Index: include/clang/AST/DeclBase.h =================================================================== --- include/clang/AST/DeclBase.h +++ include/clang/AST/DeclBase.h @@ -52,6 +52,7 @@ class RecordDecl; class Stmt; class StoredDeclsMap; +class TemplateDecl; class TranslationUnitDecl; class UsingDirectiveDecl; } @@ -905,6 +906,10 @@ DeclKind == FunctionTemplate; } + /// \brief If this is a declaration that describes some template, this + /// method returns that template declaration. + TemplateDecl *getDescribedTemplate() const; + /// \brief Returns the function itself, or the templated function if this is a /// function template. FunctionDecl *getAsFunction() LLVM_READONLY; Index: include/clang/Basic/DiagnosticGroups.td =================================================================== --- include/clang/Basic/DiagnosticGroups.td +++ include/clang/Basic/DiagnosticGroups.td @@ -75,6 +75,8 @@ def GNUDesignator : DiagGroup<"gnu-designator">; def GNUStringLiteralOperatorTemplate : DiagGroup<"gnu-string-literal-operator-template">; +def UndefinedVarTemplate : DiagGroup<"undefined-var-template">; +def UndefinedFuncTemplate : DiagGroup<"undefined-func-template">; def DeleteIncomplete : DiagGroup<"delete-incomplete">; def DeleteNonVirtualDtor : DiagGroup<"delete-non-virtual-dtor">; Index: include/clang/Basic/DiagnosticSemaKinds.td =================================================================== --- include/clang/Basic/DiagnosticSemaKinds.td +++ include/clang/Basic/DiagnosticSemaKinds.td @@ -3883,7 +3883,18 @@ "in instantiation of template type alias %0 requested here">; def note_template_exception_spec_instantiation_here : Note< "in instantiation of exception specification for %0 requested here">; - +def warn_var_template_missing : Warning<"instantiation of variable %q0 " + "required here, but no definition is available">, + InGroup; +def warn_func_template_missing : Warning<"instantiation of function %q0 " + "required here, but no definition is available">, + InGroup, DefaultIgnore; +def note_forward_template_decl : Note< + "forward declaration of template entity is here">; +def note_inst_declaration_hint : Note<"add an explicit instantiation " + "declaration to suppress this warning if %q0 is explicitly instantiated in " + "another translation unit">; + def note_default_arg_instantiation_here : Note< "in instantiation of default argument for '%0' required here">; def note_default_function_arg_instantiation_here : Note< Index: include/clang/Sema/Sema.h =================================================================== --- include/clang/Sema/Sema.h +++ include/clang/Sema/Sema.h @@ -7171,7 +7171,8 @@ void InstantiateFunctionDefinition(SourceLocation PointOfInstantiation, FunctionDecl *Function, bool Recursive = false, - bool DefinitionRequired = false); + bool DefinitionRequired = false, + bool AtEndOfTU = false); VarTemplateSpecializationDecl *BuildVarTemplateInstantiation( VarTemplateDecl *VarTemplate, VarDecl *FromVar, const TemplateArgumentList &TemplateArgList, @@ -7195,7 +7196,8 @@ const MultiLevelTemplateArgumentList &TemplateArgs); void InstantiateVariableDefinition(SourceLocation PointOfInstantiation, VarDecl *Var, bool Recursive = false, - bool DefinitionRequired = false); + bool DefinitionRequired = false, + bool AtEndOfTU = false); void InstantiateStaticDataMemberDefinition( SourceLocation PointOfInstantiation, VarDecl *Var, Index: lib/AST/DeclBase.cpp =================================================================== --- lib/AST/DeclBase.cpp +++ lib/AST/DeclBase.cpp @@ -196,6 +196,17 @@ return isa(this); } +TemplateDecl *Decl::getDescribedTemplate() const { + if (auto *FD = dyn_cast(this)) + return FD->getDescribedFunctionTemplate(); + else if (auto *RD = dyn_cast(this)) + return RD->getDescribedClassTemplate(); + else if (auto *VD = dyn_cast(this)) + return VD->getDescribedVarTemplate(); + + return nullptr; +} + const DeclContext *Decl::getParentFunctionOrMethod() const { for (const DeclContext *DC = getDeclContext(); DC && !DC->isTranslationUnit() && !DC->isNamespace(); Index: lib/Sema/SemaOverload.cpp =================================================================== --- lib/Sema/SemaOverload.cpp +++ lib/Sema/SemaOverload.cpp @@ -9324,11 +9324,8 @@ } static TemplateDecl *getDescribedTemplate(Decl *Templated) { - if (FunctionDecl *FD = dyn_cast(Templated)) - return FD->getDescribedFunctionTemplate(); - else if (CXXRecordDecl *RD = dyn_cast(Templated)) - return RD->getDescribedClassTemplate(); - + if (TemplateDecl *TD = Templated->getDescribedTemplate()) + return TD; llvm_unreachable("Unsupported: Getting the described template declaration" " for bad deduction diagnosis"); } Index: lib/Sema/SemaTemplateInstantiateDecl.cpp =================================================================== --- lib/Sema/SemaTemplateInstantiateDecl.cpp +++ lib/Sema/SemaTemplateInstantiateDecl.cpp @@ -3530,7 +3530,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation, FunctionDecl *Function, bool Recursive, - bool DefinitionRequired) { + bool DefinitionRequired, + bool AtEndOfTU) { if (Function->isInvalidDecl() || Function->isDefined()) return; @@ -3604,6 +3605,16 @@ assert(!Recursive); PendingInstantiations.push_back( std::make_pair(Function, PointOfInstantiation)); + } else if (Function->getTemplateSpecializationKind() + == TSK_ImplicitInstantiation) { + if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) { + Diag(PointOfInstantiation, diag::warn_func_template_missing) + << Function; + Diag(PatternDecl->getLocation(), diag::note_forward_template_decl); + if (getLangOpts().CPlusPlus11) + Diag(PointOfInstantiation, diag::note_inst_declaration_hint) + << Function; + } } return; @@ -3951,7 +3962,7 @@ void Sema::InstantiateVariableDefinition(SourceLocation PointOfInstantiation, VarDecl *Var, bool Recursive, - bool DefinitionRequired) { + bool DefinitionRequired, bool AtEndOfTU) { if (Var->isInvalidDecl()) return; @@ -4083,6 +4094,16 @@ == TSK_ExplicitInstantiationDefinition) { PendingInstantiations.push_back( std::make_pair(Var, PointOfInstantiation)); + } else if (Var->getTemplateSpecializationKind() + == TSK_ImplicitInstantiation) { + // Warn about missing definition at the end of translation unit. + if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) { + Diag(PointOfInstantiation, diag::warn_var_template_missing) + << Var; + Diag(PatternDecl->getLocation(), diag::note_forward_template_decl); + if (getLangOpts().CPlusPlus11) + Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var; + } } return; @@ -4852,7 +4873,7 @@ bool DefinitionRequired = Function->getTemplateSpecializationKind() == TSK_ExplicitInstantiationDefinition; InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true, - DefinitionRequired); + DefinitionRequired, true); continue; } @@ -4893,7 +4914,7 @@ // Instantiate static data member definitions or variable template // specializations. InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true, - DefinitionRequired); + DefinitionRequired, true); } } Index: test/CXX/temp/temp.decls/temp.mem/p1.cpp =================================================================== --- test/CXX/temp/temp.decls/temp.mem/p1.cpp +++ test/CXX/temp/temp.decls/temp.mem/p1.cpp @@ -10,6 +10,7 @@ } }; }; +extern template bool A::cond; int foo() { A::cond = true; Index: test/OpenMP/parallel_ast_print.cpp =================================================================== --- test/OpenMP/parallel_ast_print.cpp +++ test/OpenMP/parallel_ast_print.cpp @@ -227,4 +227,7 @@ } } +template +T S::TS = 0; + #endif Index: test/OpenMP/parallel_sections_ast_print.cpp =================================================================== --- test/OpenMP/parallel_sections_ast_print.cpp +++ test/OpenMP/parallel_sections_ast_print.cpp @@ -141,4 +141,7 @@ return tmain(b, &b) + tmain(x, &x); } +template +T S::TS = 0; + #endif Index: test/OpenMP/target_parallel_ast_print.cpp =================================================================== --- test/OpenMP/target_parallel_ast_print.cpp +++ test/OpenMP/target_parallel_ast_print.cpp @@ -227,4 +227,7 @@ return tmain(argc, &argc) + tmain(argv[0][0], argv[0]); } +extern template int S::TS; +extern template char S::TS; + #endif Index: test/OpenMP/task_ast_print.cpp =================================================================== --- test/OpenMP/task_ast_print.cpp +++ test/OpenMP/task_ast_print.cpp @@ -149,4 +149,7 @@ return tmain(b, &b) + tmain(x, &x); } +extern template int S::TS; +extern template long S::TS; + #endif Index: test/OpenMP/teams_ast_print.cpp =================================================================== --- test/OpenMP/teams_ast_print.cpp +++ test/OpenMP/teams_ast_print.cpp @@ -109,4 +109,6 @@ return tmain(b, &b) + tmain(x, &x); } +extern template int S::TS; +extern template long S::TS; #endif Index: test/OpenMP/threadprivate_ast_print.cpp =================================================================== --- test/OpenMP/threadprivate_ast_print.cpp +++ test/OpenMP/threadprivate_ast_print.cpp @@ -69,4 +69,5 @@ return (foo()); } +extern template int ST::m; #endif Index: test/SemaCXX/PR10177.cpp =================================================================== --- test/SemaCXX/PR10177.cpp +++ test/SemaCXX/PR10177.cpp @@ -54,6 +54,7 @@ namespace { template extern int n; } template int g() { return n; } +namespace { extern template int n; } #endif Index: test/SemaCXX/undefined-internal.cpp =================================================================== --- test/SemaCXX/undefined-internal.cpp +++ test/SemaCXX/undefined-internal.cpp @@ -82,6 +82,7 @@ static int var; // expected-warning {{variable 'test5::B::var' has internal linkage but is not defined}} static void foo(); // expected-warning {{function 'test5::B::foo' has internal linkage but is not defined}} }; + extern template int B::var; void test() { B::var = 0; // expected-note {{used here}} Index: test/SemaTemplate/undefined-template.cpp =================================================================== --- /dev/null +++ test/SemaTemplate/undefined-template.cpp @@ -0,0 +1,139 @@ +// RUN: %clang_cc1 -fsyntax-only -verify -std=c++14 -Wundefined-func-template %s + +template struct C1 { + static char s_var_1; // expected-note{{forward declaration of template entity is here}} + static char s_var_2; // expected-note{{forward declaration of template entity is here}} + static void s_func_1(); // expected-note{{forward declaration of template entity is here}} + static void s_func_2(); // expected-note{{forward declaration of template entity is here}} + void meth_1(); // expected-note2{{forward declaration of template entity is here}} + void meth_2(); + template static char s_tvar_2; // expected-note{{forward declaration of template entity is here}} + template static void s_tfunc_2(); // expected-note{{forward declaration of template entity is here}} + template struct C2 { + static char s_var_2; // expected-note{{forward declaration of template entity is here}} + static void s_func_2(); // expected-note{{forward declaration of template entity is here}} + void meth_2(); // expected-note{{forward declaration of template entity is here}} + template static char s_tvar_2; // expected-note{{forward declaration of template entity is here}} + template void tmeth_2(); // expected-note{{forward declaration of template entity is here}} + }; +}; + +extern template char C1::s_var_2; +extern template void C1::s_func_2(); +extern template void C1::meth_2(); +extern template char C1::s_tvar_2; +extern template void C1::s_tfunc_2(); +extern template void C1::C2::s_var_2; +extern template void C1::C2::s_func_2(); +extern template void C1::C2::meth_2(); +extern template char C1::C2::s_tvar_2; +extern template void C1::C2::tmeth_2(); + +char func_01() { + return C1::s_var_2; +} + +char func_02() { + return C1::s_var_1; // expected-warning{{instantiation of variable 'C1::s_var_1' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::s_var_1' is explicitly instantiated in another translation unit}} +} + +char func_03() { + return C1::s_var_2; // expected-warning{{instantiation of variable 'C1::s_var_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::s_var_2' is explicitly instantiated in another translation unit}} +} + +void func_04() { + C1::s_func_1(); // expected-warning{{instantiation of function 'C1::s_func_1' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::s_func_1' is explicitly instantiated in another translation unit}} +} + +void func_05() { + C1::s_func_2(); +} + +void func_06() { + C1::s_func_2(); // expected-warning{{instantiation of function 'C1::s_func_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::s_func_2' is explicitly instantiated in another translation unit}} +} + +void func_07(C1 *x) { + x->meth_1(); // expected-warning{{instantiation of function 'C1::meth_1' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::meth_1' is explicitly instantiated in another translation unit}} +} + +void func_08(C1 *x) { + x->meth_2(); +} + +void func_09(C1 *x) { + x->meth_1(); // expected-warning{{instantiation of function 'C1::meth_1' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::meth_1' is explicitly instantiated in another translation unit}} +} + +char func_10() { + return C1::s_tvar_2; +} + +char func_11() { + return C1::s_tvar_2; // expected-warning{{instantiation of variable 'C1::s_tvar_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::s_tvar_2' is explicitly instantiated in another translation unit}} +} + +void func_12() { + C1::s_tfunc_2(); +} + +void func_13() { + C1::s_tfunc_2(); // expected-warning{{instantiation of function 'C1::s_tfunc_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::s_tfunc_2' is explicitly instantiated in another translation unit}} +} + +char func_14() { + return C1::C2::s_var_2; +} + +char func_15() { + return C1::C2::s_var_2; //expected-warning {{instantiation of variable 'C1::C2::s_var_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::C2::s_var_2' is explicitly instantiated in another translation unit}} +} + +void func_16() { + C1::C2::s_func_2(); +} + +void func_17() { + C1::C2::s_func_2(); // expected-warning{{instantiation of function 'C1::C2::s_func_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::C2::s_func_2' is explicitly instantiated in another translation unit}} +} + +void func_18(C1::C2 *x) { + x->meth_2(); +} + +void func_19(C1::C2 *x) { + x->meth_2(); // expected-warning{{instantiation of function 'C1::C2::meth_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::C2::meth_2' is explicitly instantiated in another translation unit}} +} + +char func_20() { + return C1::C2::s_tvar_2; +} + +char func_21() { + return C1::C2::s_tvar_2; // expected-warning{{instantiation of variable 'C1::C2::s_tvar_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::C2::s_tvar_2' is explicitly instantiated in another translation unit}} +} + +void func_22(C1::C2 *x) { + x->tmeth_2(); +} + +void func_23(C1::C2 *x) { + x->tmeth_2(); // expected-warning{{instantiation of function 'C1::C2::tmeth_2' required here, but no definition is available}} + // expected-note@-1{{add an explicit instantiation declaration to suppress this warning if 'C1::C2::tmeth_2' is explicitly instantiated in another translation unit}} +} + +int main() { + return 0; +}