+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.
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)
struct _Unwind_Context *target)
{
long i;
+ void *target_cfa;
#if __GTHREADS
{
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