re PR middle-end/12526 ([tree-ssa] internal compiler error: Segmentation fault)

        PR middle-end/12526
        * tree.c (build): A CALL_EXPR has side-effects if its arguments do.
        * calls.c (call_expr_flags): New fn.
        * tree.h: Declare it.

From-SVN: r73589

gcc/ChangeLog

+2003-11-14  Jason Merrill  <jason@redhat.com>
+
+	PR middle-end/12526
+	* tree.c (build): A CALL_EXPR has side-effects if its arguments do.
+	* calls.c (call_expr_flags): New fn.
+	* tree.h: Declare it.
+
 2003-11-13  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* config/h8300/lib1funcs.asm (__udivsi3): Remove.

gcc/calls.c

@@ -744,6 +744,28 @@ flags_from_decl_or_type (tree exp)
   return flags;
 }
 
+/* Detect flags from a CALL_EXPR.  */
+
+int
+call_expr_flags (tree t)
+{
+  int flags;
+  tree decl = get_callee_fndecl (t);
+
+  if (decl)
+    flags = flags_from_decl_or_type (decl);
+  else
+    {
+      t = TREE_TYPE (TREE_OPERAND (t, 0));
+      if (t && TREE_CODE (t) == POINTER_TYPE)
+	flags = flags_from_decl_or_type (TREE_TYPE (t));
+      else
+	flags = 0;
+    }
+
+  return flags;
+}
+
 /* Precompute all register parameters as described by ARGS, storing values
    into fields within the ARGS array.
 

gcc/tree.c

@@ -2294,6 +2294,7 @@ build (enum tree_code code, tree tt, ...)
   int fro;
   int constant;
   va_list p;
+  tree node;
 
   va_start (p, tt);
 
@@ -2380,10 +2381,17 @@ build (enum tree_code code, tree tt, ...)
     {
       /* Calls have side-effects, except those to const or
 	 pure functions.  */
-      tree fn = get_callee_fndecl (t);
-
-      if (!fn || (!DECL_IS_PURE (fn) && !TREE_READONLY (fn)))
+      i = call_expr_flags (t);
+      if (!(i & (ECF_CONST | ECF_PURE)))
 	TREE_SIDE_EFFECTS (t) = 1;
+
+      /* And even those have side-effects if their arguments do.  */
+      else for (node = TREE_OPERAND (t, 1); node; node = TREE_CHAIN (node))
+	if (TREE_SIDE_EFFECTS (TREE_VALUE (node)))
+	  {
+	    TREE_SIDE_EFFECTS (t) = 1;
+	    break;
+	  }
     }
 
   return t;

gcc/tree.h

@@ -2941,6 +2941,7 @@ extern rtx emit_line_note (location_t);
 #define ECF_LIBCALL_BLOCK	4096
 
 extern int flags_from_decl_or_type (tree);
+extern int call_expr_flags (tree);
 
 extern int setjmp_call_p (tree);
 extern bool alloca_call_p (tree);