On January 3, 2018 9:42:01 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com> wrote:
>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?
OK.
Richard.
>2018-01-03 Jakub Jelinek <ja...@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
