llvm-project/clang/Driver/RewriteMacros.cpp

185 lines
6.5 KiB
C++

//===--- 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.h"
#include "clang/Rewrite/Rewriter.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/Support/Streams.h"
#include "llvm/System/Path.h"
#include <fstream>
using namespace clang;
/// isSameToken - Return true if the two specified tokens start have the same
/// content.
static bool isSameToken(Token &RawTok, Token &PPTok) {
if (PPTok.getKind() == RawTok.getKind())
return true;
if (PPTok.getIdentifierInfo() &&
PPTok.getIdentifierInfo() == RawTok.getIdentifierInfo())
return true;
return false;
}
static void GetNextRawTok(Lexer &RawLex, Token &RawTok, Preprocessor &PP) {
RawLex.LexRawToken(RawTok);
// If we have an identifier with no identifier info for our raw token, look
// up the indentifier info.
if (RawTok.is(tok::identifier) && !RawTok.getIdentifierInfo())
RawTok.setIdentifierInfo(PP.LookUpIdentifierInfo(RawTok));
}
/// RewriteMacrosInInput - Implement -rewrite-macros mode.
void clang::RewriteMacrosInInput(Preprocessor &PP,const std::string &InFileName,
const std::string &OutFileName) {
SourceManager &SM = PP.getSourceManager();
Rewriter Rewrite;
Rewrite.setSourceMgr(SM);
RewriteBuffer &RB = Rewrite.getEditBuffer(SM.getMainFileID());
const SourceManager &SourceMgr = PP.getSourceManager();
std::pair<const char*, const char*> File =
SourceMgr.getBufferData(SM.getMainFileID());
// 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.
Lexer RawLex(SourceLocation::getFileLoc(SM.getMainFileID(), 0),
PP.getLangOptions(), File.first, File.second);
Token RawTok;
GetNextRawTok(RawLex, RawTok, PP);
// 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 bug 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.getLogicalLoc(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 input file, but we don't want to treat them as such... just ignore
// them.
if (RawTok.is(tok::hash) && RawTok.isAtStartOfLine()) {
GetNextRawTok(RawLex, RawTok, PP);
while (!RawTok.isAtStartOfLine() && RawTok.isNot(tok::eof))
GetNextRawTok(RawLex, RawTok, PP);
continue;
}
// Okay, both tokens are from the same file. Get their offsets from the
// start of the file.
unsigned PPOffs = SM.getFullFilePos(PPLoc);
unsigned RawOffs = SM.getFullFilePos(RawTok.getLocation());
// If the offsets are the same and the token kind is the same, ignore them.
if (PPOffs == RawOffs && isSameToken(RawTok, PPTok)) {
GetNextRawTok(RawLex, RawTok, PP);
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.
RB.InsertTextAfter(RawOffs, "/*", 2);
unsigned EndPos;
// Switch on comment lexing. If we get a comment, we don't want to
// include it as part of our run of tokens, because we don't want to
// nest /* */ comments.
RawLex.SetCommentRetentionState(true);
do {
EndPos = RawOffs+RawTok.getLength();
GetNextRawTok(RawLex, RawTok, PP);
RawOffs = SM.getFullFilePos(RawTok.getLocation());
if (RawTok.is(tok::comment)) {
RawLex.SetCommentRetentionState(false);
// Skip past the comment.
GetNextRawTok(RawLex, RawTok, PP);
break;
}
} while (RawOffs <= PPOffs && !RawTok.isAtStartOfLine() &&
(PPOffs != RawOffs || !isSameToken(RawTok, PPTok)));
RawLex.SetCommentRetentionState(false);
RB.InsertTextBefore(EndPos, "*/", 2);
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.getLogicalLoc(PPTok.getLocation());
PPOffs = SM.getFullFilePos(PPLoc);
}
Expansion += ' ';
RB.InsertTextBefore(InsertPos, &Expansion[0], Expansion.size());
}
// Create the output file.
std::ostream *OutFile;
if (OutFileName == "-") {
OutFile = llvm::cout.stream();
} else if (!OutFileName.empty()) {
OutFile = new std::ofstream(OutFileName.c_str(),
std::ios_base::binary|std::ios_base::out);
} else if (InFileName == "-") {
OutFile = llvm::cout.stream();
} else {
llvm::sys::Path Path(InFileName);
Path.eraseSuffix();
Path.appendSuffix("cpp");
OutFile = new std::ofstream(Path.toString().c_str(),
std::ios_base::binary|std::ios_base::out);
}
// 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");
*OutFile << std::string(RewriteBuf->begin(), RewriteBuf->end());
} else {
fprintf(stderr, "No changes\n");
}
}