In C++0x we can have an initializer that is potentially constant and yet
still type-dependent if it involves a call, so we need to handle that.
For 4.7 I'm explicitly testing for type-dependency; for 4.6 I've made a
smaller change to make value_dependent_expression_p return true for
type-dependent expressions as well.
Tested x86_64-pc-linux-gnu, applied to trunk and 4.6.
commit 8d43d26b5dc0392f91ad6015955b92b1905e64ce
Author: Jason Merrill <ja...@redhat.com>
Date: Sat Apr 23 23:18:00 2011 -0400
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.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 6a612e9..fd477a4 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -5106,6 +5106,7 @@ 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);
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index d97ccf3..92e0d48 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5701,6 +5701,36 @@ initialize_artificial_var (tree decl,
VEC(constructor_elt,gc) *v)
}
/* 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. */
static bool
@@ -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)
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index cb8ebfd..6765931 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -18457,6 +18457,19 @@ any_type_dependent_arguments_p (const VEC(tree,gc)
*args)
}
/* 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. */
bool
diff --git a/gcc/testsuite/g++.dg/cpp0x/regress/template-const2.C
b/gcc/testsuite/g++.dg/cpp0x/regress/template-const2.C
new file mode 100644
index 0000000..25354b3
--- /dev/null
+++ b/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();
commit 6b978a4d2e33771d8fd95f39a301f8df180ac98c
Author: Jason Merrill <ja...@redhat.com>
Date: Mon Apr 25 16:44:03 2011 -0400
PR c++/48707
* pt.c (value_dependent_expression_p): Handle type-dependent
expression.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index ed48203..fc5177d 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -18068,6 +18068,11 @@ value_dependent_expression_p (tree expression)
if (DECL_P (expression) && type_dependent_expression_p (expression))
return true;
+ /* We shouldn't have gotten here for a type-dependent expression, but
+ let's handle it properly anyway. */
+ if (TREE_TYPE (expression) == NULL_TREE)
+ return true;
+
switch (TREE_CODE (expression))
{
case IDENTIFIER_NODE:
diff --git a/gcc/testsuite/g++.dg/cpp0x/regress/template-const2.C
b/gcc/testsuite/g++.dg/cpp0x/regress/template-const2.C
new file mode 100644
index 0000000..25354b3
--- /dev/null
+++ b/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();
