Sometimes an expression that is non-constant at one point in the
translation unit can become constant later, when a constexpr function is
defined. So let's not cache failure.
Tested x86_64-pc-linux-gnu, applying to trunk. This isn't a regression,
but as before, since C++11 support is still experimental I consider
patches that fix C++11 bugs and don't affect C++98 code to be acceptable.
commit 639cadeb21c26f4d5e98e9bf2b211a4c39a61b9c
Author: Jason Merrill ja...@redhat.com
Date: Mon Jan 9 09:40:34 2012 -0500
PR c++/51433
* semantics.c (cxx_eval_call_expression): Always retry previously
non-constant expressions.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index fbb74e1..2c351be 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -6576,7 +6576,7 @@ cxx_eval_call_expression (const constexpr_call *old_call, tree t,
else
{
result = entry-result;
- if (!result || (result == error_mark_node !allow_non_constant))
+ if (!result || result == error_mark_node)
result = (cxx_eval_constant_expression
(new_call, new_call.fundef-body,
allow_non_constant, addr,
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-cache1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-cache1.C
new file mode 100644
index 000..b6d7b64
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-cache1.C
@@ -0,0 +1,9 @@
+// PR c++/51433
+// { dg-options -std=c++0x }
+
+constexpr int f();
+constexpr int g() { return f(); }
+extern const int n = g(); // dynamic initialization
+constexpr int f() { return 42; }
+extern const int m = g();
+static_assert(m == 42, m == 42);
