1//===--- TokenRewriter.cpp - Token-based code rewriting interface ---------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements the TokenRewriter class, which is used for code
11//  transformations.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Rewrite/Core/TokenRewriter.h"
16#include "clang/Basic/SourceManager.h"
17#include "clang/Lex/Lexer.h"
18#include "clang/Lex/ScratchBuffer.h"
19using namespace clang;
20
21TokenRewriter::TokenRewriter(FileID FID, SourceManager &SM,
22                             const LangOptions &LangOpts) {
23  ScratchBuf.reset(new ScratchBuffer(SM));
24
25  // Create a lexer to lex all the tokens of the main file in raw mode.
26  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
27  Lexer RawLex(FID, FromFile, SM, LangOpts);
28
29  // Return all comments and whitespace as tokens.
30  RawLex.SetKeepWhitespaceMode(true);
31
32  // Lex the file, populating our datastructures.
33  Token RawTok;
34  RawLex.LexFromRawLexer(RawTok);
35  while (RawTok.isNot(tok::eof)) {
36#if 0
37    if (Tok.is(tok::raw_identifier)) {
38      // Look up the identifier info for the token.  This should use
39      // IdentifierTable directly instead of PP.
40      PP.LookUpIdentifierInfo(Tok);
41    }
42#endif
43
44    AddToken(RawTok, TokenList.end());
45    RawLex.LexFromRawLexer(RawTok);
46  }
47}
48
49TokenRewriter::~TokenRewriter() {
50}
51
52
53/// RemapIterator - Convert from token_iterator (a const iterator) to
54/// TokenRefTy (a non-const iterator).
55TokenRewriter::TokenRefTy TokenRewriter::RemapIterator(token_iterator I) {
56  if (I == token_end()) return TokenList.end();
57
58  // FIXME: This is horrible, we should use our own list or something to avoid
59  // this.
60  std::map<SourceLocation, TokenRefTy>::iterator MapIt =
61    TokenAtLoc.find(I->getLocation());
62  assert(MapIt != TokenAtLoc.end() && "iterator not in rewriter?");
63  return MapIt->second;
64}
65
66
67/// AddToken - Add the specified token into the Rewriter before the other
68/// position.
69TokenRewriter::TokenRefTy
70TokenRewriter::AddToken(const Token &T, TokenRefTy Where) {
71  Where = TokenList.insert(Where, T);
72
73  bool InsertSuccess = TokenAtLoc.insert(std::make_pair(T.getLocation(),
74                                                        Where)).second;
75  assert(InsertSuccess && "Token location already in rewriter!");
76  (void)InsertSuccess;
77  return Where;
78}
79
80
81TokenRewriter::token_iterator
82TokenRewriter::AddTokenBefore(token_iterator I, const char *Val) {
83  unsigned Len = strlen(Val);
84
85  // Plop the string into the scratch buffer, then create a token for this
86  // string.
87  Token Tok;
88  Tok.startToken();
89  const char *Spelling;
90  Tok.setLocation(ScratchBuf->getToken(Val, Len, Spelling));
91  Tok.setLength(Len);
92
93  // TODO: Form a whole lexer around this and relex the token!  For now, just
94  // set kind to tok::unknown.
95  Tok.setKind(tok::unknown);
96
97  return AddToken(Tok, RemapIterator(I));
98}
99
100