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emit-rtl.c (remove_unnecessary_notes): Verify proper nesting of block notes and exception handling notes.

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* emit-rtl.c (remove_unnecessary_notes): Verify proper nesting
        of block notes and exception handling notes.

From-SVN: r40295
This commit is contained in:
Richard Henderson
2001-03-07 10:36:23 -08:00
committed by Richard Henderson
parent dd1f09c21c
commit 542d73aeff
2 changed files with 60 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
gcc/ChangeLog
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@@ -1,3 +1,8 @@
2001-03-07 Richard Henderson <rth@redhat.com>
* emit-rtl.c (remove_unnecessary_notes): Verify proper nesting
of block notes and exception handling notes.
2001-03-06 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* fixinc/Makefile.in (FIXINC_DEFS): Add -DHAVE_CONFIG_H.

80
gcc/emit-rtl.c
View File

@@ -2825,8 +2825,11 @@ reorder_insns_with_line_notes (from, to, after)
void
remove_unnecessary_notes ()
{
rtx block_stack = NULL_RTX;
rtx eh_stack = NULL_RTX;
rtx insn;
rtx next;
rtx tmp;
/* We must not remove the first instruction in the function because
the compiler depends on the first instruction being a note. */
@@ -2839,55 +2842,78 @@ remove_unnecessary_notes ()
if (GET_CODE (insn) != NOTE)
continue;
/* By now, all notes indicating lexical blocks should have
NOTE_BLOCK filled in. */
if ((NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
|| NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
&& NOTE_BLOCK (insn) == NULL_TREE)
abort ();
/* Remove NOTE_INSN_DELETED notes. */
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED)
remove_insn (insn);
else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
switch (NOTE_LINE_NUMBER (insn))
{
case NOTE_INSN_DELETED:
remove_insn (insn);
break;
case NOTE_INSN_EH_REGION_BEG:
eh_stack = alloc_INSN_LIST (insn, eh_stack);
break;
case NOTE_INSN_EH_REGION_END:
/* Too many end notes. */
if (eh_stack == NULL_RTX)
abort ();
/* Mismatched nesting. */
if (NOTE_EH_HANDLER (XEXP (eh_stack, 0)) != NOTE_EH_HANDLER (insn))
abort ();
tmp = eh_stack;
eh_stack = XEXP (eh_stack, 1);
free_INSN_LIST_node (tmp);
break;
case NOTE_INSN_BLOCK_BEG:
/* By now, all notes indicating lexical blocks should have
NOTE_BLOCK filled in. */
if (NOTE_BLOCK (insn) == NULL_TREE)
abort ();
block_stack = alloc_INSN_LIST (insn, block_stack);
break;
case NOTE_INSN_BLOCK_END:
/* Too many end notes. */
if (block_stack == NULL_RTX)
abort ();
/* Mismatched nesting. */
if (NOTE_BLOCK (XEXP (block_stack, 0)) != NOTE_BLOCK (insn))
abort ();
tmp = block_stack;
block_stack = XEXP (block_stack, 1);
free_INSN_LIST_node (tmp);
/* Scan back to see if there are any non-note instructions
between INSN and the beginning of this block. If not,
then there is no PC range in the generated code that will
actually be in this block, so there's no point in
remembering the existence of the block. */
rtx prev;
for (prev = PREV_INSN (insn); prev; prev = PREV_INSN (prev))
for (tmp = PREV_INSN (insn); tmp ; tmp = PREV_INSN (tmp))
{
/* This block contains a real instruction. Note that we
don't include labels; if the only thing in the block
is a label, then there are still no PC values that
lie within the block. */
if (INSN_P (prev))
if (INSN_P (tmp))
break;
/* We're only interested in NOTEs. */
if (GET_CODE (prev) != NOTE)
if (GET_CODE (tmp) != NOTE)
continue;
if (NOTE_LINE_NUMBER (prev) == NOTE_INSN_BLOCK_BEG)
if (NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BLOCK_BEG)
{
/* If the BLOCKs referred to by these notes don't
match, then something is wrong with our BLOCK
nesting structure. */
if (NOTE_BLOCK (prev) != NOTE_BLOCK (insn))
abort ();
/* We just verified that this BLOCK matches us
with the block_stack check above. */
if (debug_ignore_block (NOTE_BLOCK (insn)))
{
BLOCK_DEAD (NOTE_BLOCK (insn)) = 1;
remove_insn (prev);
remove_insn (tmp);
remove_insn (insn);
}
break;
}
else if (NOTE_LINE_NUMBER (prev) == NOTE_INSN_BLOCK_END)
else if (NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BLOCK_END)
/* There's a nested block. We need to leave the
current block in place since otherwise the debugger
wouldn't be able to show symbols from our block in
@@ -2896,6 +2922,10 @@ remove_unnecessary_notes ()
}
}
}
/* Too many begin notes. */
if (block_stack || eh_stack)
abort ();
}