[C++ PATCH] Clear TREE_READONLY on static vars that need runtime initialization

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

This is similar problem that we had in PR20073 with TREE_READONLY
static vars that have non-trivial constructors, but this time with
initializers that need to run during static initialization.

Tested on x86_64-linux, ok for 4.3 (and after a few days for 4.2/4.1)?

2007-05-30  Jakub Jelinek  <jakub@redhat.com>

	PR c++/31809
	* decl.c (cp_finish_decl): Clear TREE_READONLY flag on TREE_STATIC
	variables that need runtime initialization.

	* g++.dg/opt/static5.C: New test.

--- gcc/cp/decl.c.jj	2007-05-30 14:54:50.000000000 +0200
+++ gcc/cp/decl.c	2007-05-30 21:03:07.000000000 +0200
@@ -5357,7 +5357,14 @@ cp_finish_decl (tree decl, tree init, bo
 	     initializer.  It is not legal to redeclare a static data
 	     member, so this issue does not arise in that case.  */
 	  if (var_definition_p && TREE_STATIC (decl))
-	    expand_static_init (decl, init);
+	    {
+	      /* If a TREE_READONLY variable needs initialization
+		 at runtime, it is no longer readonly and we need to
+		 avoid MEM_READONLY_P being set on RTL created for it.  */
+	      if (init && TREE_READONLY (decl))
+		TREE_READONLY (decl) = 0;
+	      expand_static_init (decl, init);
+	    }
 	}
     }
 
--- gcc/testsuite/g++.dg/opt/static5.C.jj	2007-05-30 21:17:28.000000000 +0200
+++ gcc/testsuite/g++.dg/opt/static5.C	2007-05-30 21:15:57.000000000 +0200
@@ -0,0 +1,29 @@
+// PR c++/31809
+// { dg-do run }
+// { dg-options "-O2" }
+
+struct S
+{
+  unsigned v;
+  static inline S f (unsigned a);
+};
+
+inline S
+S::f (unsigned a)
+{
+  static S t = { a };
+  return t;
+}
+
+const static S s = S::f (26);
+
+extern "C" void abort (void);
+
+int
+main ()
+{
+  S t = s;
+  if (t.v != 26)
+    abort ();
+  return 0;
+}

	Jakub