2008-08-18 Manuel Lopez-Ibanez <manu@gcc.gnu.org>

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa.c

diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index fbfcbf2..fb692f8 100644 (file)
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -1165,12 +1165,18 @@ useless_type_conversion_p_1 (tree outer_type, tree inner_type)
       if (TREE_CODE (inner_type) != TREE_CODE (outer_type))
        return false;
 
-      /* ???  Add structural equivalence check.  */
+      /* ???  This seems to be necessary even for aggregates that don't
+        have TYPE_STRUCTURAL_EQUALITY_P set.  */
 
       /* ???  This should eventually just return false.  */
       return lang_hooks.types_compatible_p (inner_type, outer_type);
     }
-
+  /* Also for functions and possibly other types with
+     TYPE_STRUCTURAL_EQUALITY_P set.  */
+  else if (TYPE_STRUCTURAL_EQUALITY_P (inner_type)
+          && TYPE_STRUCTURAL_EQUALITY_P (outer_type))
+    return lang_hooks.types_compatible_p (inner_type, outer_type);
+  
   return false;
 }
 
@@ -1408,20 +1414,23 @@ warn_uninit (tree t, const char *gmsgid, void *data)
   location = (context != NULL && gimple_has_location (context))
             ? gimple_location (context)
             : DECL_SOURCE_LOCATION (var);
-  warning_at (location, OPT_Wuninitialized, gmsgid, var);
   xloc = expand_location (location);
   floc = expand_location (DECL_SOURCE_LOCATION (cfun->decl));
-  if (xloc.file != floc.file
-      || xloc.line < floc.line
-      || xloc.line > LOCATION_LINE (cfun->function_end_locus))
-    inform ("%J%qD was declared here", var, var);
+  if (warning_at (location, OPT_Wuninitialized, gmsgid, var))
+    {
+      TREE_NO_WARNING (var) = 1;
 
-  TREE_NO_WARNING (var) = 1;
+      if (xloc.file != floc.file
+         || xloc.line < floc.line
+         || xloc.line > LOCATION_LINE (cfun->function_end_locus))
+       inform (input_location, "%J%qD was declared here", var, var);
+    }
 }
 
 struct walk_data {
   gimple stmt;
   bool always_executed;
+  bool warn_possibly_uninitialized;
 };
 
 /* Called via walk_tree, look for SSA_NAMEs that have empty definitions
@@ -1442,7 +1451,7 @@ warn_uninitialized_var (tree *tp, int *walk_subtrees, void *data_)
       if (data->always_executed)
         warn_uninit (t, "%qD is used uninitialized in this function",
                     data->stmt);
-      else
+      else if (data->warn_possibly_uninitialized)
         warn_uninit (t, "%qD may be used uninitialized in this function",
                     data->stmt);
       *walk_subtrees = 0;
@@ -1488,12 +1497,14 @@ warn_uninitialized_phi (gimple phi)
 }
 
 static unsigned int
-execute_early_warn_uninitialized (void)
+warn_uninitialized_vars (bool warn_possibly_uninitialized)
 {
   gimple_stmt_iterator gsi;
   basic_block bb;
   struct walk_data data;
 
+  data.warn_possibly_uninitialized = warn_possibly_uninitialized;
+
   calculate_dominance_info (CDI_POST_DOMINATORS);
 
   FOR_EACH_BB (bb)
@@ -1513,6 +1524,19 @@ execute_early_warn_uninitialized (void)
 }
 
 static unsigned int
+execute_early_warn_uninitialized (void)
+{
+  /* Currently, this pass runs always but
+     execute_late_warn_uninitialized only runs with optimization. With
+     optimization we want to warn about possible uninitialized as late
+     as possible, thus don't do it here.  However, without
+     optimization we need to warn here about "may be uninitialized".
+  */
+  warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
+  return 0;
+}
+
+static unsigned int
 execute_late_warn_uninitialized (void)
 {
   basic_block bb;
@@ -1521,7 +1545,7 @@ execute_late_warn_uninitialized (void)
   /* Re-do the plain uninitialized variable check, as optimization may have
      straightened control flow.  Do this first so that we don't accidentally
      get a "may be" warning when we'd have seen an "is" warning later.  */
-  execute_early_warn_uninitialized ();
+  warn_uninitialized_vars (/*warn_possibly_uninitialized=*/1);
 
   FOR_EACH_BB (bb)
     for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))