1 files changed, 81 insertions, 46 deletions

diff --git a/lib/Sema/SemaLambda.cpp b/lib/Sema/SemaLambda.cpp
index 986524e6d56b..c6b19a0b195c 100644
--- a/lib/Sema/SemaLambda.cpp
+++ b/lib/Sema/SemaLambda.cpp
@@ -272,12 +272,11 @@ static bool isInInlineFunction(const DeclContext *DC) {
   return false;
 }
 
-MangleNumberingContext *
-Sema::getCurrentMangleNumberContext(const DeclContext *DC,
-                                    Decl *&ManglingContextDecl) {
+std::tuple<MangleNumberingContext *, Decl *>
+Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
   // Compute the context for allocating mangling numbers in the current
   // expression, if the ABI requires them.
-  ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
+  Decl *ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
 
   enum ContextKind {
     Normal,
@@ -325,22 +324,18 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC,
     if ((IsInNonspecializedTemplate &&
          !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) ||
         isInInlineFunction(CurContext)) {
-      ManglingContextDecl = nullptr;
       while (auto *CD = dyn_cast<CapturedDecl>(DC))
         DC = CD->getParent();
-      return &Context.getManglingNumberContext(DC);
+      return std::make_tuple(&Context.getManglingNumberContext(DC), nullptr);
     }
 
-    ManglingContextDecl = nullptr;
-    return nullptr;
+    return std::make_tuple(nullptr, nullptr);
   }
 
   case StaticDataMember:
     //  -- the initializers of nonspecialized static members of template classes
-    if (!IsInNonspecializedTemplate) {
-      ManglingContextDecl = nullptr;
-      return nullptr;
-    }
+    if (!IsInNonspecializedTemplate)
+      return std::make_tuple(nullptr, ManglingContextDecl);
     // Fall through to get the current context.
     LLVM_FALLTHROUGH;
 
@@ -352,29 +347,24 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC,
     //  -- the initializers of inline variables
   case VariableTemplate:
     //  -- the initializers of templated variables
-    return &ExprEvalContexts.back().getMangleNumberingContext(Context);
+    return std::make_tuple(
+        &Context.getManglingNumberContext(ASTContext::NeedExtraManglingDecl,
+                                          ManglingContextDecl),
+        ManglingContextDecl);
   }
 
   llvm_unreachable("unexpected context");
 }
 
-MangleNumberingContext &
-Sema::ExpressionEvaluationContextRecord::getMangleNumberingContext(
-    ASTContext &Ctx) {
-  assert(ManglingContextDecl && "Need to have a context declaration");
-  if (!MangleNumbering)
-    MangleNumbering = Ctx.createMangleNumberingContext();
-  return *MangleNumbering;
-}
-
-CXXMethodDecl *Sema::startLambdaDefinition(
-    CXXRecordDecl *Class, SourceRange IntroducerRange,
-    TypeSourceInfo *MethodTypeInfo, SourceLocation EndLoc,
-    ArrayRef<ParmVarDecl *> Params, ConstexprSpecKind ConstexprKind,
-    Optional<std::pair<unsigned, Decl *>> Mangling) {
+CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
+                                           SourceRange IntroducerRange,
+                                           TypeSourceInfo *MethodTypeInfo,
+                                           SourceLocation EndLoc,
+                                           ArrayRef<ParmVarDecl *> Params,
+                                           ConstexprSpecKind ConstexprKind) {
   QualType MethodType = MethodTypeInfo->getType();
   TemplateParameterList *TemplateParams =
-            getGenericLambdaTemplateParameterList(getCurLambda(), *this);
+      getGenericLambdaTemplateParameterList(getCurLambda(), *this);
   // If a lambda appears in a dependent context or is a generic lambda (has
   // template parameters) and has an 'auto' return type, deduce it to a
   // dependent type.
@@ -407,6 +397,8 @@ CXXMethodDecl *Sema::startLambdaDefinition(
       MethodType, MethodTypeInfo, SC_None,
       /*isInline=*/true, ConstexprKind, EndLoc);
   Method->setAccess(AS_public);
+  if (!TemplateParams)
+    Class->addDecl(Method);
 
   // Temporarily set the lexical declaration context to the current
   // context, so that the Scope stack matches the lexical nesting.
@@ -418,9 +410,10 @@ CXXMethodDecl *Sema::startLambdaDefinition(
                                          TemplateParams,
                                          Method) : nullptr;
   if (TemplateMethod) {
-    TemplateMethod->setLexicalDeclContext(CurContext);
     TemplateMethod->setAccess(AS_public);
     Method->setDescribedFunctionTemplate(TemplateMethod);
+    Class->addDecl(TemplateMethod);
+    TemplateMethod->setLexicalDeclContext(CurContext);
   }
 
   // Add parameters.
@@ -433,19 +426,56 @@ CXXMethodDecl *Sema::startLambdaDefinition(
       P->setOwningFunction(Method);
   }
 
+  return Method;
+}
+
+void Sema::handleLambdaNumbering(
+    CXXRecordDecl *Class, CXXMethodDecl *Method,
+    Optional<std::tuple<unsigned, bool, Decl *>> Mangling) {
   if (Mangling) {
-    Class->setLambdaMangling(Mangling->first, Mangling->second);
-  } else {
+    unsigned ManglingNumber;
+    bool HasKnownInternalLinkage;
     Decl *ManglingContextDecl;
-    if (MangleNumberingContext *MCtx =
-            getCurrentMangleNumberContext(Class->getDeclContext(),
-                                          ManglingContextDecl)) {
-      unsigned ManglingNumber = MCtx->getManglingNumber(Method);
-      Class->setLambdaMangling(ManglingNumber, ManglingContextDecl);
-    }
+    std::tie(ManglingNumber, HasKnownInternalLinkage, ManglingContextDecl) =
+        Mangling.getValue();
+    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
+                             HasKnownInternalLinkage);
+    return;
   }
 
-  return Method;
+  auto getMangleNumberingContext =
+      [this](CXXRecordDecl *Class,
+             Decl *ManglingContextDecl) -> MangleNumberingContext * {
+    // Get mangle numbering context if there's any extra decl context.
+    if (ManglingContextDecl)
+      return &Context.getManglingNumberContext(
+          ASTContext::NeedExtraManglingDecl, ManglingContextDecl);
+    // Otherwise, from that lambda's decl context.
+    auto DC = Class->getDeclContext();
+    while (auto *CD = dyn_cast<CapturedDecl>(DC))
+      DC = CD->getParent();
+    return &Context.getManglingNumberContext(DC);
+  };
+
+  MangleNumberingContext *MCtx;
+  Decl *ManglingContextDecl;
+  std::tie(MCtx, ManglingContextDecl) =
+      getCurrentMangleNumberContext(Class->getDeclContext());
+  bool HasKnownInternalLinkage = false;
+  if (!MCtx && getLangOpts().CUDA) {
+    // Force lambda numbering in CUDA/HIP as we need to name lambdas following
+    // ODR. Both device- and host-compilation need to have a consistent naming
+    // on kernel functions. As lambdas are potential part of these `__global__`
+    // function names, they needs numbering following ODR.
+    MCtx = getMangleNumberingContext(Class, ManglingContextDecl);
+    assert(MCtx && "Retrieving mangle numbering context failed!");
+    HasKnownInternalLinkage = true;
+  }
+  if (MCtx) {
+    unsigned ManglingNumber = MCtx->getManglingNumber(Method);
+    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
+                             HasKnownInternalLinkage);
+  }
 }
 
 void Sema::buildLambdaScope(LambdaScopeInfo *LSI,
@@ -839,6 +869,8 @@ VarDecl *Sema::createLambdaInitCaptureVarDecl(SourceLocation Loc,
   NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
   NewVD->markUsed(Context);
   NewVD->setInit(Init);
+  if (NewVD->isParameterPack())
+    getCurLambda()->LocalPacks.push_back(NewVD);
   return NewVD;
 }
 
@@ -928,12 +960,12 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
 
     // Check for unexpanded parameter packs in the method type.
     if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
-      ContainsUnexpandedParameterPack = true;
+      DiagnoseUnexpandedParameterPack(Intro.Range.getBegin(), MethodTyInfo,
+                                      UPPC_DeclarationType);
   }
 
   CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
                                                  KnownDependent, Intro.Default);
-
   CXXMethodDecl *Method =
       startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
                             ParamInfo.getDeclSpec().getConstexprSpecifier());
@@ -956,6 +988,9 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   if (getLangOpts().CUDA)
     CUDASetLambdaAttrs(Method);
 
+  // Number the lambda for linkage purposes if necessary.
+  handleLambdaNumbering(Class, Method);
+
   // Introduce the function call operator as the current declaration context.
   PushDeclContext(CurScope, Method);
 
@@ -1053,7 +1088,7 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
 
       if (C->Init.get()->containsUnexpandedParameterPack() &&
           !C->InitCaptureType.get()->getAs<PackExpansionType>())
-        ContainsUnexpandedParameterPack = true;
+        DiagnoseUnexpandedParameterPack(C->Init.get(), UPPC_Initializer);
 
       unsigned InitStyle;
       switch (C->InitKind) {
@@ -1184,7 +1219,7 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   }
   finishLambdaExplicitCaptures(LSI);
 
-  LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
+  LSI->ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack;
 
   // Add lambda parameters into scope.
   addLambdaParameters(Intro.Captures, Method, CurScope);
@@ -1639,8 +1674,9 @@ ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
         ? CallOperator->getDescribedFunctionTemplate()
         : cast<Decl>(CallOperator);
 
+    // FIXME: Is this really the best choice? Keeping the lexical decl context
+    // set as CurContext seems more faithful to the source.
     TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
-    Class->addDecl(TemplateOrNonTemplateCallOperatorDecl);
 
     PopExpressionEvaluationContext();
 
@@ -1776,10 +1812,9 @@ ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
       !CallOperator->isConstexpr() &&
       !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
       !Class->getDeclContext()->isDependentContext()) {
-    TentativeAnalysisScope DiagnosticScopeGuard(*this);
     CallOperator->setConstexprKind(
-        (CheckConstexprFunctionDecl(CallOperator) &&
-         CheckConstexprFunctionBody(CallOperator, CallOperator->getBody()))
+        CheckConstexprFunctionDefinition(CallOperator,
+                                         CheckConstexprKind::CheckValid)
             ? CSK_constexpr
             : CSK_unspecified);
   }