1 files changed, 217 insertions, 0 deletions
diff --git a/lib/Rewrite/Frontend/RewriteMacros.cpp b/lib/Rewrite/Frontend/RewriteMacros.cpp
new file mode 100644
index 000000000000..f399dd5d7ce9
--- /dev/null
+++ b/lib/Rewrite/Frontend/RewriteMacros.cpp
@@ -0,0 +1,217 @@
+//===--- RewriteMacros.cpp - Rewrite macros into their expansions ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This code rewrites macro invocations into their expansions.  This gives you
+// a macro expanded file that retains comments and #includes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Frontend/Rewriters.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Path.h"
+#include "llvm/ADT/OwningPtr.h"
+#include <cstdio>
+
+using namespace clang;
+
+/// isSameToken - Return true if the two specified tokens start have the same
+/// content.
+static bool isSameToken(Token &RawTok, Token &PPTok) {
+  // If two tokens have the same kind and the same identifier info, they are
+  // obviously the same.
+  if (PPTok.getKind() == RawTok.getKind() &&
+      PPTok.getIdentifierInfo() == RawTok.getIdentifierInfo())
+    return true;
+
+  // Otherwise, if they are different but have the same identifier info, they
+  // are also considered to be the same.  This allows keywords and raw lexed
+  // identifiers with the same name to be treated the same.
+  if (PPTok.getIdentifierInfo() &&
+      PPTok.getIdentifierInfo() == RawTok.getIdentifierInfo())
+    return true;
+
+  return false;
+}
+
+
+/// GetNextRawTok - Return the next raw token in the stream, skipping over
+/// comments if ReturnComment is false.
+static const Token &GetNextRawTok(const std::vector<Token> &RawTokens,
+                                  unsigned &CurTok, bool ReturnComment) {
+  assert(CurTok < RawTokens.size() && "Overran eof!");
+
+  // If the client doesn't want comments and we have one, skip it.
+  if (!ReturnComment && RawTokens[CurTok].is(tok::comment))
+    ++CurTok;
+
+  return RawTokens[CurTok++];
+}
+
+
+/// LexRawTokensFromMainFile - Lets all the raw tokens from the main file into
+/// the specified vector.
+static void LexRawTokensFromMainFile(Preprocessor &PP,
+                                     std::vector<Token> &RawTokens) {
+  SourceManager &SM = PP.getSourceManager();
+
+  // Create a lexer to lex all the tokens of the main file in raw mode.  Even
+  // though it is in raw mode, it will not return comments.
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(SM.getMainFileID());
+  Lexer RawLex(SM.getMainFileID(), FromFile, SM, PP.getLangOpts());
+
+  // Switch on comment lexing because we really do want them.
+  RawLex.SetCommentRetentionState(true);
+
+  Token RawTok;
+  do {
+    RawLex.LexFromRawLexer(RawTok);
+
+    // If we have an identifier with no identifier info for our raw token, look
+    // up the indentifier info.  This is important for equality comparison of
+    // identifier tokens.
+    if (RawTok.is(tok::raw_identifier))
+      PP.LookUpIdentifierInfo(RawTok);
+
+    RawTokens.push_back(RawTok);
+  } while (RawTok.isNot(tok::eof));
+}
+
+
+/// RewriteMacrosInInput - Implement -rewrite-macros mode.
+void clang::RewriteMacrosInInput(Preprocessor &PP, raw_ostream *OS) {
+  SourceManager &SM = PP.getSourceManager();
+
+  Rewriter Rewrite;
+  Rewrite.setSourceMgr(SM, PP.getLangOpts());
+  RewriteBuffer &RB = Rewrite.getEditBuffer(SM.getMainFileID());
+
+  std::vector<Token> RawTokens;
+  LexRawTokensFromMainFile(PP, RawTokens);
+  unsigned CurRawTok = 0;
+  Token RawTok = GetNextRawTok(RawTokens, CurRawTok, false);
+
+
+  // Get the first preprocessing token.
+  PP.EnterMainSourceFile();
+  Token PPTok;
+  PP.Lex(PPTok);
+
+  // Preprocess the input file in parallel with raw lexing the main file. Ignore
+  // all tokens that are preprocessed from a file other than the main file (e.g.
+  // a header).  If we see tokens that are in the preprocessed file but not the
+  // lexed file, we have a macro expansion.  If we see tokens in the lexed file
+  // that aren't in the preprocessed view, we have macros that expand to no
+  // tokens, or macro arguments etc.
+  while (RawTok.isNot(tok::eof) || PPTok.isNot(tok::eof)) {
+    SourceLocation PPLoc = SM.getExpansionLoc(PPTok.getLocation());
+
+    // If PPTok is from a different source file, ignore it.
+    if (!SM.isFromMainFile(PPLoc)) {
+      PP.Lex(PPTok);
+      continue;
+    }
+
+    // If the raw file hits a preprocessor directive, they will be extra tokens
+    // in the raw file that don't exist in the preprocsesed file.  However, we
+    // choose to preserve them in the output file and otherwise handle them
+    // specially.
+    if (RawTok.is(tok::hash) && RawTok.isAtStartOfLine()) {
+      // If this is a #warning directive or #pragma mark (GNU extensions),
+      // comment the line out.
+      if (RawTokens[CurRawTok].is(tok::identifier)) {
+        const IdentifierInfo *II = RawTokens[CurRawTok].getIdentifierInfo();
+        if (II->getName() == "warning") {
+          // Comment out #warning.
+          RB.InsertTextAfter(SM.getFileOffset(RawTok.getLocation()), "//");
+        } else if (II->getName() == "pragma" &&
+                   RawTokens[CurRawTok+1].is(tok::identifier) &&
+                   (RawTokens[CurRawTok+1].getIdentifierInfo()->getName() ==
+                    "mark")) {
+          // Comment out #pragma mark.
+          RB.InsertTextAfter(SM.getFileOffset(RawTok.getLocation()), "//");
+        }
+      }
+
+      // Otherwise, if this is a #include or some other directive, just leave it
+      // in the file by skipping over the line.
+      RawTok = GetNextRawTok(RawTokens, CurRawTok, false);
+      while (!RawTok.isAtStartOfLine() && RawTok.isNot(tok::eof))
+        RawTok = GetNextRawTok(RawTokens, CurRawTok, false);
+      continue;
+    }
+
+    // Okay, both tokens are from the same file.  Get their offsets from the
+    // start of the file.
+    unsigned PPOffs = SM.getFileOffset(PPLoc);
+    unsigned RawOffs = SM.getFileOffset(RawTok.getLocation());
+
+    // If the offsets are the same and the token kind is the same, ignore them.
+    if (PPOffs == RawOffs && isSameToken(RawTok, PPTok)) {
+      RawTok = GetNextRawTok(RawTokens, CurRawTok, false);
+      PP.Lex(PPTok);
+      continue;
+    }
+
+    // If the PP token is farther along than the raw token, something was
+    // deleted.  Comment out the raw token.
+    if (RawOffs <= PPOffs) {
+      // Comment out a whole run of tokens instead of bracketing each one with
+      // comments.  Add a leading space if RawTok didn't have one.
+      bool HasSpace = RawTok.hasLeadingSpace();
+      RB.InsertTextAfter(RawOffs, &" /*"[HasSpace]);
+      unsigned EndPos;
+
+      do {
+        EndPos = RawOffs+RawTok.getLength();
+
+        RawTok = GetNextRawTok(RawTokens, CurRawTok, true);
+        RawOffs = SM.getFileOffset(RawTok.getLocation());
+
+        if (RawTok.is(tok::comment)) {
+          // Skip past the comment.
+          RawTok = GetNextRawTok(RawTokens, CurRawTok, false);
+          break;
+        }
+
+      } while (RawOffs <= PPOffs && !RawTok.isAtStartOfLine() &&
+               (PPOffs != RawOffs || !isSameToken(RawTok, PPTok)));
+
+      RB.InsertTextBefore(EndPos, "*/");
+      continue;
+    }
+
+    // Otherwise, there was a replacement an expansion.  Insert the new token
+    // in the output buffer.  Insert the whole run of new tokens at once to get
+    // them in the right order.
+    unsigned InsertPos = PPOffs;
+    std::string Expansion;
+    while (PPOffs < RawOffs) {
+      Expansion += ' ' + PP.getSpelling(PPTok);
+      PP.Lex(PPTok);
+      PPLoc = SM.getExpansionLoc(PPTok.getLocation());
+      PPOffs = SM.getFileOffset(PPLoc);
+    }
+    Expansion += ' ';
+    RB.InsertTextBefore(InsertPos, Expansion);
+  }
+
+  // Get the buffer corresponding to MainFileID.  If we haven't changed it, then
+  // we are done.
+  if (const RewriteBuffer *RewriteBuf =
+      Rewrite.getRewriteBufferFor(SM.getMainFileID())) {
+    //printf("Changed:\n");
+    *OS << std::string(RewriteBuf->begin(), RewriteBuf->end());
+  } else {
+    fprintf(stderr, "No changes\n");
+  }
+  OS->flush();
+}