1 files changed, 228 insertions, 88 deletions

diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaLambda.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaLambda.cpp
index 6ef8d88..6414c6f 100644
--- a/contrib/llvm/tools/clang/lib/Sema/SemaLambda.cpp
+++ b/contrib/llvm/tools/clang/lib/Sema/SemaLambda.cpp
@@ -54,9 +54,7 @@ CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
                  SourceRange IntroducerRange,
                  TypeSourceInfo *MethodType,
                  SourceLocation EndLoc,
-                 llvm::ArrayRef<ParmVarDecl *> Params,
-                 llvm::Optional<unsigned> ManglingNumber,
-                 Decl *ContextDecl) {
+                 llvm::ArrayRef<ParmVarDecl *> Params) {
   // C++11 [expr.prim.lambda]p5:
   //   The closure type for a lambda-expression has a public inline function 
   //   call operator (13.5.4) whose parameters and return type are described by
@@ -98,64 +96,76 @@ CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
          P != PEnd; ++P)
       (*P)->setOwningFunction(Method);
   }
-  
-  // If we don't already have a mangling number for this lambda expression,
-  // allocate one now.
-  if (!ManglingNumber) {
-    ContextDecl = ExprEvalContexts.back().LambdaContextDecl;
-    
-    enum ContextKind {
-      Normal,
-      DefaultArgument,
-      DataMember,
-      StaticDataMember
-    } Kind = Normal;
-    
-    // Default arguments of member function parameters that appear in a class
-    // definition, as well as the initializers of data members, receive special
-    // treatment. Identify them.
-    if (ContextDecl) {
-      if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ContextDecl)) {
-        if (const DeclContext *LexicalDC
-            = Param->getDeclContext()->getLexicalParent())
-          if (LexicalDC->isRecord())
-            Kind = DefaultArgument;
-      } else if (VarDecl *Var = dyn_cast<VarDecl>(ContextDecl)) {
-        if (Var->getDeclContext()->isRecord())
-          Kind = StaticDataMember;
-      } else if (isa<FieldDecl>(ContextDecl)) {
-        Kind = DataMember;
-      }
-    }        
-    
-    switch (Kind) {
-      case Normal:
-        if (CurContext->isDependentContext() || isInInlineFunction(CurContext))
-          ManglingNumber = Context.getLambdaManglingNumber(Method);
-        else
-          ManglingNumber = 0;
-        
-        // There is no special context for this lambda.
-        ContextDecl = 0;        
-        break;
-        
-      case StaticDataMember:
-        if (!CurContext->isDependentContext()) {
-          ManglingNumber = 0;
-          ContextDecl = 0;
-          break;
-        }
-        // Fall through to assign a mangling number.
-        
-      case DataMember:
-      case DefaultArgument:
-        ManglingNumber = ExprEvalContexts.back().getLambdaMangleContext()
-                           .getManglingNumber(Method);
-        break;
+
+  // Allocate a mangling number for this lambda expression, if the ABI
+  // requires one.
+  Decl *ContextDecl = ExprEvalContexts.back().LambdaContextDecl;
+
+  enum ContextKind {
+    Normal,
+    DefaultArgument,
+    DataMember,
+    StaticDataMember
+  } Kind = Normal;
+
+  // Default arguments of member function parameters that appear in a class
+  // definition, as well as the initializers of data members, receive special
+  // treatment. Identify them.
+  if (ContextDecl) {
+    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ContextDecl)) {
+      if (const DeclContext *LexicalDC
+          = Param->getDeclContext()->getLexicalParent())
+        if (LexicalDC->isRecord())
+          Kind = DefaultArgument;
+    } else if (VarDecl *Var = dyn_cast<VarDecl>(ContextDecl)) {
+      if (Var->getDeclContext()->isRecord())
+        Kind = StaticDataMember;
+    } else if (isa<FieldDecl>(ContextDecl)) {
+      Kind = DataMember;
     }
   }
 
-  Class->setLambdaMangling(*ManglingNumber, ContextDecl);
+  // Itanium ABI [5.1.7]:
+  //   In the following contexts [...] the one-definition rule requires closure
+  //   types in different translation units to "correspond":
+  bool IsInNonspecializedTemplate =
+    !ActiveTemplateInstantiations.empty() || CurContext->isDependentContext();
+  unsigned ManglingNumber;
+  switch (Kind) {
+  case Normal:
+    //  -- the bodies of non-exported nonspecialized template functions
+    //  -- the bodies of inline functions
+    if ((IsInNonspecializedTemplate &&
+         !(ContextDecl && isa<ParmVarDecl>(ContextDecl))) ||
+        isInInlineFunction(CurContext))
+      ManglingNumber = Context.getLambdaManglingNumber(Method);
+    else
+      ManglingNumber = 0;
+
+    // There is no special context for this lambda.
+    ContextDecl = 0;
+    break;
+
+  case StaticDataMember:
+    //  -- the initializers of nonspecialized static members of template classes
+    if (!IsInNonspecializedTemplate) {
+      ManglingNumber = 0;
+      ContextDecl = 0;
+      break;
+    }
+    // Fall through to assign a mangling number.
+
+  case DataMember:
+    //  -- the in-class initializers of class members
+  case DefaultArgument:
+    //  -- default arguments appearing in class definitions
+    ManglingNumber = ExprEvalContexts.back().getLambdaMangleContext()
+                       .getManglingNumber(Method);
+    break;
+  }
+
+  Class->setLambdaMangling(ManglingNumber, ContextDecl);
+
   return Method;
 }
 
@@ -214,6 +224,141 @@ void Sema::addLambdaParameters(CXXMethodDecl *CallOperator, Scope *CurScope) {
   }
 }
 
+static bool checkReturnValueType(const ASTContext &Ctx, const Expr *E,
+                                 QualType &DeducedType,
+                                 QualType &AlternateType) {
+  // Handle ReturnStmts with no expressions.
+  if (!E) {
+    if (AlternateType.isNull())
+      AlternateType = Ctx.VoidTy;
+
+    return Ctx.hasSameType(DeducedType, Ctx.VoidTy);
+  }
+
+  QualType StrictType = E->getType();
+  QualType LooseType = StrictType;
+
+  // In C, enum constants have the type of their underlying integer type,
+  // not the enum. When inferring block return types, we should allow
+  // the enum type if an enum constant is used, unless the enum is
+  // anonymous (in which case there can be no variables of its type).
+  if (!Ctx.getLangOpts().CPlusPlus) {
+    const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
+    if (DRE) {
+      const Decl *D = DRE->getDecl();
+      if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
+        const EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext());
+        if (Enum->getDeclName() || Enum->getTypedefNameForAnonDecl())
+          LooseType = Ctx.getTypeDeclType(Enum);
+      }
+    }
+  }
+
+  // Special case for the first return statement we find.
+  // The return type has already been tentatively set, but we might still
+  // have an alternate type we should prefer.
+  if (AlternateType.isNull())
+    AlternateType = LooseType;
+
+  if (Ctx.hasSameType(DeducedType, StrictType)) {
+    // FIXME: The loose type is different when there are constants from two
+    // different enums. We could consider warning here.
+    if (AlternateType != Ctx.DependentTy)
+      if (!Ctx.hasSameType(AlternateType, LooseType))
+        AlternateType = Ctx.VoidTy;
+    return true;
+  }
+
+  if (Ctx.hasSameType(DeducedType, LooseType)) {
+    // Use DependentTy to signal that we're using an alternate type and may
+    // need to add casts somewhere.
+    AlternateType = Ctx.DependentTy;
+    return true;
+  }
+
+  if (Ctx.hasSameType(AlternateType, StrictType) ||
+      Ctx.hasSameType(AlternateType, LooseType)) {
+    DeducedType = AlternateType;
+    // Use DependentTy to signal that we're using an alternate type and may
+    // need to add casts somewhere.
+    AlternateType = Ctx.DependentTy;
+    return true;
+  }
+
+  return false;
+}
+
+void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) {
+  assert(CSI.HasImplicitReturnType);
+
+  // First case: no return statements, implicit void return type.
+  ASTContext &Ctx = getASTContext();
+  if (CSI.Returns.empty()) {
+    // It's possible there were simply no /valid/ return statements.
+    // In this case, the first one we found may have at least given us a type.
+    if (CSI.ReturnType.isNull())
+      CSI.ReturnType = Ctx.VoidTy;
+    return;
+  }
+
+  // Second case: at least one return statement has dependent type.
+  // Delay type checking until instantiation.
+  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
+  if (CSI.ReturnType->isDependentType())
+    return;
+
+  // Third case: only one return statement. Don't bother doing extra work!
+  SmallVectorImpl<ReturnStmt*>::iterator I = CSI.Returns.begin(),
+                                         E = CSI.Returns.end();
+  if (I+1 == E)
+    return;
+
+  // General case: many return statements.
+  // Check that they all have compatible return types.
+  // For now, that means "identical", with an exception for enum constants.
+  // (In C, enum constants have the type of their underlying integer type,
+  // not the type of the enum. C++ uses the type of the enum.)
+  QualType AlternateType;
+
+  // We require the return types to strictly match here.
+  for (; I != E; ++I) {
+    const ReturnStmt *RS = *I;
+    const Expr *RetE = RS->getRetValue();
+    if (!checkReturnValueType(Ctx, RetE, CSI.ReturnType, AlternateType)) {
+      // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
+      Diag(RS->getLocStart(),
+           diag::err_typecheck_missing_return_type_incompatible)
+        << (RetE ? RetE->getType() : Ctx.VoidTy) << CSI.ReturnType
+        << isa<LambdaScopeInfo>(CSI);
+      // Don't bother fixing up the return statements in the block if some of
+      // them are unfixable anyway.
+      AlternateType = Ctx.VoidTy;
+      // Continue iterating so that we keep emitting diagnostics.
+    }
+  }
+
+  // If our return statements turned out to be compatible, but we needed to
+  // pick a different return type, go through and fix the ones that need it.
+  if (AlternateType == Ctx.DependentTy) {
+    for (SmallVectorImpl<ReturnStmt*>::iterator I = CSI.Returns.begin(),
+                                                E = CSI.Returns.end();
+         I != E; ++I) {
+      ReturnStmt *RS = *I;
+      Expr *RetE = RS->getRetValue();
+      if (RetE->getType() == CSI.ReturnType)
+        continue;
+
+      // Right now we only support integral fixup casts.
+      assert(CSI.ReturnType->isIntegralOrUnscopedEnumerationType());
+      assert(RetE->getType()->isIntegralOrUnscopedEnumerationType());
+      ExprResult Casted = ImpCastExprToType(RetE, CSI.ReturnType,
+                                            CK_IntegralCast);
+      assert(Casted.isUsable());
+      RS->setRetValue(Casted.take());
+    }
+  }
+}
+
 void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
                                         Declarator &ParamInfo,
                                         Scope *CurScope) {
@@ -230,6 +375,7 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   TypeSourceInfo *MethodTyInfo;
   bool ExplicitParams = true;
   bool ExplicitResultType = true;
+  bool ContainsUnexpandedParameterPack = false;
   SourceLocation EndLoc;
   llvm::ArrayRef<ParmVarDecl *> Params;
   if (ParamInfo.getNumTypeObjects() == 0) {
@@ -269,9 +415,13 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
     FunctionProtoTypeLoc Proto = cast<FunctionProtoTypeLoc>(TL);
     Params = llvm::ArrayRef<ParmVarDecl *>(Proto.getParmArray(), 
                                            Proto.getNumArgs());
+
+    // Check for unexpanded parameter packs in the method type.
+    if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
+      ContainsUnexpandedParameterPack = true;
   }
   
-  CXXMethodDecl *Method = startLambdaDefinition(Class, Intro.Range, 
+  CXXMethodDecl *Method = startLambdaDefinition(Class, Intro.Range,
                                                 MethodTyInfo, EndLoc, Params);
   
   if (ExplicitParams)
@@ -287,7 +437,7 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   LambdaScopeInfo *LSI
     = enterLambdaScope(Method, Intro.Range, Intro.Default, ExplicitParams,
                        ExplicitResultType,
-                       (Method->getTypeQualifiers() & Qualifiers::Const) == 0);
+                       !Method->isConst());
  
   // Handle explicit captures.
   SourceLocation PrevCaptureLoc
@@ -409,8 +559,7 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
         // Just ignore the ellipsis.
       }
     } else if (Var->isParameterPack()) {
-      Diag(C->Loc, diag::err_lambda_unexpanded_pack);
-      continue;
+      ContainsUnexpandedParameterPack = true;
     }
     
     TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
@@ -419,6 +568,8 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   }
   finishLambdaExplicitCaptures(LSI);
 
+  LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
+
   // Add lambda parameters into scope.
   addLambdaParameters(Method, CurScope);
 
@@ -441,7 +592,10 @@ void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
   LambdaScopeInfo *LSI = getCurLambda();
   CXXRecordDecl *Class = LSI->Lambda;
   Class->setInvalidDecl();
-  SmallVector<Decl*, 4> Fields(Class->field_begin(), Class->field_end());
+  SmallVector<Decl*, 4> Fields;
+  for (RecordDecl::field_iterator i = Class->field_begin(),
+                                  e = Class->field_end(); i != e; ++i)
+    Fields.push_back(*i);
   ActOnFields(0, Class->getLocation(), Class, Fields, 
               SourceLocation(), SourceLocation(), 0);
   CheckCompletedCXXClass(Class);
@@ -578,6 +732,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
   bool ExplicitParams;
   bool ExplicitResultType;
   bool LambdaExprNeedsCleanups;
+  bool ContainsUnexpandedParameterPack;
   llvm::SmallVector<VarDecl *, 4> ArrayIndexVars;
   llvm::SmallVector<unsigned, 4> ArrayIndexStarts;
   {
@@ -588,6 +743,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
     ExplicitParams = LSI->ExplicitParams;
     ExplicitResultType = !LSI->HasImplicitReturnType;
     LambdaExprNeedsCleanups = LSI->ExprNeedsCleanups;
+    ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
     ArrayIndexVars.swap(LSI->ArrayIndexVars);
     ArrayIndexStarts.swap(LSI->ArrayIndexStarts);
     
@@ -639,32 +795,14 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
     //   denotes the following type:
     // FIXME: Assumes current resolution to core issue 975.
     if (LSI->HasImplicitReturnType) {
+      deduceClosureReturnType(*LSI);
+
       //   - if there are no return statements in the
       //     compound-statement, or all return statements return
       //     either an expression of type void or no expression or
       //     braced-init-list, the type void;
       if (LSI->ReturnType.isNull()) {
         LSI->ReturnType = Context.VoidTy;
-      } else {
-        // C++11 [expr.prim.lambda]p4:
-        //   - if the compound-statement is of the form
-        //
-        //       { attribute-specifier-seq[opt] return expression ; }
-        //
-        //     the type of the returned expression after
-        //     lvalue-to-rvalue conversion (4.1), array-to-pointer
-        //     conver- sion (4.2), and function-to-pointer conversion
-        //     (4.3);
-        //
-        // Since we're accepting the resolution to a post-C++11 core
-        // issue with a non-trivial extension, provide a warning (by
-        // default).
-        CompoundStmt *CompoundBody = cast<CompoundStmt>(Body);
-        if (!(CompoundBody->size() == 1 &&
-              isa<ReturnStmt>(*CompoundBody->body_begin())) &&
-            !Context.hasSameType(LSI->ReturnType, Context.VoidTy))
-          Diag(IntroducerRange.getBegin(), 
-               diag::ext_lambda_implies_void_return);
       }
 
       // Create a function type with the inferred return type.
@@ -704,7 +842,10 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
       addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
     
     // Finalize the lambda class.
-    SmallVector<Decl*, 4> Fields(Class->field_begin(), Class->field_end());
+    SmallVector<Decl*, 4> Fields;
+    for (RecordDecl::field_iterator i = Class->field_begin(),
+                                    e = Class->field_end(); i != e; ++i)
+      Fields.push_back(*i);
     ActOnFields(0, Class->getLocation(), Class, Fields, 
                 SourceLocation(), SourceLocation(), 0);
     CheckCompletedCXXClass(Class);
@@ -717,7 +858,8 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
                                           CaptureDefault, Captures, 
                                           ExplicitParams, ExplicitResultType,
                                           CaptureInits, ArrayIndexVars, 
-                                          ArrayIndexStarts, Body->getLocEnd());
+                                          ArrayIndexStarts, Body->getLocEnd(),
+                                          ContainsUnexpandedParameterPack);
 
   // C++11 [expr.prim.lambda]p2:
   //   A lambda-expression shall not appear in an unevaluated operand
@@ -807,9 +949,7 @@ ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
 
   // Add a fake function body to the block. IR generation is responsible
   // for filling in the actual body, which cannot be expressed as an AST.
-  Block->setBody(new (Context) CompoundStmt(Context, 0, 0, 
-                                            ConvLocation,
-                                            ConvLocation));
+  Block->setBody(new (Context) CompoundStmt(ConvLocation));
 
   // Create the block literal expression.
   Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());