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unwind-dw2.c (uw_update_context_1): Only set cfa as sp if previous frame didn't save sp.

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* unwind-dw2.c (uw_update_context_1): Only set cfa as sp if
        previous frame didn't save sp.  Clear sp for next frame.
        (uw_install_context_1): Honor saved sp from frame.

From-SVN: r66526
This commit is contained in:
Richard Henderson 2003-05-06 10:28:37 -07:00 • committed by Richard Henderson
parent 3612c9efbb
commit 8b6891963b
2 changed files with 27 additions and 7 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2003-05-06 Richard Henderson <rth@redhat.com>
* unwind-dw2.c (uw_update_context_1): Only set cfa as sp if
previous frame didn't save sp. Clear sp for next frame.
(uw_install_context_1): Honor saved sp from frame.
2003-05-06 Richard Sandiford <rsandifo@redhat.com>
* config/mips/mips-protos.h (mips_subword, mips_output_move): Declare.

28
gcc/unwind-dw2.c
View file

@ -1089,11 +1089,17 @@ uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs)
In very special situations (such as unwind info for signal return),
there may be location expressions that use the stack pointer as well.
Given that other unwind mechanisms generally won't work if you try
to represent stack pointer saves and restores directly, we don't
bother conditionalizing this at all. */
tmp_sp = (_Unwind_Ptr) context->cfa;
_Unwind_SetGRPtr (&orig_context, __builtin_dwarf_sp_column (), &tmp_sp);
Do this conditionally for one frame. This allows the unwind info
for one frame to save a copy of the stack pointer from the previous
frame, and be able to use much easier CFA mechanisms to do it.
Always zap the saved stack pointer value for the next frame; carrying
the value over from one frame to another doesn't make sense. */
if (!_Unwind_GetGRPtr (&orig_context, __builtin_dwarf_sp_column ()))
{
tmp_sp = (_Unwind_Ptr) context->cfa;
_Unwind_SetGRPtr (&orig_context, __builtin_dwarf_sp_column (), &tmp_sp);
}
_Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), NULL);
/* Compute this frame's CFA. */
switch (fs->cfa_how)
@ -1234,6 +1240,7 @@ uw_install_context_1 (struct _Unwind_Context *current,
struct _Unwind_Context *target)
{
long i;
void *target_cfa;
#if __GTHREADS
{
@ -1256,11 +1263,18 @@ uw_install_context_1 (struct _Unwind_Context *current,
memcpy (c, t, dwarf_reg_size_table[i]);
}
/* If the last frame records a saved stack pointer, use it. */
if (_Unwind_GetGRPtr (target, __builtin_dwarf_sp_column ()))
target_cfa = (void *)(_Unwind_Ptr)
_Unwind_GetGR (target, __builtin_dwarf_sp_column ());
else
target_cfa = target->cfa;
/* We adjust SP by the difference between CURRENT and TARGET's CFA. */
if (STACK_GROWS_DOWNWARD)
return target->cfa - current->cfa + target->args_size;
return target_cfa - current->cfa + target->args_size;
else
return current->cfa - target->cfa - target->args_size;
return current->cfa - target_cfa - target->args_size;
}
static inline _Unwind_Ptr