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//===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This code simply runs the preprocessor on the input file and prints out the
// result. This is the traditional behavior of the -E option.
//
//===----------------------------------------------------------------------===//
#include "clang.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/Pragma.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/Diagnostic.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/System/Path.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Config/config.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdio>
using namespace clang;
//===----------------------------------------------------------------------===//
// Preprocessed token printer
//===----------------------------------------------------------------------===//
static llvm::cl::opt<bool>
DisableLineMarkers("P", llvm::cl::desc("Disable linemarker output in -E mode"));
static llvm::cl::opt<bool>
EnableCommentOutput("C", llvm::cl::desc("Enable comment output in -E mode"));
static llvm::cl::opt<bool>
EnableMacroCommentOutput("CC",
llvm::cl::desc("Enable comment output in -E mode, "
"even from macro expansions"));
namespace {
class PrintPPOutputPPCallbacks : public PPCallbacks {
Preprocessor &PP;
public:
llvm::raw_ostream &OS;
private:
unsigned CurLine;
bool EmittedTokensOnThisLine;
SrcMgr::Characteristic_t FileType;
llvm::SmallString<512> CurFilename;
bool Initialized;
public:
PrintPPOutputPPCallbacks(Preprocessor &pp, llvm::raw_ostream &os)
: PP(pp), OS(os) {
CurLine = 0;
CurFilename += "<uninit>";
EmittedTokensOnThisLine = false;
FileType = SrcMgr::C_User;
Initialized = false;
}
void SetEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }
bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }
virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
SrcMgr::Characteristic_t FileType);
virtual void Ident(SourceLocation Loc, const std::string &str);
bool HandleFirstTokOnLine(Token &Tok);
bool MoveToLine(SourceLocation Loc);
bool AvoidConcat(const Token &PrevTok, const Token &Tok);
void WriteLineInfo(unsigned LineNo, const char *Extra=0, unsigned ExtraLen=0);
};
} // end anonymous namespace
void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,
const char *Extra,
unsigned ExtraLen) {
if (EmittedTokensOnThisLine) {
OS << '\n';
EmittedTokensOnThisLine = false;
}
OS << '#' << ' ' << LineNo << ' ' << '"';
OS.write(&CurFilename[0], CurFilename.size());
OS << '"';
if (ExtraLen)
OS.write(Extra, ExtraLen);
if (FileType == SrcMgr::C_System)
OS.write(" 3", 2);
else if (FileType == SrcMgr::C_ExternCSystem)
OS.write(" 3 4", 4);
OS << '\n';
}
/// MoveToLine - Move the output to the source line specified by the location
/// object. We can do this by emitting some number of \n's, or be emitting a
/// #line directive. This returns false if already at the specified line, true
/// if some newlines were emitted.
bool PrintPPOutputPPCallbacks::MoveToLine(SourceLocation Loc) {
unsigned LineNo = PP.getSourceManager().getLogicalLineNumber(Loc);
if (DisableLineMarkers) {
if (LineNo == CurLine) return false;
CurLine = LineNo;
if (!EmittedTokensOnThisLine)
return true;
OS << '\n';
EmittedTokensOnThisLine = false;
return true;
}
// If this line is "close enough" to the original line, just print newlines,
// otherwise print a #line directive.
if (LineNo-CurLine <= 8) {
if (LineNo-CurLine == 1)
OS << '\n';
else if (LineNo == CurLine)
return false; // Phys line moved, but logical line didn't.
else {
const char *NewLines = "\n\n\n\n\n\n\n\n";
OS.write(NewLines, LineNo-CurLine);
}
} else {
WriteLineInfo(LineNo, 0, 0);
}
CurLine = LineNo;
return true;
}
/// FileChanged - Whenever the preprocessor enters or exits a #include file
/// it invokes this handler. Update our conception of the current source
/// position.
void PrintPPOutputPPCallbacks::FileChanged(SourceLocation Loc,
FileChangeReason Reason,
SrcMgr::Characteristic_t NewFileType) {
// Unless we are exiting a #include, make sure to skip ahead to the line the
// #include directive was at.
SourceManager &SourceMgr = PP.getSourceManager();
if (Reason == PPCallbacks::EnterFile) {
MoveToLine(SourceMgr.getIncludeLoc(Loc));
} else if (Reason == PPCallbacks::SystemHeaderPragma) {
MoveToLine(Loc);
// TODO GCC emits the # directive for this directive on the line AFTER the
// directive and emits a bunch of spaces that aren't needed. Emulate this
// strange behavior.
}
Loc = SourceMgr.getLogicalLoc(Loc);
CurLine = SourceMgr.getLineNumber(Loc);
if (DisableLineMarkers) return;
CurFilename.clear();
CurFilename += SourceMgr.getSourceName(Loc);
Lexer::Stringify(CurFilename);
FileType = NewFileType;
if (!Initialized) {
WriteLineInfo(CurLine);
Initialized = true;
}
switch (Reason) {
case PPCallbacks::EnterFile:
WriteLineInfo(CurLine, " 1", 2);
break;
case PPCallbacks::ExitFile:
WriteLineInfo(CurLine, " 2", 2);
break;
case PPCallbacks::SystemHeaderPragma:
case PPCallbacks::RenameFile:
WriteLineInfo(CurLine);
break;
}
}
/// HandleIdent - Handle #ident directives when read by the preprocessor.
///
void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, const std::string &S) {
MoveToLine(Loc);
OS.write("#ident ", strlen("#ident "));
OS.write(&S[0], S.size());
EmittedTokensOnThisLine = true;
}
/// HandleFirstTokOnLine - When emitting a preprocessed file in -E mode, this
/// is called for the first token on each new line. If this really is the start
/// of a new logical line, handle it and return true, otherwise return false.
/// This may not be the start of a logical line because the "start of line"
/// marker is set for physical lines, not logical ones.
bool PrintPPOutputPPCallbacks::HandleFirstTokOnLine(Token &Tok) {
// Figure out what line we went to and insert the appropriate number of
// newline characters.
if (!MoveToLine(Tok.getLocation()))
return false;
// Print out space characters so that the first token on a line is
// indented for easy reading.
const SourceManager &SourceMgr = PP.getSourceManager();
unsigned ColNo = SourceMgr.getLogicalColumnNumber(Tok.getLocation());
// This hack prevents stuff like:
// #define HASH #
// HASH define foo bar
// From having the # character end up at column 1, which makes it so it
// is not handled as a #define next time through the preprocessor if in
// -fpreprocessed mode.
if (ColNo <= 1 && Tok.is(tok::hash))
OS << ' ';
// Otherwise, indent the appropriate number of spaces.
for (; ColNo > 1; --ColNo)
OS << ' ';
return true;
}
namespace {
struct UnknownPragmaHandler : public PragmaHandler {
const char *Prefix;
PrintPPOutputPPCallbacks *Callbacks;
UnknownPragmaHandler(const char *prefix, PrintPPOutputPPCallbacks *callbacks)
: PragmaHandler(0), Prefix(prefix), Callbacks(callbacks) {}
virtual void HandlePragma(Preprocessor &PP, Token &PragmaTok) {
// Figure out what line we went to and insert the appropriate number of
// newline characters.
Callbacks->MoveToLine(PragmaTok.getLocation());
Callbacks->OS.write(Prefix, strlen(Prefix));
// Read and print all of the pragma tokens.
while (PragmaTok.isNot(tok::eom)) {
if (PragmaTok.hasLeadingSpace())
Callbacks->OS << ' ';
std::string TokSpell = PP.getSpelling(PragmaTok);
Callbacks->OS.write(&TokSpell[0], TokSpell.size());
PP.LexUnexpandedToken(PragmaTok);
}
Callbacks->OS << '\n';
}
};
} // end anonymous namespace
enum AvoidConcatInfo {
/// By default, a token never needs to avoid concatenation. Most tokens (e.g.
/// ',', ')', etc) don't cause a problem when concatenated.
aci_never_avoid_concat = 0,
/// aci_custom_firstchar - AvoidConcat contains custom code to handle this
/// token's requirements, and it needs to know the first character of the
/// token.
aci_custom_firstchar = 1,
/// aci_custom - AvoidConcat contains custom code to handle this token's
/// requirements, but it doesn't need to know the first character of the
/// token.
aci_custom = 2,
/// aci_avoid_equal - Many tokens cannot be safely followed by an '='
/// character. For example, "<<" turns into "<<=" when followed by an =.
aci_avoid_equal = 4
};
/// This array contains information for each token on what action to take when
/// avoiding concatenation of tokens in the AvoidConcat method.
static char TokenInfo[tok::NUM_TOKENS];
/// InitAvoidConcatTokenInfo - Tokens that must avoid concatenation should be
/// marked by this function.
static void InitAvoidConcatTokenInfo() {
// These tokens have custom code in AvoidConcat.
TokenInfo[tok::identifier ] |= aci_custom;
TokenInfo[tok::numeric_constant] |= aci_custom_firstchar;
TokenInfo[tok::period ] |= aci_custom_firstchar;
TokenInfo[tok::amp ] |= aci_custom_firstchar;
TokenInfo[tok::plus ] |= aci_custom_firstchar;
TokenInfo[tok::minus ] |= aci_custom_firstchar;
TokenInfo[tok::slash ] |= aci_custom_firstchar;
TokenInfo[tok::less ] |= aci_custom_firstchar;
TokenInfo[tok::greater ] |= aci_custom_firstchar;
TokenInfo[tok::pipe ] |= aci_custom_firstchar;
TokenInfo[tok::percent ] |= aci_custom_firstchar;
TokenInfo[tok::colon ] |= aci_custom_firstchar;
TokenInfo[tok::hash ] |= aci_custom_firstchar;
TokenInfo[tok::arrow ] |= aci_custom_firstchar;
// These tokens change behavior if followed by an '='.
TokenInfo[tok::amp ] |= aci_avoid_equal; // &=
TokenInfo[tok::plus ] |= aci_avoid_equal; // +=
TokenInfo[tok::minus ] |= aci_avoid_equal; // -=
TokenInfo[tok::slash ] |= aci_avoid_equal; // /=
TokenInfo[tok::less ] |= aci_avoid_equal; // <=
TokenInfo[tok::greater ] |= aci_avoid_equal; // >=
TokenInfo[tok::pipe ] |= aci_avoid_equal; // |=
TokenInfo[tok::percent ] |= aci_avoid_equal; // %=
TokenInfo[tok::star ] |= aci_avoid_equal; // *=
TokenInfo[tok::exclaim ] |= aci_avoid_equal; // !=
TokenInfo[tok::lessless ] |= aci_avoid_equal; // <<=
TokenInfo[tok::greaterequal] |= aci_avoid_equal; // >>=
TokenInfo[tok::caret ] |= aci_avoid_equal; // ^=
TokenInfo[tok::equal ] |= aci_avoid_equal; // ==
}
/// StartsWithL - Return true if the spelling of this token starts with 'L'.
static bool StartsWithL(const Token &Tok, Preprocessor &PP) {
if (!Tok.needsCleaning()) {
SourceManager &SrcMgr = PP.getSourceManager();
return *SrcMgr.getCharacterData(SrcMgr.getPhysicalLoc(Tok.getLocation()))
== 'L';
}
if (Tok.getLength() < 256) {
char Buffer[256];
const char *TokPtr = Buffer;
PP.getSpelling(Tok, TokPtr);
return TokPtr[0] == 'L';
}
return PP.getSpelling(Tok)[0] == 'L';
}
/// IsIdentifierL - Return true if the spelling of this token is literally 'L'.
static bool IsIdentifierL(const Token &Tok, Preprocessor &PP) {
if (!Tok.needsCleaning()) {
if (Tok.getLength() != 1)
return false;
SourceManager &SrcMgr = PP.getSourceManager();
return *SrcMgr.getCharacterData(SrcMgr.getPhysicalLoc(Tok.getLocation()))
== 'L';
}
if (Tok.getLength() < 256) {
char Buffer[256];
const char *TokPtr = Buffer;
if (PP.getSpelling(Tok, TokPtr) != 1)
return false;
return TokPtr[0] == 'L';
}
return PP.getSpelling(Tok) == "L";
}
/// AvoidConcat - If printing PrevTok immediately followed by Tok would cause
/// the two individual tokens to be lexed as a single token, return true (which
/// causes a space to be printed between them). This allows the output of -E
/// mode to be lexed to the same token stream as lexing the input directly
/// would.
///
/// This code must conservatively return true if it doesn't want to be 100%
/// accurate. This will cause the output to include extra space characters, but
/// the resulting output won't have incorrect concatenations going on. Examples
/// include "..", which we print with a space between, because we don't want to
/// track enough to tell "x.." from "...".
bool PrintPPOutputPPCallbacks::AvoidConcat(const Token &PrevTok,
const Token &Tok) {
char Buffer[256];
tok::TokenKind PrevKind = PrevTok.getKind();
if (PrevTok.getIdentifierInfo()) // Language keyword or named operator.
PrevKind = tok::identifier;
// Look up information on when we should avoid concatenation with prevtok.
unsigned ConcatInfo = TokenInfo[PrevKind];
// If prevtok never causes a problem for anything after it, return quickly.
if (ConcatInfo == 0) return false;
if (ConcatInfo & aci_avoid_equal) {
// If the next token is '=' or '==', avoid concatenation.
if (Tok.is(tok::equal) || Tok.is(tok::equalequal))
return true;
ConcatInfo &= ~aci_avoid_equal;
}
if (ConcatInfo == 0) return false;
// Basic algorithm: we look at the first character of the second token, and
// determine whether it, if appended to the first token, would form (or would
// contribute) to a larger token if concatenated.
char FirstChar = 0;
if (ConcatInfo & aci_custom) {
// If the token does not need to know the first character, don't get it.
} else if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
// Avoid spelling identifiers, the most common form of token.
FirstChar = II->getName()[0];
} else if (!Tok.needsCleaning()) {
SourceManager &SrcMgr = PP.getSourceManager();
FirstChar =
*SrcMgr.getCharacterData(SrcMgr.getPhysicalLoc(Tok.getLocation()));
} else if (Tok.getLength() < 256) {
const char *TokPtr = Buffer;
PP.getSpelling(Tok, TokPtr);
FirstChar = TokPtr[0];
} else {
FirstChar = PP.getSpelling(Tok)[0];
}
switch (PrevKind) {
default: assert(0 && "InitAvoidConcatTokenInfo built wrong");
case tok::identifier: // id+id or id+number or id+L"foo".
if (Tok.is(tok::numeric_constant) || Tok.getIdentifierInfo() ||
Tok.is(tok::wide_string_literal) /* ||
Tok.is(tok::wide_char_literal)*/)
return true;
// If this isn't identifier + string, we're done.
if (Tok.isNot(tok::char_constant) && Tok.isNot(tok::string_literal))
return false;
// FIXME: need a wide_char_constant!
// If the string was a wide string L"foo" or wide char L'f', it would concat
// with the previous identifier into fooL"bar". Avoid this.
if (StartsWithL(Tok, PP))
return true;
// Otherwise, this is a narrow character or string. If the *identifier* is
// a literal 'L', avoid pasting L "foo" -> L"foo".
return IsIdentifierL(PrevTok, PP);
case tok::numeric_constant:
return isalnum(FirstChar) || Tok.is(tok::numeric_constant) ||
FirstChar == '+' || FirstChar == '-' || FirstChar == '.';
case tok::period: // ..., .*, .1234
return FirstChar == '.' || FirstChar == '*' || isdigit(FirstChar);
case tok::amp: // &&
return FirstChar == '&';
case tok::plus: // ++
return FirstChar == '+';
case tok::minus: // --, ->, ->*
return FirstChar == '-' || FirstChar == '>';
case tok::slash: //, /*, //
return FirstChar == '*' || FirstChar == '/';
case tok::less: // <<, <<=, <:, <%
return FirstChar == '<' || FirstChar == ':' || FirstChar == '%';
case tok::greater: // >>, >>=
return FirstChar == '>';
case tok::pipe: // ||
return FirstChar == '|';
case tok::percent: // %>, %:
return FirstChar == '>' || FirstChar == ':';
case tok::colon: // ::, :>
return FirstChar == ':' || FirstChar == '>';
case tok::hash: // ##, #@, %:%:
return FirstChar == '#' || FirstChar == '@' || FirstChar == '%';
case tok::arrow: // ->*
return FirstChar == '*';
}
}
/// DoPrintPreprocessedInput - This implements -E mode.
///
void clang::DoPrintPreprocessedInput(Preprocessor &PP,
const std::string &OutFile) {
// Inform the preprocessor whether we want it to retain comments or not, due
// to -C or -CC.
PP.SetCommentRetentionState(EnableCommentOutput, EnableMacroCommentOutput);
InitAvoidConcatTokenInfo();
// Open the output buffer.
std::string Err;
llvm::raw_fd_ostream OS(OutFile.empty() ? "-" : OutFile.c_str(), Err);
if (!Err.empty()) {
fprintf(stderr, "%s\n", Err.c_str());
exit(1);
}
OS.SetBufferSize(64*1024);
Token Tok, PrevTok;
char Buffer[256];
PrintPPOutputPPCallbacks *Callbacks = new PrintPPOutputPPCallbacks(PP, OS);
PP.setPPCallbacks(Callbacks);
PP.AddPragmaHandler(0, new UnknownPragmaHandler("#pragma", Callbacks));
PP.AddPragmaHandler("GCC", new UnknownPragmaHandler("#pragma GCC",Callbacks));
// After we have configured the preprocessor, enter the main file.
// Start parsing the specified input file.
PP.EnterMainSourceFile();
// Consume all of the tokens that come from the predefines buffer. Those
// should not be emitted into the output and are guaranteed to be at the
// start.
const SourceManager &SourceMgr = PP.getSourceManager();
do PP.Lex(Tok);
while (Tok.isNot(tok::eof) && Tok.getLocation().isFileID() &&
!strcmp(SourceMgr.getSourceName(Tok.getLocation()), "<predefines>"));
while (1) {
// If this token is at the start of a line, emit newlines if needed.
if (Tok.isAtStartOfLine() && Callbacks->HandleFirstTokOnLine(Tok)) {
// done.
} else if (Tok.hasLeadingSpace() ||
// If we haven't emitted a token on this line yet, PrevTok isn't
// useful to look at and no concatenation could happen anyway.
(Callbacks->hasEmittedTokensOnThisLine() &&
// Don't print "-" next to "-", it would form "--".
Callbacks->AvoidConcat(PrevTok, Tok))) {
OS << ' ';
}
if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
const char *Str = II->getName();
unsigned Len = Tok.needsCleaning() ? strlen(Str) : Tok.getLength();
OS.write(Str, Len);
} else if (Tok.getLength() < 256) {
const char *TokPtr = Buffer;
unsigned Len = PP.getSpelling(Tok, TokPtr);
OS.write(TokPtr, Len);
} else {
std::string S = PP.getSpelling(Tok);
OS.write(&S[0], S.size());
}
Callbacks->SetEmittedTokensOnThisLine();
if (Tok.is(tok::eof)) break;
PrevTok = Tok;
PP.Lex(Tok);
}
OS << '\n';
// Flush the ostream.
OS.flush();
// If an error occurred, remove the output file.
if (PP.getDiagnostics().hasErrorOccurred() && !OutFile.empty())
llvm::sys::Path(OutFile).eraseFromDisk();
}