"Reapply "GH58368: Correct concept checking in a lambda defined in concept""

This reverts commit cecc9a92cfca71c1b6c2a35c5e302ab649496d11.

The problem ended up being how we were handling the lambda-context in
code generation: we were assuming any decl context here would be a
named-decl, but that isn't the case.  Instead, we just replace it with
the concept's owning context.

Differential Revision: https://reviews.llvm.org/D136451

diff --git a/clang/include/clang/AST/ASTNodeTraverser.h b/clang/include/clang/AST/ASTNodeTraverser.h
index 44dc52b..6df3a83 100644 (file)
--- a/clang/include/clang/AST/ASTNodeTraverser.h
+++ b/clang/include/clang/AST/ASTNodeTraverser.h
@@ -623,7 +623,14 @@ public:
     Visit(D->getConstraintExpr());
   }
 
+  void VisitImplicitConceptSpecializationDecl(
+      const ImplicitConceptSpecializationDecl *CSD) {
+    for (const TemplateArgument &Arg : CSD->getTemplateArguments())
+      Visit(Arg);
+  }
+
   void VisitConceptSpecializationExpr(const ConceptSpecializationExpr *CSE) {
+    Visit(CSE->getSpecializationDecl());
     if (CSE->hasExplicitTemplateArgs())
       for (const auto &ArgLoc : CSE->getTemplateArgsAsWritten()->arguments())
         dumpTemplateArgumentLoc(ArgLoc);

diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
index ae10744..d1dfe73 100644 (file)
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -3259,7 +3259,7 @@ public:
   static bool classofKind(Kind K) { return K == VarTemplate; }
 };
 
-/// Declaration of a C++2a concept.
+/// Declaration of a C++20 concept.
 class ConceptDecl : public TemplateDecl, public Mergeable<ConceptDecl> {
 protected:
   Expr *ConstraintExpr;
@@ -3304,6 +3304,40 @@ public:
   friend class ASTDeclWriter;
 };
 
+// An implementation detail of ConceptSpecialicationExpr that holds the template
+// arguments, so we can later use this to reconstitute the template arguments
+// during constraint checking.
+class ImplicitConceptSpecializationDecl final
+    : public Decl,
+      private llvm::TrailingObjects<ImplicitConceptSpecializationDecl,
+                                    TemplateArgument> {
+  unsigned NumTemplateArgs;
+
+  ImplicitConceptSpecializationDecl(DeclContext *DC, SourceLocation SL,
+                                    ArrayRef<TemplateArgument> ConvertedArgs);
+  ImplicitConceptSpecializationDecl(EmptyShell Empty, unsigned NumTemplateArgs);
+
+public:
+  static ImplicitConceptSpecializationDecl *
+  Create(const ASTContext &C, DeclContext *DC, SourceLocation SL,
+         ArrayRef<TemplateArgument> ConvertedArgs);
+  static ImplicitConceptSpecializationDecl *
+  CreateDeserialized(const ASTContext &C, unsigned ID,
+                     unsigned NumTemplateArgs);
+
+  ArrayRef<TemplateArgument> getTemplateArguments() const {
+    return ArrayRef<TemplateArgument>(getTrailingObjects<TemplateArgument>(),
+                                      NumTemplateArgs);
+  }
+  void setTemplateArguments(ArrayRef<TemplateArgument> Converted);
+
+  static bool classofKind(Kind K) { return K == ImplicitConceptSpecialization; }
+  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
+
+  friend TrailingObjects;
+  friend class ASTDeclReader;
+};
+
 /// A template parameter object.
 ///
 /// Template parameter objects represent values of class type used as template

diff --git a/clang/include/clang/AST/ExprConcepts.h b/clang/include/clang/AST/ExprConcepts.h
index fd9cd31..6dedeb5 100644 (file)
--- a/clang/include/clang/AST/ExprConcepts.h
+++ b/clang/include/clang/AST/ExprConcepts.h
@@ -37,18 +37,17 @@ class ASTStmtWriter;
 ///
 /// According to C++2a [expr.prim.id]p3 an id-expression that denotes the
 /// specialization of a concept results in a prvalue of type bool.
-class ConceptSpecializationExpr final : public Expr, public ConceptReference,
-      private llvm::TrailingObjects<ConceptSpecializationExpr,
-                                    TemplateArgument> {
+class ConceptSpecializationExpr final : public Expr, public ConceptReference {
+  friend class ASTReader;
   friend class ASTStmtReader;
-  friend TrailingObjects;
+
 public:
   using SubstitutionDiagnostic = std::pair<SourceLocation, std::string>;
 
 protected:
-  /// \brief The number of template arguments in the tail-allocated list of
-  /// converted template arguments.
-  unsigned NumTemplateArgs;
+  /// \brief The Implicit Concept Specialization Decl, which holds the template
+  /// arguments for this specialization.
+  ImplicitConceptSpecializationDecl *SpecDecl;
 
   /// \brief Information about the satisfaction of the named concept with the
   /// given arguments. If this expression is value dependent, this is to be
@@ -60,51 +59,46 @@ protected:
                             DeclarationNameInfo ConceptNameInfo,
                             NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
                             const ASTTemplateArgumentListInfo *ArgsAsWritten,
-                            ArrayRef<TemplateArgument> ConvertedArgs,
+                            ImplicitConceptSpecializationDecl *SpecDecl,
                             const ConstraintSatisfaction *Satisfaction);
 
   ConceptSpecializationExpr(const ASTContext &C, ConceptDecl *NamedConcept,
-                            ArrayRef<TemplateArgument> ConvertedArgs,
+                            ImplicitConceptSpecializationDecl *SpecDecl,
                             const ConstraintSatisfaction *Satisfaction,
                             bool Dependent,
                             bool ContainsUnexpandedParameterPack);
-
-  ConceptSpecializationExpr(EmptyShell Empty, unsigned NumTemplateArgs);
+  ConceptSpecializationExpr(EmptyShell Empty);
 
 public:
-
   static ConceptSpecializationExpr *
   Create(const ASTContext &C, NestedNameSpecifierLoc NNS,
          SourceLocation TemplateKWLoc, DeclarationNameInfo ConceptNameInfo,
          NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
          const ASTTemplateArgumentListInfo *ArgsAsWritten,
-         ArrayRef<TemplateArgument> ConvertedArgs,
+         ImplicitConceptSpecializationDecl *SpecDecl,
          const ConstraintSatisfaction *Satisfaction);
 
   static ConceptSpecializationExpr *
   Create(const ASTContext &C, ConceptDecl *NamedConcept,
-         ArrayRef<TemplateArgument> ConvertedArgs,
-         const ConstraintSatisfaction *Satisfaction,
-         bool Dependent,
+         ImplicitConceptSpecializationDecl *SpecDecl,
+         const ConstraintSatisfaction *Satisfaction, bool Dependent,
          bool ContainsUnexpandedParameterPack);
 
-  static ConceptSpecializationExpr *
-  Create(ASTContext &C, EmptyShell Empty, unsigned NumTemplateArgs);
-
   ArrayRef<TemplateArgument> getTemplateArguments() const {
-    return ArrayRef<TemplateArgument>(getTrailingObjects<TemplateArgument>(),
-                                      NumTemplateArgs);
+    return SpecDecl->getTemplateArguments();
   }
 
-  /// \brief Set new template arguments for this concept specialization.
-  void setTemplateArguments(ArrayRef<TemplateArgument> Converted);
+  const ImplicitConceptSpecializationDecl *getSpecializationDecl() const {
+    assert(SpecDecl && "Template Argument Decl not initialized");
+    return SpecDecl;
+  }
 
   /// \brief Whether or not the concept with the given arguments was satisfied
   /// when the expression was created.
   /// The expression must not be dependent.
   bool isSatisfied() const {
-    assert(!isValueDependent()
-           && "isSatisfied called on a dependent ConceptSpecializationExpr");
+    assert(!isValueDependent() &&
+           "isSatisfied called on a dependent ConceptSpecializationExpr");
     return Satisfaction->IsSatisfied;
   }
 
@@ -112,8 +106,8 @@ public:
   /// satisfaction of the named concept.
   /// The expression must not be dependent.
   const ASTConstraintSatisfaction &getSatisfaction() const {
-    assert(!isValueDependent()
-           && "getSatisfaction called on dependent ConceptSpecializationExpr");
+    assert(!isValueDependent() &&
+           "getSatisfaction called on dependent ConceptSpecializationExpr");
     return *Satisfaction;
   }
 

diff --git a/clang/include/clang/AST/RecursiveASTVisitor.h b/clang/include/clang/AST/RecursiveASTVisitor.h
index b5c24e1..8c54126 100644 (file)
--- a/clang/include/clang/AST/RecursiveASTVisitor.h
+++ b/clang/include/clang/AST/RecursiveASTVisitor.h
@@ -2304,6 +2304,11 @@ DEF_TRAVERSE_DECL(ParmVarDecl, {
 
 DEF_TRAVERSE_DECL(RequiresExprBodyDecl, {})
 
+DEF_TRAVERSE_DECL(ImplicitConceptSpecializationDecl, {
+  TRY_TO(TraverseTemplateArguments(D->getTemplateArguments().data(),
+                                   D->getTemplateArguments().size()));
+})
+
 #undef DEF_TRAVERSE_DECL
 
 // ----------------- Stmt traversal -----------------

diff --git a/clang/include/clang/Basic/DeclNodes.td b/clang/include/clang/Basic/DeclNodes.td
index 386c0a1..c94c84b 100644 (file)
--- a/clang/include/clang/Basic/DeclNodes.td
+++ b/clang/include/clang/Basic/DeclNodes.td
@@ -90,6 +90,7 @@ def Named : DeclNode<Decl, "named declarations", 1>;
       def ObjCImplementation : DeclNode<ObjCImpl>;
   def ObjCProperty : DeclNode<Named, "Objective-C properties">;
   def ObjCCompatibleAlias : DeclNode<Named>;
+def ImplicitConceptSpecialization : DeclNode<Decl>;
 def LinkageSpec : DeclNode<Decl>, DeclContext;
 def Export : DeclNode<Decl>, DeclContext;
 def ObjCPropertyImpl : DeclNode<Decl>;

diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
index 3bbd272..77d4a8a 100644 (file)
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -41,7 +41,7 @@ namespace serialization {
 /// Version 4 of AST files also requires that the version control branch and
 /// revision match exactly, since there is no backward compatibility of
 /// AST files at this time.
-const unsigned VERSION_MAJOR = 22;
+const unsigned VERSION_MAJOR = 23;
 
 /// AST file minor version number supported by this version of
 /// Clang.
@@ -1514,7 +1514,10 @@ enum DeclCode {
   /// A HLSLBufferDecl record.
   DECL_HLSL_BUFFER,
 
-  DECL_LAST = DECL_HLSL_BUFFER
+  /// An ImplicitConceptSpecializationDecl record.
+  DECL_IMPLICIT_CONCEPT_SPECIALIZATION,
+
+  DECL_LAST = DECL_IMPLICIT_CONCEPT_SPECIALIZATION
 };
 
 /// Record codes for each kind of statement or expression.

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 1685214..08cbe2a 100644 (file)
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -761,9 +761,13 @@ canonicalizeImmediatelyDeclaredConstraint(const ASTContext &C, Expr *IDC,
     NewConverted.push_back(ConstrainedType);
     llvm::append_range(NewConverted, OldConverted.drop_front(1));
   }
+  auto *CSD = ImplicitConceptSpecializationDecl::Create(
+      C, CSE->getNamedConcept()->getDeclContext(),
+      CSE->getNamedConcept()->getLocation(), NewConverted);
+
   Expr *NewIDC = ConceptSpecializationExpr::Create(
-      C, CSE->getNamedConcept(), NewConverted, nullptr,
-      CSE->isInstantiationDependent(), CSE->containsUnexpandedParameterPack());
+      C, CSE->getNamedConcept(), CSD, nullptr, CSE->isInstantiationDependent(),
+      CSE->containsUnexpandedParameterPack());
 
   if (auto *OrigFold = dyn_cast<CXXFoldExpr>(IDC))
     NewIDC = new (C) CXXFoldExpr(

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 510910b..0480864 100644 (file)
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1262,8 +1262,13 @@ LinkageInfo LinkageComputer::getLVForClosure(const DeclContext *DC,
   else if (isa<ParmVarDecl>(ContextDecl))
     Owner =
         dyn_cast<NamedDecl>(ContextDecl->getDeclContext()->getRedeclContext());
-  else
+  else if (isa<ImplicitConceptSpecializationDecl>(ContextDecl)) {
+    // Replace with the concept's owning decl, which is either a namespace or a
+    // TU, so this needs a dyn_cast.
+    Owner = dyn_cast<NamedDecl>(ContextDecl->getDeclContext());
+  } else {
     Owner = cast<NamedDecl>(ContextDecl);
+  }
 
   if (!Owner)
     return LinkageInfo::none();

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 72922ef..5cb5523 100644 (file)
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -874,6 +874,7 @@ unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
     case Empty:
     case LifetimeExtendedTemporary:
     case RequiresExprBody:
+    case ImplicitConceptSpecialization:
       // Never looked up by name.
       return 0;
   }

diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index 9a2932c..deed47e 100644 (file)
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -1053,6 +1053,44 @@ ConceptDecl *ConceptDecl::CreateDeserialized(ASTContext &C,
 }
 
 //===----------------------------------------------------------------------===//
+// ImplicitConceptSpecializationDecl Implementation
+//===----------------------------------------------------------------------===//
+ImplicitConceptSpecializationDecl::ImplicitConceptSpecializationDecl(
+    DeclContext *DC, SourceLocation SL,
+    ArrayRef<TemplateArgument> ConvertedArgs)
+    : Decl(ImplicitConceptSpecialization, DC, SL),
+      NumTemplateArgs(ConvertedArgs.size()) {
+  setTemplateArguments(ConvertedArgs);
+}
+
+ImplicitConceptSpecializationDecl::ImplicitConceptSpecializationDecl(
+    EmptyShell Empty, unsigned NumTemplateArgs)
+    : Decl(ImplicitConceptSpecialization, Empty),
+      NumTemplateArgs(NumTemplateArgs) {}
+
+ImplicitConceptSpecializationDecl *ImplicitConceptSpecializationDecl::Create(
+    const ASTContext &C, DeclContext *DC, SourceLocation SL,
+    ArrayRef<TemplateArgument> ConvertedArgs) {
+  return new (C, DC,
+              additionalSizeToAlloc<TemplateArgument>(ConvertedArgs.size()))
+      ImplicitConceptSpecializationDecl(DC, SL, ConvertedArgs);
+}
+
+ImplicitConceptSpecializationDecl *
+ImplicitConceptSpecializationDecl::CreateDeserialized(
+    const ASTContext &C, unsigned ID, unsigned NumTemplateArgs) {
+  return new (C, ID, additionalSizeToAlloc<TemplateArgument>(NumTemplateArgs))
+      ImplicitConceptSpecializationDecl(EmptyShell{}, NumTemplateArgs);
+}
+
+void ImplicitConceptSpecializationDecl::setTemplateArguments(
+    ArrayRef<TemplateArgument> Converted) {
+  assert(Converted.size() == NumTemplateArgs);
+  std::uninitialized_copy(Converted.begin(), Converted.end(),
+                          getTrailingObjects<TemplateArgument>());
+}
+
+//===----------------------------------------------------------------------===//
 // ClassTemplatePartialSpecializationDecl Implementation
 //===----------------------------------------------------------------------===//
 void ClassTemplatePartialSpecializationDecl::anchor() {}

diff --git a/clang/lib/AST/ExprConcepts.cpp b/clang/lib/AST/ExprConcepts.cpp
index c17453f..fc8f1eb 100644 (file)
--- a/clang/lib/AST/ExprConcepts.cpp
+++ b/clang/lib/AST/ExprConcepts.cpp
@@ -35,16 +35,15 @@ ConceptSpecializationExpr::ConceptSpecializationExpr(
     SourceLocation TemplateKWLoc, DeclarationNameInfo ConceptNameInfo,
     NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
     const ASTTemplateArgumentListInfo *ArgsAsWritten,
-    ArrayRef<TemplateArgument> ConvertedArgs,
+    ImplicitConceptSpecializationDecl *SpecDecl,
     const ConstraintSatisfaction *Satisfaction)
     : Expr(ConceptSpecializationExprClass, C.BoolTy, VK_PRValue, OK_Ordinary),
       ConceptReference(NNS, TemplateKWLoc, ConceptNameInfo, FoundDecl,
                        NamedConcept, ArgsAsWritten),
-      NumTemplateArgs(ConvertedArgs.size()),
+      SpecDecl(SpecDecl),
       Satisfaction(Satisfaction
                        ? ASTConstraintSatisfaction::Create(C, *Satisfaction)
                        : nullptr) {
-  setTemplateArguments(ConvertedArgs);
   setDependence(computeDependence(this, /*ValueDependent=*/!Satisfaction));
 
   // Currently guaranteed by the fact concepts can only be at namespace-scope.
@@ -56,50 +55,34 @@ ConceptSpecializationExpr::ConceptSpecializationExpr(
          "should not be value-dependent");
 }
 
-ConceptSpecializationExpr::ConceptSpecializationExpr(EmptyShell Empty,
-                                                     unsigned NumTemplateArgs)
-    : Expr(ConceptSpecializationExprClass, Empty),
-      NumTemplateArgs(NumTemplateArgs) {}
+ConceptSpecializationExpr::ConceptSpecializationExpr(EmptyShell Empty)
+    : Expr(ConceptSpecializationExprClass, Empty) {}
 
-void ConceptSpecializationExpr::setTemplateArguments(
-    ArrayRef<TemplateArgument> Converted) {
-  assert(Converted.size() == NumTemplateArgs);
-  std::uninitialized_copy(Converted.begin(), Converted.end(),
-                          getTrailingObjects<TemplateArgument>());
-}
-
-ConceptSpecializationExpr *
-ConceptSpecializationExpr::Create(const ASTContext &C,
-                                  NestedNameSpecifierLoc NNS,
-                                  SourceLocation TemplateKWLoc,
-                                  DeclarationNameInfo ConceptNameInfo,
-                                  NamedDecl *FoundDecl,
-                                  ConceptDecl *NamedConcept,
-                               const ASTTemplateArgumentListInfo *ArgsAsWritten,
-                                  ArrayRef<TemplateArgument> ConvertedArgs,
-                                  const ConstraintSatisfaction *Satisfaction) {
-  void *Buffer = C.Allocate(totalSizeToAlloc<TemplateArgument>(
-                                ConvertedArgs.size()));
-  return new (Buffer) ConceptSpecializationExpr(C, NNS, TemplateKWLoc,
-                                                ConceptNameInfo, FoundDecl,
-                                                NamedConcept, ArgsAsWritten,
-                                                ConvertedArgs, Satisfaction);
+ConceptSpecializationExpr *ConceptSpecializationExpr::Create(
+    const ASTContext &C, NestedNameSpecifierLoc NNS,
+    SourceLocation TemplateKWLoc, DeclarationNameInfo ConceptNameInfo,
+    NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
+    const ASTTemplateArgumentListInfo *ArgsAsWritten,
+    ImplicitConceptSpecializationDecl *SpecDecl,
+    const ConstraintSatisfaction *Satisfaction) {
+  return new (C) ConceptSpecializationExpr(
+      C, NNS, TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
+      ArgsAsWritten, SpecDecl, Satisfaction);
 }
 
 ConceptSpecializationExpr::ConceptSpecializationExpr(
     const ASTContext &C, ConceptDecl *NamedConcept,
-    ArrayRef<TemplateArgument> ConvertedArgs,
+    ImplicitConceptSpecializationDecl *SpecDecl,
     const ConstraintSatisfaction *Satisfaction, bool Dependent,
     bool ContainsUnexpandedParameterPack)
     : Expr(ConceptSpecializationExprClass, C.BoolTy, VK_PRValue, OK_Ordinary),
       ConceptReference(NestedNameSpecifierLoc(), SourceLocation(),
                        DeclarationNameInfo(), NamedConcept, NamedConcept,
                        nullptr),
-      NumTemplateArgs(ConvertedArgs.size()),
+      SpecDecl(SpecDecl),
       Satisfaction(Satisfaction
                        ? ASTConstraintSatisfaction::Create(C, *Satisfaction)
                        : nullptr) {
-  setTemplateArguments(ConvertedArgs);
   ExprDependence D = ExprDependence::None;
   if (!Satisfaction)
     D |= ExprDependence::Value;
@@ -110,26 +93,14 @@ ConceptSpecializationExpr::ConceptSpecializationExpr(
   setDependence(D);
 }
 
-ConceptSpecializationExpr *
-ConceptSpecializationExpr::Create(const ASTContext &C,
-                                  ConceptDecl *NamedConcept,
-                                  ArrayRef<TemplateArgument> ConvertedArgs,
-                                  const ConstraintSatisfaction *Satisfaction,
-                                  bool Dependent,
-                                  bool ContainsUnexpandedParameterPack) {
-  void *Buffer = C.Allocate(totalSizeToAlloc<TemplateArgument>(
-                                ConvertedArgs.size()));
-  return new (Buffer) ConceptSpecializationExpr(
-      C, NamedConcept, ConvertedArgs, Satisfaction, Dependent,
-      ContainsUnexpandedParameterPack);
-}
-
-ConceptSpecializationExpr *
-ConceptSpecializationExpr::Create(ASTContext &C, EmptyShell Empty,
-                                  unsigned NumTemplateArgs) {
-  void *Buffer = C.Allocate(totalSizeToAlloc<TemplateArgument>(
-                                NumTemplateArgs));
-  return new (Buffer) ConceptSpecializationExpr(Empty, NumTemplateArgs);
+ConceptSpecializationExpr *ConceptSpecializationExpr::Create(
+    const ASTContext &C, ConceptDecl *NamedConcept,
+    ImplicitConceptSpecializationDecl *SpecDecl,
+    const ConstraintSatisfaction *Satisfaction, bool Dependent,
+    bool ContainsUnexpandedParameterPack) {
+  return new (C)
+      ConceptSpecializationExpr(C, NamedConcept, SpecDecl, Satisfaction,
+                                Dependent, ContainsUnexpandedParameterPack);
 }
 
 const TypeConstraint *

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 8f28f96..2bf104b 100644 (file)
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -127,6 +127,7 @@ void CodeGenFunction::EmitDecl(const Decl &D) {
   case Decl::OMPRequires:
   case Decl::Empty:
   case Decl::Concept:
+  case Decl::ImplicitConceptSpecialization:
   case Decl::LifetimeExtendedTemporary:
   case Decl::RequiresExprBody:
     // None of these decls require codegen support.

diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index 484c024..e5ee950 100644 (file)
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -265,7 +265,8 @@ static ExprResult calculateConstraintSatisfaction(
   return calculateConstraintSatisfaction(
       S, ConstraintExpr, Satisfaction, [&](const Expr *AtomicExpr) {
         EnterExpressionEvaluationContext ConstantEvaluated(
-            S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
+            S, Sema::ExpressionEvaluationContext::ConstantEvaluated,
+            Sema::ReuseLambdaContextDecl);
 
         // Atomic constraint - substitute arguments and check satisfaction.
         ExprResult SubstitutedExpression;

diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 2143b81..a22708d 100644 (file)
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -282,7 +282,8 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
     DataMember,
     StaticDataMember,
     InlineVariable,
-    VariableTemplate
+    VariableTemplate,
+    Concept
   } Kind = Normal;
 
   // Default arguments of member function parameters that appear in a class
@@ -307,6 +308,8 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
       }
     } else if (isa<FieldDecl>(ManglingContextDecl)) {
       Kind = DataMember;
+    } else if (isa<ImplicitConceptSpecializationDecl>(ManglingContextDecl)) {
+      Kind = Concept;
     }
   }
 
@@ -330,6 +333,11 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
     return std::make_tuple(nullptr, nullptr);
   }
 
+  case Concept:
+    // Concept definitions aren't code generated and thus aren't mangled,
+    // however the ManglingContextDecl is important for the purposes of
+    // re-forming the template argument list of the lambda for constraint
+    // evaluation.
   case StaticDataMember:
     //  -- the initializers of nonspecialized static members of template classes
     if (!IsInNonspecializedTemplate)

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index f6627c9..d81ed15 100644 (file)
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -4866,6 +4866,9 @@ Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
                                 /*UpdateArgsWithConversions=*/false))
     return ExprError();
 
+  auto *CSD = ImplicitConceptSpecializationDecl::Create(
+      Context, NamedConcept->getDeclContext(), NamedConcept->getLocation(),
+      Converted);
   ConstraintSatisfaction Satisfaction;
   bool AreArgsDependent =
       TemplateSpecializationType::anyDependentTemplateArguments(*TemplateArgs,
@@ -4873,6 +4876,10 @@ Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
   MultiLevelTemplateArgumentList MLTAL;
   MLTAL.addOuterTemplateArguments(NamedConcept, Converted);
   LocalInstantiationScope Scope(*this);
+
+  EnterExpressionEvaluationContext EECtx{
+      *this, ExpressionEvaluationContext::ConstantEvaluated, CSD};
+
   if (!AreArgsDependent &&
       CheckConstraintSatisfaction(
           NamedConcept, {NamedConcept->getConstraintExpr()}, MLTAL,
@@ -4881,10 +4888,11 @@ Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
           Satisfaction))
     return ExprError();
 
-  return ConceptSpecializationExpr::Create(Context,
+  return ConceptSpecializationExpr::Create(
+      Context,
       SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc{},
       TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
-      ASTTemplateArgumentListInfo::Create(Context, *TemplateArgs), Converted,
+      ASTTemplateArgumentListInfo::Create(Context, *TemplateArgs), CSD,
       AreArgsDependent ? nullptr : &Satisfaction);
 }
 

diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 1400693..7475289 100644 (file)
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -231,6 +231,15 @@ Response HandleRecordDecl(const CXXRecordDecl *Rec,
   return Response::UseNextDecl(Rec);
 }
 
+Response HandleImplicitConceptSpecializationDecl(
+    const ImplicitConceptSpecializationDecl *CSD,
+    MultiLevelTemplateArgumentList &Result) {
+  Result.addOuterTemplateArguments(
+      const_cast<ImplicitConceptSpecializationDecl *>(CSD),
+      CSD->getTemplateArguments());
+  return Response::UseNextDecl(CSD);
+}
+
 Response HandleGenericDeclContext(const Decl *CurDecl) {
   return Response::UseNextDecl(CurDecl);
 }
@@ -289,6 +298,9 @@ MultiLevelTemplateArgumentList Sema::getTemplateInstantiationArgs(
                          ForConstraintInstantiation);
     } else if (const auto *Rec = dyn_cast<CXXRecordDecl>(CurDecl)) {
       R = HandleRecordDecl(Rec, Result, Context, ForConstraintInstantiation);
+    } else if (const auto *CSD =
+                   dyn_cast<ImplicitConceptSpecializationDecl>(CurDecl)) {
+      R = HandleImplicitConceptSpecializationDecl(CSD, Result);
     } else if (!isa<DeclContext>(CurDecl)) {
       R = Response::DontClearRelativeToPrimaryNextDecl(CurDecl);
       if (CurDecl->getDeclContext()->isTranslationUnit()) {

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 2c7fc8d..dc694b2 100644 (file)
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3965,6 +3965,11 @@ Decl *TemplateDeclInstantiator::VisitConceptDecl(ConceptDecl *D) {
   llvm_unreachable("Concept definitions cannot reside inside a template");
 }
 
+Decl *TemplateDeclInstantiator::VisitImplicitConceptSpecializationDecl(
+    ImplicitConceptSpecializationDecl *D) {
+  llvm_unreachable("Concept specializations cannot reside inside a template");
+}
+
 Decl *
 TemplateDeclInstantiator::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
   return RequiresExprBodyDecl::Create(SemaRef.Context, D->getDeclContext(),

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 4f6ee07..ebb83f1 100644 (file)
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -12606,7 +12606,8 @@ TreeTransform<Derived>::TransformRequiresExpr(RequiresExpr *E) {
   // C++2a [expr.prim.req]p2
   // Expressions appearing within a requirement-body are unevaluated operands.
   EnterExpressionEvaluationContext Ctx(
-      SemaRef, Sema::ExpressionEvaluationContext::Unevaluated);
+      SemaRef, Sema::ExpressionEvaluationContext::Unevaluated,
+      Sema::ReuseLambdaContextDecl);
 
   RequiresExprBodyDecl *Body = RequiresExprBodyDecl::Create(
       getSema().Context, getSema().CurContext,

diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp
index 53e4c88..152037d 100644 (file)
--- a/clang/lib/Serialization/ASTCommon.cpp
+++ b/clang/lib/Serialization/ASTCommon.cpp
@@ -430,6 +430,7 @@ bool serialization::isRedeclarableDeclKind(unsigned Kind) {
   case Decl::Decomposition:
   case Decl::Binding:
   case Decl::Concept:
+  case Decl::ImplicitConceptSpecialization:
   case Decl::LifetimeExtendedTemporary:
   case Decl::RequiresExprBody:
   case Decl::UnresolvedUsingIfExists:

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 3662910..94a1d24 100644 (file)
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -384,6 +384,8 @@ namespace clang {
     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
     void VisitTemplateDecl(TemplateDecl *D);
     void VisitConceptDecl(ConceptDecl *D);
+    void VisitImplicitConceptSpecializationDecl(
+        ImplicitConceptSpecializationDecl *D);
     void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
     RedeclarableResult VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
     void VisitClassTemplateDecl(ClassTemplateDecl *D);
@@ -2234,6 +2236,17 @@ void ASTDeclReader::VisitConceptDecl(ConceptDecl *D) {
   mergeMergeable(D);
 }
 
+void ASTDeclReader::VisitImplicitConceptSpecializationDecl(
+    ImplicitConceptSpecializationDecl *D) {
+  // The size of the template list was read during creation of the Decl, so we
+  // don't have to re-read it here.
+  VisitDecl(D);
+  llvm::SmallVector<TemplateArgument, 4> Args;
+  for (unsigned I = 0; I < D->NumTemplateArgs; ++I)
+    Args.push_back(Record.readTemplateArgument(/*Canonicalize=*/true));
+  D->setTemplateArguments(Args);
+}
+
 void ASTDeclReader::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
 }
 
@@ -3900,6 +3913,10 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
   case DECL_HLSL_BUFFER:
     D = HLSLBufferDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_IMPLICIT_CONCEPT_SPECIALIZATION:
+    D = ImplicitConceptSpecializationDecl::CreateDeserialized(Context, ID,
+                                                              Record.readInt());
+    break;
   }
 
   assert(D && "Unknown declaration reading AST file");

diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 98b8a96..f6a2f85 100644 (file)
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -794,17 +794,13 @@ readConstraintSatisfaction(ASTRecordReader &Record) {
 void ASTStmtReader::VisitConceptSpecializationExpr(
         ConceptSpecializationExpr *E) {
   VisitExpr(E);
-  unsigned NumTemplateArgs = Record.readInt();
   E->NestedNameSpec = Record.readNestedNameSpecifierLoc();
   E->TemplateKWLoc = Record.readSourceLocation();
   E->ConceptName = Record.readDeclarationNameInfo();
   E->NamedConcept = readDeclAs<ConceptDecl>();
   E->FoundDecl = Record.readDeclAs<NamedDecl>();
+  E->SpecDecl = Record.readDeclAs<ImplicitConceptSpecializationDecl>();
   E->ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
-  llvm::SmallVector<TemplateArgument, 4> Args;
-  for (unsigned I = 0; I < NumTemplateArgs; ++I)
-    Args.push_back(Record.readTemplateArgument(/*Canonicalize*/ true));
-  E->setTemplateArguments(Args);
   E->Satisfaction = E->isValueDependent() ? nullptr :
       ASTConstraintSatisfaction::Create(Record.getContext(),
                                         readConstraintSatisfaction(Record));
@@ -4003,8 +3999,7 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       break;
 
     case EXPR_CONCEPT_SPECIALIZATION: {
-      unsigned numTemplateArgs = Record[ASTStmtReader::NumExprFields];
-      S = ConceptSpecializationExpr::Create(Context, Empty, numTemplateArgs);
+      S = new (Context) ConceptSpecializationExpr(Empty);
       break;
     }
 

diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index afe59ef..93785ee 100644 (file)
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -107,6 +107,8 @@ namespace clang {
     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
     void VisitTemplateDecl(TemplateDecl *D);
     void VisitConceptDecl(ConceptDecl *D);
+    void VisitImplicitConceptSpecializationDecl(
+        ImplicitConceptSpecializationDecl *D);
     void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
     void VisitClassTemplateDecl(ClassTemplateDecl *D);
@@ -1517,6 +1519,15 @@ void ASTDeclWriter::VisitConceptDecl(ConceptDecl *D) {
   Code = serialization::DECL_CONCEPT;
 }
 
+void ASTDeclWriter::VisitImplicitConceptSpecializationDecl(
+    ImplicitConceptSpecializationDecl *D) {
+  Record.push_back(D->getTemplateArguments().size());
+  VisitDecl(D);
+  for (const TemplateArgument &Arg : D->getTemplateArguments())
+    Record.AddTemplateArgument(Arg);
+  Code = serialization::DECL_IMPLICIT_CONCEPT_SPECIALIZATION;
+}
+
 void ASTDeclWriter::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
   Code = serialization::DECL_REQUIRES_EXPR_BODY;
 }

diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 6576156..be28ad6 100644 (file)
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -433,16 +433,13 @@ addSubstitutionDiagnostic(
 void ASTStmtWriter::VisitConceptSpecializationExpr(
         ConceptSpecializationExpr *E) {
   VisitExpr(E);
-  ArrayRef<TemplateArgument> TemplateArgs = E->getTemplateArguments();
-  Record.push_back(TemplateArgs.size());
   Record.AddNestedNameSpecifierLoc(E->getNestedNameSpecifierLoc());
   Record.AddSourceLocation(E->getTemplateKWLoc());
   Record.AddDeclarationNameInfo(E->getConceptNameInfo());
   Record.AddDeclRef(E->getNamedConcept());
   Record.AddDeclRef(E->getFoundDecl());
+  Record.AddDeclRef(E->getSpecializationDecl());
   Record.AddASTTemplateArgumentListInfo(E->getTemplateArgsAsWritten());
-  for (const TemplateArgument &Arg : TemplateArgs)
-    Record.AddTemplateArgument(Arg);
   if (!E->isValueDependent())
     addConstraintSatisfaction(Record, E->getSatisfaction());
 

diff --git a/clang/test/AST/ast-dump-concepts.cpp b/clang/test/AST/ast-dump-concepts.cpp
index dff300a..06518a7 100644 (file)
--- a/clang/test/AST/ast-dump-concepts.cpp
+++ b/clang/test/AST/ast-dump-concepts.cpp
@@ -19,6 +19,11 @@ template <typename T>
 struct Foo {
   // CHECK:      TemplateTypeParmDecl {{.*}} referenced Concept {{.*}} 'binary_concept'
   // CHECK-NEXT: `-ConceptSpecializationExpr {{.*}} <col:13, col:31> 'bool' Concept {{.*}} 'binary_concept'
+  // CHECK-NEXT:   |-ImplicitConceptSpecializationDecl {{.*}} <line:13:9> col:9
+  // CHECK-NEXT:   | |-TemplateArgument type 'type-parameter-1-0'  
+  // CHECK-NEXT:   | | `-TemplateTypeParmType {{.*}} 'type-parameter-1-0' dependent {{.*}}depth 1 index 0
+  // CHECK-NEXT:   | `-TemplateArgument type 'int'
+  // CHECK-NEXT:   |   `-BuiltinType {{.*}} 'int'
   // CHECK-NEXT:   |-TemplateArgument {{.*}} type 'R'
   // CHECK-NEXT:   | `-TemplateTypeParmType {{.*}} 'R'
   // CHECK-NEXT:   |   `-TemplateTypeParm {{.*}} 'R'
@@ -29,6 +34,9 @@ struct Foo {
 
   // CHECK:      TemplateTypeParmDecl {{.*}} referenced Concept {{.*}} 'unary_concept'
   // CHECK-NEXT: `-ConceptSpecializationExpr {{.*}} <col:13> 'bool'
+  // CHECK-NEXT:   |-ImplicitConceptSpecializationDecl {{.*}} <line:10:9> col:9
+  // CHECK-NEXT:   | `-TemplateArgument type 'type-parameter-1-0'
+  // CHECK-NEXT:   |   `-TemplateTypeParmType {{.*}} 'type-parameter-1-0' dependent {{.*}}depth 1 index 0
   template <unary_concept R>
   Foo(R);
 

diff --git a/clang/test/SemaTemplate/concepts-lambda.cpp b/clang/test/SemaTemplate/concepts-lambda.cpp
index 13c402e..eace722 100644 (file)
--- a/clang/test/SemaTemplate/concepts-lambda.cpp
+++ b/clang/test/SemaTemplate/concepts-lambda.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++20 -verify %s
+// RUN: %clang_cc1 -std=c++20 -verify %s -triple powerpc64-ibm-aix
 // expected-no-diagnostics
 
 namespace GH57945 {
@@ -55,3 +56,39 @@ namespace GH57971 {
   using function_ptr = void(*)(int);
   function_ptr ptr = f<void>;
 }
+
+// GH58368: A lambda defined in a concept requires we store
+// the concept as a part of the lambda context.
+namespace LambdaInConcept {
+using size_t = unsigned long;
+
+template<size_t...Ts>
+struct IdxSeq{};
+
+template <class T, class... Ts>
+concept NotLike = true;
+
+template <size_t, class... Ts>
+struct AnyExcept {
+  template <NotLike<Ts...> T> operator T&() const;
+  template <NotLike<Ts...> T> operator T&&() const;
+};
+
+template <class T>
+  concept ConstructibleWithN = (requires {
+                                []<size_t I, size_t... Idxs>
+                                (IdxSeq<I, Idxs...>)
+                                requires requires { T{AnyExcept<I, T>{}}; }
+                                { }
+                                (IdxSeq<1,2,3>{});
+    });
+
+struct Foo {
+  int i;
+  double j;
+  char k;
+};
+
+static_assert(ConstructibleWithN<Foo>);
+
+}

diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 69d3464..9cdbddd 100644 (file)
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -6700,6 +6700,7 @@ CXCursor clang_getCursorDefinition(CXCursor C) {
   case Decl::PragmaDetectMismatch:
   case Decl::UsingPack:
   case Decl::Concept:
+  case Decl::ImplicitConceptSpecialization:
   case Decl::LifetimeExtendedTemporary:
   case Decl::RequiresExprBody:
   case Decl::UnresolvedUsingIfExists: