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. The entry
//  point is Sema::CheckInitList(), but all of the work is performed
//  within the InitListChecker class.
//
//===----------------------------------------------------------------------===//

#include "Sema.h"
#include "clang/Parse/Designator.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include <map>
using namespace clang;

/// @brief Semantic checking for initializer lists.
///
/// The InitListChecker class contains a set of routines that each
/// handle the initialization of a certain kind of entity, e.g.,
/// arrays, vectors, struct/union types, scalars, etc. The
/// InitListChecker itself performs a recursive walk of the subobject
/// structure of the type to be initialized, while stepping through
/// the initializer list one element at a time. The IList and Index
/// parameters to each of the Check* routines contain the active
/// (syntactic) initializer list and the index into that initializer
/// list that represents the current initializer. Each routine is
/// responsible for moving that Index forward as it consumes elements.
///
/// Each Check* routine also has a StructuredList/StructuredIndex
/// arguments, which contains the current the "structured" (semantic)
/// initializer list and the index into that initializer list where we
/// are copying initializers as we map them over to the semantic
/// list. Once we have completed our recursive walk of the subobject
/// structure, we will have constructed a full semantic initializer
/// list.
///
/// C99 designators cause changes in the initializer list traversal,
/// because they make the initialization "jump" into a specific
/// subobject and then continue the initialization from that
/// point. CheckDesignatedInitializer() recursively steps into the
/// designated subobject and manages backing out the recursion to
/// initialize the subobjects after the one designated.
namespace clang {
class InitListChecker {
  Sema *SemaRef;
  bool hadError;
  std::map<InitListExpr *, InitListExpr *> SyntacticToSemantic;
  InitListExpr *FullyStructuredList;
  
  void CheckImplicitInitList(InitListExpr *ParentIList, QualType T, 
                             unsigned &Index, InitListExpr *StructuredList,
                             unsigned &StructuredIndex);
  void CheckExplicitInitList(InitListExpr *IList, QualType &T,
                             unsigned &Index, InitListExpr *StructuredList,
                             unsigned &StructuredIndex);
  void CheckListElementTypes(InitListExpr *IList, QualType &DeclType, 
                             bool SubobjectIsDesignatorContext, 
                             unsigned &Index,
                             InitListExpr *StructuredList,
                             unsigned &StructuredIndex);
  void CheckSubElementType(InitListExpr *IList, QualType ElemType, 
                           unsigned &Index,
                           InitListExpr *StructuredList,
                           unsigned &StructuredIndex);
  // FIXME: Does DeclType need to be a reference type?
  void CheckScalarType(InitListExpr *IList, QualType &DeclType, 
                       unsigned &Index,
                       InitListExpr *StructuredList,
                       unsigned &StructuredIndex);
  void CheckVectorType(InitListExpr *IList, QualType DeclType, unsigned &Index,
                       InitListExpr *StructuredList,
                       unsigned &StructuredIndex);
  void CheckStructUnionTypes(InitListExpr *IList, QualType DeclType, 
                             RecordDecl::field_iterator Field, 
                             bool SubobjectIsDesignatorContext, unsigned &Index,
                             InitListExpr *StructuredList,
                             unsigned &StructuredIndex);
  void CheckArrayType(InitListExpr *IList, QualType &DeclType, 
                      llvm::APSInt elementIndex, 
                      bool SubobjectIsDesignatorContext, unsigned &Index,
                      InitListExpr *StructuredList,
                      unsigned &StructuredIndex);
  bool CheckDesignatedInitializer(InitListExpr *IList, DesignatedInitExpr *DIE, 
                                  DesignatedInitExpr::designators_iterator D,
                                  QualType &CurrentObjectType, 
                                  RecordDecl::field_iterator *NextField,
                                  llvm::APSInt *NextElementIndex,
                                  unsigned &Index,
                                  InitListExpr *StructuredList,
                                  unsigned &StructuredIndex,
                                  bool FinishSubobjectInit = true);
  InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
                                           QualType CurrentObjectType,
                                           InitListExpr *StructuredList,
                                           unsigned StructuredIndex,
                                           SourceRange InitRange);
  void UpdateStructuredListElement(InitListExpr *StructuredList,