path: root/lib/Sema/SemaChecking.cpp

//===--- SemaChecking.cpp - Extra Semantic Checking -----------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements extra semantic analysis beyond what is enforced 
//  by the C type system.
//
//===----------------------------------------------------------------------===//

#include "Sema.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Lex/Preprocessor.h"
#include <limits>
using namespace clang;

/// getLocationOfStringLiteralByte - Return a source location that points to the
/// specified byte of the specified string literal.
///
/// Strings are amazingly complex.  They can be formed from multiple tokens and
/// can have escape sequences in them in addition to the usual trigraph and
/// escaped newline business.  This routine handles this complexity.
///
SourceLocation Sema::getLocationOfStringLiteralByte(const StringLiteral *SL,
                                                    unsigned ByteNo) const {
  assert(!SL->isWide() && "This doesn't work for wide strings yet");
  
  // Loop over all of the tokens in this string until we find the one that
  // contains the byte we're looking for.
  unsigned TokNo = 0;
  while (1) {
    assert(TokNo < SL->getNumConcatenated() && "Invalid byte number!");
    SourceLocation StrTokLoc = SL->getStrTokenLoc(TokNo);
   
    // Get the spelling of the string so that we can get the data that makes up
    // the string literal, not the identifier for the macro it is potentially
    // expanded through.
    SourceLocation StrTokSpellingLoc = SourceMgr.getSpellingLoc(StrTokLoc);

    // Re-lex the token to get its length and original spelling.
    std::pair<FileID, unsigned> LocInfo =
      SourceMgr.getDecomposedLoc(StrTokSpellingLoc);
    std::pair<const char *,const char *> Buffer =
      SourceMgr.getBufferData(LocInfo.first);
    const char *StrData