llvm-project/clang/lib/Sema/MultiplexExternalSemaSource.cpp
Richard Smith bc73ef0031 PR60985: Fix merging of lambda closure types across modules.
Previously, distinct lambdas would get merged, and multiple definitions
of the same lambda would not get merged, because we attempted to
identify lambdas by their ordinal position within their lexical
DeclContext. This failed for lambdas within namespace-scope variables
and within variable templates, where the lexical position in the context
containing the variable didn't uniquely identify the lambda.

In this patch, we instead identify lambda closure types by index within
their context declaration, which does uniquely identify them in a way
that's consistent across modules.

This change causes a deserialization cycle between the type of a
variable with deduced type and a lambda appearing as the initializer of
the variable -- reading the variable's type requires reading and merging
the lambda, and reading the lambda requires reading and merging the
variable. This is addressed by deferring loading the deduced type of a
variable until after we finish recursive deserialization.

This also exposes a pre-existing subtle issue where loading a
variable declaration would trigger immediate loading of its initializer,
which could recursively refer back to properties of the variable. This
particularly causes problems if the initializer contains a
lambda-expression, but can be problematic in general. That is addressed
by switching to lazily loading the initializers of variables rather than
always loading them with the variable declaration. As well as fixing a
deserialization cycle, that should improve laziness of deserialization
in general.

LambdaDefinitionData had 63 spare bits in it, presumably caused by an
off-by-one-error in some previous change. This change claims 32 of those bits
as a counter for the lambda within its context. We could probably move the
numbering to separate storage, like we do for the device-side mangling number,
to optimize the likely-common case where all three numbers (host-side mangling
number, device-side mangling number, and index within the context declaration)
are zero, but that's not done in this change.

Fixes #60985.

Reviewed By: #clang-language-wg, aaron.ballman

Differential Revision: https://reviews.llvm.org/D145737
2023-03-30 14:22:40 -07:00

350 lines
12 KiB
C++

//===--- MultiplexExternalSemaSource.cpp ---------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the event dispatching to the subscribed clients.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/MultiplexExternalSemaSource.h"
#include "clang/Sema/Lookup.h"
using namespace clang;
char MultiplexExternalSemaSource::ID;
/// Constructs a new multiplexing external sema source and appends the
/// given element to it.
///
MultiplexExternalSemaSource::MultiplexExternalSemaSource(
ExternalSemaSource *S1, ExternalSemaSource *S2) {
S1->Retain();
S2->Retain();
Sources.push_back(S1);
Sources.push_back(S2);
}
// pin the vtable here.
MultiplexExternalSemaSource::~MultiplexExternalSemaSource() {
for (auto *S : Sources)
S->Release();
}
/// Appends new source to the source list.
///
///\param[in] source - An ExternalSemaSource.
///
void MultiplexExternalSemaSource::AddSource(ExternalSemaSource *Source) {
Source->Retain();
Sources.push_back(Source);
}
//===----------------------------------------------------------------------===//
// ExternalASTSource.
//===----------------------------------------------------------------------===//
Decl *MultiplexExternalSemaSource::GetExternalDecl(uint32_t ID) {
for(size_t i = 0; i < Sources.size(); ++i)
if (Decl *Result = Sources[i]->GetExternalDecl(ID))
return Result;
return nullptr;
}
void MultiplexExternalSemaSource::CompleteRedeclChain(const Decl *D) {
for (size_t i = 0; i < Sources.size(); ++i)
Sources[i]->CompleteRedeclChain(D);
}
Selector MultiplexExternalSemaSource::GetExternalSelector(uint32_t ID) {
Selector Sel;
for(size_t i = 0; i < Sources.size(); ++i) {
Sel = Sources[i]->GetExternalSelector(ID);
if (!Sel.isNull())
return Sel;
}
return Sel;
}
uint32_t MultiplexExternalSemaSource::GetNumExternalSelectors() {
uint32_t total = 0;
for(size_t i = 0; i < Sources.size(); ++i)
total += Sources[i]->GetNumExternalSelectors();
return total;
}
Stmt *MultiplexExternalSemaSource::GetExternalDeclStmt(uint64_t Offset) {
for(size_t i = 0; i < Sources.size(); ++i)
if (Stmt *Result = Sources[i]->GetExternalDeclStmt(Offset))
return Result;
return nullptr;
}
CXXBaseSpecifier *MultiplexExternalSemaSource::GetExternalCXXBaseSpecifiers(
uint64_t Offset){
for(size_t i = 0; i < Sources.size(); ++i)
if (CXXBaseSpecifier *R = Sources[i]->GetExternalCXXBaseSpecifiers(Offset))
return R;
return nullptr;
}
CXXCtorInitializer **
MultiplexExternalSemaSource::GetExternalCXXCtorInitializers(uint64_t Offset) {
for (auto *S : Sources)
if (auto *R = S->GetExternalCXXCtorInitializers(Offset))
return R;
return nullptr;
}
ExternalASTSource::ExtKind
MultiplexExternalSemaSource::hasExternalDefinitions(const Decl *D) {
for (const auto &S : Sources)
if (auto EK = S->hasExternalDefinitions(D))
if (EK != EK_ReplyHazy)
return EK;
return EK_ReplyHazy;
}
bool MultiplexExternalSemaSource::
FindExternalVisibleDeclsByName(const DeclContext *DC, DeclarationName Name) {
bool AnyDeclsFound = false;
for (size_t i = 0; i < Sources.size(); ++i)
AnyDeclsFound |= Sources[i]->FindExternalVisibleDeclsByName(DC, Name);
return AnyDeclsFound;
}
void MultiplexExternalSemaSource::completeVisibleDeclsMap(const DeclContext *DC){
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->completeVisibleDeclsMap(DC);
}
void MultiplexExternalSemaSource::FindExternalLexicalDecls(
const DeclContext *DC, llvm::function_ref<bool(Decl::Kind)> IsKindWeWant,
SmallVectorImpl<Decl *> &Result) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->FindExternalLexicalDecls(DC, IsKindWeWant, Result);
}
void MultiplexExternalSemaSource::FindFileRegionDecls(FileID File,
unsigned Offset,
unsigned Length,
SmallVectorImpl<Decl *> &Decls){
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->FindFileRegionDecls(File, Offset, Length, Decls);
}
void MultiplexExternalSemaSource::CompleteType(TagDecl *Tag) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->CompleteType(Tag);
}
void MultiplexExternalSemaSource::CompleteType(ObjCInterfaceDecl *Class) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->CompleteType(Class);
}
void MultiplexExternalSemaSource::ReadComments() {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadComments();
}
void MultiplexExternalSemaSource::StartedDeserializing() {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->StartedDeserializing();
}
void MultiplexExternalSemaSource::FinishedDeserializing() {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->FinishedDeserializing();
}
void MultiplexExternalSemaSource::StartTranslationUnit(ASTConsumer *Consumer) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->StartTranslationUnit(Consumer);
}
void MultiplexExternalSemaSource::PrintStats() {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->PrintStats();
}
Module *MultiplexExternalSemaSource::getModule(unsigned ID) {
for (size_t i = 0; i < Sources.size(); ++i)
if (auto M = Sources[i]->getModule(ID))
return M;
return nullptr;
}
bool MultiplexExternalSemaSource::layoutRecordType(const RecordDecl *Record,
uint64_t &Size,
uint64_t &Alignment,
llvm::DenseMap<const FieldDecl *, uint64_t> &FieldOffsets,
llvm::DenseMap<const CXXRecordDecl *, CharUnits> &BaseOffsets,
llvm::DenseMap<const CXXRecordDecl *, CharUnits> &VirtualBaseOffsets){
for(size_t i = 0; i < Sources.size(); ++i)
if (Sources[i]->layoutRecordType(Record, Size, Alignment, FieldOffsets,
BaseOffsets, VirtualBaseOffsets))
return true;
return false;
}
void MultiplexExternalSemaSource::
getMemoryBufferSizes(MemoryBufferSizes &sizes) const {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->getMemoryBufferSizes(sizes);
}
//===----------------------------------------------------------------------===//
// ExternalSemaSource.
//===----------------------------------------------------------------------===//
void MultiplexExternalSemaSource::InitializeSema(Sema &S) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->InitializeSema(S);
}
void MultiplexExternalSemaSource::ForgetSema() {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ForgetSema();
}
void MultiplexExternalSemaSource::ReadMethodPool(Selector Sel) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadMethodPool(Sel);
}
void MultiplexExternalSemaSource::updateOutOfDateSelector(Selector Sel) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->updateOutOfDateSelector(Sel);
}
void MultiplexExternalSemaSource::ReadKnownNamespaces(
SmallVectorImpl<NamespaceDecl*> &Namespaces){
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadKnownNamespaces(Namespaces);
}
void MultiplexExternalSemaSource::ReadUndefinedButUsed(
llvm::MapVector<NamedDecl *, SourceLocation> &Undefined) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadUndefinedButUsed(Undefined);
}
void MultiplexExternalSemaSource::ReadMismatchingDeleteExpressions(
llvm::MapVector<FieldDecl *,
llvm::SmallVector<std::pair<SourceLocation, bool>, 4>> &
Exprs) {
for (auto &Source : Sources)
Source->ReadMismatchingDeleteExpressions(Exprs);
}
bool MultiplexExternalSemaSource::LookupUnqualified(LookupResult &R, Scope *S){
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->LookupUnqualified(R, S);
return !R.empty();
}
void MultiplexExternalSemaSource::ReadTentativeDefinitions(
SmallVectorImpl<VarDecl*> &TentativeDefs) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadTentativeDefinitions(TentativeDefs);
}
void MultiplexExternalSemaSource::ReadUnusedFileScopedDecls(
SmallVectorImpl<const DeclaratorDecl*> &Decls) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadUnusedFileScopedDecls(Decls);
}
void MultiplexExternalSemaSource::ReadDelegatingConstructors(
SmallVectorImpl<CXXConstructorDecl*> &Decls) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadDelegatingConstructors(Decls);
}
void MultiplexExternalSemaSource::ReadExtVectorDecls(
SmallVectorImpl<TypedefNameDecl*> &Decls) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadExtVectorDecls(Decls);
}
void MultiplexExternalSemaSource::ReadDeclsToCheckForDeferredDiags(
llvm::SmallSetVector<Decl *, 4> &Decls) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadDeclsToCheckForDeferredDiags(Decls);
}
void MultiplexExternalSemaSource::ReadUnusedLocalTypedefNameCandidates(
llvm::SmallSetVector<const TypedefNameDecl *, 4> &Decls) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadUnusedLocalTypedefNameCandidates(Decls);
}
void MultiplexExternalSemaSource::ReadReferencedSelectors(
SmallVectorImpl<std::pair<Selector, SourceLocation> > &Sels) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadReferencedSelectors(Sels);
}
void MultiplexExternalSemaSource::ReadWeakUndeclaredIdentifiers(
SmallVectorImpl<std::pair<IdentifierInfo*, WeakInfo> > &WI) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadWeakUndeclaredIdentifiers(WI);
}
void MultiplexExternalSemaSource::ReadUsedVTables(
SmallVectorImpl<ExternalVTableUse> &VTables) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadUsedVTables(VTables);
}
void MultiplexExternalSemaSource::ReadPendingInstantiations(
SmallVectorImpl<std::pair<ValueDecl*,
SourceLocation> > &Pending) {
for(size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadPendingInstantiations(Pending);
}
void MultiplexExternalSemaSource::ReadLateParsedTemplates(
llvm::MapVector<const FunctionDecl *, std::unique_ptr<LateParsedTemplate>>
&LPTMap) {
for (size_t i = 0; i < Sources.size(); ++i)
Sources[i]->ReadLateParsedTemplates(LPTMap);
}
TypoCorrection MultiplexExternalSemaSource::CorrectTypo(
const DeclarationNameInfo &Typo,
int LookupKind, Scope *S, CXXScopeSpec *SS,
CorrectionCandidateCallback &CCC,
DeclContext *MemberContext,
bool EnteringContext,
const ObjCObjectPointerType *OPT) {
for (size_t I = 0, E = Sources.size(); I < E; ++I) {
if (TypoCorrection C = Sources[I]->CorrectTypo(Typo, LookupKind, S, SS, CCC,
MemberContext,
EnteringContext, OPT))
return C;
}
return TypoCorrection();
}
bool MultiplexExternalSemaSource::MaybeDiagnoseMissingCompleteType(
SourceLocation Loc, QualType T) {
for (size_t I = 0, E = Sources.size(); I < E; ++I) {
if (Sources[I]->MaybeDiagnoseMissingCompleteType(Loc, T))
return true;
}
return false;
}
void MultiplexExternalSemaSource::AssignedLambdaNumbering(
const CXXRecordDecl *Lambda) {
for (auto *Source : Sources)
Source->AssignedLambdaNumbering(Lambda);
}