This revision was automatically updated to reflect the committed changes.
Closed by commit rL283207: Do not find friend function definitions inside
non-instantiated class. (authored by sepavloff).
Changed prior to commit:
https://reviews.llvm.org/D16989?vs=70134&id=73440#toc
Repository:
rL LLVM
https://reviews.llvm.org/D16989
Files:
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/lib/Sema/SemaDeclCXX.cpp
cfe/trunk/test/SemaCXX/PR25848.cpp
cfe/trunk/test/SemaCXX/friend2.cpp
cfe/trunk/test/SemaCXX/function-redecl-2.cpp
Index: cfe/trunk/include/clang/Sema/Sema.h
===================================================================
--- cfe/trunk/include/clang/Sema/Sema.h
+++ cfe/trunk/include/clang/Sema/Sema.h
@@ -1760,6 +1760,7 @@
bool CheckFunctionDeclaration(Scope *S,
FunctionDecl *NewFD, LookupResult &Previous,
bool IsExplicitSpecialization);
+ bool shouldLinkDependentDeclWithPrevious(Decl *D, Decl *OldDecl);
void CheckMain(FunctionDecl *FD, const DeclSpec &D);
void CheckMSVCRTEntryPoint(FunctionDecl *FD);
Decl *ActOnParamDeclarator(Scope *S, Declarator &D);
Index: cfe/trunk/test/SemaCXX/PR25848.cpp
===================================================================
--- cfe/trunk/test/SemaCXX/PR25848.cpp
+++ cfe/trunk/test/SemaCXX/PR25848.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+struct A;
+
+inline int g(); // expected-warning{{inline function 'g' is not defined}}
+
+template<int M>
+struct R {
+ friend int g() {
+ return M;
+ }
+};
+
+void m() {
+ g(); // expected-note{{used here}}
+}
Index: cfe/trunk/test/SemaCXX/function-redecl-2.cpp
===================================================================
--- cfe/trunk/test/SemaCXX/function-redecl-2.cpp
+++ cfe/trunk/test/SemaCXX/function-redecl-2.cpp
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+
+namespace redecl_in_templ {
+template<typename T> void redecl_in_templ() {
+ extern void func_1(); // expected-note {{previous declaration is here}}
+ extern int func_1(); // expected-error {{functions that differ only in their return type cannot be overloaded}}
+}
+
+void g();
+constexpr void (*p)() = g;
+
+template<bool> struct X {};
+template<> struct X<true> { typedef int type; };
+
+template<typename T> void f() {
+ extern void g();
+ X<&g == p>::type n;
+}
+}
Index: cfe/trunk/test/SemaCXX/friend2.cpp
===================================================================
--- cfe/trunk/test/SemaCXX/friend2.cpp
+++ cfe/trunk/test/SemaCXX/friend2.cpp
@@ -0,0 +1,172 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11
+
+// If a friend function is defined in several non-template classes,
+// it is an error.
+
+void func1(int);
+struct C1a {
+ friend void func1(int) {} // expected-note{{previous definition is here}}
+};
+struct C1b {
+ friend void func1(int) {} // expected-error{{redefinition of 'func1'}}
+};
+
+
+// If a friend function is defined in both non-template and template
+// classes it is an error only if the template is instantiated.
+
+void func2(int);
+struct C2a {
+ friend void func2(int) {}
+};
+template<typename T> struct C2b {
+ friend void func2(int) {}
+};
+
+void func3(int);
+struct C3a {
+ friend void func3(int) {} // expected-note{{previous definition is here}}
+};
+template<typename T> struct C3b {
+ friend void func3(int) {} // expected-error{{redefinition of 'func3'}}
+};
+C3b<long> c3; // expected-note{{in instantiation of template class 'C3b<long>' requested here}}
+
+
+// If a friend function is defined in several template classes it is an error
+// only if several templates are instantiated.
+
+void func4(int);
+template<typename T> struct C4a {
+ friend void func4(int) {}
+};
+template<typename T> struct C4b {
+ friend void func4(int) {}
+};
+
+
+void func5(int);
+template<typename T> struct C5a {
+ friend void func5(int) {}
+};
+template<typename T> struct C5b {
+ friend void func5(int) {}
+};
+C5a<long> c5a;
+
+void func6(int);
+template<typename T> struct C6a {
+ friend void func6(int) {} // expected-note{{previous definition is here}}
+};
+template<typename T> struct C6b {
+ friend void func6(int) {} // expected-error{{redefinition of 'func6'}}
+};
+C6a<long> c6a;
+C6b<int*> c6b; // expected-note{{in instantiation of template class 'C6b<int *>' requested here}}
+
+void func7(int);
+template<typename T> struct C7 {
+ friend void func7(int) {} // expected-error{{redefinition of 'func7'}}
+ // expected-note@-1{{previous definition is here}}
+};
+C7<long> c7a;
+C7<int*> c7b; // expected-note{{in instantiation of template class 'C7<int *>' requested here}}
+
+
+// Even if clases are not instantiated and hence friend functions defined in them are not
+// available, their declarations can be checked.
+
+void func8(int); // expected-note{{previous declaration is here}}
+template<typename T> struct C8a {
+ friend long func8(int); // expected-error{{functions that differ only in their return type cannot be overloaded}}
+};
+
+void func9(int); // expected-note{{previous declaration is here}}
+template<typename T> struct C9a {
+ friend int func9(int); // expected-error{{functions that differ only in their return type cannot be overloaded}}
+};
+
+void func10(int); // expected-note{{previous declaration is here}}
+template<typename T> struct C10a {
+ friend int func10(int); // expected-error{{functions that differ only in their return type cannot be overloaded}}
+};
+
+void func_11(); // expected-note{{previous declaration is here}}
+template<typename T> class C11 {
+ friend int func_11(); // expected-error{{functions that differ only in their return type cannot be overloaded}}
+};
+
+void func_12(int x); // expected-note{{previous declaration is here}}
+template<typename T> class C12 {
+ friend void func_12(int x = 0); // expected-error{{friend declaration specifying a default argument must be the only declaration}}
+};
+
+
+namespace pr22307 {
+
+struct t {
+ friend int leak(t);
+};
+
+template<typename v>
+struct m {
+ friend int leak(t) { return sizeof(v); } // expected-error{{redefinition of 'leak'}} expected-note{{previous definition is here}}
+};
+
+template struct m<char>;
+template struct m<short>; // expected-note{{in instantiation of template class 'pr22307::m<short>' requested here}}
+
+int main() {
+ leak(t());
+}
+
+}
+
+namespace pr17923 {
+
+void f(unsigned long long);
+
+template<typename T> struct X {
+ friend void f(unsigned long long) {
+ T t;
+ }
+};
+
+int main() { f(1234); }
+
+}
+
+namespace pr17923a {
+
+int get();
+
+template< int value >
+class set {
+ friend int get()
+ { return value; } // return 0; is OK
+};
+
+template class set< 5 >;
+
+int main() {
+ get();
+}
+
+}
+
+namespace pr8035 {
+
+void Function();
+
+int main(int argc, char* argv[]) {
+ Function();
+}
+
+template <typename T>
+struct Test {
+ friend void Function() { }
+};
+
+template class Test<int>;
+
+}
Index: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp
@@ -13786,9 +13786,14 @@
// and shall be the only declaration of the function or function
// template in the translation unit.
if (functionDeclHasDefaultArgument(FD)) {
- if (FunctionDecl *OldFD = FD->getPreviousDecl()) {
+ // We can't look at FD->getPreviousDecl() because it may not have been set
+ // if we're in a dependent context. If we get this far with a non-empty
+ // Previous set, we must have a valid previous declaration of this
+ // function.
+ if (!Previous.empty()) {
Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
- Diag(OldFD->getLocation(), diag::note_previous_declaration);
+ Diag(Previous.getRepresentativeDecl()->getLocation(),
+ diag::note_previous_declaration);
} else if (!D.isFunctionDefinition())
Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def);
}
Index: cfe/trunk/lib/Sema/SemaDecl.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp
+++ cfe/trunk/lib/Sema/SemaDecl.cpp
@@ -8664,6 +8664,32 @@
return NewFD;
}
+/// \brief Checks if the new declaration declared in dependent context must be
+/// put in the same redeclaration chain as the specified declaration.
+///
+/// \param D Declaration that is checked.
+/// \param PrevDecl Previous declaration found with proper lookup method for the
+/// same declaration name.
+/// \returns True if D must be added to the redeclaration chain which PrevDecl
+/// belongs to.
+///
+bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) {
+ // Any declarations should be put into redeclaration chains except for
+ // friend declaration in a dependent context that names a function in
+ // namespace scope.
+ //
+ // This allows to compile code like:
+ //
+ // void func();
+ // template<typename T> class C1 { friend void func() { } };
+ // template<typename T> class C2 { friend void func() { } };
+ //
+ // This code snippet is a valid code unless both templates are instantiated.
+ return !(D->getLexicalDeclContext()->isDependentContext() &&
+ D->getDeclContext()->isFileContext() &&
+ D->getFriendObjectKind() != Decl::FOK_None);
+}
+
/// \brief Perform semantic checking of a new function declaration.
///
/// Performs semantic analysis of the new function declaration
@@ -8847,11 +8873,14 @@
}
} else {
- // This needs to happen first so that 'inline' propagates.
- NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl));
-
- if (isa<CXXMethodDecl>(NewFD))
- NewFD->setAccess(OldDecl->getAccess());
+ if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) {
+ // This needs to happen first so that 'inline' propagates.
+ NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl));
+ if (isa<CXXMethodDecl>(NewFD))
+ NewFD->setAccess(OldDecl->getAccess());
+ } else {
+ Redeclaration = false;
+ }
}
}
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