unwind-dw2.c (uw_update_context_1): Only set cfa as sp if previous frame didn't save sp.
* 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: r66527
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8f14981..a6e456c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -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.
+
2003-05-03 Richard Henderson <rth@redhat.com>
* builtins.c (expand_builtin) <BUILT_IN_DWARF_FP_REGNUM>: Remove.
diff --git a/gcc/unwind-dw2.c b/gcc/unwind-dw2.c
index d4269df..52b0b8d 100644
--- a/gcc/unwind-dw2.c
+++ b/gcc/unwind-dw2.c
@@ -1033,11 +1033,17 @@
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;
- orig_context.reg[__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 (!orig_context.reg[__builtin_dwarf_sp_column ()])
+ {
+ tmp_sp = (_Unwind_Ptr) context->cfa;
+ orig_context.reg[__builtin_dwarf_sp_column ()] = &tmp_sp;
+ }
+ context->reg[__builtin_dwarf_sp_column ()] = NULL;
/* Compute this frame's CFA. */
switch (fs->cfa_how)
@@ -1170,6 +1176,7 @@
struct _Unwind_Context *target)
{
long i;
+ void *target_cfa;
#if __GTHREADS
{
@@ -1191,11 +1198,18 @@
memcpy (c, t, dwarf_reg_size_table[i]);
}
+ /* If the last frame records a saved stack pointer, use it. */
+ if (target->reg[__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
