Re: [PATCH] opts: fix -gtoggle + optimize attribute

["Martin Liška" <mliska@suse.cz>]

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On 3/1/22 09:48, Richard Biener wrote:
> I think moving flag_gtoggle handling before the flag_syntax_only handling
> is a good thing.  But I don't quite understand the flag_var_tracking disabling
> or how it worked before.

Well, as you know, the debugging options are a can of worms. During GCC 12 development I moved
most of the option logic to finish_options which is a place that is used both for command line
option processing and optimize/target pragma/attribute processing.

That's why we see this problem. OPT_LEVELS_1_PLUS enables flag_var_tracking but we have to drop
debug debug_info_level == DINFO_LEVEL_NONE.

> At least I think you want to check for
> debug_info_level == NONE, no?  Why should DINFO_LEVEL_TERSE be
> special?

No, sending updated version of the patch.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin

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From 1d9f77f00f208cca4142abc9c56995b865291229 Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Fri, 4 Feb 2022 15:50:17 +0100
Subject: [PATCH] opts: fix -gtoggle + optimize attribute

Note -fvar-tracking is enabled automatically with OPT_LEVELS_1_PLUS and
so we need to drop it if we are called from optimize attribute and the
option is unset.

	PR middle-end/104381

gcc/ChangeLog:

	* opts.cc (finish_options): If debug info is disabled
	(debug_info_level) and -fvar-tracking is unset, disable it.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr104381.c: New test.
---
 gcc/opts.cc                     | 49 +++++++++++++++++++--------------
 gcc/testsuite/gcc.dg/pr104381.c | 20 ++++++++++++++
 2 files changed, 48 insertions(+), 21 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr104381.c

diff --git a/gcc/opts.cc b/gcc/opts.cc
index 19c68aed065..ef5fe9b11ca 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -1302,6 +1302,34 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
     SET_OPTION_IF_UNSET (opts, opts_set, flag_vect_cost_model,
 			 VECT_COST_MODEL_CHEAP);
 
+  if (flag_gtoggle)
+    {
+      /* Make sure to process -gtoggle only once.  */
+      flag_gtoggle = false;
+      if (debug_info_level == DINFO_LEVEL_NONE)
+	{
+	  debug_info_level = DINFO_LEVEL_NORMAL;
+
+	  if (write_symbols == NO_DEBUG)
+	    write_symbols = PREFERRED_DEBUGGING_TYPE;
+	}
+      else
+	debug_info_level = DINFO_LEVEL_NONE;
+    }
+
+  if (!OPTION_SET_P (debug_nonbind_markers_p))
+    debug_nonbind_markers_p
+      = (optimize
+	 && debug_info_level >= DINFO_LEVEL_NORMAL
+	 && dwarf_debuginfo_p ()
+	 && !(flag_selective_scheduling || flag_selective_scheduling2));
+
+  /* Note -fvar-tracking is enabled automatically with OPT_LEVELS_1_PLUS and
+     so we need to drop it if we are called from optimize attribute.  */
+  if (debug_info_level == DINFO_LEVEL_NONE
+      && !OPTION_SET_P (flag_var_tracking))
+    flag_var_tracking = false;
+
   /* One could use EnabledBy, but it would lead to a circular dependency.  */
   if (!OPTION_SET_P (flag_var_tracking_uninit))
      flag_var_tracking_uninit = flag_var_tracking;
@@ -1328,27 +1356,6 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
       profile_flag = 0;
     }
 
-  if (flag_gtoggle)
-    {
-      /* Make sure to process -gtoggle only once.  */
-      flag_gtoggle = false;
-      if (debug_info_level == DINFO_LEVEL_NONE)
-	{
-	  debug_info_level = DINFO_LEVEL_NORMAL;
-
-	  if (write_symbols == NO_DEBUG)
-	    write_symbols = PREFERRED_DEBUGGING_TYPE;
-	}
-      else
-	debug_info_level = DINFO_LEVEL_NONE;
-    }
-
-  if (!OPTION_SET_P (debug_nonbind_markers_p))
-    debug_nonbind_markers_p
-      = (optimize
-	 && debug_info_level >= DINFO_LEVEL_NORMAL
-	 && dwarf_debuginfo_p ()
-	 && !(flag_selective_scheduling || flag_selective_scheduling2));
 
   diagnose_options (opts, opts_set, loc);
 }
diff --git a/gcc/testsuite/gcc.dg/pr104381.c b/gcc/testsuite/gcc.dg/pr104381.c
new file mode 100644
index 00000000000..a3aec919bee
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr104381.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -g -gtoggle -fdump-tree-optimized" } */
+
+int foo (int x)
+{
+  int tem = x + 1;
+  int tem2 = tem - 1;
+  return tem2;
+}
+
+int
+__attribute__((optimize("no-tree-pre")))
+bar (int x)
+{
+  int tem = x + 1;
+  int tem2 = tem - 1;
+  return tem2;
+}
+
+// { dg-final { scan-tree-dump-not "DEBUG " "optimized" } }
-- 
2.35.1