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Re: Fix to debugging problem on Alpha
On May 23, 2000, Richard Henderson <rth@cygnus.com> wrote:
> On Mon, May 22, 2000 at 07:09:05PM -0700, Richard Henderson wrote:
>> Namely, in thread_prologue_epilogue_insns, after emitting the
>> prologue, move all of the line number notes after the prologue.
> * function.c (thread_prologue_and_epilogue_insns): Make sure
> existing line number notes appear after the prologue.
Here's a trivial back-port of this patch to the 2.95 branch. Ok to
install?
Index: gcc/ChangeLog
from Alexandre Oliva <aoliva@cygnus.com>
2000-05-22 Richard Henderson <rth@cygnus.com>
* function.c (thread_prologue_and_epilogue_insns): Make sure
existing line number notes appear after the prologue.
Index: gcc/function.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/function.c,v
retrieving revision 1.90.4.2
diff -u -r1.90.4.2 function.c
--- gcc/function.c 1999/09/07 07:34:04 1.90.4.2
+++ gcc/function.c 2000/05/24 03:26:55
@@ -6695,7 +6695,10 @@
thread_prologue_and_epilogue_insns (f)
rtx f ATTRIBUTE_UNUSED;
{
- int insertted = 0;
+ int inserted = 0;
+#ifdef HAVE_prologue
+ rtx prologue_end = NULL_RTX;
+#endif
prologue = 0;
#ifdef HAVE_prologue
@@ -6712,7 +6715,7 @@
seq = get_insns ();
prologue = record_insns (seq);
- emit_note (NULL, NOTE_INSN_PROLOGUE_END);
+ prologue_end = emit_note (NULL, NOTE_INSN_PROLOGUE_END);
seq = gen_sequence ();
end_sequence ();
@@ -6725,7 +6728,7 @@
abort ();
insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
- insertted = 1;
+ inserted = 1;
}
else
emit_insn_after (seq, f);
@@ -6857,8 +6860,56 @@
}
#endif
- if (insertted)
+ if (inserted)
commit_edge_insertions ();
+
+#ifdef HAVE_prologue
+ if (prologue_end)
+ {
+ rtx insn, prev;
+
+ /* GDB handles `break f' by setting a breakpoint on the first
+ line note *after* the prologue. Which means (1) that if
+ there are line number notes before where we inserted the
+ prologue we should move them, and (2) if there is no such
+ note, then we should generate one at the prologue. */
+
+ for (insn = prologue_end; insn ; insn = prev)
+ {
+ prev = PREV_INSN (insn);
+ if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
+ {
+ /* Note that we cannot reorder the first insn in the
+ chain, since rest_of_compilation relies on that
+ remaining constant. Do the next best thing. */
+ if (prev == NULL)
+ {
+ emit_line_note_after (NOTE_SOURCE_FILE (insn),
+ NOTE_LINE_NUMBER (insn),
+ prologue_end);
+ NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
+ }
+ else
+ reorder_insns (insn, insn, prologue_end);
+ }
+ }
+
+ insn = NEXT_INSN (prologue_end);
+ if (! insn || GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) <= 0)
+ {
+ for (insn = next_active_insn (f); insn ; insn = PREV_INSN (insn))
+ {
+ if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
+ {
+ emit_line_note_after (NOTE_SOURCE_FILE (insn),
+ NOTE_LINE_NUMBER (insn),
+ prologue_end);
+ break;
+ }
+ }
+ }
+ }
+ #endif
}
/* Reposition the prologue-end and epilogue-begin notes after instruction
--
Alexandre Oliva Enjoy Guaranį, see http://www.ic.unicamp.br/~oliva/
Cygnus Solutions, a Red Hat company aoliva@{redhat, cygnus}.com
Free Software Developer and Evangelist CS PhD student at IC-Unicamp
oliva@{lsd.ic.unicamp.br, gnu.org} Write to mailing lists, not to me