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From 4ebec68ee3aee90ba13a4c4bc70afbb4a613468b Mon Sep 17 00:00:00 2001
From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 29 Mar 2011 14:24:19 +0000
Subject: [PATCH 023/200] PR c++/47504
* semantics.c (cxx_eval_constant_expression) [NOP_EXPR]: Don't let
the conversion set TREE_OVERFLOW.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@171664 138bc75d-0d04-0410-961f-82ee72b054a4
index d23effe..5fe1414 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -7030,6 +7030,11 @@ cxx_eval_constant_expression (const constexpr_call *call, tree t,
conversion. */
return fold (t);
r = fold_build1 (TREE_CODE (t), to, op);
+ /* Conversion of an out-of-range value has implementation-defined
+ behavior; the language considers it different from arithmetic
+ overflow, which is undefined. */
+ if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op))
+ TREE_OVERFLOW (r) = false;
}
break;
index 598cae6..2d614ec 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-data2.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-data2.C
@@ -44,5 +44,4 @@ extern template struct A3<int, 510>;
// Use.
A3<int, 1111> a31;
-// FIXME should this be an error?
A3<char, 9999> a32; // { dg-warning "overflow" }
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-overflow2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-overflow2.C
new file mode 100644
index 0000000..5d5749c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-overflow2.C
@@ -0,0 +1,8 @@
+// PR c++/47504
+// { dg-options -std=c++0x }
+
+char constexpr sub(char arg)
+{ return char(arg - char(1)); }
+
+int main()
+{ static char constexpr m = sub(-1); }
--
1.7.0.4
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