constexpr fallout. In fold_non_dependent_expr, we determined that the
expression is not type-dependent, is potentially constant, and is not
value-dependent, so we try to fold it. But it isn't potentially
constant. So this patch fixes that determination.
Tested x86_64-pc-linux-gnu, applying to trunk and 4.6 (regression).
commit e49c0a722ad7226f7dabfc4a2fea9e47f8fc235f
Author: Jason Merrill <ja...@redhat.com>
Date: Thu Apr 7 14:52:08 2011 -0400
PR c++/48500
* semantics.c (potential_constant_expression_1) [CALL_EXPR]: Check
arguments even if we don't know the function.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 2184a53..0b4d1ec 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -7358,6 +7358,8 @@ potential_constant_expression_1 (tree t, bool want_rval,
tsubst_flags_t flags)
class member access expression, including the result of the
implicit transformation in the body of the non-static
member function (9.3.1); */
+ /* FIXME this restriction seems pointless since the standard dropped
+ "potential constant expression". */
if (is_this_parameter (t))
{
if (flags & tf_error)
@@ -7373,51 +7375,63 @@ potential_constant_expression_1 (tree t, bool
want_rval, tsubst_flags_t flags)
{
tree fun = get_function_named_in_call (t);
const int nargs = call_expr_nargs (t);
- if (TREE_CODE (fun) != FUNCTION_DECL)
+ i = 0;
+
+ if (is_overloaded_fn (fun))
+ {
+ if (TREE_CODE (fun) == FUNCTION_DECL)
+ {
+ if (builtin_valid_in_constant_expr_p (fun))
+ return true;
+ if (!DECL_DECLARED_CONSTEXPR_P (fun)
+ && !morally_constexpr_builtin_function_p (fun))
+ {
+ if (flags & tf_error)
+ error ("%qD is not %<constexpr%>", fun);
+ return false;
+ }
+ /* A call to a non-static member function takes the address
+ of the object as the first argument. But in a constant
+ expression the address will be folded away, so look
+ through it now. */
+ if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun)
+ && !DECL_CONSTRUCTOR_P (fun))
+ {
+ tree x = get_nth_callarg (t, 0);
+ if (is_this_parameter (x))
+ /* OK. */;
+ else if (!potential_constant_expression_1 (x, rval, flags))
+ {
+ if (flags & tf_error)
+ error ("object argument is not a potential "
+ "constant expression");
+ return false;
+ }
+ i = 1;
+ }
+ }
+ else
+ fun = get_first_fn (fun);
+ /* Skip initial arguments to base constructors. */
+ if (DECL_BASE_CONSTRUCTOR_P (fun))
+ i = num_artificial_parms_for (fun);
+ fun = DECL_ORIGIN (fun);
+ }
+ else
{
if (potential_constant_expression_1 (fun, rval, flags))
- /* Might end up being a constant function pointer. */
- return true;
- if (flags & tf_error)
- error ("%qE is not a function name", fun);
- return false;
- }
- /* Skip initial arguments to base constructors. */
- if (DECL_BASE_CONSTRUCTOR_P (fun))
- i = num_artificial_parms_for (fun);
- else
- i = 0;
- fun = DECL_ORIGIN (fun);
- if (builtin_valid_in_constant_expr_p (fun))
- return true;
- if (!DECL_DECLARED_CONSTEXPR_P (fun)
- && !morally_constexpr_builtin_function_p (fun))
- {
- if (flags & tf_error)
- error ("%qD is not %<constexpr%>", fun);
- return false;
+ /* Might end up being a constant function pointer. */;
+ else
+ {
+ if (flags & tf_error)
+ error ("%qE is not a function name", fun);
+ return false;
+ }
}
for (; i < nargs; ++i)
{
tree x = get_nth_callarg (t, i);
- /* A call to a non-static member function takes the
- address of the object as the first argument.
- But in a constant expression the address will be folded
- away, so look through it now. */
- if (i == 0 && DECL_NONSTATIC_MEMBER_P (fun)
- && !DECL_CONSTRUCTOR_P (fun))
- {
- if (is_this_parameter (x))
- /* OK. */;
- else if (!potential_constant_expression_1 (x, rval, flags))
- {
- if (flags & tf_error)
- error ("object argument is not a potential constant "
- "expression");
- return false;
- }
- }
- else if (!potential_constant_expression_1 (x, rval, flags))
+ if (!potential_constant_expression_1 (x, rval, flags))
{
if (flags & tf_error)
error ("argument in position %qP is not a "
diff --git a/gcc/testsuite/g++.dg/cpp0x/regress/call1.C
b/gcc/testsuite/g++.dg/cpp0x/regress/call1.C
new file mode 100644
index 0000000..833318b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/regress/call1.C
@@ -0,0 +1,13 @@
+// PR c++/48500
+// { dg-options -std=c++0x }
+
+struct linked_ptr {
+};
+template <typename T> linked_ptr make_linked_ptr(T* ptr);
+struct Concrete;
+struct NewedClass {
+ NewedClass(const Concrete& req){}
+};
+template<typename ArgT> void AddObjToChange(const ArgT& req) {
+ linked_ptr p = make_linked_ptr(new NewedClass(req));
+}
