[clang] f94c481 - [clang] Track source deduction guide for alias template deduction guides (#123875)
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cfe-commits at lists.llvm.org
Mon Jan 27 15:59:15 PST 2025
Author: antangelo
Date: 2025-01-27T18:59:12-05:00
New Revision: f94c481543bdd3b11a668ad78d46593cf974788f
URL: https://github.com/llvm/llvm-project/commit/f94c481543bdd3b11a668ad78d46593cf974788f
DIFF: https://github.com/llvm/llvm-project/commit/f94c481543bdd3b11a668ad78d46593cf974788f.diff
LOG: [clang] Track source deduction guide for alias template deduction guides (#123875)
For deduction guides generated from alias template CTAD, store the
deduction guide they were originated from. The source kind is also
maintained for future expansion in CTAD from inherited constructors.
This tracking is required to determine whether an alias template already
has a deduction guide corresponding to some deduction guide on the
original template, in order to support deduction guides for the alias
from deduction guides declared after the initial usage.
Added:
Modified:
clang/include/clang/AST/DeclCXX.h
clang/lib/AST/ASTImporter.cpp
clang/lib/AST/DeclCXX.cpp
clang/lib/Sema/SemaTemplateDeductionGuide.cpp
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
clang/lib/Serialization/ASTReaderDecl.cpp
clang/lib/Serialization/ASTWriterDecl.cpp
clang/unittests/AST/ASTImporterTest.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index fa3f4ec98eb369..79fd403c2718c8 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -1967,17 +1967,29 @@ class ExplicitSpecifier {
class CXXDeductionGuideDecl : public FunctionDecl {
void anchor() override;
+public:
+ // Represents the relationship between this deduction guide and the
+ // deduction guide that it was generated from (or lack thereof).
+ // See the SourceDeductionGuide member for more details.
+ enum class SourceDeductionGuideKind : uint8_t {
+ None,
+ Alias,
+ };
+
private:
CXXDeductionGuideDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
ExplicitSpecifier ES,
const DeclarationNameInfo &NameInfo, QualType T,
TypeSourceInfo *TInfo, SourceLocation EndLocation,
CXXConstructorDecl *Ctor, DeductionCandidate Kind,
- Expr *TrailingRequiresClause)
+ Expr *TrailingRequiresClause,
+ const CXXDeductionGuideDecl *GeneratedFrom,
+ SourceDeductionGuideKind SourceKind)
: FunctionDecl(CXXDeductionGuide, C, DC, StartLoc, NameInfo, T, TInfo,
SC_None, false, false, ConstexprSpecKind::Unspecified,
TrailingRequiresClause),
- Ctor(Ctor), ExplicitSpec(ES) {
+ Ctor(Ctor), ExplicitSpec(ES),
+ SourceDeductionGuide(GeneratedFrom, SourceKind) {
if (EndLocation.isValid())
setRangeEnd(EndLocation);
setDeductionCandidateKind(Kind);
@@ -1985,6 +1997,12 @@ class CXXDeductionGuideDecl : public FunctionDecl {
CXXConstructorDecl *Ctor;
ExplicitSpecifier ExplicitSpec;
+ // The deduction guide, if any, that this deduction guide was generated from,
+ // in the case of alias template deduction. The SourceDeductionGuideKind
+ // member indicates which of these sources applies, or is None otherwise.
+ llvm::PointerIntPair<const CXXDeductionGuideDecl *, 2,
+ SourceDeductionGuideKind>
+ SourceDeductionGuide;
void setExplicitSpecifier(ExplicitSpecifier ES) { ExplicitSpec = ES; }
public:
@@ -1997,7 +2015,9 @@ class CXXDeductionGuideDecl : public FunctionDecl {
TypeSourceInfo *TInfo, SourceLocation EndLocation,
CXXConstructorDecl *Ctor = nullptr,
DeductionCandidate Kind = DeductionCandidate::Normal,
- Expr *TrailingRequiresClause = nullptr);
+ Expr *TrailingRequiresClause = nullptr,
+ const CXXDeductionGuideDecl *SourceDG = nullptr,
+ SourceDeductionGuideKind SK = SourceDeductionGuideKind::None);
static CXXDeductionGuideDecl *CreateDeserialized(ASTContext &C,
GlobalDeclID ID);
@@ -2017,6 +2037,25 @@ class CXXDeductionGuideDecl : public FunctionDecl {
/// this is an implicit deduction guide.
CXXConstructorDecl *getCorrespondingConstructor() const { return Ctor; }
+ /// Get the deduction guide from which this deduction guide was generated,
+ /// if it was generated as part of alias template deduction or from an
+ /// inherited constructor.
+ const CXXDeductionGuideDecl *getSourceDeductionGuide() const {
+ return SourceDeductionGuide.getPointer();
+ }
+
+ void setSourceDeductionGuide(CXXDeductionGuideDecl *DG) {
+ SourceDeductionGuide.setPointer(DG);
+ }
+
+ SourceDeductionGuideKind getSourceDeductionGuideKind() const {
+ return SourceDeductionGuide.getInt();
+ }
+
+ void setSourceDeductionGuideKind(SourceDeductionGuideKind SK) {
+ SourceDeductionGuide.setInt(SK);
+ }
+
void setDeductionCandidateKind(DeductionCandidate K) {
FunctionDeclBits.DeductionCandidateKind = static_cast<unsigned char>(K);
}
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index f661de54504a9c..5433b6120ab9f2 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -3997,14 +3997,16 @@ ExpectedDecl ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
importExplicitSpecifier(Err, Guide->getExplicitSpecifier());
CXXConstructorDecl *Ctor =
importChecked(Err, Guide->getCorrespondingConstructor());
+ const CXXDeductionGuideDecl *SourceDG =
+ importChecked(Err, Guide->getSourceDeductionGuide());
if (Err)
return std::move(Err);
if (GetImportedOrCreateDecl<CXXDeductionGuideDecl>(
ToFunction, D, Importer.getToContext(), DC, ToInnerLocStart, ESpec,
- NameInfo, T, TInfo, ToEndLoc, Ctor))
+ NameInfo, T, TInfo, ToEndLoc, Ctor,
+ Guide->getDeductionCandidateKind(), TrailingRequiresClause,
+ SourceDG, Guide->getSourceDeductionGuideKind()))
return ToFunction;
- cast<CXXDeductionGuideDecl>(ToFunction)
- ->setDeductionCandidateKind(Guide->getDeductionCandidateKind());
} else {
if (GetImportedOrCreateDecl(
ToFunction, D, Importer.getToContext(), DC, ToInnerLocStart,
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index c0a4356dcb004f..a023a9f456a0e4 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -2292,18 +2292,22 @@ CXXDeductionGuideDecl *CXXDeductionGuideDecl::Create(
ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
ExplicitSpecifier ES, const DeclarationNameInfo &NameInfo, QualType T,
TypeSourceInfo *TInfo, SourceLocation EndLocation, CXXConstructorDecl *Ctor,
- DeductionCandidate Kind, Expr *TrailingRequiresClause) {
- return new (C, DC)
- CXXDeductionGuideDecl(C, DC, StartLoc, ES, NameInfo, T, TInfo,
- EndLocation, Ctor, Kind, TrailingRequiresClause);
+ DeductionCandidate Kind, Expr *TrailingRequiresClause,
+ const CXXDeductionGuideDecl *GeneratedFrom,
+ SourceDeductionGuideKind SourceKind) {
+ return new (C, DC) CXXDeductionGuideDecl(
+ C, DC, StartLoc, ES, NameInfo, T, TInfo, EndLocation, Ctor, Kind,
+ TrailingRequiresClause, GeneratedFrom, SourceKind);
}
CXXDeductionGuideDecl *
CXXDeductionGuideDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
return new (C, ID) CXXDeductionGuideDecl(
- C, nullptr, SourceLocation(), ExplicitSpecifier(), DeclarationNameInfo(),
- QualType(), nullptr, SourceLocation(), nullptr,
- DeductionCandidate::Normal, nullptr);
+ C, /*DC=*/nullptr, SourceLocation(), ExplicitSpecifier(),
+ DeclarationNameInfo(), QualType(), /*TInfo=*/nullptr, SourceLocation(),
+ /*Ctor=*/nullptr, DeductionCandidate::Normal,
+ /*TrailingRequiresClause=*/nullptr,
+ /*GeneratedFrom=*/nullptr, SourceDeductionGuideKind::None);
}
RequiresExprBodyDecl *RequiresExprBodyDecl::Create(
diff --git a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp
index 950783303efb32..00c5dfd3d7a438 100644
--- a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp
+++ b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp
@@ -1175,8 +1175,12 @@ BuildDeductionGuideForTypeAlias(Sema &SemaRef,
GG->getTypeSourceInfo(), AliasTemplate->getBeginLoc(),
AliasTemplate->getLocation(), AliasTemplate->getEndLoc(),
F->isImplicit()));
- cast<CXXDeductionGuideDecl>(Result->getTemplatedDecl())
- ->setDeductionCandidateKind(GG->getDeductionCandidateKind());
+ auto *DGuide = cast<CXXDeductionGuideDecl>(Result->getTemplatedDecl());
+ DGuide->setDeductionCandidateKind(GG->getDeductionCandidateKind());
+ DGuide->setSourceDeductionGuide(
+ cast<CXXDeductionGuideDecl>(F->getTemplatedDecl()));
+ DGuide->setSourceDeductionGuideKind(
+ CXXDeductionGuideDecl::SourceDeductionGuideKind::Alias);
return Result;
}
return nullptr;
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 337262e4b5fc38..ebe2dd91865cae 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2269,7 +2269,9 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(
SemaRef.Context, DC, D->getInnerLocStart(),
InstantiatedExplicitSpecifier, NameInfo, T, TInfo,
D->getSourceRange().getEnd(), DGuide->getCorrespondingConstructor(),
- DGuide->getDeductionCandidateKind(), TrailingRequiresClause);
+ DGuide->getDeductionCandidateKind(), TrailingRequiresClause,
+ DGuide->getSourceDeductionGuide(),
+ DGuide->getSourceDeductionGuideKind());
Function->setAccess(D->getAccess());
} else {
Function = FunctionDecl::Create(
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 0b75468a94103f..87e1931ee47fd6 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -2295,6 +2295,10 @@ void ASTDeclReader::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
VisitFunctionDecl(D);
D->setDeductionCandidateKind(
static_cast<DeductionCandidate>(Record.readInt()));
+ D->setSourceDeductionGuide(readDeclAs<CXXDeductionGuideDecl>());
+ D->setSourceDeductionGuideKind(
+ static_cast<CXXDeductionGuideDecl::SourceDeductionGuideKind>(
+ Record.readInt()));
}
void ASTDeclReader::VisitCXXMethodDecl(CXXMethodDecl *D) {
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 8b9ba04dce91c4..fa2294da95de8d 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -846,6 +846,9 @@ void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
Record.AddDeclRef(D->Ctor);
VisitFunctionDecl(D);
Record.push_back(static_cast<unsigned char>(D->getDeductionCandidateKind()));
+ Record.AddDeclRef(D->getSourceDeductionGuide());
+ Record.push_back(
+ static_cast<unsigned char>(D->getSourceDeductionGuideKind()));
Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
}
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index e77860521335ed..114d0b461dae88 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -8125,6 +8125,9 @@ TEST_P(ImportFunctions, CTADImplicit) {
auto *ToD = Import(FromD, Lang_CXX17);
ASSERT_TRUE(ToD);
EXPECT_EQ(ToD->getDeductionCandidateKind(), DeductionCandidate::Copy);
+ EXPECT_EQ(ToD->getSourceDeductionGuide(), nullptr);
+ EXPECT_EQ(ToD->getSourceDeductionGuideKind(),
+ CXXDeductionGuideDecl::SourceDeductionGuideKind::None);
// Check that the deduced class template is also imported.
EXPECT_TRUE(findFromTU(FromD)->Importer->GetAlreadyImportedOrNull(
FromD->getDeducedTemplate()));
@@ -8149,6 +8152,9 @@ TEST_P(ImportFunctions, CTADUserDefinedExplicit) {
ASSERT_TRUE(ToD);
EXPECT_FALSE(FromD->isImplicit());
EXPECT_TRUE(ToD->isExplicit());
+ EXPECT_EQ(ToD->getSourceDeductionGuide(), nullptr);
+ EXPECT_EQ(ToD->getSourceDeductionGuideKind(),
+ CXXDeductionGuideDecl::SourceDeductionGuideKind::None);
}
TEST_P(ImportFunctions, CTADWithLocalTypedef) {
@@ -8167,6 +8173,26 @@ TEST_P(ImportFunctions, CTADWithLocalTypedef) {
ASSERT_TRUE(ToD);
}
+TEST_P(ImportFunctions, CTADAliasTemplate) {
+ Decl *TU = getTuDecl(
+ R"(
+ template <typename T> struct A {
+ A(T);
+ };
+ template<typename T>
+ using B = A<T>;
+ B b{(int)0};
+ )",
+ Lang_CXX20, "input.cc");
+ auto *FromD = FirstDeclMatcher<CXXDeductionGuideDecl>().match(
+ TU, cxxDeductionGuideDecl(hasParameter(0, hasType(asString("int")))));
+ auto *ToD = Import(FromD, Lang_CXX20);
+ ASSERT_TRUE(ToD);
+ EXPECT_TRUE(ToD->getSourceDeductionGuideKind() ==
+ CXXDeductionGuideDecl::SourceDeductionGuideKind::Alias);
+ EXPECT_TRUE(ToD->getSourceDeductionGuide());
+}
+
TEST_P(ImportFunctions, ParmVarDeclDeclContext) {
constexpr auto FromTUCode = R"(
void f(int P);
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