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C++ PATCH for c++/46930 (ICE with uninitialized constexpr static data member)
- From: Jason Merrill <jason at redhat dot com>
- To: gcc-patches List <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 14 Dec 2010 17:32:49 -0500
- Subject: C++ PATCH for c++/46930 (ICE with uninitialized constexpr static data member)
A constexpr variable, must be initialized when it is declared; you can't
forward declare a constexpr variable. This applies to static data
members, too.
Tested x86_64-pc-linux-gnu, applied to trunk.
commit 67091a3efa479b3611252b8174c878265f029a1a
Author: Jason Merrill <jason@redhat.com>
Date: Tue Dec 14 01:52:54 2010 -0500
PR c++/46930
* decl.c (grokdeclarator): Reject uninitialized constexpr
static data member.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1be0f97..f9331bc 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -9763,6 +9763,13 @@ grokdeclarator (const cp_declarator *declarator,
if (thread_p)
DECL_TLS_MODEL (decl) = decl_default_tls_model (decl);
+
+ if (constexpr_p && !initialized)
+ {
+ error ("constexpr static data member %qD must have an "
+ "initializer", decl);
+ constexpr_p = false;
+ }
}
else
{
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-decl.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-decl.C
new file mode 100644
index 0000000..0a3fcb6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-decl.C
@@ -0,0 +1,10 @@
+// PR c++/46930
+// { dg-options -std=c++0x }
+
+struct S {
+ static constexpr int size; // { dg-error "must have an initializer" }
+ // { dg-error "previous declaration" "" { target *-*-* } 5 }
+};
+
+const int limit = 2 * S::size;
+constexpr int S::size = 256; // { dg-error "" }
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-ex1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-ex1.C
index c7757f4..6b090a0 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-ex1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-ex1.C
@@ -16,9 +16,9 @@ struct S {
constexpr int twice();
constexpr int t(); // { dg-message "used but never defined" }
private:
- static constexpr int val; // constexpr variable
+ static constexpr int val = 7; // constexpr variable
};
-constexpr int S::val = 7;
+
constexpr int S::twice() { return val + val; }
constexpr S s = { };
int x1 = s.twice(); // ok
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-static5.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-static5.C
index cb553a2..a401cc0 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-static5.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-static5.C
@@ -3,10 +3,10 @@
template <class T>
struct A
{
- constexpr static T t;
+ constexpr static T t = T(); // { dg-error "literal" }
};
template <class T>
-constexpr T A<T>::t = T(); // { dg-error "not literal" }
+constexpr T A<T>::t;
struct B
{