This silences a maybe-uninitialized warning, removes an obsolete comment and
changes the CFA offset of individual registers to comprise the global CFA
offset, thus making it possible to remove the special-casing of signal frames
from sparc64_frob_update_context.
Tested on SPARC/Solaris, applied on the mainline.
2013-05-22 Eric Botcazou <ebotca...@adacore.com>
* config/sparc/sol2-unwind.h (sparc64_frob_update_context): Do it for
signal frames as well.
(MD_FALLBACK_FRAME_STATE_FOR): Do minor cleanups throughout and add the
STACK_BIAS to the CFA offset.
--
Eric BotcazouIndex: libgcc/config/sparc/sol2-unwind.h
===================================================================
--- libgcc/config/sparc/sol2-unwind.h (revision 199091)
+++ libgcc/config/sparc/sol2-unwind.h (working copy)
@@ -155,12 +155,10 @@ sparc64_frob_update_context (struct _Unw
{
/* The column of %sp contains the old CFA, not the old value of %sp.
The CFA offset already comprises the stack bias so, when %sp is the
- CFA register, we must avoid counting the stack bias twice. Do not
- do that for signal frames as the offset is artificial for them. */
+ CFA register, we must avoid counting the stack bias twice. */
if (fs->regs.cfa_reg == __builtin_dwarf_sp_column ()
&& fs->regs.cfa_how == CFA_REG_OFFSET
- && fs->regs.cfa_offset != 0
- && !fs->signal_frame)
+ && fs->regs.cfa_offset != 0)
{
long i;
@@ -296,9 +294,8 @@ MD_FALLBACK_FRAME_STATE_FOR (struct _Unw
_Unwind_FrameState *fs)
{
void *pc = context->ra;
- struct frame *fp = (struct frame *) context->cfa;
- int nframes;
void *this_cfa = context->cfa;
+ int nframes = 0;
long new_cfa;
void *ra_location, *shifted_ra_location;
mcontext_t *mctx;
@@ -318,21 +315,22 @@ MD_FALLBACK_FRAME_STATE_FOR (struct _Unw
return _URC_NO_REASON;
}
+ /* Do some pattern matching at the return address. */
if (IS_SIGHANDLER (pc, this_cfa, &nframes))
{
+ struct frame *fp = (struct frame *) this_cfa;
struct handler_args {
struct frame frwin;
ucontext_t ucontext;
} *handler_args;
ucontext_t *ucp;
- /* context->cfa points into the frame after the saved frame pointer and
+ /* this_cfa points into the frame after the saved frame pointer and
saved pc (struct frame).
The ucontext_t structure is in the kernel frame after a struct
frame. Since the frame sizes vary even within OS releases, we
need to walk the stack to get there. */
-
for (i = 0; i < nframes; i++)
fp = (struct frame *) ((char *)fp->fr_savfp + STACK_BIAS);
@@ -340,19 +338,15 @@ MD_FALLBACK_FRAME_STATE_FOR (struct _Unw
ucp = &handler_args->ucontext;
mctx = &ucp->uc_mcontext;
}
-
- /* Exit if the pattern at the return address does not match the
- previous three patterns. */
else
return _URC_END_OF_STACK;
- new_cfa = mctx->gregs[REG_SP];
/* The frame address is %sp + STACK_BIAS in 64-bit mode. */
- new_cfa += STACK_BIAS;
+ new_cfa = mctx->gregs[REG_SP] + STACK_BIAS;
fs->regs.cfa_how = CFA_REG_OFFSET;
fs->regs.cfa_reg = __builtin_dwarf_sp_column ();
- fs->regs.cfa_offset = new_cfa - (long) this_cfa;
+ fs->regs.cfa_offset = new_cfa - (long) this_cfa + STACK_BIAS;
/* Restore global and out registers (in this order) from the
ucontext_t structure, uc_mcontext.gregs field. */
@@ -372,7 +366,7 @@ MD_FALLBACK_FRAME_STATE_FOR (struct _Unw
for (i = 0; i < 16; i++)
{
fs->regs.reg[i + 16].how = REG_SAVED_OFFSET;
- fs->regs.reg[i + 16].loc.offset = i*sizeof(long);
+ fs->regs.reg[i + 16].loc.offset = i * sizeof(long);
}
/* Check whether we need to restore FPU registers. */
