path: root/lib/Sema/SemaLambda.cpp

//===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements semantic analysis for C++ lambda expressions.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/DeclSpec.h"
#include "clang/AST/ExprCXX.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaInternal.h"
using namespace clang;
using namespace sema;

CXXRecordDecl *Sema::createLambdaClosureType(SourceRange IntroducerRange,
                                             TypeSourceInfo *Info,
                                             bool KnownDependent) {
  DeclContext *DC = CurContext;
  while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
    DC = DC->getParent();
  
  // Start constructing the lambda class.
  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
                                                     IntroducerRange.getBegin(),
                                                     KnownDependent);
  DC->addDecl(Class);
  
  return Class;
}

/// \brief Determine whether the given context is or is enclosed in an inline
/// function.
static bool isInInlineFunction(const DeclContext *DC) {
  while (!DC->isFileContext()) {
    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
      if (FD->isInlined())
        return true;
    
    DC = DC->getLexicalParent();
  }
  
  return false;
}

CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
                 SourceRange IntroducerRange,
                 TypeSourceInfo *MethodType,
                 SourceLocation EndLoc,
                 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
  //   the lambda-expression's parameter-declaration-clause and 
  //   trailing-return-type respectively.
  DeclarationName MethodName
    = Context.DeclarationNames.getCXXOperatorName(OO_Call);
  DeclarationNameLoc MethodNameLoc;
  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
    = IntroducerRange.getBegin().getRawEncoding();
  MethodNameLoc.CXXOperatorName.EndOpNameLoc
    = IntroducerRange.getEnd().getRawEncoding();
  CXXMethodDecl *Method
    = CXXMethodDecl::Create(Context, Class, EndLoc,
                            DeclarationNameInfo(MethodName, 
                                                IntroducerRange.getBegin(),
                                                MethodNameLoc),
                            MethodType->getType(), MethodType,
                            SC_None,
                            /*isInline=*/true,
                            /*isConstExpr=*/false,
                            EndLoc);
  Method->setAccess(AS_public);
  
  // Temporarily set the lexical declaration context to the current
  // context, so that the Scope stack matches the lexical nesting.
  Method->setLexicalDeclContext(CurContext);  
  
  // Add parameters.
  if (!Params.empty()) {
    Method->setParams(Params);
    CheckParmsForFunctionDef(const_cast<ParmVarDecl **>(Params.begin()),
                             const_cast<ParmVarDecl **>(Params.end()),
                             /*CheckParameterNames=*/false);
    
    for (CXXMethodDecl::param_iterator P = Method->param_begin(), 
                                    PEnd = Method->param_end();
         P != PEnd; ++P)
      (*P)->setOwningFunction(Method);
  }

  // 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;
    }
  }

  // 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