re PR c++/48707 ([c++0x] ICE initializing static const int)

PR c++/48707
	* decl.c (type_dependent_init_p): New.
	(cp_finish_decl): Check it.
	* pt.c (any_type_dependent_elements_p): New.
	* cp-tree.h: Declare it.

From-SVN: r172941

gcc/cp/ChangeLog

@@ -1,3 +1,11 @@
+2011-04-25  Jason Merrill  <jason@redhat.com>
+
+	PR c++/48707
+	* decl.c (type_dependent_init_p): New.
+	(cp_finish_decl): Check it.
+	* pt.c (any_type_dependent_elements_p): New.
+	* cp-tree.h: Declare it.
+
 2011-04-20  Jason Merrill  <jason@redhat.com>
 
 	* semantics.c (finish_compound_literal): Don't put an array

gcc/cp/cp-tree.h

@@ -5105,6 +5105,7 @@ extern bool dependent_template_p		(tree);
 extern bool dependent_template_id_p		(tree, tree);
 extern bool type_dependent_expression_p		(tree);
 extern bool any_type_dependent_arguments_p      (const VEC(tree,gc) *);
+extern bool any_type_dependent_elements_p       (const_tree);
 extern bool type_dependent_expression_p_push	(tree);
 extern bool value_dependent_expression_p	(tree);
 extern bool any_value_dependent_elements_p      (const_tree);

gcc/cp/decl.c

@@ -5700,6 +5700,36 @@ initialize_artificial_var (tree decl, VEC(constructor_elt,gc) *v)
   make_rtl_for_nonlocal_decl (decl, init, /*asmspec=*/NULL);
 }
 
+/* INIT is the initializer for a variable, as represented by the
+   parser.  Returns true iff INIT is type-dependent.  */
+
+static bool
+type_dependent_init_p (tree init)
+{
+  if (TREE_CODE (init) == TREE_LIST)
+    /* A parenthesized initializer, e.g.: int i (3, 2); ? */
+    return any_type_dependent_elements_p (init);
+  else if (TREE_CODE (init) == CONSTRUCTOR)
+  /* A brace-enclosed initializer, e.g.: int i = { 3 }; ? */
+    {
+      VEC(constructor_elt, gc) *elts;
+      size_t nelts;
+      size_t i;
+
+      elts = CONSTRUCTOR_ELTS (init);
+      nelts = VEC_length (constructor_elt, elts);
+      for (i = 0; i < nelts; ++i)
+	if (type_dependent_init_p (VEC_index (constructor_elt,
+					      elts, i)->value))
+	  return true;
+    }
+  else
+    /* It must be a simple expression, e.g., int i = 3;  */
+    return type_dependent_expression_p (init);
+
+  return false;
+}
+
 /* INIT is the initializer for a variable, as represented by the
    parser.  Returns true iff INIT is value-dependent.  */
 
@@ -5876,19 +5906,25 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	 template is instantiated.  But, if DECL is a variable constant
 	 then it can be used in future constant expressions, so its value
 	 must be available. */
-      if (init
-	  && init_const_expr_p
-	  && !type_dependent_p
-	  && decl_maybe_constant_var_p (decl)
-	  && !value_dependent_init_p (init))
+
+      if (TREE_CODE (decl) != VAR_DECL || dependent_type_p (type))
+	/* We can't do anything if the decl has dependent type.  */;
+      else if (init
+	       && init_const_expr_p
+	       && !type_dependent_p
+	       && decl_maybe_constant_var_p (decl)
+	       && !type_dependent_init_p (init)
+	       && !value_dependent_init_p (init))
 	{
+	  /* This variable seems to be a non-dependent constant, so process
+	     its initializer.  If check_initializer returns non-null the
+	     initialization wasn't constant after all.  */
 	  tree init_code = check_initializer (decl, init, flags, &cleanup);
 	  if (init_code == NULL_TREE)
 	    init = NULL_TREE;
 	}
-      else if (TREE_CODE (decl) == VAR_DECL
-	       && !DECL_PRETTY_FUNCTION_P (decl)
-	       && !type_dependent_p)
+      else if (!DECL_PRETTY_FUNCTION_P (decl))
+	/* Deduce array size even if the initializer is dependent.  */
 	maybe_deduce_size_from_array_init (decl, init);
 
       if (init)

gcc/cp/pt.c

@@ -18456,6 +18456,19 @@ any_type_dependent_arguments_p (const VEC(tree,gc) *args)
   return false;
 }
 
+/* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
+   expressions) contains any type-dependent expressions.  */
+
+bool
+any_type_dependent_elements_p (const_tree list)
+{
+  for (; list; list = TREE_CHAIN (list))
+    if (value_dependent_expression_p (TREE_VALUE (list)))
+      return true;
+
+  return false;
+}
+
 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
    expressions) contains any value-dependent expressions.  */
 

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2011-04-25  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/cpp0x/regress/template-const2.C: New.
+
 2011-04-25  Jeff Law <law@redhat.com>
 
 	* gcc.dg/tree-ssa/vrp56.c: new test.

gcc/testsuite/g++.dg/cpp0x/regress/template-const2.C

@@ -0,0 +1,14 @@
+// PR c++/48707
+// { dg-options -std=c++0x }
+
+struct A {
+  static int a();
+};
+
+template<typename X>
+struct B: A {
+  static int const b;
+};
+
+template<typename X>
+int const B<X>::b=B<X>::a();