Author: Chuanqi Xu Date: 2024-07-02T11:43:26+08:00 New Revision: 18f3bcbb13ca83d33223b00761d8cddf463e9ffb
URL: https://github.com/llvm/llvm-project/commit/18f3bcbb13ca83d33223b00761d8cddf463e9ffb DIFF: https://github.com/llvm/llvm-project/commit/18f3bcbb13ca83d33223b00761d8cddf463e9ffb.diff LOG: [C++20] [Modules] Correct the linkage for template instantiations in named modules Close https://github.com/llvm/llvm-project/issues/97313 In the previous patch (https://github.com/llvm/llvm-project/pull/75912), I made an oversight that I ignored the templates in named module when calculating the linkage for the vtables. In this patch, I tried to correct the behavior by merging the logics to calculate the linkage with key functions with named modules. Added: clang/test/Modules/pr97313.cppm Modified: clang/lib/CodeGen/CGVTables.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp index 3e88cd73e8c1f..10d972ec8a362 100644 --- a/clang/lib/CodeGen/CGVTables.cpp +++ b/clang/lib/CodeGen/CGVTables.cpp @@ -1079,33 +1079,38 @@ CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { if (!RD->isExternallyVisible()) return llvm::GlobalVariable::InternalLinkage; - // V-tables for non-template classes with an owning module are always - // uniquely emitted in that module. - if (RD->isInNamedModule()) - return llvm::GlobalVariable::ExternalLinkage; - - // We're at the end of the translation unit, so the current key - // function is fully correct. - const CXXMethodDecl *keyFunction = Context.getCurrentKeyFunction(RD); - if (keyFunction && !RD->hasAttr<DLLImportAttr>()) { + bool IsInNamedModule = RD->isInNamedModule(); + // If the CXXRecordDecl are not in a module unit, we need to get + // its key function. We're at the end of the translation unit, so the current + // key function is fully correct. + const CXXMethodDecl *keyFunction = + IsInNamedModule ? nullptr : Context.getCurrentKeyFunction(RD); + if (IsInNamedModule || (keyFunction && !RD->hasAttr<DLLImportAttr>())) { // If this class has a key function, use that to determine the // linkage of the vtable. const FunctionDecl *def = nullptr; - if (keyFunction->hasBody(def)) + if (keyFunction && keyFunction->hasBody(def)) keyFunction = cast<CXXMethodDecl>(def); - switch (keyFunction->getTemplateSpecializationKind()) { - case TSK_Undeclared: - case TSK_ExplicitSpecialization: + bool IsExternalDefinition = + IsInNamedModule ? RD->shouldEmitInExternalSource() : !def; + + TemplateSpecializationKind Kind = + IsInNamedModule ? RD->getTemplateSpecializationKind() + : keyFunction->getTemplateSpecializationKind(); + + switch (Kind) { + case TSK_Undeclared: + case TSK_ExplicitSpecialization: assert( - (def || CodeGenOpts.OptimizationLevel > 0 || + (IsInNamedModule || def || CodeGenOpts.OptimizationLevel > 0 || CodeGenOpts.getDebugInfo() != llvm::codegenoptions::NoDebugInfo) && - "Shouldn't query vtable linkage without key function, " - "optimizations, or debug info"); - if (!def && CodeGenOpts.OptimizationLevel > 0) + "Shouldn't query vtable linkage without the class in module units, " + "key function, optimizations, or debug info"); + if (IsExternalDefinition && CodeGenOpts.OptimizationLevel > 0) return llvm::GlobalVariable::AvailableExternallyLinkage; - if (keyFunction->isInlined()) + if (keyFunction && keyFunction->isInlined()) return !Context.getLangOpts().AppleKext ? llvm::GlobalVariable::LinkOnceODRLinkage : llvm::Function::InternalLinkage; @@ -1124,7 +1129,7 @@ CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { case TSK_ExplicitInstantiationDeclaration: llvm_unreachable("Should not have been asked to emit this"); - } + } } // -fapple-kext mode does not support weak linkage, so we must use diff --git a/clang/test/Modules/pr97313.cppm b/clang/test/Modules/pr97313.cppm new file mode 100644 index 0000000000000..ebbd0ee4e2c65 --- /dev/null +++ b/clang/test/Modules/pr97313.cppm @@ -0,0 +1,118 @@ +// REQUIRES: !system-windows +// +// RUN: rm -rf %t +// RUN: mkdir -p %t +// RUN: split-file %s %t +// +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/Base.cppm \ +// RUN: -emit-module-interface -o %t/Base.pcm +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/Sub.cppm \ +// RUN: -emit-module-interface -o %t/Sub.pcm -fprebuilt-module-path=%t +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/Sub.pcm \ +// RUN: -emit-llvm -o %t/Sub.pcm -o - -fprebuilt-module-path=%t | \ +// RUN: FileCheck %t/Sub.cppm +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/main.cpp \ +// RUN: -emit-llvm -fprebuilt-module-path=%t -o - | FileCheck %t/main.cpp +// +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/Mod.cppm \ +// RUN: -emit-module-interface -o %t/Mod.pcm +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/Mod.pcm \ +// RUN: -emit-llvm -o - | FileCheck %t/Mod.cppm +// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple %t/Use.cpp \ +// RUN: -emit-llvm -fprebuilt-module-path=%t -o - | \ +// RUN: FileCheck %t/Use.cpp + +//--- Base.cppm +export module Base; + +export template <class> +class Base +{ +public: + constexpr Base(); + constexpr virtual ~Base(); +}; + +template <class X> +constexpr Base<X>::Base() = default; + +template <class X> +constexpr Base<X>::~Base() = default; + +//--- Sub.cppm +export module Sub; +export import Base; + +export class Sub : public Base<int> +{ +}; + +// CHECK: @_ZTIW4Base4BaseIiE = {{.*}}linkonce_odr + +//--- main.cpp +import Sub; + +int main() +{ + Base<int> *b = new Sub(); + delete b; +} + +// CHECK: @_ZTIW4Base4BaseIiE = {{.*}}linkonce_odr + +//--- Mod.cppm +export module Mod; + +export class NonTemplate { +public: + virtual ~NonTemplate(); +}; + +// CHECK: @_ZTIW3Mod11NonTemplate = {{.*}}constant + +export template <class C> +class Template { +public: + virtual ~Template(); +}; + +export template<> +class Template<char> { +public: + virtual ~Template(); +}; + +// CHECK: @_ZTIW3Mod8TemplateIcE = {{.*}}constant + +export template class Template<unsigned>; + +// CHECK: @_ZTIW3Mod8TemplateIjE = {{.*}}weak_odr + +export extern template class Template<double>; + +auto v = new Template<signed int>(); + +// CHECK: @_ZTIW3Mod8TemplateIiE = {{.*}}linkonce_odr + +//--- Use.cpp +import Mod; + +auto v1 = new NonTemplate(); +auto v2 = new Template<char>(); +auto v3 = new Template<unsigned>(); +auto v4 = new Template<double>(); +auto v5 = new Template<signed int>(); +auto v6 = new Template<NonTemplate>(); + +// CHECK: @_ZTVW3Mod11NonTemplate = {{.*}}external +// CHECK: @_ZTVW3Mod8TemplateIcE = {{.*}}external +// CHECK: @_ZTVW3Mod8TemplateIjE = {{.*}}weak_odr +// CHECK: @_ZTSW3Mod8TemplateIjE = {{.*}}weak_odr +// CHECK: @_ZTIW3Mod8TemplateIjE = {{.*}}weak_odr +// CHECK: @_ZTVW3Mod8TemplateIdE = {{.*}}external +// CHECK: @_ZTVW3Mod8TemplateIiE = {{.*}}linkonce_odr +// CHECK: @_ZTSW3Mod8TemplateIiE = {{.*}}linkonce_odr +// CHECK: @_ZTIW3Mod8TemplateIiE = {{.*}}linkonce_odr +// CHECK: @_ZTVW3Mod8TemplateIS_11NonTemplateE = {{.*}}linkonce_odr +// CHECK: @_ZTSW3Mod8TemplateIS_11NonTemplateE = {{.*}}linkonce_odr +// CHECK: @_ZTIW3Mod8TemplateIS_11NonTemplateE = {{.*}}linkonce_odr _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
