register (SP_REGNUM);
+ else /* fi->next means this is not the innermost frame */
+ if (fi->using_frame_pointer) /* we have an FP */
+ if (fi->next->fsr.regs[FP_REGNUM] != 0) /* caller saved our FP */
+ fi->frame = read_memory_integer (fi->next->fsr.regs[FP_REGNUM], 4);
for (reg = 0; reg < NUM_REGS; reg++)
if (fi->fsr.regs[reg] != 0)
- fi->fsr.regs[reg] = fi->frame + framesize - fi->fsr.regs[reg];
+ fi->fsr.regs[reg] = fi->frame + fi->framesize - fi->fsr.regs[reg];
}
/* Find the caller of this frame. We do this by seeing if RP_REGNUM is saved
@@ -222,27 +232,19 @@ m32r_find_callers_reg (fi, regnum)
/* Given a GDB frame, determine the address of the calling function's frame.
This will be used to create a new GDB frame struct, and then
INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
- For m32r, simply get the saved FP off the stack.
+ For m32r, we save the frame size when we initialize the frame_info.
*/
CORE_ADDR
m32r_frame_chain (fi)
struct frame_info *fi;
{
- CORE_ADDR saved_fp = fi->fsr.regs[FP_REGNUM];
- CORE_ADDR fn_start, fn_end;
-
- if (saved_fp != 0)
- return read_memory_integer (saved_fp, 4);
- else {
- if (find_pc_partial_function (fi->pc, 0, &fn_start, &fn_end))
- if (fn_start == entry_point_address ())
- return 0; /* in _start fn, don't chain further */
- else
- return read_register (FP_REGNUM);
- else /* in the woods, what to do? */
- return 0; /* for now, play it safe and give up... */
- }
+ CORE_ADDR fn_start;
+
+ if (find_pc_partial_function (fi->pc, 0, &fn_start, 0))
+ if (fn_start == entry_point_address ())
+ return 0; /* in _start fn, don't chain further */
+ return fi->frame + fi->framesize;
}
/* All we do here is record SP and FP on the call dummy stack */