I'm improving the C++11 coverage of the testsuite, which resulted in
several failures on non-type argument tests in the current testsuite.
Fixed by folding constant expressions in fewer cases.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit b1ec006abd6e4dbf45fca99160b09dab0827a10c
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Nov 8 20:36:49 2011 -0500
* pt.c (convert_nontype_argument): Only integral arguments
get early folding.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 8c91a9e..38c26a7 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -5681,10 +5681,24 @@ convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
&& (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
expr = convert (type, expr);
- /* In C++11, non-type template arguments can be arbitrary constant
- expressions. But don't fold a PTRMEM_CST to a CONSTRUCTOR yet. */
- if (cxx_dialect >= cxx0x && TREE_CODE (expr) != PTRMEM_CST)
- expr = maybe_constant_value (expr);
+ /* In C++11, integral or enumeration non-type template arguments can be
+ arbitrary constant expressions. Pointer and pointer to
+ member arguments can be general constant expressions that evaluate
+ to a null value, but otherwise still need to be of a specific form. */
+ if (cxx_dialect >= cxx0x)
+ {
+ if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
+ expr = maybe_constant_value (expr);
+ else if (TYPE_PTR_P (type)
+ || (TYPE_PTR_TO_MEMBER_P (type)
+ && TREE_CODE (expr) != PTRMEM_CST))
+ {
+ tree folded = maybe_constant_value (expr);
+ if (TYPE_PTR_P (type) ? integer_zerop (folded)
+ : null_member_pointer_value_p (folded))
+ expr = folded;
+ }
+ }
/* HACK: Due to double coercion, we can get a
NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
