r348473 - Diagnose friend function template redefinitions.
Serge Pavlov via cfe-commits
cfe-commits at lists.llvm.org
Thu Dec 6 01:35:04 PST 2018
Author: sepavloff
Date: Thu Dec 6 01:35:04 2018
New Revision: 348473
URL: http://llvm.org/viewvc/llvm-project?rev=348473&view=rev
Log:
Diagnose friend function template redefinitions.
Friend function template defined in a class template becomes available if
the enclosing class template is instantiated. Until the function template
is used, it does not have a body, but still is considered a definition for
the purpose of redeclaration checks.
This change modifies redefinition check so that it can find the friend
function template definitions in instantiated classes.
Differential Revision: http://reviews.llvm.org/D21508
Modified:
cfe/trunk/include/clang/AST/DeclBase.h
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp
cfe/trunk/test/Modules/friend-definition.cpp
cfe/trunk/test/SemaCXX/friend-template-redecl.cpp
cfe/trunk/test/SemaCXX/friend2.cpp
Modified: cfe/trunk/include/clang/AST/DeclBase.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/DeclBase.h?rev=348473&r1=348472&r2=348473&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/DeclBase.h (original)
+++ cfe/trunk/include/clang/AST/DeclBase.h Thu Dec 6 01:35:04 2018
@@ -1065,11 +1065,11 @@ public:
unsigned OldNS = IdentifierNamespace;
assert((OldNS & (IDNS_Tag | IDNS_Ordinary |
IDNS_TagFriend | IDNS_OrdinaryFriend |
- IDNS_LocalExtern)) &&
+ IDNS_LocalExtern | IDNS_NonMemberOperator)) &&
"namespace includes neither ordinary nor tag");
assert(!(OldNS & ~(IDNS_Tag | IDNS_Ordinary | IDNS_Type |
IDNS_TagFriend | IDNS_OrdinaryFriend |
- IDNS_LocalExtern)) &&
+ IDNS_LocalExtern | IDNS_NonMemberOperator)) &&
"namespace includes other than ordinary or tag");
Decl *Prev = getPreviousDecl();
@@ -1082,7 +1082,8 @@ public:
IdentifierNamespace |= IDNS_Tag | IDNS_Type;
}
- if (OldNS & (IDNS_Ordinary | IDNS_OrdinaryFriend | IDNS_LocalExtern)) {
+ if (OldNS & (IDNS_Ordinary | IDNS_OrdinaryFriend |
+ IDNS_LocalExtern | IDNS_NonMemberOperator)) {
IdentifierNamespace |= IDNS_OrdinaryFriend;
if (PerformFriendInjection ||
(Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary))
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=348473&r1=348472&r2=348473&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Thu Dec 6 01:35:04 2018
@@ -12737,6 +12737,29 @@ Sema::CheckForFunctionRedefinition(Funct
}
}
}
+
+ if (!Definition)
+ // Similar to friend functions a friend function template may be a
+ // definition and do not have a body if it is instantiated in a class
+ // template.
+ if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate()) {
+ for (auto I : FTD->redecls()) {
+ auto D = cast<FunctionTemplateDecl>(I);
+ if (D != FTD) {
+ assert(!D->isThisDeclarationADefinition() &&
+ "More than one definition in redeclaration chain");
+ if (D->getFriendObjectKind() != Decl::FOK_None)
+ if (FunctionTemplateDecl *FT =
+ D->getInstantiatedFromMemberTemplate()) {
+ if (FT->isThisDeclarationADefinition()) {
+ Definition = D->getTemplatedDecl();
+ break;
+ }
+ }
+ }
+ }
+ }
+
if (!Definition)
return;
Modified: cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp?rev=348473&r1=348472&r2=348473&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplateInstantiateDecl.cpp Thu Dec 6 01:35:04 2018
@@ -1817,7 +1817,9 @@ Decl *TemplateDeclInstantiator::VisitFun
// If the original function was part of a friend declaration,
// inherit its namespace state and add it to the owner.
if (isFriend) {
- PrincipalDecl->setObjectOfFriendDecl();
+ Function->setObjectOfFriendDecl();
+ if (FunctionTemplateDecl *FT = Function->getDescribedFunctionTemplate())
+ FT->setObjectOfFriendDecl();
DC->makeDeclVisibleInContext(PrincipalDecl);
bool QueuedInstantiation = false;
Modified: cfe/trunk/test/Modules/friend-definition.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/friend-definition.cpp?rev=348473&r1=348472&r2=348473&view=diff
==============================================================================
--- cfe/trunk/test/Modules/friend-definition.cpp (original)
+++ cfe/trunk/test/Modules/friend-definition.cpp Thu Dec 6 01:35:04 2018
@@ -7,6 +7,7 @@ module A {}
#pragma clang module begin A
template<typename T> struct A {
friend A operator+(const A&, const A&) { return {}; }
+ template<typename T2> friend void func_1(const A&, const T2 &) {}
};
#pragma clang module end
#pragma clang module endbuild
@@ -36,4 +37,5 @@ inline void g() { A<int> a; }
void h() {
A<int> a;
a + a;
+ func_1(a, 0);
}
Modified: cfe/trunk/test/SemaCXX/friend-template-redecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/friend-template-redecl.cpp?rev=348473&r1=348472&r2=348473&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/friend-template-redecl.cpp (original)
+++ cfe/trunk/test/SemaCXX/friend-template-redecl.cpp Thu Dec 6 01:35:04 2018
@@ -18,16 +18,3 @@ void f() {
foo(x);
bar(x);
}
-
-namespace PR39742 {
-template<typename>
-struct wrapper {
- template<typename>
- friend void friend_function_template() {}
-};
-
-wrapper<bool> x;
-// FIXME: We should really error here because of the redefinition of
-// friend_function_template.
-wrapper<int> y;
-}
Modified: cfe/trunk/test/SemaCXX/friend2.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/friend2.cpp?rev=348473&r1=348472&r2=348473&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/friend2.cpp (original)
+++ cfe/trunk/test/SemaCXX/friend2.cpp Thu Dec 6 01:35:04 2018
@@ -129,6 +129,83 @@ C22b<int> c22bi;
void func_22() {} // expected-error{{redefinition of 'func_22'}}
+// Case of template friend functions.
+
+template<typename T> void func_31(T *x);
+template<typename T1>
+struct C31a {
+ template<typename T> friend void func_31(T *x) {}
+};
+template<typename T1>
+struct C31b {
+ template<typename T> friend void func_31(T *x) {}
+};
+
+
+template<typename T> inline void func_32(T *x) {}
+template<typename T1>
+struct C32a {
+ template<typename T> friend void func_32(T *x) {}
+};
+template<typename T1>
+struct C32b {
+ template<typename T> friend void func_32(T *x) {}
+};
+
+
+template<typename T1>
+struct C33a {
+ template<typename T> friend void func_33(T *x) {}
+};
+template<typename T1>
+struct C33b {
+ template<typename T> friend void func_33(T *x) {}
+};
+
+
+template<typename T> inline void func_34(T *x) {} // expected-note{{previous definition is here}}
+template<typename T1>
+struct C34 {
+ template<typename T> friend void func_34(T *x) {} // expected-error{{redefinition of 'func_34'}}
+};
+
+C34<int> v34; // expected-note{{in instantiation of template class 'C34<int>' requested here}}
+
+
+template<typename T> inline void func_35(T *x);
+template<typename T1>
+struct C35a {
+ template<typename T> friend void func_35(T *x) {} // expected-note{{previous definition is here}}
+};
+template<typename T1>
+struct C35b {
+ template<typename T> friend void func_35(T *x) {} // expected-error{{redefinition of 'func_35'}}
+};
+
+C35a<int> v35a;
+C35b<int> v35b; // expected-note{{in instantiation of template class 'C35b<int>' requested here}}
+
+
+template<typename T> void func_36(T *x);
+template<typename T1>
+struct C36 {
+ template<typename T> friend void func_36(T *x) {} // expected-error{{redefinition of 'func_36'}}
+ // expected-note at -1{{previous definition is here}}
+};
+
+C36<int> v36a;
+C36<long> v36b; //expected-note{{in instantiation of template class 'C36<long>' requested here}}
+
+
+template<typename T> void func_37(T *x);
+template<typename T1>
+struct C37 {
+ template<typename T> friend void func_37(T *x) {} // expected-note{{previous definition is here}}
+};
+
+C37<int> v37;
+template<typename T> void func_37(T *x) {} // expected-error{{redefinition of 'func_37'}}
+
namespace pr22307 {
@@ -235,3 +312,15 @@ void func() {
cache.insert();
}
}
+
+namespace PR39742 {
+template<typename>
+struct wrapper {
+ template<typename>
+ friend void friend_function_template() {} // expected-error{{redefinition of 'friend_function_template'}}
+ // expected-note at -1{{previous definition is here}}
+};
+
+wrapper<bool> x;
+wrapper<int> y; // expected-note{{in instantiation of template class 'PR39742::wrapper<int>' requested here}}
+}
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