middle-end/105537 - debug processing

The following makes sure to have a consistent state of
flag_var_tracking_assignments with the distributed handling
in process_options and finish_options by moving everything to
finish_options which also restores diagnostics for
-g0 -fvar-tracking which was lost with previous changes.

2022-05-10  Richard Biener  <rguenther@suse.de>

	PR middle-end/105537
	* toplev.cc (process_options): Move flag_var_tracking
	handling ...
	* opts.cc (finish_options): ... here.

	* gcc.dg/torture/pr105537.c: New testcase.

3 files changed, 57 insertions, 28 deletions

diff --git a/gcc/opts.cc b/gcc/opts.cc
index a0baec9..c9badd2 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -1333,10 +1333,29 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
 	 && !(opts->x_flag_selective_scheduling
 	      || opts->x_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 (opts->x_debug_info_level < DINFO_LEVEL_NORMAL)
-    opts->x_flag_var_tracking = false;
+  /* We know which debug output will be used so we can set flag_var_tracking
+     and flag_var_tracking_uninit if the user has not specified them.  Note
+     we have not yet initialized debug_hooks so we might uselessly run
+     var-tracking on targets without var_location debug hook support.  */
+  if (opts->x_debug_info_level < DINFO_LEVEL_NORMAL
+      || !dwarf_debuginfo_p (opts))
+    {
+      if ((opts_set->x_flag_var_tracking && opts->x_flag_var_tracking == 1)
+	  || (opts_set->x_flag_var_tracking_uninit
+	      && opts->x_flag_var_tracking_uninit == 1))
+	{
+	  if (opts->x_debug_info_level < DINFO_LEVEL_NORMAL)
+	    warning_at (UNKNOWN_LOCATION, 0,
+			"variable tracking requested, but useless unless "
+			"producing debug info");
+	  else
+	    warning_at (UNKNOWN_LOCATION, 0,
+			"variable tracking requested, but not supported "
+			"by this debug format");
+	}
+      opts->x_flag_var_tracking = 0;
+      opts->x_flag_var_tracking_uninit = 0;
+    }
 
   /* One could use EnabledBy, but it would lead to a circular dependency.  */
   if (!opts_set->x_flag_var_tracking_uninit)
diff --git a/gcc/testsuite/gcc.dg/torture/pr105537.c b/gcc/testsuite/gcc.dg/torture/pr105537.c
new file mode 100644
index 0000000..2e4825c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr105537.c
@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-ffast-math -fsignaling-nans -fvar-tracking-assignments -fno-move-loop-stores -ftree-loop-distribution" } */
+
+int n;
+
+double
+ext1 (int);
+
+void
+ext2 (double);
+
+int
+sum (int v1, int v2)
+{
+  return v1 + v2;
+}
+
+void
+bar (void)
+{
+  ext2 (ext1 (n));
+}
+
+__attribute__ ((optimize ("-O3"))) void
+foo (int *x)
+{
+  static int i;
+
+  bar ();
+  for (i = 0; i != 2; i = sum (i, 1))
+    n = *x = 0;
+}
+
+/* { dg-message "other options take precedence" "" { target *-*-* } 0 } */
diff --git a/gcc/toplev.cc b/gcc/toplev.cc
index ed546b2..055e064 100644
--- a/gcc/toplev.cc
+++ b/gcc/toplev.cc
@@ -1458,30 +1458,6 @@ process_options (bool no_backend)
 		debug_type_names[debug_set_to_format (write_symbols)]);
     }
 
-  /* We know which debug output will be used so we can set flag_var_tracking
-     and flag_var_tracking_uninit if the user has not specified them.  */
-  if (debug_info_level < DINFO_LEVEL_NORMAL
-      || !dwarf_debuginfo_p ()
-      || debug_hooks->var_location == do_nothing_debug_hooks.var_location)
-    {
-      if ((OPTION_SET_P (flag_var_tracking) && flag_var_tracking == 1)
-	  || (OPTION_SET_P (flag_var_tracking_uninit)
-	      && flag_var_tracking_uninit == 1))
-        {
-	  if (debug_info_level < DINFO_LEVEL_NORMAL)
-	    warning_at (UNKNOWN_LOCATION, 0,
-			"variable tracking requested, but useless unless "
-			"producing debug info");
-	  else
-	    warning_at (UNKNOWN_LOCATION, 0,
-			"variable tracking requested, but not supported "
-			"by this debug format");
-	}
-      flag_var_tracking = 0;
-      flag_var_tracking_uninit = 0;
-      flag_var_tracking_assignments = 0;
-    }
-
   /* The debug hooks are used to implement -fdump-go-spec because it
      gives a simple and stable API for all the information we need to
      dump.  */