Make clang's rewrite engine a core feature

The rewrite facility's footprint is small so it's not worth going to these
lengths to support disabling at configure time, particularly since key compiler
features now depend on it.

Meanwhile the Objective-C rewriters have been moved under the
ENABLE_CLANG_ARCMT umbrella for now as they're comparatively heavy and still
potentially worth excluding from lightweight builds.

Tests are now passing with any combination of feature flags. The flags
historically haven't been tested by LLVM's build servers so caveat emptor.

llvm-svn: 213171

1 files changed, 99 insertions, 0 deletions

diff --git a/clang/lib/Rewrite/TokenRewriter.cpp b/clang/lib/Rewrite/TokenRewriter.cpp
new file mode 100644
index 00000000000..494defdedaa
--- /dev/null
+++ b/clang/lib/Rewrite/TokenRewriter.cpp
@@ -0,0 +1,99 @@
+//===--- TokenRewriter.cpp - Token-based code rewriting interface ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the TokenRewriter class, which is used for code
+//  transformations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Core/TokenRewriter.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/ScratchBuffer.h"
+using namespace clang;
+
+TokenRewriter::TokenRewriter(FileID FID, SourceManager &SM,
+                             const LangOptions &LangOpts) {
+  ScratchBuf.reset(new ScratchBuffer(SM));
+
+  // Create a lexer to lex all the tokens of the main file in raw mode.
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+  Lexer RawLex(FID, FromFile, SM, LangOpts);
+
+  // Return all comments and whitespace as tokens.
+  RawLex.SetKeepWhitespaceMode(true);
+
+  // Lex the file, populating our datastructures.
+  Token RawTok;
+  RawLex.LexFromRawLexer(RawTok);
+  while (RawTok.isNot(tok::eof)) {
+#if 0
+    if (Tok.is(tok::raw_identifier)) {
+      // Look up the identifier info for the token.  This should use
+      // IdentifierTable directly instead of PP.
+      PP.LookUpIdentifierInfo(Tok);
+    }
+#endif
+
+    AddToken(RawTok, TokenList.end());
+    RawLex.LexFromRawLexer(RawTok);
+  }
+}
+
+TokenRewriter::~TokenRewriter() {
+}
+
+
+/// RemapIterator - Convert from token_iterator (a const iterator) to
+/// TokenRefTy (a non-const iterator).
+TokenRewriter::TokenRefTy TokenRewriter::RemapIterator(token_iterator I) {
+  if (I == token_end()) return TokenList.end();
+
+  // FIXME: This is horrible, we should use our own list or something to avoid
+  // this.
+  std::map<SourceLocation, TokenRefTy>::iterator MapIt =
+    TokenAtLoc.find(I->getLocation());
+  assert(MapIt != TokenAtLoc.end() && "iterator not in rewriter?");
+  return MapIt->second;
+}
+
+
+/// AddToken - Add the specified token into the Rewriter before the other
+/// position.
+TokenRewriter::TokenRefTy
+TokenRewriter::AddToken(const Token &T, TokenRefTy Where) {
+  Where = TokenList.insert(Where, T);
+
+  bool InsertSuccess = TokenAtLoc.insert(std::make_pair(T.getLocation(),
+                                                        Where)).second;
+  assert(InsertSuccess && "Token location already in rewriter!");
+  (void)InsertSuccess;
+  return Where;
+}
+
+
+TokenRewriter::token_iterator
+TokenRewriter::AddTokenBefore(token_iterator I, const char *Val) {
+  unsigned Len = strlen(Val);
+
+  // Plop the string into the scratch buffer, then create a token for this
+  // string.
+  Token Tok;
+  Tok.startToken();
+  const char *Spelling;
+  Tok.setLocation(ScratchBuf->getToken(Val, Len, Spelling));
+  Tok.setLength(Len);
+
+  // TODO: Form a whole lexer around this and relex the token!  For now, just
+  // set kind to tok::unknown.
+  Tok.setKind(tok::unknown);
+
+  return AddToken(Tok, RemapIterator(I));
+}
+