[clang] 15bb026 - [C++20] [Modules] [Itanium ABI] Generate the vtable in the module unit of dynamic classes (#75912)
via cfe-commits
cfe-commits at lists.llvm.org
Sun Jun 16 19:25:39 PDT 2024
Author: Chuanqi Xu
Date: 2024-06-17T10:25:35+08:00
New Revision: 15bb02650e26875c48889053d6a9697444583721
URL: https://github.com/llvm/llvm-project/commit/15bb02650e26875c48889053d6a9697444583721
DIFF: https://github.com/llvm/llvm-project/commit/15bb02650e26875c48889053d6a9697444583721.diff
LOG: [C++20] [Modules] [Itanium ABI] Generate the vtable in the module unit of dynamic classes (#75912)
Close https://github.com/llvm/llvm-project/issues/70585 and reflect
https://github.com/itanium-cxx-abi/cxx-abi/issues/170.
The significant change of the patch is: for dynamic classes attached to
module units, we generate the vtable to the attached module units
directly and the key functions for such classes is meaningless.
Added:
clang/test/CodeGenCXX/pr70585.cppm
Modified:
clang/include/clang/AST/DeclBase.h
clang/include/clang/Serialization/ASTBitCodes.h
clang/include/clang/Serialization/ASTReader.h
clang/include/clang/Serialization/ASTWriter.h
clang/lib/AST/DeclBase.cpp
clang/lib/CodeGen/CGVTables.cpp
clang/lib/CodeGen/ItaniumCXXABI.cpp
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaDeclCXX.cpp
clang/lib/Serialization/ASTReader.cpp
clang/lib/Serialization/ASTReaderDecl.cpp
clang/lib/Serialization/ASTWriter.cpp
clang/lib/Serialization/ASTWriterDecl.cpp
clang/test/CodeGenCXX/modules-vtable.cppm
Removed:
################################################################################
diff --git a/clang/include/clang/AST/DeclBase.h b/clang/include/clang/AST/DeclBase.h
index 5f19af1891b74..3310f57acc683 100644
--- a/clang/include/clang/AST/DeclBase.h
+++ b/clang/include/clang/AST/DeclBase.h
@@ -670,6 +670,9 @@ class alignas(8) Decl {
/// Whether this declaration comes from another module unit.
bool isInAnotherModuleUnit() const;
+ /// Whether this declaration comes from the same module unit being compiled.
+ bool isInCurrentModuleUnit() const;
+
/// Whether the definition of the declaration should be emitted in external
/// sources.
bool shouldEmitInExternalSource() const;
diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
index 4ce6cd74dd834..a4728b1c06b3f 100644
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -697,6 +697,9 @@ enum ASTRecordTypes {
/// Record code for \#pragma clang unsafe_buffer_usage begin/end
PP_UNSAFE_BUFFER_USAGE = 69,
+
+ /// Record code for vtables to emit.
+ VTABLES_TO_EMIT = 70,
};
/// Record types used within a source manager block.
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 0a9006223dcbd..08f302c01f538 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -805,6 +805,11 @@ class ASTReader
/// the consumer eagerly.
SmallVector<GlobalDeclID, 16> EagerlyDeserializedDecls;
+ /// The IDs of all vtables to emit. The referenced declarations are passed
+ /// to the consumers's HandleVTable eagerly after passing
+ /// EagerlyDeserializedDecls.
+ SmallVector<GlobalDeclID, 16> VTablesToEmit;
+
/// The IDs of all tentative definitions stored in the chain.
///
/// Sema keeps track of all tentative definitions in a TU because it has to
@@ -1514,6 +1519,7 @@ class ASTReader
bool isConsumerInterestedIn(Decl *D);
void PassInterestingDeclsToConsumer();
void PassInterestingDeclToConsumer(Decl *D);
+ void PassVTableToConsumer(CXXRecordDecl *RD);
void finishPendingActions();
void diagnoseOdrViolations();
diff --git a/clang/include/clang/Serialization/ASTWriter.h b/clang/include/clang/Serialization/ASTWriter.h
index fcc007d6f8637..e66b675510179 100644
--- a/clang/include/clang/Serialization/ASTWriter.h
+++ b/clang/include/clang/Serialization/ASTWriter.h
@@ -495,6 +495,10 @@ class ASTWriter : public ASTDeserializationListener,
std::vector<SourceRange> NonAffectingRanges;
std::vector<SourceLocation::UIntTy> NonAffectingOffsetAdjustments;
+ /// A list of classes which need to emit the VTable in the corresponding
+ /// object file.
+ llvm::SmallVector<CXXRecordDecl *> PendingEmittingVTables;
+
/// Computes input files that didn't affect compilation of the current module,
/// and initializes data structures necessary for leaving those files out
/// during \c SourceManager serialization.
@@ -849,6 +853,8 @@ class ASTWriter : public ASTDeserializationListener,
bool getDoneWritingDeclsAndTypes() const { return DoneWritingDeclsAndTypes; }
+ void handleVTable(CXXRecordDecl *RD);
+
private:
// ASTDeserializationListener implementation
void ReaderInitialized(ASTReader *Reader) override;
@@ -943,6 +949,7 @@ class PCHGenerator : public SemaConsumer {
void InitializeSema(Sema &S) override { SemaPtr = &S; }
void HandleTranslationUnit(ASTContext &Ctx) override;
+ void HandleVTable(CXXRecordDecl *RD) override { Writer.handleVTable(RD); }
ASTMutationListener *GetASTMutationListener() override;
ASTDeserializationListener *GetASTDeserializationListener() override;
bool hasEmittedPCH() const { return Buffer->IsComplete; }
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index e64a8326e8d5d..78768792f1032 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -1128,6 +1128,15 @@ bool Decl::isInAnotherModuleUnit() const {
return M != getASTContext().getCurrentNamedModule();
}
+bool Decl::isInCurrentModuleUnit() const {
+ auto *M = getOwningModule();
+
+ if (!M || !M->isNamedModule())
+ return false;
+
+ return M == getASTContext().getCurrentNamedModule();
+}
+
bool Decl::shouldEmitInExternalSource() const {
ExternalASTSource *Source = getASTContext().getExternalSource();
if (!Source)
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 001633453f242..55c3032dc9332 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -1051,6 +1051,11 @@ 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);
@@ -1185,6 +1190,21 @@ bool CodeGenVTables::isVTableExternal(const CXXRecordDecl *RD) {
TSK == TSK_ExplicitInstantiationDefinition)
return false;
+ // Itanium C++ ABI [5.2.3]:
+ // Virtual tables for dynamic classes are emitted as follows:
+ //
+ // - If the class is templated, the tables are emitted in every object that
+ // references any of them.
+ // - Otherwise, if the class is attached to a module, the tables are uniquely
+ // emitted in the object for the module unit in which it is defined.
+ // - Otherwise, if the class has a key function (see below), the tables are
+ // emitted in the object for the translation unit containing the definition of
+ // the key function. This is unique if the key function is not inline.
+ // - Otherwise, the tables are emitted in every object that references any of
+ // them.
+ if (RD->isInNamedModule())
+ return RD->shouldEmitInExternalSource();
+
// Otherwise, if the class doesn't have a key function (possibly
// anymore), the vtable must be defined here.
const CXXMethodDecl *keyFunction = CGM.getContext().getCurrentKeyFunction(RD);
@@ -1194,13 +1214,7 @@ bool CodeGenVTables::isVTableExternal(const CXXRecordDecl *RD) {
const FunctionDecl *Def;
// Otherwise, if we don't have a definition of the key function, the
// vtable must be defined somewhere else.
- if (!keyFunction->hasBody(Def))
- return true;
-
- assert(Def && "The body of the key function is not assigned to Def?");
- // If the non-inline key function comes from another module unit, the vtable
- // must be defined there.
- return Def->shouldEmitInExternalSource() && !Def->isInlineSpecified();
+ return !keyFunction->hasBody(Def);
}
/// Given that we're currently at the end of the translation unit, and
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 8427286dee887..c15176463866a 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2130,6 +2130,9 @@ bool ItaniumCXXABI::canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const {
if (!canSpeculativelyEmitVTableAsBaseClass(RD))
return false;
+ if (RD->shouldEmitInExternalSource())
+ return false;
+
// For a complete-object vtable (or more specifically, for the VTT), we need
// to be able to speculatively emit the vtables of all dynamic virtual bases.
for (const auto &B : RD->vbases()) {
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 95a6fe66babae..8d4c639c1c30f 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -18333,6 +18333,15 @@ void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD,
if (NumInitMethods > 1 || !Def->hasInitMethod())
Diag(RD->getLocation(), diag::err_sycl_special_type_num_init_method);
}
+
+ // If we're defining a dynamic class in a module interface unit, we always
+ // need to produce the vtable for it even if the vtable is not used in the
+ // current TU.
+ //
+ // The case that the current class is not dynamic is handled in
+ // MarkVTableUsed.
+ if (getCurrentModule() && getCurrentModule()->isInterfaceOrPartition())
+ MarkVTableUsed(RD->getLocation(), RD, /*DefinitionRequired=*/true);
}
// Exit this scope of this tag's definition.
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 37f0df2a6a27d..7718b24955b06 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18706,11 +18706,15 @@ bool Sema::DefineUsedVTables() {
bool DefineVTable = true;
- // If this class has a key function, but that key function is
- // defined in another translation unit, we don't need to emit the
- // vtable even though we're using it.
const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class);
- if (KeyFunction && !KeyFunction->hasBody()) {
+ // V-tables for non-template classes with an owning module are always
+ // uniquely emitted in that module.
+ if (Class->isInCurrentModuleUnit())
+ DefineVTable = true;
+ else if (KeyFunction && !KeyFunction->hasBody()) {
+ // If this class has a key function, but that key function is
+ // defined in another translation unit, we don't need to emit the
+ // vtable even though we're using it.
// The key function is in another translation unit.
DefineVTable = false;
TemplateSpecializationKind TSK =
@@ -18755,7 +18759,7 @@ bool Sema::DefineUsedVTables() {
DefinedAnything = true;
MarkVirtualMembersReferenced(Loc, Class);
CXXRecordDecl *Canonical = Class->getCanonicalDecl();
- if (VTablesUsed[Canonical])
+ if (VTablesUsed[Canonical] && !Class->shouldEmitInExternalSource())
Consumer.HandleVTable(Class);
// Warn if we're emitting a weak vtable. The vtable will be weak if there is
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 89bab014c86ba..a2c322087fd1e 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3903,6 +3903,13 @@ llvm::Error ASTReader::ReadASTBlock(ModuleFile &F,
}
break;
+ case VTABLES_TO_EMIT:
+ if (F.Kind == MK_MainFile ||
+ getContext().getLangOpts().BuildingPCHWithObjectFile)
+ for (unsigned I = 0, N = Record.size(); I != N;)
+ VTablesToEmit.push_back(getGlobalDeclID(F, LocalDeclID(Record[I++])));
+ break;
+
case IMPORTED_MODULES:
if (!F.isModule()) {
// If we aren't loading a module (which has its own exports), make
@@ -8067,6 +8074,10 @@ void ASTReader::PassInterestingDeclToConsumer(Decl *D) {
Consumer->HandleInterestingDecl(DeclGroupRef(D));
}
+void ASTReader::PassVTableToConsumer(CXXRecordDecl *RD) {
+ Consumer->HandleVTable(RD);
+}
+
void ASTReader::StartTranslationUnit(ASTConsumer *Consumer) {
this->Consumer = Consumer;
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index cf2dc32e30b91..eb0c8c6c099b1 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -4219,6 +4219,13 @@ void ASTReader::PassInterestingDeclsToConsumer() {
// If we add any new potential interesting decl in the last call, consume it.
ConsumingPotentialInterestingDecls();
+
+ for (GlobalDeclID ID : VTablesToEmit) {
+ auto *RD = cast<CXXRecordDecl>(GetDecl(ID));
+ assert(!RD->shouldEmitInExternalSource());
+ PassVTableToConsumer(RD);
+ }
+ VTablesToEmit.clear();
}
void ASTReader::loadDeclUpdateRecords(PendingUpdateRecord &Record) {
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index ef165979f9a9e..713091e070805 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -927,6 +927,7 @@ void ASTWriter::WriteBlockInfoBlock() {
RECORD(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS);
RECORD(PP_ASSUME_NONNULL_LOC);
RECORD(PP_UNSAFE_BUFFER_USAGE);
+ RECORD(VTABLES_TO_EMIT);
// SourceManager Block.
BLOCK(SOURCE_MANAGER_BLOCK);
@@ -3957,6 +3958,10 @@ void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
Stream.EmitRecord(INTERESTING_IDENTIFIERS, InterestingIdents);
}
+void ASTWriter::handleVTable(CXXRecordDecl *RD) {
+ PendingEmittingVTables.push_back(RD);
+}
+
//===----------------------------------------------------------------------===//
// DeclContext's Name Lookup Table Serialization
//===----------------------------------------------------------------------===//
@@ -5141,6 +5146,13 @@ void ASTWriter::PrepareWritingSpecialDecls(Sema &SemaRef) {
// Write all of the DeclsToCheckForDeferredDiags.
for (auto *D : SemaRef.DeclsToCheckForDeferredDiags)
GetDeclRef(D);
+
+ // Write all classes need to emit the vtable definitions if required.
+ if (isWritingStdCXXNamedModules())
+ for (CXXRecordDecl *RD : PendingEmittingVTables)
+ GetDeclRef(RD);
+ else
+ PendingEmittingVTables.clear();
}
void ASTWriter::WriteSpecialDeclRecords(Sema &SemaRef) {
@@ -5295,6 +5307,17 @@ void ASTWriter::WriteSpecialDeclRecords(Sema &SemaRef) {
}
if (!DeleteExprsToAnalyze.empty())
Stream.EmitRecord(DELETE_EXPRS_TO_ANALYZE, DeleteExprsToAnalyze);
+
+ RecordData VTablesToEmit;
+ for (CXXRecordDecl *RD : PendingEmittingVTables) {
+ if (!wasDeclEmitted(RD))
+ continue;
+
+ AddDeclRef(RD, VTablesToEmit);
+ }
+
+ if (!VTablesToEmit.empty())
+ Stream.EmitRecord(VTABLES_TO_EMIT, VTablesToEmit);
}
ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 5a6ab4408eb2b..49b2f9bc1e6cf 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -1537,8 +1537,14 @@ void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
if (D->isThisDeclarationADefinition())
Record.AddCXXDefinitionData(D);
+ if (D->isCompleteDefinition() && D->isInNamedModule())
+ Writer.AddDeclRef(D, Writer.ModularCodegenDecls);
+
// Store (what we currently believe to be) the key function to avoid
// deserializing every method so we can compute it.
+ //
+ // FIXME: Avoid adding the key function if the class is defined in
+ // module purview since the key function is meaningless in module purview.
if (D->isCompleteDefinition())
Record.AddDeclRef(Context.getCurrentKeyFunction(D));
diff --git a/clang/test/CodeGenCXX/modules-vtable.cppm b/clang/test/CodeGenCXX/modules-vtable.cppm
index fb179b1de4880..5cc3504d72628 100644
--- a/clang/test/CodeGenCXX/modules-vtable.cppm
+++ b/clang/test/CodeGenCXX/modules-vtable.cppm
@@ -24,6 +24,8 @@
// RUN: %t/M-A.cppm -o %t/M-A.pcm
// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 -fmodule-file=M:A=%t/M-A.pcm \
// RUN: %t/M-B.cppm -emit-llvm -o - | FileCheck %t/M-B.cppm
+// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 \
+// RUN: %t/M-A.pcm -emit-llvm -o - | FileCheck %t/M-A.cppm
//--- Mod.cppm
export module Mod;
@@ -41,9 +43,10 @@ Base::~Base() {}
// CHECK: @_ZTSW3Mod4Base = constant
// CHECK: @_ZTIW3Mod4Base = constant
-// CHECK-INLINE: @_ZTVW3Mod4Base = linkonce_odr {{.*}}unnamed_addr constant
-// CHECK-INLINE: @_ZTSW3Mod4Base = linkonce_odr {{.*}}constant
-// CHECK-INLINE: @_ZTIW3Mod4Base = linkonce_odr {{.*}}constant
+// With the new Itanium C++ ABI, the linkage of vtables in modules don't need to be linkonce ODR.
+// CHECK-INLINE: @_ZTVW3Mod4Base = {{.*}}unnamed_addr constant
+// CHECK-INLINE: @_ZTSW3Mod4Base = {{.*}}constant
+// CHECK-INLINE: @_ZTIW3Mod4Base = {{.*}}constant
module :private;
int private_use() {
@@ -58,13 +61,13 @@ int use() {
return 43;
}
-// CHECK-NOT: @_ZTSW3Mod4Base = constant
-// CHECK-NOT: @_ZTIW3Mod4Base = constant
-// CHECK: @_ZTVW3Mod4Base = external unnamed_addr
+// CHECK-NOT: @_ZTSW3Mod4Base
+// CHECK-NOT: @_ZTIW3Mod4Base
+// CHECK: @_ZTVW3Mod4Base = external
-// CHECK-INLINE: @_ZTVW3Mod4Base = linkonce_odr {{.*}}unnamed_addr constant
-// CHECK-INLINE: @_ZTSW3Mod4Base = linkonce_odr {{.*}}constant
-// CHECK-INLINE: @_ZTIW3Mod4Base = linkonce_odr {{.*}}constant
+// CHECK-INLINE-NOT: @_ZTSW3Mod4Base
+// CHECK-INLINE-NOT: @_ZTIW3Mod4Base
+// CHECK-INLINE: @_ZTVW3Mod4Base = external
// Check the case that the declaration of the key function comes from another
// module unit but the definition of the key function comes from the current
@@ -82,6 +85,10 @@ int a_use() {
return 43;
}
+// CHECK: @_ZTVW1M1C = unnamed_addr constant
+// CHECK: @_ZTSW1M1C = constant
+// CHECK: @_ZTIW1M1C = constant
+
//--- M-B.cppm
export module M:B;
import :A;
@@ -93,6 +100,6 @@ int b_use() {
return 43;
}
-// CHECK: @_ZTVW1M1C = unnamed_addr constant
-// CHECK: @_ZTSW1M1C = constant
-// CHECK: @_ZTIW1M1C = constant
+// CHECK: @_ZTVW1M1C = external
+// CHECK-NOT: @_ZTSW1M1C
+// CHECK-NOT: @_ZTIW1M1C
diff --git a/clang/test/CodeGenCXX/pr70585.cppm b/clang/test/CodeGenCXX/pr70585.cppm
new file mode 100644
index 0000000000000..ad4e13589d86e
--- /dev/null
+++ b/clang/test/CodeGenCXX/pr70585.cppm
@@ -0,0 +1,47 @@
+// REQUIRES: !system-windows
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: cd %t
+//
+// RUN: %clang_cc1 -std=c++20 %t/layer1.cppm -triple %itanium_abi_triple \
+// RUN: -emit-module-interface -o %t/foo-layer1.pcm
+// RUN: %clang_cc1 -std=c++20 %t/layer2.cppm -triple %itanium_abi_triple \
+// RUN: -emit-module-interface -fmodule-file=foo:layer1=%t/foo-layer1.pcm \
+// RUN: -o %t/foo-layer2.pcm
+// RUN: %clang_cc1 -std=c++20 %t/foo-layer1.pcm -emit-llvm -o - | FileCheck %t/layer1.cppm
+// RUN: %clang_cc1 -std=c++20 %t/foo-layer2.pcm -emit-llvm -o - \
+// RUN: -fmodule-file=foo:layer1=%t/foo-layer1.pcm | FileCheck %t/layer2.cppm
+//
+// Check the case about emitting object files from sources directly.
+// RUN: %clang_cc1 -std=c++20 %t/layer1.cppm -triple %itanium_abi_triple \
+// RUN: -emit-llvm -o - | FileCheck %t/layer1.cppm
+// RUN: %clang_cc1 -std=c++20 %t/layer2.cppm -triple %itanium_abi_triple -emit-llvm \
+// RUN: -fmodule-file=foo:layer1=%t/foo-layer1.pcm -o - | FileCheck %t/layer2.cppm
+
+//--- layer1.cppm
+export module foo:layer1;
+struct Fruit {
+ virtual ~Fruit() = default;
+ virtual void eval();
+};
+
+// CHECK-DAG: @_ZTVW3foo5Fruit = unnamed_addr constant
+// CHECK-DAG: @_ZTSW3foo5Fruit = constant
+// CHECK-DAG: @_ZTIW3foo5Fruit = constant
+
+// Testing that:
+// (1) The use of virtual functions won't produce the vtable.
+// (2) The definition of key functions won't produce the vtable.
+//
+//--- layer2.cppm
+export module foo:layer2;
+import :layer1;
+export void layer2_fun() {
+ Fruit *b = new Fruit();
+ b->eval();
+}
+void Fruit::eval() {}
+// CHECK: @_ZTVW3foo5Fruit = external unnamed_addr constant
+// CHECK-NOT: @_ZTSW3foo5Fruit
+// CHECK-NOT: @_ZTIW3foo5Fruit
More information about the cfe-commits
mailing list