[clang] [Clang] Fix handling of brace ellison when building deduction guides (PR #94889)
Younan Zhang via cfe-commits
cfe-commits at lists.llvm.org
Thu Jun 13 01:38:32 PDT 2024
https://github.com/zyn0217 updated https://github.com/llvm/llvm-project/pull/94889
>From 217c00f47aaa65b113d1c1cfd93a9c4e1d235c1a Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Sun, 9 Jun 2024 11:49:18 +0800
Subject: [PATCH 1/8] [Clang] Fix two issues of CTAD for aggregates
---
clang/lib/Sema/SemaInit.cpp | 56 +++++++++++++++------
clang/test/SemaTemplate/deduction-guide.cpp | 19 +++++++
2 files changed, 60 insertions(+), 15 deletions(-)
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 79bdc8e9f8783..de2ea639bbba8 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -313,6 +313,8 @@ class InitListChecker {
InitListExpr *FullyStructuredList = nullptr;
NoInitExpr *DummyExpr = nullptr;
SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr;
+ SmallVectorImpl<QualType>
+ *AggrDeductionCandidateParamTypesWithoutBraceElision = nullptr;
NoInitExpr *getDummyInit() {
if (!DummyExpr)
@@ -506,14 +508,19 @@ class InitListChecker {
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid,
bool InOverloadResolution = false,
- SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr);
+ SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr,
+ SmallVectorImpl<QualType>
+ *AggrDeductionCandidateParamTypesWithoutBraceElision = nullptr);
InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
QualType &T,
- SmallVectorImpl<QualType> &AggrDeductionCandidateParamTypes)
+ SmallVectorImpl<QualType> &AggrDeductionCandidateParamTypes,
+ SmallVectorImpl<QualType>
+ &AggrDeductionCandidateParamTypesWithoutBraceElision)
: InitListChecker(S, Entity, IL, T, /*VerifyOnly=*/true,
/*TreatUnavailableAsInvalid=*/false,
/*InOverloadResolution=*/false,
- &AggrDeductionCandidateParamTypes){};
+ &AggrDeductionCandidateParamTypes,
+ &AggrDeductionCandidateParamTypesWithoutBraceElision) {}
bool HadError() { return hadError; }
@@ -982,11 +989,15 @@ static bool hasAnyDesignatedInits(const InitListExpr *IL) {
InitListChecker::InitListChecker(
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid, bool InOverloadResolution,
- SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes)
+ SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes,
+ SmallVectorImpl<QualType>
+ *AggrDeductionCandidateParamTypesWithoutBraceElision)
: SemaRef(S), VerifyOnly(VerifyOnly),
TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
InOverloadResolution(InOverloadResolution),
- AggrDeductionCandidateParamTypes(AggrDeductionCandidateParamTypes) {
+ AggrDeductionCandidateParamTypes(AggrDeductionCandidateParamTypes),
+ AggrDeductionCandidateParamTypesWithoutBraceElision(
+ AggrDeductionCandidateParamTypesWithoutBraceElision) {
if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
FullyStructuredList =
createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
@@ -1448,13 +1459,17 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
// brace elision is not considered for any aggregate element that has a
// dependent non-array type or an array type with a value-dependent
// bound
- assert(AggrDeductionCandidateParamTypes);
- if (!isa_and_nonnull<ConstantArrayType>(
+ assert(AggrDeductionCandidateParamTypes &&
+ AggrDeductionCandidateParamTypesWithoutBraceElision);
+ if (!isa_and_present<ConstantArrayType>(
SemaRef.Context.getAsArrayType(ElemType))) {
++Index;
AggrDeductionCandidateParamTypes->push_back(ElemType);
return;
}
+ // For array types with known bounds, we still want the brace version even
+ // though the braces can be elided.
+ AggrDeductionCandidateParamTypesWithoutBraceElision->push_back(ElemType);
} else {
InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
/*TopLevelOfInitList*/ true);
@@ -10918,22 +10933,24 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
if (!(RD->getDefinition() && RD->isAggregate()))
return;
QualType Ty = Context.getRecordType(RD);
- SmallVector<QualType, 8> ElementTypes;
-
- InitListChecker CheckInitList(*this, Entity, ListInit, Ty, ElementTypes);
- if (!CheckInitList.HadError()) {
+ auto BuildAggregateDeductionGuide = [&](MutableArrayRef<QualType>
+ ElementTypes,
+ bool BracedVersion = false) {
+ if (ElementTypes.empty())
+ return;
// C++ [over.match.class.deduct]p1.8:
// if e_i is of array type and x_i is a braced-init-list, T_i is an
// rvalue reference to the declared type of e_i and
// C++ [over.match.class.deduct]p1.9:
- // if e_i is of array type and x_i is a bstring-literal, T_i is an
+ // if e_i is of array type and x_i is a string-literal, T_i is an
// lvalue reference to the const-qualified declared type of e_i and
// C++ [over.match.class.deduct]p1.10:
// otherwise, T_i is the declared type of e_i
- for (int I = 0, E = ListInit->getNumInits();
+ for (int I = 0, E = BracedVersion ? ElementTypes.size()
+ : ListInit->getNumInits();
I < E && !isa<PackExpansionType>(ElementTypes[I]); ++I)
if (ElementTypes[I]->isArrayType()) {
- if (isa<InitListExpr>(ListInit->getInit(I)))
+ if (isa<InitListExpr, DesignatedInitExpr>(ListInit->getInit(I)))
ElementTypes[I] = Context.getRValueReferenceType(ElementTypes[I]);
else if (isa<StringLiteral>(
ListInit->getInit(I)->IgnoreParenImpCasts()))
@@ -10951,7 +10968,16 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
/*AllowAggregateDeductionCandidate=*/true);
HasAnyDeductionGuide = true;
}
- }
+ };
+ SmallVector<QualType, 8> ElementTypes, ElementTypesWithoutBraceElision;
+
+ InitListChecker CheckInitList(*this, Entity, ListInit, Ty, ElementTypes,
+ ElementTypesWithoutBraceElision);
+ if (CheckInitList.HadError())
+ return;
+ BuildAggregateDeductionGuide(ElementTypes);
+ BuildAggregateDeductionGuide(ElementTypesWithoutBraceElision,
+ /*BracedVersion=*/true);
};
for (auto I = Guides.begin(), E = Guides.end(); I != E; ++I) {
diff --git a/clang/test/SemaTemplate/deduction-guide.cpp b/clang/test/SemaTemplate/deduction-guide.cpp
index 758ca14e4b1c3..a72b2f0de1a58 100644
--- a/clang/test/SemaTemplate/deduction-guide.cpp
+++ b/clang/test/SemaTemplate/deduction-guide.cpp
@@ -335,3 +335,22 @@ namespace TTP {
// CHECK-NEXT: `-TemplateArgument type 'T':'type-parameter-0-0'{{$}}
// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0{{$}}
// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'T'{{$}}
+
+namespace GH83368 {
+
+template <int N> struct A {
+ int f1[N];
+};
+
+A a{.f1 = {1}};
+
+} // namespace GH83368
+
+namespace GH64625 {
+template <class T> struct X {
+ T t[2];
+};
+
+X x = {{1, 2}};
+
+} // namespace GH64625
>From 6c723e85d59317cf415b8aa96fc7327772078391 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Mon, 10 Jun 2024 11:49:56 +0800
Subject: [PATCH 2/8] Release notes & AST verification.
---
clang/docs/ReleaseNotes.rst | 1 +
clang/test/SemaTemplate/deduction-guide.cpp | 69 ++++++++++++++++++---
2 files changed, 61 insertions(+), 9 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0c700d23257bf..e5efcae2289c6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -823,6 +823,7 @@ Bug Fixes to C++ Support
differering by their constraints when only one of these function was variadic.
- Fix a crash when a variable is captured by a block nested inside a lambda. (Fixes #GH93625).
- Fixed a type constraint substitution issue involving a generic lambda expression. (#GH93821)
+- Fixed two issues when building CTAD deduction guides for aggregates. (#GH64625), (#GH83368).
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/test/SemaTemplate/deduction-guide.cpp b/clang/test/SemaTemplate/deduction-guide.cpp
index a72b2f0de1a58..1cce455d966df 100644
--- a/clang/test/SemaTemplate/deduction-guide.cpp
+++ b/clang/test/SemaTemplate/deduction-guide.cpp
@@ -336,6 +336,50 @@ namespace TTP {
// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0{{$}}
// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'T'{{$}}
+namespace GH64625 {
+
+template <class T> struct X {
+ T t[2];
+};
+
+X x = {{1, 2}}, y = {1, 2};
+
+// CHECK-LABEL: Dumping GH64625::<deduction guide for X>:
+// CHECK-NEXT: FunctionTemplateDecl {{.+}} <{{.+}}:[[#@LINE - 7]]:1, col:27> col:27 implicit <deduction guide for X>
+// CHECK-NEXT: |-TemplateTypeParmDecl {{.+}} <col:11, col:17> col:17 referenced class depth 0 index 0 T
+// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:27> col:27 implicit <deduction guide for X> 'auto (T (&&)[2]) -> X<T>' aggregate
+// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:27> col:27 'T (&&)[2]'
+// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:27> col:27 implicit used <deduction guide for X> 'auto (int (&&)[2]) -> GH64625::X<int>' implicit_instantiation aggregate
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:27> col:27 'int (&&)[2]'
+// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (T (&&)[2]) -> X<T>' dependent trailing_return
+// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'X<T>' dependent
+// CHECK-NEXT: | `-CXXRecord {{.+}} 'X'
+// CHECK-NEXT: `-RValueReferenceType {{.+}} 'T (&&)[2]' dependent
+// CHECK-NEXT: `-ConstantArrayType {{.+}} 'T[2]' dependent 2
+// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'T'
+
+// Brace-elision version:
+// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:27> col:27 implicit <deduction guide for X> 'auto (T, T) -> X<T>' aggregate
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:27> col:27 'T'
+// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:27> col:27 'T'
+// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:27> col:27 implicit used <deduction guide for X> 'auto (int, int) -> GH64625::X<int>' implicit_instantiation aggregate
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:27> col:27 'int'
+// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:27> col:27 'int'
+// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (T, T) -> X<T>' dependent trailing_return
+// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'X<T>' dependent
+// CHECK-NEXT: | `-CXXRecord {{.+}} 'X'
+// CHECK-NEXT: |-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'T'
+// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'T'
+
+} // namespace GH64625
+
namespace GH83368 {
template <int N> struct A {
@@ -344,13 +388,20 @@ template <int N> struct A {
A a{.f1 = {1}};
-} // namespace GH83368
+// CHECK-LABEL: Dumping GH83368::<deduction guide for A>:
+// CHECK-NEXT: FunctionTemplateDecl 0x{{.+}} <{{.+}}:[[#@LINE - 7]]:1, col:25> col:25 implicit <deduction guide for A>
+// CHECK-NEXT: |-NonTypeTemplateParmDecl {{.+}} <col:11, col:15> col:15 referenced 'int' depth 0 index 0 N
+// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:25> col:25 implicit <deduction guide for A> 'auto (int (&&)[N]) -> A<N>' aggregate
+// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:25> col:25 'int (&&)[N]'
+// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:25> col:25 implicit used <deduction guide for A> 'auto (int (&&)[1]) -> GH83368::A<1>' implicit_instantiation aggregate
+// CHECK-NEXT: |-TemplateArgument integral '1'
+// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:25> col:25 'int (&&)[1]'
+// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (int (&&)[N]) -> A<N>' dependent trailing_return
+// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'A<N>' dependent
+// CHECK-NEXT: | `-CXXRecord {{.+}} 'A'
+// CHECK-NEXT: `-RValueReferenceType {{.+}} 'int (&&)[N]' dependent
+// CHECK-NEXT: `-DependentSizedArrayType {{.+}} 'int[N]' dependent
+// CHECK-NEXT: |-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: `-DeclRefExpr {{.+}} <col:10> 'int' NonTypeTemplateParm {{.+}} 'N' 'int'
-namespace GH64625 {
-template <class T> struct X {
- T t[2];
-};
-
-X x = {{1, 2}};
-
-} // namespace GH64625
+} // namespace GH83368
>From da3df4040f5810916f1b12054f569959158cb6a1 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Mon, 10 Jun 2024 23:07:18 +0800
Subject: [PATCH 3/8] Apply Corentin's feedback
---
clang/docs/ReleaseNotes.rst | 2 +-
clang/lib/Sema/SemaInit.cpp | 103 ++++++++++++++++++++----------------
2 files changed, 59 insertions(+), 46 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index e5efcae2289c6..b8712a60a37c1 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -823,7 +823,7 @@ Bug Fixes to C++ Support
differering by their constraints when only one of these function was variadic.
- Fix a crash when a variable is captured by a block nested inside a lambda. (Fixes #GH93625).
- Fixed a type constraint substitution issue involving a generic lambda expression. (#GH93821)
-- Fixed two issues when building CTAD deduction guides for aggregates. (#GH64625), (#GH83368).
+- Fixed handling of brace ellison when building deduction guides. (#GH64625), (#GH83368).
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index de2ea639bbba8..c47c2b3533920 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -305,6 +305,24 @@ namespace {
/// structured list even in 'verify only' mode, so that we can track which
/// elements need 'empty' initializtion.
class InitListChecker {
+public:
+ struct CandidateParamTypesForAggregateDeduction {
+ /// Pointer to a container that would hold the parameter types of a
+ /// deduction guide for an aggregate.
+ SmallVectorImpl<QualType> *ParamTypes;
+ /// Pointer to a container that would hold the parameter types of a
+ /// deduction guide for an aggregate as if the brace elision were not
+ /// applied.
+ SmallVectorImpl<QualType> *ParamTypesWithoutBraceElision;
+
+ CandidateParamTypesForAggregateDeduction(
+ SmallVectorImpl<QualType> *ParamTypes = nullptr,
+ SmallVectorImpl<QualType> *ParamTypesWithoutBraceElision = nullptr)
+ : ParamTypes(ParamTypes),
+ ParamTypesWithoutBraceElision(ParamTypesWithoutBraceElision) {}
+ };
+
+private:
Sema &SemaRef;
bool hadError = false;
bool VerifyOnly; // No diagnostics.
@@ -312,9 +330,7 @@ class InitListChecker {
bool InOverloadResolution;
InitListExpr *FullyStructuredList = nullptr;
NoInitExpr *DummyExpr = nullptr;
- SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr;
- SmallVectorImpl<QualType>
- *AggrDeductionCandidateParamTypesWithoutBraceElision = nullptr;
+ CandidateParamTypesForAggregateDeduction ParamTypesForAggregateDeduction;
NoInitExpr *getDummyInit() {
if (!DummyExpr)
@@ -508,19 +524,16 @@ class InitListChecker {
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid,
bool InOverloadResolution = false,
- SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr,
- SmallVectorImpl<QualType>
- *AggrDeductionCandidateParamTypesWithoutBraceElision = nullptr);
- InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
- QualType &T,
- SmallVectorImpl<QualType> &AggrDeductionCandidateParamTypes,
- SmallVectorImpl<QualType>
- &AggrDeductionCandidateParamTypesWithoutBraceElision)
+ CandidateParamTypesForAggregateDeduction ParamTypesForAggregateDeduction =
+ CandidateParamTypesForAggregateDeduction());
+ InitListChecker(
+ Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
+ CandidateParamTypesForAggregateDeduction ParamTypesForAggregateDeduction)
: InitListChecker(S, Entity, IL, T, /*VerifyOnly=*/true,
/*TreatUnavailableAsInvalid=*/false,
/*InOverloadResolution=*/false,
- &AggrDeductionCandidateParamTypes,
- &AggrDeductionCandidateParamTypesWithoutBraceElision) {}
+ /*ParamTypesForAggregateDeduction=*/
+ std::move(ParamTypesForAggregateDeduction)) {}
bool HadError() { return hadError; }
@@ -989,15 +1002,11 @@ static bool hasAnyDesignatedInits(const InitListExpr *IL) {
InitListChecker::InitListChecker(
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid, bool InOverloadResolution,
- SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes,
- SmallVectorImpl<QualType>
- *AggrDeductionCandidateParamTypesWithoutBraceElision)
+ CandidateParamTypesForAggregateDeduction ParamsForDeduction)
: SemaRef(S), VerifyOnly(VerifyOnly),
TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
InOverloadResolution(InOverloadResolution),
- AggrDeductionCandidateParamTypes(AggrDeductionCandidateParamTypes),
- AggrDeductionCandidateParamTypesWithoutBraceElision(
- AggrDeductionCandidateParamTypesWithoutBraceElision) {
+ ParamTypesForAggregateDeduction(std::move(ParamsForDeduction)) {
if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
FullyStructuredList =
createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
@@ -1011,7 +1020,7 @@ InitListChecker::InitListChecker(
CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
/*TopLevelObject=*/true);
- if (!hadError && !AggrDeductionCandidateParamTypes && FullyStructuredList) {
+ if (!hadError && !ParamsForDeduction.ParamTypes && FullyStructuredList) {
bool RequiresSecondPass = false;
FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
/*OuterILE=*/nullptr, /*OuterIndex=*/0);
@@ -1395,8 +1404,8 @@ void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
// brace elision is not considered for any aggregate element that has a
// dependent non-array type or an array type with a value-dependent bound
++Index;
- assert(AggrDeductionCandidateParamTypes);
- AggrDeductionCandidateParamTypes->push_back(DeclType);
+ assert(ParamTypesForAggregateDeduction.ParamTypes);
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
} else {
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
@@ -1459,17 +1468,18 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
// brace elision is not considered for any aggregate element that has a
// dependent non-array type or an array type with a value-dependent
// bound
- assert(AggrDeductionCandidateParamTypes &&
- AggrDeductionCandidateParamTypesWithoutBraceElision);
+ assert(ParamTypesForAggregateDeduction.ParamTypes &&
+ ParamTypesForAggregateDeduction.ParamTypesWithoutBraceElision);
if (!isa_and_present<ConstantArrayType>(
SemaRef.Context.getAsArrayType(ElemType))) {
++Index;
- AggrDeductionCandidateParamTypes->push_back(ElemType);
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(ElemType);
return;
}
- // For array types with known bounds, we still want the brace version even
- // though the braces can be elided.
- AggrDeductionCandidateParamTypesWithoutBraceElision->push_back(ElemType);
+ // For array types with known bounds, we still want a deduction guide for
+ // the brace initializer even though the brace can be elided.
+ ParamTypesForAggregateDeduction.ParamTypesWithoutBraceElision->push_back(
+ ElemType);
} else {
InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
/*TopLevelOfInitList*/ true);
@@ -1494,8 +1504,8 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
getDummyInit());
}
++Index;
- if (AggrDeductionCandidateParamTypes)
- AggrDeductionCandidateParamTypes->push_back(ElemType);
+ if (ParamTypesForAggregateDeduction.ParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(ElemType);
return;
}
}
@@ -1715,8 +1725,8 @@ void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
- if (AggrDeductionCandidateParamTypes)
- AggrDeductionCandidateParamTypes->push_back(DeclType);
+ if (ParamTypesForAggregateDeduction.ParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
}
void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
@@ -1772,8 +1782,8 @@ void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
- if (AggrDeductionCandidateParamTypes)
- AggrDeductionCandidateParamTypes->push_back(DeclType);
+ if (ParamTypesForAggregateDeduction.ParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
}
void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
@@ -1825,8 +1835,8 @@ void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
- if (AggrDeductionCandidateParamTypes)
- AggrDeductionCandidateParamTypes->push_back(elementType);
+ if (ParamTypesForAggregateDeduction.ParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(elementType);
return;
}
@@ -1990,8 +2000,8 @@ void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
}
++Index;
- if (AggrDeductionCandidateParamTypes)
- AggrDeductionCandidateParamTypes->push_back(DeclType);
+ if (ParamTypesForAggregateDeduction.ParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
return;
}
}
@@ -2229,8 +2239,8 @@ void InitListChecker::CheckStructUnionTypes(
// trailing sequence of parameters corresponding to a trailing
// aggregate element that is a pack expansion (if any) is replaced
// by a single parameter of the form T_n....
- if (AggrDeductionCandidateParamTypes && Base.isPackExpansion()) {
- AggrDeductionCandidateParamTypes->push_back(
+ if (ParamTypesForAggregateDeduction.ParamTypes && Base.isPackExpansion()) {
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(
SemaRef.Context.getPackExpansionType(Base.getType(), std::nullopt));
// Trailing pack expansion
@@ -2467,7 +2477,7 @@ void InitListChecker::CheckStructUnionTypes(
InitializedEntity::InitializeMember(*Field, &Entity);
if (isa<InitListExpr>(IList->getInit(Index)) ||
- AggrDeductionCandidateParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes)
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
else
@@ -2619,8 +2629,9 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
Result.get());
}
++Index;
- if (AggrDeductionCandidateParamTypes)
- AggrDeductionCandidateParamTypes->push_back(CurrentObjectType);
+ if (ParamTypesForAggregateDeduction.ParamTypes)
+ ParamTypesForAggregateDeduction.ParamTypes->push_back(
+ CurrentObjectType);
return !Seq;
}
@@ -10971,8 +10982,10 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
};
SmallVector<QualType, 8> ElementTypes, ElementTypesWithoutBraceElision;
- InitListChecker CheckInitList(*this, Entity, ListInit, Ty, ElementTypes,
- ElementTypesWithoutBraceElision);
+ InitListChecker CheckInitList(
+ *this, Entity, ListInit, Ty,
+ InitListChecker::CandidateParamTypesForAggregateDeduction(
+ &ElementTypes, &ElementTypesWithoutBraceElision));
if (CheckInitList.HadError())
return;
BuildAggregateDeductionGuide(ElementTypes);
>From c644f1089b083119c303eaae4f7962171bb767af Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Tue, 11 Jun 2024 23:28:22 +0800
Subject: [PATCH 4/8] Fix handling of two or more aggregates
---
clang/lib/Sema/SemaInit.cpp | 116 ++++++++++----------
clang/test/SemaTemplate/deduction-guide.cpp | 49 ++++++---
2 files changed, 87 insertions(+), 78 deletions(-)
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index c47c2b3533920..8cfc541164494 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -305,32 +305,16 @@ namespace {
/// structured list even in 'verify only' mode, so that we can track which
/// elements need 'empty' initializtion.
class InitListChecker {
-public:
- struct CandidateParamTypesForAggregateDeduction {
- /// Pointer to a container that would hold the parameter types of a
- /// deduction guide for an aggregate.
- SmallVectorImpl<QualType> *ParamTypes;
- /// Pointer to a container that would hold the parameter types of a
- /// deduction guide for an aggregate as if the brace elision were not
- /// applied.
- SmallVectorImpl<QualType> *ParamTypesWithoutBraceElision;
-
- CandidateParamTypesForAggregateDeduction(
- SmallVectorImpl<QualType> *ParamTypes = nullptr,
- SmallVectorImpl<QualType> *ParamTypesWithoutBraceElision = nullptr)
- : ParamTypes(ParamTypes),
- ParamTypesWithoutBraceElision(ParamTypesWithoutBraceElision) {}
- };
-
-private:
Sema &SemaRef;
bool hadError = false;
bool VerifyOnly; // No diagnostics.
bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
bool InOverloadResolution;
+ bool BraceElisionOccurredForDeductionGuides = false;
+ bool NoBraceElisionForDeductionGuides;
InitListExpr *FullyStructuredList = nullptr;
NoInitExpr *DummyExpr = nullptr;
- CandidateParamTypesForAggregateDeduction ParamTypesForAggregateDeduction;
+ SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr;
NoInitExpr *getDummyInit() {
if (!DummyExpr)
@@ -524,22 +508,26 @@ class InitListChecker {
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid,
bool InOverloadResolution = false,
- CandidateParamTypesForAggregateDeduction ParamTypesForAggregateDeduction =
- CandidateParamTypesForAggregateDeduction());
- InitListChecker(
- Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
- CandidateParamTypesForAggregateDeduction ParamTypesForAggregateDeduction)
+ bool NoBraceElisionForDeductionGuides = false,
+ SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr);
+ InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
+ QualType &T, bool NoBraceElisionForDeductionGuides,
+ SmallVectorImpl<QualType> &AggrDeductionCandidateParamTypes)
: InitListChecker(S, Entity, IL, T, /*VerifyOnly=*/true,
/*TreatUnavailableAsInvalid=*/false,
/*InOverloadResolution=*/false,
- /*ParamTypesForAggregateDeduction=*/
- std::move(ParamTypesForAggregateDeduction)) {}
+ NoBraceElisionForDeductionGuides,
+ &AggrDeductionCandidateParamTypes) {}
bool HadError() { return hadError; }
// Retrieves the fully-structured initializer list used for
// semantic analysis and code generation.
InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
+
+ bool HadBraceElisionOccurredForDeductionGuides() const {
+ return BraceElisionOccurredForDeductionGuides;
+ }
};
} // end anonymous namespace
@@ -1002,11 +990,13 @@ static bool hasAnyDesignatedInits(const InitListExpr *IL) {
InitListChecker::InitListChecker(
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid, bool InOverloadResolution,
- CandidateParamTypesForAggregateDeduction ParamsForDeduction)
+ bool NoBraceElisionForDeductionGuides,
+ SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes)
: SemaRef(S), VerifyOnly(VerifyOnly),
TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
InOverloadResolution(InOverloadResolution),
- ParamTypesForAggregateDeduction(std::move(ParamsForDeduction)) {
+ NoBraceElisionForDeductionGuides(NoBraceElisionForDeductionGuides),
+ AggrDeductionCandidateParamTypes(AggrDeductionCandidateParamTypes) {
if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
FullyStructuredList =
createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
@@ -1020,7 +1010,7 @@ InitListChecker::InitListChecker(
CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
/*TopLevelObject=*/true);
- if (!hadError && !ParamsForDeduction.ParamTypes && FullyStructuredList) {
+ if (!hadError && !AggrDeductionCandidateParamTypes && FullyStructuredList) {
bool RequiresSecondPass = false;
FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
/*OuterILE=*/nullptr, /*OuterIndex=*/0);
@@ -1404,8 +1394,8 @@ void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
// brace elision is not considered for any aggregate element that has a
// dependent non-array type or an array type with a value-dependent bound
++Index;
- assert(ParamTypesForAggregateDeduction.ParamTypes);
- ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
+ assert(AggrDeductionCandidateParamTypes);
+ AggrDeductionCandidateParamTypes->push_back(DeclType);
} else {
if (!VerifyOnly)
SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
@@ -1468,18 +1458,15 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
// brace elision is not considered for any aggregate element that has a
// dependent non-array type or an array type with a value-dependent
// bound
- assert(ParamTypesForAggregateDeduction.ParamTypes &&
- ParamTypesForAggregateDeduction.ParamTypesWithoutBraceElision);
+ assert(AggrDeductionCandidateParamTypes);
if (!isa_and_present<ConstantArrayType>(
- SemaRef.Context.getAsArrayType(ElemType))) {
+ SemaRef.Context.getAsArrayType(ElemType)) ||
+ NoBraceElisionForDeductionGuides) {
++Index;
- ParamTypesForAggregateDeduction.ParamTypes->push_back(ElemType);
+ AggrDeductionCandidateParamTypes->push_back(ElemType);
return;
}
- // For array types with known bounds, we still want a deduction guide for
- // the brace initializer even though the brace can be elided.
- ParamTypesForAggregateDeduction.ParamTypesWithoutBraceElision->push_back(
- ElemType);
+ BraceElisionOccurredForDeductionGuides = true;
} else {
InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
/*TopLevelOfInitList*/ true);
@@ -1504,8 +1491,8 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
getDummyInit());
}
++Index;
- if (ParamTypesForAggregateDeduction.ParamTypes)
- ParamTypesForAggregateDeduction.ParamTypes->push_back(ElemType);
+ if (AggrDeductionCandidateParamTypes)
+ AggrDeductionCandidateParamTypes->push_back(ElemType);
return;
}
}
@@ -1725,8 +1712,8 @@ void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
- if (ParamTypesForAggregateDeduction.ParamTypes)
- ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
+ if (AggrDeductionCandidateParamTypes)
+ AggrDeductionCandidateParamTypes->push_back(DeclType);
}
void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
@@ -1782,8 +1769,8 @@ void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
- if (ParamTypesForAggregateDeduction.ParamTypes)
- ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
+ if (AggrDeductionCandidateParamTypes)
+ AggrDeductionCandidateParamTypes->push_back(DeclType);
}
void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
@@ -1835,8 +1822,8 @@ void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
- if (ParamTypesForAggregateDeduction.ParamTypes)
- ParamTypesForAggregateDeduction.ParamTypes->push_back(elementType);
+ if (AggrDeductionCandidateParamTypes)
+ AggrDeductionCandidateParamTypes->push_back(elementType);
return;
}
@@ -2000,8 +1987,8 @@ void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
}
++Index;
- if (ParamTypesForAggregateDeduction.ParamTypes)
- ParamTypesForAggregateDeduction.ParamTypes->push_back(DeclType);
+ if (AggrDeductionCandidateParamTypes)
+ AggrDeductionCandidateParamTypes->push_back(DeclType);
return;
}
}
@@ -2239,8 +2226,8 @@ void InitListChecker::CheckStructUnionTypes(
// trailing sequence of parameters corresponding to a trailing
// aggregate element that is a pack expansion (if any) is replaced
// by a single parameter of the form T_n....
- if (ParamTypesForAggregateDeduction.ParamTypes && Base.isPackExpansion()) {
- ParamTypesForAggregateDeduction.ParamTypes->push_back(
+ if (AggrDeductionCandidateParamTypes && Base.isPackExpansion()) {
+ AggrDeductionCandidateParamTypes->push_back(
SemaRef.Context.getPackExpansionType(Base.getType(), std::nullopt));
// Trailing pack expansion
@@ -2477,7 +2464,7 @@ void InitListChecker::CheckStructUnionTypes(
InitializedEntity::InitializeMember(*Field, &Entity);
if (isa<InitListExpr>(IList->getInit(Index)) ||
- ParamTypesForAggregateDeduction.ParamTypes)
+ AggrDeductionCandidateParamTypes)
CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
StructuredList, StructuredIndex);
else
@@ -2629,9 +2616,8 @@ InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
Result.get());
}
++Index;
- if (ParamTypesForAggregateDeduction.ParamTypes)
- ParamTypesForAggregateDeduction.ParamTypes->push_back(
- CurrentObjectType);
+ if (AggrDeductionCandidateParamTypes)
+ AggrDeductionCandidateParamTypes->push_back(CurrentObjectType);
return !Seq;
}
@@ -10982,15 +10968,23 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
};
SmallVector<QualType, 8> ElementTypes, ElementTypesWithoutBraceElision;
- InitListChecker CheckInitList(
- *this, Entity, ListInit, Ty,
- InitListChecker::CandidateParamTypesForAggregateDeduction(
- &ElementTypes, &ElementTypesWithoutBraceElision));
+ InitListChecker CheckInitList(*this, Entity, ListInit, Ty,
+ /*NoBraceElisionForDeductionGuides=*/false,
+ ElementTypes);
if (CheckInitList.HadError())
return;
BuildAggregateDeductionGuide(ElementTypes);
- BuildAggregateDeductionGuide(ElementTypesWithoutBraceElision,
- /*BracedVersion=*/true);
+ if (CheckInitList.HadBraceElisionOccurredForDeductionGuides()) {
+ // We still want a deduction guide for the brace initializer even though
+ // the brace can be elided.
+ InitListChecker CheckInitList(*this, Entity, ListInit, Ty,
+ /*NoBraceElisionForDeductionGuides=*/true,
+ ElementTypesWithoutBraceElision);
+ if (CheckInitList.HadError())
+ return;
+ BuildAggregateDeductionGuide(ElementTypesWithoutBraceElision,
+ /*BracedVersion=*/true);
+ }
};
for (auto I = Guides.begin(), E = Guides.end(); I != E; ++I) {
diff --git a/clang/test/SemaTemplate/deduction-guide.cpp b/clang/test/SemaTemplate/deduction-guide.cpp
index 1cce455d966df..735ea258ae163 100644
--- a/clang/test/SemaTemplate/deduction-guide.cpp
+++ b/clang/test/SemaTemplate/deduction-guide.cpp
@@ -342,7 +342,7 @@ template <class T> struct X {
T t[2];
};
-X x = {{1, 2}}, y = {1, 2};
+X x = {{1, 2}};
// CHECK-LABEL: Dumping GH64625::<deduction guide for X>:
// CHECK-NEXT: FunctionTemplateDecl {{.+}} <{{.+}}:[[#@LINE - 7]]:1, col:27> col:27 implicit <deduction guide for X>
@@ -361,22 +361,37 @@ X x = {{1, 2}}, y = {1, 2};
// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'T'
-// Brace-elision version:
-// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:27> col:27 implicit <deduction guide for X> 'auto (T, T) -> X<T>' aggregate
-// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:27> col:27 'T'
-// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:27> col:27 'T'
-// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:27> col:27 implicit used <deduction guide for X> 'auto (int, int) -> GH64625::X<int>' implicit_instantiation aggregate
-// CHECK-NEXT: |-TemplateArgument type 'int'
-// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
-// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:27> col:27 'int'
-// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:27> col:27 'int'
-// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (T, T) -> X<T>' dependent trailing_return
-// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'X<T>' dependent
-// CHECK-NEXT: | `-CXXRecord {{.+}} 'X'
-// CHECK-NEXT: |-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
-// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'T'
-// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
-// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'T'
+template <class T, class U> struct TwoArrays {
+ T t[2];
+ U u[3];
+};
+
+TwoArrays ta = {{1, 2}, {3, 4, 5}};
+// CHECK-LABEL: Dumping GH64625::<deduction guide for TwoArrays>:
+// CHECK-NEXT: FunctionTemplateDecl {{.+}} <{{.+}}:[[#@LINE - 7]]:1, col:36> col:36 implicit <deduction guide for TwoArrays>
+// CHECK-NEXT: |-TemplateTypeParmDecl {{.+}} <col:11, col:17> col:17 referenced class depth 0 index 0 T
+// CHECK-NEXT: |-TemplateTypeParmDecl {{.+}} <col:20, col:26> col:26 referenced class depth 0 index 1 U
+// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:36> col:36 implicit <deduction guide for TwoArrays> 'auto (T (&&)[2], U (&&)[3]) -> TwoArrays<T, U>' aggregate
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:36> col:36 'T (&&)[2]'
+// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:36> col:36 'U (&&)[3]'
+// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:36> col:36 implicit used <deduction guide for TwoArrays> 'auto (int (&&)[2], int (&&)[3]) -> GH64625::TwoArrays<int, int>' implicit_instantiation aggregate
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:36> col:36 'int (&&)[2]'
+// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:36> col:36 'int (&&)[3]'
+// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (T (&&)[2], U (&&)[3]) -> TwoArrays<T, U>' dependent trailing_return
+// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'TwoArrays<T, U>' dependent
+// CHECK-NEXT: | `-CXXRecord {{.+}} 'TwoArrays'
+// CHECK-NEXT: |-RValueReferenceType {{.+}} 'T (&&)[2]' dependent
+// CHECK-NEXT: | `-ConstantArrayType {{.+}} 'T[2]' dependent 2
+// CHECK-NEXT: | `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'T'
+// CHECK-NEXT: `-RValueReferenceType {{.+}} 'U (&&)[3]' dependent
+// CHECK-NEXT: `-ConstantArrayType {{.+}} 'U[3]' dependent 3
+// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'U' dependent depth 0 index 1
+// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'U'
} // namespace GH64625
>From 16cf879782d8dd7b6326fb60409d4b00ae9e8ba8 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Wed, 12 Jun 2024 14:43:19 +0800
Subject: [PATCH 5/8] Simplify the whole things
---
clang/lib/Sema/SemaInit.cpp | 52 +++++---------------
clang/test/SemaTemplate/deduction-guide.cpp | 54 +++++++++++++++++++++
2 files changed, 65 insertions(+), 41 deletions(-)
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 8cfc541164494..ee8befbdea1eb 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -310,8 +310,6 @@ class InitListChecker {
bool VerifyOnly; // No diagnostics.
bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
bool InOverloadResolution;
- bool BraceElisionOccurredForDeductionGuides = false;
- bool NoBraceElisionForDeductionGuides;
InitListExpr *FullyStructuredList = nullptr;
NoInitExpr *DummyExpr = nullptr;
SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr;
@@ -508,15 +506,13 @@ class InitListChecker {
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid,
bool InOverloadResolution = false,
- bool NoBraceElisionForDeductionGuides = false,
SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes = nullptr);
InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
- QualType &T, bool NoBraceElisionForDeductionGuides,
+ QualType &T,
SmallVectorImpl<QualType> &AggrDeductionCandidateParamTypes)
: InitListChecker(S, Entity, IL, T, /*VerifyOnly=*/true,
/*TreatUnavailableAsInvalid=*/false,
/*InOverloadResolution=*/false,
- NoBraceElisionForDeductionGuides,
&AggrDeductionCandidateParamTypes) {}
bool HadError() { return hadError; }
@@ -524,10 +520,6 @@ class InitListChecker {
// Retrieves the fully-structured initializer list used for
// semantic analysis and code generation.
InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
-
- bool HadBraceElisionOccurredForDeductionGuides() const {
- return BraceElisionOccurredForDeductionGuides;
- }
};
} // end anonymous namespace
@@ -990,12 +982,10 @@ static bool hasAnyDesignatedInits(const InitListExpr *IL) {
InitListChecker::InitListChecker(
Sema &S, const InitializedEntity &Entity, InitListExpr *IL, QualType &T,
bool VerifyOnly, bool TreatUnavailableAsInvalid, bool InOverloadResolution,
- bool NoBraceElisionForDeductionGuides,
SmallVectorImpl<QualType> *AggrDeductionCandidateParamTypes)
: SemaRef(S), VerifyOnly(VerifyOnly),
TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
InOverloadResolution(InOverloadResolution),
- NoBraceElisionForDeductionGuides(NoBraceElisionForDeductionGuides),
AggrDeductionCandidateParamTypes(AggrDeductionCandidateParamTypes) {
if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
FullyStructuredList =
@@ -1459,14 +1449,15 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
// dependent non-array type or an array type with a value-dependent
// bound
assert(AggrDeductionCandidateParamTypes);
- if (!isa_and_present<ConstantArrayType>(
- SemaRef.Context.getAsArrayType(ElemType)) ||
- NoBraceElisionForDeductionGuides) {
+ // Don't consider the brace elision version if the initializer is in brace
+ // form.
+ if (isa<InitListExpr, DesignatedInitExpr>(expr) ||
+ !isa_and_present<ConstantArrayType>(
+ SemaRef.Context.getAsArrayType(ElemType))) {
++Index;
AggrDeductionCandidateParamTypes->push_back(ElemType);
return;
}
- BraceElisionOccurredForDeductionGuides = true;
} else {
InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
/*TopLevelOfInitList*/ true);
@@ -10930,11 +10921,10 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
if (!(RD->getDefinition() && RD->isAggregate()))
return;
QualType Ty = Context.getRecordType(RD);
- auto BuildAggregateDeductionGuide = [&](MutableArrayRef<QualType>
- ElementTypes,
- bool BracedVersion = false) {
- if (ElementTypes.empty())
- return;
+ SmallVector<QualType, 8> ElementTypes;
+
+ InitListChecker CheckInitList(*this, Entity, ListInit, Ty, ElementTypes);
+ if (!CheckInitList.HadError()) {
// C++ [over.match.class.deduct]p1.8:
// if e_i is of array type and x_i is a braced-init-list, T_i is an
// rvalue reference to the declared type of e_i and
@@ -10943,8 +10933,7 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
// lvalue reference to the const-qualified declared type of e_i and
// C++ [over.match.class.deduct]p1.10:
// otherwise, T_i is the declared type of e_i
- for (int I = 0, E = BracedVersion ? ElementTypes.size()
- : ListInit->getNumInits();
+ for (int I = 0, E = ListInit->getNumInits();
I < E && !isa<PackExpansionType>(ElementTypes[I]); ++I)
if (ElementTypes[I]->isArrayType()) {
if (isa<InitListExpr, DesignatedInitExpr>(ListInit->getInit(I)))
@@ -10965,25 +10954,6 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
/*AllowAggregateDeductionCandidate=*/true);
HasAnyDeductionGuide = true;
}
- };
- SmallVector<QualType, 8> ElementTypes, ElementTypesWithoutBraceElision;
-
- InitListChecker CheckInitList(*this, Entity, ListInit, Ty,
- /*NoBraceElisionForDeductionGuides=*/false,
- ElementTypes);
- if (CheckInitList.HadError())
- return;
- BuildAggregateDeductionGuide(ElementTypes);
- if (CheckInitList.HadBraceElisionOccurredForDeductionGuides()) {
- // We still want a deduction guide for the brace initializer even though
- // the brace can be elided.
- InitListChecker CheckInitList(*this, Entity, ListInit, Ty,
- /*NoBraceElisionForDeductionGuides=*/true,
- ElementTypesWithoutBraceElision);
- if (CheckInitList.HadError())
- return;
- BuildAggregateDeductionGuide(ElementTypesWithoutBraceElision,
- /*BracedVersion=*/true);
}
};
diff --git a/clang/test/SemaTemplate/deduction-guide.cpp b/clang/test/SemaTemplate/deduction-guide.cpp
index 735ea258ae163..41708d8c5c9c1 100644
--- a/clang/test/SemaTemplate/deduction-guide.cpp
+++ b/clang/test/SemaTemplate/deduction-guide.cpp
@@ -393,6 +393,60 @@ TwoArrays ta = {{1, 2}, {3, 4, 5}};
// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'U' dependent depth 0 index 1
// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'U'
+TwoArrays tb = {1, 2, {3, 4, 5}};
+// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:36> col:36 implicit <deduction guide for TwoArrays> 'auto (T, T, U (&&)[3]) -> TwoArrays<T, U>' aggregate
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:36> col:36 'T'
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:36> col:36 'T'
+// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:36> col:36 'U (&&)[3]'
+// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:36> col:36 implicit used <deduction guide for TwoArrays> 'auto (int, int, int (&&)[3]) -> GH64625::TwoArrays<int, int>' implicit_instantiation aggregate
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:36> col:36 'int'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:36> col:36 'int'
+// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:36> col:36 'int (&&)[3]'
+// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (T, T, U (&&)[3]) -> TwoArrays<T, U>' dependent trailing_return
+// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'TwoArrays<T, U>' dependent
+// CHECK-NEXT: | `-CXXRecord {{.+}} 'TwoArrays'
+// CHECK-NEXT: |-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'T'
+// CHECK-NEXT: |-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'T'
+// CHECK-NEXT: `-RValueReferenceType {{.+}} 'U (&&)[3]' dependent
+// CHECK-NEXT: `-ConstantArrayType {{.+}} 'U[3]' dependent 3
+// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'U' dependent depth 0 index 1
+// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'U'
+
+TwoArrays tc = {{1, 2}, 3, 4, 5};
+// CHECK: |-CXXDeductionGuideDecl {{.+}} <col:36> col:36 implicit <deduction guide for TwoArrays> 'auto (T (&&)[2], U, U, U) -> TwoArrays<T, U>' aggregate
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:36> col:36 'T (&&)[2]'
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:36> col:36 'U'
+// CHECK-NEXT: | |-ParmVarDecl {{.+}} <col:36> col:36 'U'
+// CHECK-NEXT: | `-ParmVarDecl {{.+}} <col:36> col:36 'U'
+// CHECK-NEXT: `-CXXDeductionGuideDecl {{.+}} <col:36> col:36 implicit used <deduction guide for TwoArrays> 'auto (int (&&)[2], int, int, int) -> GH64625::TwoArrays<int, int>' implicit_instantiation aggregate
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-TemplateArgument type 'int'
+// CHECK-NEXT: | `-BuiltinType {{.+}} 'int'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:36> col:36 'int (&&)[2]'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:36> col:36 'int'
+// CHECK-NEXT: |-ParmVarDecl {{.+}} <col:36> col:36 'int'
+// CHECK-NEXT: `-ParmVarDecl {{.+}} <col:36> col:36 'int'
+// CHECK-NEXT: FunctionProtoType {{.+}} 'auto (T (&&)[2], U, U, U) -> TwoArrays<T, U>' dependent trailing_return
+// CHECK-NEXT: |-InjectedClassNameType {{.+}} 'TwoArrays<T, U>' dependent
+// CHECK-NEXT: | `-CXXRecord {{.+}} 'TwoArrays'
+// CHECK-NEXT: |-RValueReferenceType {{.+}} 'T (&&)[2]' dependent
+// CHECK-NEXT: | `-ConstantArrayType {{.+}} 'T[2]' dependent 2
+// CHECK-NEXT: | `-TemplateTypeParmType {{.+}} 'T' dependent depth 0 index 0
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'T'
+// CHECK-NEXT: |-TemplateTypeParmType {{.+}} 'U' dependent depth 0 index 1
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'U'
+// CHECK-NEXT: |-TemplateTypeParmType {{.+}} 'U' dependent depth 0 index 1
+// CHECK-NEXT: | `-TemplateTypeParm {{.+}} 'U'
+// CHECK-NEXT: `-TemplateTypeParmType {{.+}} 'U' dependent depth 0 index 1
+// CHECK-NEXT: `-TemplateTypeParm {{.+}} 'U'
+
} // namespace GH64625
namespace GH83368 {
>From b3dd755613bd57b768a05480287f39ab6dd42c4f Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Wed, 12 Jun 2024 14:55:46 +0800
Subject: [PATCH 6/8] Tidy up the comment
---
clang/lib/Sema/SemaInit.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index ee8befbdea1eb..1c6f82a3f6129 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -1449,8 +1449,8 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
// dependent non-array type or an array type with a value-dependent
// bound
assert(AggrDeductionCandidateParamTypes);
- // Don't consider the brace elision version if the initializer is in brace
- // form.
+ // Don't consider the brace elision if the initializer is a
+ // braced-init-list.
if (isa<InitListExpr, DesignatedInitExpr>(expr) ||
!isa_and_present<ConstantArrayType>(
SemaRef.Context.getAsArrayType(ElemType))) {
>From 7a70867c8370a1b6247b6dad8a0378c4770fc329 Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Thu, 13 Jun 2024 11:40:36 +0800
Subject: [PATCH 7/8] Clarify the comments
---
clang/lib/Sema/SemaInit.cpp | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 1c6f82a3f6129..da894fedaf2f1 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -1449,8 +1449,19 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
// dependent non-array type or an array type with a value-dependent
// bound
assert(AggrDeductionCandidateParamTypes);
- // Don't consider the brace elision if the initializer is a
- // braced-init-list.
+
+ // In the presence of a braced-init-list within the initializer, we should
+ // not fall through to the brace-elision logic, even if the brace elision
+ // is applicable. Given the example,
+ //
+ // template <class T> struct Foo {
+ // T t[2];
+ // };
+ //
+ // Foo t = {{1, 2}};
+ //
+ // we don't want the (T, T) but rather (T [2]) in terms of the initializer
+ // {{1, 2}}.
if (isa<InitListExpr, DesignatedInitExpr>(expr) ||
!isa_and_present<ConstantArrayType>(
SemaRef.Context.getAsArrayType(ElemType))) {
>From 1477377241032b8b7a61869545c8e10bb468f1be Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Thu, 13 Jun 2024 16:37:36 +0800
Subject: [PATCH 8/8] Address comments
---
clang/lib/Sema/SemaInit.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index da894fedaf2f1..bafaf3f5d8534 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -1451,8 +1451,8 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
assert(AggrDeductionCandidateParamTypes);
// In the presence of a braced-init-list within the initializer, we should
- // not fall through to the brace-elision logic, even if the brace elision
- // is applicable. Given the example,
+ // not perform brace-elision, even if brace elision would otherwise be
+ // applicable. For example, given:
//
// template <class T> struct Foo {
// T t[2];
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