[PATCH] Fix ICE with statement frontiers (PR debug/83645)
Jakub Jelinek
jakub@redhat.com
Wed Jan 3 20:42:00 GMT 2018
Hi!
When var-tracking pass isn't done (e.g. with -O2 -g -fno-var-tracking
or -O2 -gstatement-frontiers), rest_of_handle_final calls
variable_tracking_main in order to perform delete_vta_debug_insns
- replace the debug marker insns with notes. The problem with that is
that final pass is after freeing cfg, so using FOR_EACH_BB/FOR_BB_INSNS_SAFE
is incorrect as the attached patch shows, e.g. the barriers pass swaps a
barrier with the statement notes and nothing updates the bb boundaries.
Fixed by doing the replacements on the raw insn stream when called from
final.c. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?
2018-01-03 Jakub Jelinek <jakub@redhat.com>
PR debug/83645
* var-tracking.c (delete_vta_debug_insn): New inline function.
(delete_vta_debug_insns): Add USE_CFG argument, if true, walk just
insns from get_insns () to NULL instead of each bb separately.
Use delete_vta_debug_insn. No longer static.
(vt_debug_insns_local, variable_tracking_main_1): Adjust
delete_vta_debug_insns callers.
* rtl.h (delete_vta_debug_insns): Declare.
* final.c (rest_of_handle_final): Call delete_vta_debug_insns
instead of variable_tracking_main.
* gcc.dg/pr83645.c: New test.
--- gcc/var-tracking.c.jj 2018-01-03 10:19:54.385533834 +0100
+++ gcc/var-tracking.c 2018-01-03 16:01:48.608217538 +0100
@@ -10271,11 +10271,40 @@ vt_initialize (void)
static int debug_label_num = 1;
+/* Remove from the insn stream a single debug insn used for
+ variable tracking at assignments. */
+
+static inline void
+delete_vta_debug_insn (rtx_insn *insn)
+{
+ if (DEBUG_MARKER_INSN_P (insn))
+ {
+ reemit_marker_as_note (insn);
+ return;
+ }
+
+ tree decl = INSN_VAR_LOCATION_DECL (insn);
+ if (TREE_CODE (decl) == LABEL_DECL
+ && DECL_NAME (decl)
+ && !DECL_RTL_SET_P (decl))
+ {
+ PUT_CODE (insn, NOTE);
+ NOTE_KIND (insn) = NOTE_INSN_DELETED_DEBUG_LABEL;
+ NOTE_DELETED_LABEL_NAME (insn)
+ = IDENTIFIER_POINTER (DECL_NAME (decl));
+ SET_DECL_RTL (decl, insn);
+ CODE_LABEL_NUMBER (insn) = debug_label_num++;
+ }
+ else
+ delete_insn (insn);
+}
+
/* Remove from the insn stream all debug insns used for variable
- tracking at assignments. */
+ tracking at assignments. USE_CFG should be false if the cfg is no
+ longer usable. */
-static void
-delete_vta_debug_insns (void)
+void
+delete_vta_debug_insns (bool use_cfg)
{
basic_block bb;
rtx_insn *insn, *next;
@@ -10283,33 +10312,20 @@ delete_vta_debug_insns (void)
if (!MAY_HAVE_DEBUG_INSNS)
return;
- FOR_EACH_BB_FN (bb, cfun)
- {
- FOR_BB_INSNS_SAFE (bb, insn, next)
+ if (use_cfg)
+ FOR_EACH_BB_FN (bb, cfun)
+ {
+ FOR_BB_INSNS_SAFE (bb, insn, next)
+ if (DEBUG_INSN_P (insn))
+ delete_vta_debug_insn (insn);
+ }
+ else
+ for (insn = get_insns (); insn; insn = next)
+ {
+ next = NEXT_INSN (insn);
if (DEBUG_INSN_P (insn))
- {
- if (DEBUG_MARKER_INSN_P (insn))
- {
- reemit_marker_as_note (insn);
- continue;
- }
-
- tree decl = INSN_VAR_LOCATION_DECL (insn);
- if (TREE_CODE (decl) == LABEL_DECL
- && DECL_NAME (decl)
- && !DECL_RTL_SET_P (decl))
- {
- PUT_CODE (insn, NOTE);
- NOTE_KIND (insn) = NOTE_INSN_DELETED_DEBUG_LABEL;
- NOTE_DELETED_LABEL_NAME (insn)
- = IDENTIFIER_POINTER (DECL_NAME (decl));
- SET_DECL_RTL (decl, insn);
- CODE_LABEL_NUMBER (insn) = debug_label_num++;
- }
- else
- delete_insn (insn);
- }
- }
+ delete_vta_debug_insn (insn);
+ }
}
/* Run a fast, BB-local only version of var tracking, to take care of
@@ -10322,7 +10338,7 @@ static void
vt_debug_insns_local (bool skipped ATTRIBUTE_UNUSED)
{
/* ??? Just skip it all for now. */
- delete_vta_debug_insns ();
+ delete_vta_debug_insns (true);
}
/* Free the data structures needed for variable tracking. */
@@ -10395,7 +10411,7 @@ variable_tracking_main_1 (void)
any pseudos at this point. */
|| targetm.no_register_allocation)
{
- delete_vta_debug_insns ();
+ delete_vta_debug_insns (true);
return 0;
}
@@ -10423,7 +10439,7 @@ variable_tracking_main_1 (void)
{
vt_finalize ();
- delete_vta_debug_insns ();
+ delete_vta_debug_insns (true);
/* This is later restored by our caller. */
flag_var_tracking_assignments = 0;
--- gcc/rtl.h.jj 2018-01-03 10:19:55.184533962 +0100
+++ gcc/rtl.h 2018-01-03 15:56:13.089080504 +0100
@@ -4254,6 +4254,7 @@ extern GTY(()) rtx stack_limit_rtx;
/* In var-tracking.c */
extern unsigned int variable_tracking_main (void);
+extern void delete_vta_debug_insns (bool);
/* In stor-layout.c. */
extern void get_mode_bounds (scalar_int_mode, int,
--- gcc/final.c.jj 2018-01-03 10:19:54.049533777 +0100
+++ gcc/final.c 2018-01-03 15:56:48.509091487 +0100
@@ -4544,7 +4544,7 @@ rest_of_handle_final (void)
/* Turn debug markers into notes if the var-tracking pass has not
been invoked. */
if (!flag_var_tracking && MAY_HAVE_DEBUG_MARKER_INSNS)
- variable_tracking_main ();
+ delete_vta_debug_insns (false);
assemble_start_function (current_function_decl, fnname);
final_start_function (get_insns (), asm_out_file, optimize);
--- gcc/testsuite/gcc.dg/pr83645.c.jj 2018-01-03 15:57:37.669106731 +0100
+++ gcc/testsuite/gcc.dg/pr83645.c 2018-01-03 15:57:06.575097090 +0100
@@ -0,0 +1,14 @@
+/* PR debug/83645 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -g -fno-var-tracking" } */
+
+int a, b, c[1];
+
+void
+foo (void)
+{
+ int i = 0;
+ b = a;
+ for (;;)
+ c[i++] = 7;
+}
Jakub
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