erik.pilkington created this revision.
erik.pilkington added reviewers: rsmith, faisalv.
erik.pilkington added a subscriber: cfe-commits.
This is a regression that only affects -std=c++1z, introduced in r273754. The
following test case (thanks rsmith!) fails to compile:
```
template<int N> struct X {};
template<typename T> struct Y {
static constexpr int s_v[] = {0};
X<*s_v> x; // Clang incorrectly says: error, *s_v is not a constant expression
};
template struct Y<int>;
```
The problem is that the initializer for `s_v` (an implicitly inline variable in
c++1z) is not instantiated. This patch requires that the initializer for an
IncompleteArrayType is instantiated, which is the same rule as an initializer
for an `auto` type.
Fixes PR28385.
Thanks!
http://reviews.llvm.org/D22053
Files:
lib/Sema/SemaTemplateInstantiateDecl.cpp
test/CXX/temp/temp.spec/temp.inst/p1.cpp
Index: test/CXX/temp/temp.spec/temp.inst/p1.cpp
===================================================================
--- test/CXX/temp/temp.spec/temp.inst/p1.cpp
+++ test/CXX/temp/temp.spec/temp.inst/p1.cpp
@@ -109,5 +109,16 @@
int test2 = g<int>(); // expected-note {{here}}
}
+namespace PR28385 {
+template <int N> struct X {};
+
+template <typename T> struct Y {
+ static constexpr int s_v[] = {0};
+ X<*s_v> x;
+};
+
+template struct Y<int>;
+}
+
// FIXME:
//- - member anonymous unions
Index: lib/Sema/SemaTemplateInstantiateDecl.cpp
===================================================================
--- lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3858,11 +3858,12 @@
// Delay instantiation of the initializer for variable templates or inline
// static data members until a definition of the variable is needed. We need
- // it right away if the type contains 'auto'.
+ // it right away if the type contains 'auto' or is an IncompleteArrayType.
if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
!InstantiatingVarTemplate &&
!(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
- NewVar->getType()->isUndeducedType())
+ NewVar->getType()->isUndeducedType() ||
+ NewVar->getType()->isIncompleteArrayType())
InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
// Diagnose unused local variables with dependent types, where the diagnostic
Index: test/CXX/temp/temp.spec/temp.inst/p1.cpp
===================================================================
--- test/CXX/temp/temp.spec/temp.inst/p1.cpp
+++ test/CXX/temp/temp.spec/temp.inst/p1.cpp
@@ -109,5 +109,16 @@
int test2 = g<int>(); // expected-note {{here}}
}
+namespace PR28385 {
+template <int N> struct X {};
+
+template <typename T> struct Y {
+ static constexpr int s_v[] = {0};
+ X<*s_v> x;
+};
+
+template struct Y<int>;
+}
+
// FIXME:
//- - member anonymous unions
Index: lib/Sema/SemaTemplateInstantiateDecl.cpp
===================================================================
--- lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3858,11 +3858,12 @@
// Delay instantiation of the initializer for variable templates or inline
// static data members until a definition of the variable is needed. We need
- // it right away if the type contains 'auto'.
+ // it right away if the type contains 'auto' or is an IncompleteArrayType.
if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
!InstantiatingVarTemplate &&
!(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
- NewVar->getType()->isUndeducedType())
+ NewVar->getType()->isUndeducedType() ||
+ NewVar->getType()->isIncompleteArrayType())
InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
// Diagnose unused local variables with dependent types, where the diagnostic
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