path: root/lib/Sema/SemaInit.cpp

//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
//
//                     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 initializers.
//
//===----------------------------------------------------------------------===//

#include "Sema.h"
#include "clang/Parse/Designator.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/Basic/DiagnosticSema.h"
using namespace clang;

/// Recursively replaces NULL values within the given initializer list
/// with expressions that perform value-initialization of the
/// appropriate type.
static void fillInValueInitializations(ASTContext &Context, InitListExpr *ILE) {
  assert((ILE->getType() != Context.VoidTy) && "Should not have void type");
  if (const RecordType *RType = ILE->getType()->getAsRecordType()) {
    unsigned Init = 0, NumInits = ILE->getNumInits();
    for (RecordDecl::field_iterator Field = RType->getDecl()->field_begin(),
                                 FieldEnd = RType->getDecl()->field_end();
         Field != FieldEnd; ++Field) {
      if (Field->isUnnamedBitfield())
        continue;

      if (Init >= NumInits)
        break;

      // FIXME: Check for fields with reference type in C++?
      if (!ILE->getInit(Init))
        ILE->setInit(Init, 
                     new (Context) CXXZeroInitValueExpr(Field->getType(), 
                                                        SourceLocation(),
                                                        SourceLocation()));
      else if (InitListExpr *InnerILE = dyn_cast<InitListExpr>(ILE->getInit(Init)))
        fillInValueInitializations(Context, InnerILE);
      ++Init;
    }

    return;
  } 

  QualType ElementType;
  
  if (const ArrayType *AType = Context.getAsArrayType(ILE->getType()))
    ElementType = AType->getElementType();
  else if (const VectorType *VType = ILE->getType()->getAsVectorType())
    ElementType = VType->getElementType();
  else 
    ElementType = ILE->getType();
  
  for (unsigned Init = 0, NumInits = ILE->getNumInits(); Init != NumInits; 
       ++Init) {
    if (!ILE->getInit(Init))
      ILE->setInit(Init, new (Context) CXXZeroInitValueExpr(ElementType, 
                                                            SourceLocation(),
                                                            SourceLocation()));
    else if (InitListExpr *InnerILE = dyn_cast<InitListExpr>(ILE->getInit(Init)))
      fillInValueInitializations(Context, InnerILE);
  }
}

InitListChecker::InitListChecker(Sema *S, InitListExpr *IL, QualType &T) {
  hadError = false;
  SemaRef = S;

  unsigned newIndex = 0;
  unsigned newStructuredIndex = 0;
  FullyStructuredList 
    = getStructuredSubobjectInit(IL, newIndex, T, 0, 0, SourceRange());
  CheckExplicitInitList(IL, T, newIndex, FullyStructuredList, newStructuredIndex);

  if (!hadError) {
    fillInValueInitializations(SemaRef->Context, FullyStructuredList);
  }
}

int InitListChecker::numArrayElements(QualType DeclType) {
  // FIXME: use a proper constant
  int maxElements = 0x7FFFFFFF;
  if (const ConstantArrayType *CAT =
        SemaRef->Context.getAsConstantArrayType(DeclType)) {
    maxElements = static_cast<int>(CAT->getSize().getZExtValue());
  }
  return maxElements;
}

int InitListChecker::numStructUnionElements(QualType DeclType) {
  RecordDecl *structDecl = DeclType->getAsRecordType()->getDecl();
  int InitializableMembers = 0;
  for (RecordDecl::field_iterator Field = structDecl->field_begin(),
                               FieldEnd = structDecl->field_end();
       Field != FieldEnd; ++Field) {
    if ((*Field)->getIdentifier() || !(*Field)->isBitField())
      ++InitializableMembers;
  }
  if (structDecl->isUnion())
    return std::min(InitializableMembers, 1);
  return InitializableMembers - structDecl->hasFlexibleArrayMember();
}

void InitListChecker::CheckImplicitInitList(InitListExpr *ParentIList, 
                                            QualType T, unsigned &Index,
                                            InitListExpr *StructuredList,
                                            unsigned &StructuredIndex) {
  int maxElements = 0;
  
  if (T->isArrayType())
    maxElements = numArrayElements(T);
  else if (T->isStructureType() || T->isUnionType())