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//===--- Lexer.cpp - C Language Family Lexer ------------------------------===//
//
// 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 Lexer and Token interfaces.
//
//===----------------------------------------------------------------------===//
//
// TODO: GCC Diagnostics emitted by the lexer:
// PEDWARN: (form feed|vertical tab) in preprocessing directive
//
// Universal characters, unicode, char mapping:
// WARNING: `%.*s' is not in NFKC
// WARNING: `%.*s' is not in NFC
//
// Other:
// TODO: Options to support:
// -fexec-charset,-fwide-exec-charset
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/Lexer.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/CodeCompletionHandler.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cstring>
using namespace clang;
static void InitCharacterInfo();
//===----------------------------------------------------------------------===//
// Token Class Implementation
//===----------------------------------------------------------------------===//
/// isObjCAtKeyword - Return true if we have an ObjC keyword identifier.
bool Token::isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const {
if (IdentifierInfo *II = getIdentifierInfo())
return II->getObjCKeywordID() == objcKey;
return false;
}
/// getObjCKeywordID - Return the ObjC keyword kind.
tok::ObjCKeywordKind Token::getObjCKeywordID() const {
IdentifierInfo *specId = getIdentifierInfo();
return specId ? specId->getObjCKeywordID() : tok::objc_not_keyword;
}
//===----------------------------------------------------------------------===//
// Lexer Class Implementation
//===----------------------------------------------------------------------===//
void Lexer::anchor() { }
void Lexer::InitLexer(const char *BufStart, const char *BufPtr,
const char *BufEnd) {
InitCharacterInfo();
BufferStart = BufStart;
BufferPtr = BufPtr;
BufferEnd = BufEnd;
assert(BufEnd[0] == 0 &&
"We assume that the input buffer has a null character at the end"
" to simplify lexing!");
// Check whether we have a BOM in the beginning of the buffer. If yes - act
// accordingly. Right now we support only UTF-8 with and without BOM, so, just
// skip the UTF-8 BOM if it's present.
if (BufferStart == BufferPtr) {
// Determine the size of the BOM.
StringRef Buf(BufferStart, BufferEnd - BufferStart);
size_t BOMLength = llvm::StringSwitch<size_t>(Buf)
.StartsWith("\xEF\xBB\xBF", 3) // UTF-8 BOM
.Default(0);
// Skip the BOM.
BufferPtr += BOMLength;
}
Is_PragmaLexer = false;
CurrentConflictMarkerState = CMK_None;
// Start of the file is a start of line.
IsAtStartOfLine = true;
// We are not after parsing a #.
ParsingPreprocessorDirective = false;
// We are not after parsing #include.
ParsingFilename = false;
// We are not in raw mode. Raw mode disables diagnostics and interpretation
// of tokens (e.g. identifiers, thus disabling macro expansion). It is used
// to quickly lex the tokens of the buffer, e.g. when handling a "#if 0" block
// or otherwise skipping over tokens.
LexingRawMode = false;
// Default to not keeping comments.
ExtendedTokenMode = 0;
}
/// Lexer constructor - Create a new lexer object for the specified buffer
/// with the specified preprocessor managing the lexing process. This lexer
/// assumes that the associated file buffer and Preprocessor objects will
/// outlive it, so it doesn't take ownership of either of them.
Lexer::Lexer(FileID FID, const llvm::MemoryBuffer *InputFile, Preprocessor &PP)
: PreprocessorLexer(&PP, FID),
FileLoc(PP.getSourceManager().getLocForStartOfFile(FID)),
LangOpts(PP.getLangOpts()) {
InitLexer(InputFile->getBufferStart(), InputFile->getBufferStart(),
InputFile->getBufferEnd());
// Default to keeping comments if the preprocessor wants them.
SetCommentRetentionState(PP.getCommentRetentionState());
}
/// Lexer constructor - Create a new raw lexer object. This object is only
/// suitable for calls to 'LexRawToken'. This lexer assumes that the text
/// range will outlive it, so it doesn't take ownership of it.
Lexer::Lexer(SourceLocation fileloc, const LangOptions &langOpts,
const char *BufStart, const char *BufPtr, const char *BufEnd)
: FileLoc(fileloc), LangOpts(langOpts) {
InitLexer(BufStart, BufPtr, BufEnd);
// We *are* in raw mode.
LexingRawMode = true;
}
/// Lexer constructor - Create a new raw lexer object. This object is only
/// suitable for calls to 'LexRawToken'. This lexer assumes that the text
/// range will outlive it, so it doesn't take ownership of it.
Lexer::Lexer(FileID FID, const llvm::MemoryBuffer *FromFile,
const SourceManager &SM, const LangOptions &langOpts)
: FileLoc(SM.getLocForStartOfFile(FID)), LangOpts(langOpts) {
InitLexer(FromFile->getBufferStart(), FromFile->getBufferStart(),
FromFile->getBufferEnd());
// We *are* in raw mode.
LexingRawMode = true;
}
/// Create_PragmaLexer: Lexer constructor - Create a new lexer object for
/// _Pragma expansion. This has a variety of magic semantics that this method
/// sets up. It returns a new'd Lexer that must be delete'd when done.
///
/// On entrance to this routine, TokStartLoc is a macro location which has a
/// spelling loc that indicates the bytes to be lexed for the token and an
/// expansion location that indicates where all lexed tokens should be
/// "expanded from".
///
/// FIXME: It would really be nice to make _Pragma just be a wrapper around a
/// normal lexer that remaps tokens as they fly by. This would require making
/// Preprocessor::Lex virtual. Given that, we could just dump in a magic lexer
/// interface that could handle this stuff. This would pull GetMappedTokenLoc
/// out of the critical path of the lexer!
///
Lexer *Lexer::Create_PragmaLexer(SourceLocation SpellingLoc,
SourceLocation ExpansionLocStart,
SourceLocation ExpansionLocEnd,
unsigned TokLen, Preprocessor &PP) {
SourceManager &SM = PP.getSourceManager();
// Create the lexer as if we were going to lex the file normally.
FileID SpellingFID = SM.getFileID(SpellingLoc);
const llvm::MemoryBuffer *InputFile = SM.getBuffer(SpellingFID);
Lexer *L = new Lexer(SpellingFID, InputFile, PP);
// Now that the lexer is created, change the start/end locations so that we
// just lex the subsection of the file that we want. This is lexing from a
// scratch buffer.
const char *StrData = SM.getCharacterData(SpellingLoc);
L->BufferPtr = StrData;
L->BufferEnd = StrData+TokLen;
assert(L->BufferEnd[0] == 0 && "Buffer is not nul terminated!");
// Set the SourceLocation with the remapping information. This ensures that
// GetMappedTokenLoc will remap the tokens as they are lexed.
L->FileLoc = SM.createExpansionLoc(SM.getLocForStartOfFile(SpellingFID),
ExpansionLocStart,
ExpansionLocEnd, TokLen);
// Ensure that the lexer thinks it is inside a directive, so that end \n will
// return an EOD token.
L->ParsingPreprocessorDirective = true;
// This lexer really is for _Pragma.
L->Is_PragmaLexer = true;
return L;
}
/// Stringify - Convert the specified string into a C string, with surrounding
/// ""'s, and with escaped \ and " characters.
std::string Lexer::Stringify(const std::string &Str, bool Charify) {
std::string Result = Str;
char Quote = Charify ? '\'' : '"';
for (unsigned i = 0, e = Result.size(); i != e; ++i) {
if (Result[i] == '\\' || Result[i] == Quote) {
Result.insert(Result.begin()+i, '\\');
++i; ++e;
}
}
return Result;
}
/// Stringify - Convert the specified string into a C string by escaping '\'
/// and " characters. This does not add surrounding ""'s to the string.
void Lexer::Stringify(SmallVectorImpl<char> &Str) {
for (unsigned i = 0, e = Str.size(); i != e; ++i) {
if (Str[i] == '\\' || Str[i] == '"') {
Str.insert(Str.begin()+i, '\\');
++i; ++e;
}
}
}
//===----------------------------------------------------------------------===//
// Token Spelling
//===----------------------------------------------------------------------===//
/// getSpelling() - Return the 'spelling' of this token. The spelling of a
/// token are the characters used to represent the token in the source file
/// after trigraph expansion and escaped-newline folding. In particular, this
/// wants to get the true, uncanonicalized, spelling of things like digraphs
/// UCNs, etc.
StringRef Lexer::getSpelling(SourceLocation loc,
SmallVectorImpl<char> &buffer,
const SourceManager &SM,
const LangOptions &options,
bool *invalid) {
// Break down the source location.
std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(loc);
// Try to the load the file buffer.
bool invalidTemp = false;
StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
if (invalidTemp) {
if (invalid) *invalid = true;
return StringRef();
}
const char *tokenBegin = file.data() + locInfo.second;
// Lex from the start of the given location.
Lexer lexer(SM.getLocForStartOfFile(locInfo.first), options,
file.begin(), tokenBegin, file.end());
Token token;
lexer.LexFromRawLexer(token);
unsigned length = token.getLength();
// Common case: no need for cleaning.
if (!token.needsCleaning())
return StringRef(tokenBegin, length);
// Hard case, we need to relex the characters into the string.
buffer.clear();
buffer.reserve(length);
for (const char *ti = tokenBegin, *te = ti + length; ti != te; ) {
unsigned charSize;
buffer.push_back(Lexer::getCharAndSizeNoWarn(ti, charSize, options));
ti += charSize;
}
return StringRef(buffer.data(), buffer.size());
}
/// getSpelling() - Return the 'spelling' of this token. The spelling of a
/// token are the characters used to represent the token in the source file
/// after trigraph expansion and escaped-newline folding. In particular, this
/// wants to get the true, uncanonicalized, spelling of things like digraphs
/// UCNs, etc.
std::string Lexer::getSpelling(const Token &Tok, const SourceManager &SourceMgr,
const LangOptions &LangOpts, bool *Invalid) {
assert((int)Tok.getLength() >= 0 && "Token character range is bogus!");
// If this token contains nothing interesting, return it directly.
bool CharDataInvalid = false;
const char* TokStart = SourceMgr.getCharacterData(Tok.getLocation(),
&CharDataInvalid);
if (Invalid)
*Invalid = CharDataInvalid;
if (CharDataInvalid)
return std::string();
if (!Tok.needsCleaning())
return std::string(TokStart, TokStart+Tok.getLength());
std::string Result;
Result.reserve(Tok.getLength());
// Otherwise, hard case, relex the characters into the string.
for (const char *Ptr = TokStart, *End = TokStart+Tok.getLength();
Ptr != End; ) {
unsigned CharSize;
Result.push_back(Lexer::getCharAndSizeNoWarn(Ptr, CharSize, LangOpts));
Ptr += CharSize;
}
assert(Result.size() != unsigned(Tok.getLength()) &&
"NeedsCleaning flag set on something that didn't need cleaning!");
return Result;
}
/// getSpelling - This method is used to get the spelling of a token into a
/// preallocated buffer, instead of as an std::string. The caller is required
/// to allocate enough space for the token, which is guaranteed to be at least
/// Tok.getLength() bytes long. The actual length of the token is returned.
///
/// Note that this method may do two possible things: it may either fill in
/// the buffer specified with characters, or it may *change the input pointer*
/// to point to a constant buffer with the data already in it (avoiding a
/// copy). The caller is not allowed to modify the returned buffer pointer
/// if an internal buffer is returned.
unsigned Lexer::getSpelling(const Token &Tok, const char *&Buffer,
const SourceManager &SourceMgr,
const LangOptions &LangOpts, bool *Invalid) {
assert((int)Tok.getLength() >= 0 && "Token character range is bogus!");
const char *TokStart = 0;
// NOTE: this has to be checked *before* testing for an IdentifierInfo.
if (Tok.is(tok::raw_identifier))
TokStart = Tok.getRawIdentifierData();
else if (const IdentifierInfo *II = Tok.getIdentifierInfo()) {
// Just return the string from the identifier table, which is very quick.
Buffer = II->getNameStart();
return II->getLength();
}
// NOTE: this can be checked even after testing for an IdentifierInfo.
if (Tok.isLiteral())
TokStart = Tok.getLiteralData();
if (TokStart == 0) {
// Compute the start of the token in the input lexer buffer.
bool CharDataInvalid = false;
TokStart = SourceMgr.getCharacterData(Tok.getLocation(), &CharDataInvalid);
if (Invalid)
*Invalid = CharDataInvalid;
if (CharDataInvalid) {
Buffer = "";
return 0;
}
}
// If this token contains nothing interesting, return it directly.
if (!Tok.needsCleaning()) {
Buffer = TokStart;
return Tok.getLength();
}
// Otherwise, hard case, relex the characters into the string.
char *OutBuf = const_cast<char*>(Buffer);
for (const char *Ptr = TokStart, *End = TokStart+Tok.getLength();
Ptr != End; ) {
unsigned CharSize;
*OutBuf++ = Lexer::getCharAndSizeNoWarn(Ptr, CharSize, LangOpts);
Ptr += CharSize;
}
assert(unsigned(OutBuf-Buffer) != Tok.getLength() &&
"NeedsCleaning flag set on something that didn't need cleaning!");
return OutBuf-Buffer;
}
static bool isWhitespace(unsigned char c);
/// MeasureTokenLength - Relex the token at the specified location and return
/// its length in bytes in the input file. If the token needs cleaning (e.g.
/// includes a trigraph or an escaped newline) then this count includes bytes
/// that are part of that.
unsigned Lexer::MeasureTokenLength(SourceLocation Loc,
const SourceManager &SM,
const LangOptions &LangOpts) {
// TODO: this could be special cased for common tokens like identifiers, ')',
// etc to make this faster, if it mattered. Just look at StrData[0] to handle
// all obviously single-char tokens. This could use
// Lexer::isObviouslySimpleCharacter for example to handle identifiers or
// something.
// If this comes from a macro expansion, we really do want the macro name, not
// the token this macro expanded to.
Loc = SM.getExpansionLoc(Loc);
std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
bool Invalid = false;
StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
if (Invalid)
return 0;
const char *StrData = Buffer.data()+LocInfo.second;
if (isWhitespace(StrData[0]))
return 0;
// Create a lexer starting at the beginning of this token.
Lexer TheLexer(SM.getLocForStartOfFile(LocInfo.first), LangOpts,
Buffer.begin(), StrData, Buffer.end());
TheLexer.SetCommentRetentionState(true);
Token TheTok;
TheLexer.LexFromRawLexer(TheTok);
return TheTok.getLength();
}
static SourceLocation getBeginningOfFileToken(SourceLocation Loc,
const SourceManager &SM,
const LangOptions &LangOpts) {
assert(Loc.isFileID());
std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
if (LocInfo.first.isInvalid())
return Loc;
bool Invalid = false;
StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
if (Invalid)
return Loc;
// Back up from the current location until we hit the beginning of a line
// (or the buffer). We'll relex from that point.
const char *BufStart = Buffer.data();
if (LocInfo.second >= Buffer.size())
return Loc;
const char *StrData = BufStart+LocInfo.second;
if (StrData[0] == '\n' || StrData[0] == '\r')
return Loc;
const char *LexStart = StrData;
while (LexStart != BufStart) {
if (LexStart[0] == '\n' || LexStart[0] == '\r') {
++LexStart;
break;
}
--LexStart;
}
// Create a lexer starting at the beginning of this token.
SourceLocation LexerStartLoc = Loc.getLocWithOffset(-LocInfo.second);
Lexer TheLexer(LexerStartLoc, LangOpts, BufStart, LexStart, Buffer.end());
TheLexer.SetCommentRetentionState(true);
// Lex tokens until we find the token that contains the source location.
Token TheTok;
do {
TheLexer.LexFromRawLexer(TheTok);
if (TheLexer.getBufferLocation() > StrData) {
// Lexing this token has taken the lexer past the source location we're
// looking for. If the current token encompasses our source location,
// return the beginning of that token.
if (TheLexer.getBufferLocation() - TheTok.getLength() <= StrData)
return TheTok.getLocation();
// We ended up skipping over the source location entirely, which means
// that it points into whitespace. We're done here.
break;
}
} while (TheTok.getKind() != tok::eof);
// We've passed our source location; just return the original source location.
return Loc;
}
SourceLocation Lexer::GetBeginningOfToken(SourceLocation Loc,
const SourceManager &SM,
const LangOptions &LangOpts) {
if (Loc.isFileID())
return getBeginningOfFileToken(Loc, SM, LangOpts);
if (!SM.isMacroArgExpansion(Loc))
return Loc;
SourceLocation FileLoc = SM.getSpellingLoc(Loc);
SourceLocation BeginFileLoc = getBeginningOfFileToken(FileLoc, SM, LangOpts);
std::pair<FileID, unsigned> FileLocInfo = SM.getDecomposedLoc(FileLoc);
std::pair<FileID, unsigned> BeginFileLocInfo
= SM.getDecomposedLoc(BeginFileLoc);
assert(FileLocInfo.first == BeginFileLocInfo.first &&
FileLocInfo.second >= BeginFileLocInfo.second);
return Loc.getLocWithOffset(BeginFileLocInfo.second - FileLocInfo.second);
}
namespace {
enum PreambleDirectiveKind {
PDK_Skipped,
PDK_StartIf,
PDK_EndIf,
PDK_Unknown
};
}
std::pair<unsigned, bool>
Lexer::ComputePreamble(const llvm::MemoryBuffer *Buffer,
const LangOptions &LangOpts, unsigned MaxLines) {
// Create a lexer starting at the beginning of the file. Note that we use a
// "fake" file source location at offset 1 so that the lexer will track our
// position within the file.
const unsigned StartOffset = 1;
SourceLocation StartLoc = SourceLocation::getFromRawEncoding(StartOffset);
Lexer TheLexer(StartLoc, LangOpts, Buffer->getBufferStart(),
Buffer->getBufferStart(), Buffer->getBufferEnd());
bool InPreprocessorDirective = false;
Token TheTok;
Token IfStartTok;
unsigned IfCount = 0;
unsigned MaxLineOffset = 0;
if (MaxLines) {
const char *CurPtr = Buffer->getBufferStart();
unsigned CurLine = 0;
while (CurPtr != Buffer->getBufferEnd()) {
char ch = *CurPtr++;
if (ch == '\n') {
++CurLine;
if (CurLine == MaxLines)
break;
}
}
if (CurPtr != Buffer->getBufferEnd())
MaxLineOffset = CurPtr - Buffer->getBufferStart();
}
do {
TheLexer.LexFromRawLexer(TheTok);
if (InPreprocessorDirective) {
// If we've hit the end of the file, we're done.
if (TheTok.getKind() == tok::eof) {
InPreprocessorDirective = false;
break;
}
// If we haven't hit the end of the preprocessor directive, skip this
// token.
if (!TheTok.isAtStartOfLine())
continue;
// We've passed the end of the preprocessor directive, and will look
// at this token again below.
InPreprocessorDirective = false;
}
// Keep track of the # of lines in the preamble.
if (TheTok.isAtStartOfLine()) {
unsigned TokOffset = TheTok.getLocation().getRawEncoding() - StartOffset;
// If we were asked to limit the number of lines in the preamble,
// and we're about to exceed that limit, we're done.
if (MaxLineOffset && TokOffset >= MaxLineOffset)
break;
}
// Comments are okay; skip over them.
if (TheTok.getKind() == tok::comment)
continue;
if (TheTok.isAtStartOfLine() && TheTok.getKind() == tok::hash) {
// This is the start of a preprocessor directive.
Token HashTok = TheTok;
InPreprocessorDirective = true;
// Figure out which directive this is. Since we're lexing raw tokens,
// we don't have an identifier table available. Instead, just look at
// the raw identifier to recognize and categorize preprocessor directives.
TheLexer.LexFromRawLexer(TheTok);
if (TheTok.getKind() == tok::raw_identifier && !TheTok.needsCleaning()) {
StringRef Keyword(TheTok.getRawIdentifierData(),
TheTok.getLength());
PreambleDirectiveKind PDK
= llvm::StringSwitch<PreambleDirectiveKind>(Keyword)
.Case("include", PDK_Skipped)
.Case("__include_macros", PDK_Skipped)
.Case("define", PDK_Skipped)
.Case("undef", PDK_Skipped)
.Case("line", PDK_Skipped)
.Case("error", PDK_Skipped)
.Case("pragma", PDK_Skipped)
.Case("import", PDK_Skipped)
.Case("include_next", PDK_Skipped)
.Case("warning", PDK_Skipped)
.Case("ident", PDK_Skipped)
.Case("sccs", PDK_Skipped)
.Case("assert", PDK_Skipped)
.Case("unassert", PDK_Skipped)
.Case("if", PDK_StartIf)
.Case("ifdef", PDK_StartIf)
.Case("ifndef", PDK_StartIf)
.Case("elif", PDK_Skipped)
.Case("else", PDK_Skipped)
.Case("endif", PDK_EndIf)
.Default(PDK_Unknown);
switch (PDK) {
case PDK_Skipped:
continue;
case PDK_StartIf:
if (IfCount == 0)
IfStartTok = HashTok;
++IfCount;
continue;
case PDK_EndIf:
// Mismatched #endif. The preamble ends here.
if (IfCount == 0)
break;
--IfCount;
continue;
case PDK_Unknown:
// We don't know what this directive is; stop at the '#'.
break;
}
}
// We only end up here if we didn't recognize the preprocessor
// directive or it was one that can't occur in the preamble at this
// point. Roll back the current token to the location of the '#'.
InPreprocessorDirective = false;
TheTok = HashTok;
}
// We hit a token that we don't recognize as being in the
// "preprocessing only" part of the file, so we're no longer in
// the preamble.
break;
} while (true);
SourceLocation End = IfCount? IfStartTok.getLocation() : TheTok.getLocation();
return std::make_pair(End.getRawEncoding() - StartLoc.getRawEncoding(),
IfCount? IfStartTok.isAtStartOfLine()
: TheTok.isAtStartOfLine());
}
/// AdvanceToTokenCharacter - Given a location that specifies the start of a
/// token, return a new location that specifies a character within the token.
SourceLocation Lexer::AdvanceToTokenCharacter(SourceLocation TokStart,
unsigned CharNo,
const SourceManager &SM,
const LangOptions &LangOpts) {
// Figure out how many physical characters away the specified expansion
// character is. This needs to take into consideration newlines and
// trigraphs.
bool Invalid = false;
const char *TokPtr = SM.getCharacterData(TokStart, &Invalid);
// If they request the first char of the token, we're trivially done.
if (Invalid || (CharNo == 0 && Lexer::isObviouslySimpleCharacter(*TokPtr)))
return TokStart;
unsigned PhysOffset = 0;
// The usual case is that tokens don't contain anything interesting. Skip
// over the uninteresting characters. If a token only consists of simple
// chars, this method is extremely fast.
while (Lexer::isObviouslySimpleCharacter(*TokPtr)) {
if (CharNo == 0)
return TokStart.getLocWithOffset(PhysOffset);
++TokPtr, --CharNo, ++PhysOffset;
}
// If we have a character that may be a trigraph or escaped newline, use a
// lexer to parse it correctly.
for (; CharNo; --CharNo) {
unsigned Size;
Lexer::getCharAndSizeNoWarn(TokPtr, Size, LangOpts);
TokPtr += Size;
PhysOffset += Size;
}
// Final detail: if we end up on an escaped newline, we want to return the
// location of the actual byte of the token. For example foo\<newline>bar
// advanced by 3 should return the location of b, not of \\. One compounding
// detail of this is that the escape may be made by a trigraph.
if (!Lexer::isObviouslySimpleCharacter(*TokPtr))
PhysOffset += Lexer::SkipEscapedNewLines(TokPtr)-TokPtr;
return TokStart.getLocWithOffset(PhysOffset);
}
/// \brief Computes the source location just past the end of the
/// token at this source location.
///
/// This routine can be used to produce a source location that
/// points just past the end of the token referenced by \p Loc, and
/// is generally used when a diagnostic needs to point just after a
/// token where it expected something different that it received. If
/// the returned source location would not be meaningful (e.g., if
/// it points into a macro), this routine returns an invalid
/// source location.
///
/// \param Offset an offset from the end of the token, where the source
/// location should refer to. The default offset (0) produces a source
/// location pointing just past the end of the token; an offset of 1 produces
/// a source location pointing to the last character in the token, etc.
SourceLocation Lexer::getLocForEndOfToken(SourceLocation Loc, unsigned Offset,
const SourceManager &SM,
const LangOptions &LangOpts) {
if (Loc.isInvalid())
return SourceLocation();
if (Loc.isMacroID()) {
if (Offset > 0 || !isAtEndOfMacroExpansion(Loc, SM, LangOpts, &Loc))
return SourceLocation(); // Points inside the macro expansion.
}
unsigned Len = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
if (Len > Offset)
Len = Len - Offset;
else
return Loc;
return Loc.getLocWithOffset(Len);
}
/// \brief Returns true if the given MacroID location points at the first
/// token of the macro expansion.
bool Lexer::isAtStartOfMacroExpansion(SourceLocation loc,
const SourceManager &SM,
const LangOptions &LangOpts,
SourceLocation *MacroBegin) {
assert(loc.isValid() && loc.isMacroID() && "Expected a valid macro loc");
std::pair<FileID, unsigned> infoLoc = SM.getDecomposedLoc(loc);
// FIXME: If the token comes from the macro token paste operator ('##')
// this function will always return false;
if (infoLoc.second > 0)
return false; // Does not point at the start of token.
SourceLocation expansionLoc =
SM.getSLocEntry(infoLoc.first).getExpansion().getExpansionLocStart();
if (expansionLoc.isFileID()) {
// No other macro expansions, this is the first.
if (MacroBegin)
*MacroBegin = expansionLoc;
return true;
}
return isAtStartOfMacroExpansion(expansionLoc, SM, LangOpts, MacroBegin);
}
/// \brief Returns true if the given MacroID location points at the last
/// token of the macro expansion.
bool Lexer::isAtEndOfMacroExpansion(SourceLocation loc,
const SourceManager &SM,
const LangOptions &LangOpts,
SourceLocation *MacroEnd) {
assert(loc.isValid() && loc.isMacroID() && "Expected a valid macro loc");
SourceLocation spellLoc = SM.getSpellingLoc(loc);
unsigned tokLen = MeasureTokenLength(spellLoc, SM, LangOpts);
if (tokLen == 0)
return false;
FileID FID = SM.getFileID(loc);
SourceLocation afterLoc = loc.getLocWithOffset(tokLen+1);
if (SM.isInFileID(afterLoc, FID))
return false; // Still in the same FileID, does not point to the last token.
// FIXME: If the token comes from the macro token paste operator ('##')
// or the stringify operator ('#') this function will always return false;
SourceLocation expansionLoc =
SM.getSLocEntry(FID).getExpansion().getExpansionLocEnd();
if (expansionLoc.isFileID()) {
// No other macro expansions.
if (MacroEnd)
*MacroEnd = expansionLoc;
return true;
}
return isAtEndOfMacroExpansion(expansionLoc, SM, LangOpts, MacroEnd);
}
static CharSourceRange makeRangeFromFileLocs(CharSourceRange Range,
const SourceManager &SM,
const LangOptions &LangOpts) {
SourceLocation Begin = Range.getBegin();
SourceLocation End = Range.getEnd();
assert(Begin.isFileID() && End.isFileID());
if (Range.isTokenRange()) {
End = Lexer::getLocForEndOfToken(End, 0, SM,LangOpts);
if (End.isInvalid())
return CharSourceRange();
}
// Break down the source locations.
FileID FID;
unsigned BeginOffs;
llvm::tie(FID, BeginOffs) = SM.getDecomposedLoc(Begin);
if (FID.isInvalid())
return CharSourceRange();
unsigned EndOffs;
if (!SM.isInFileID(End, FID, &EndOffs) ||
BeginOffs > EndOffs)
return CharSourceRange();
return CharSourceRange::getCharRange(Begin, End);
}
/// \brief Accepts a range and returns a character range with file locations.
///
/// Returns a null range if a part of the range resides inside a macro
/// expansion or the range does not reside on the same FileID.
CharSourceRange Lexer::makeFileCharRange(CharSourceRange Range,
const SourceManager &SM,
const LangOptions &LangOpts) {
SourceLocation Begin = Range.getBegin();
SourceLocation End = Range.getEnd();
if (Begin.isInvalid() || End.isInvalid())
return CharSourceRange();
if (Begin.isFileID() && End.isFileID())
return makeRangeFromFileLocs(Range, SM, LangOpts);
if (Begin.isMacroID() && End.isFileID()) {
if (!isAtStartOfMacroExpansion(Begin, SM, LangOpts, &Begin))
return CharSourceRange();
Range.setBegin(Begin);
return makeRangeFromFileLocs(Range, SM, LangOpts);
}
if (Begin.isFileID() && End.isMacroID()) {
if ((Range.isTokenRange() && !isAtEndOfMacroExpansion(End, SM, LangOpts,
&End)) ||
(Range.isCharRange() && !isAtStartOfMacroExpansion(End, SM, LangOpts,
&End)))
return CharSourceRange();
Range.setEnd(End);
return makeRangeFromFileLocs(Range, SM, LangOpts);
}
assert(Begin.isMacroID() && End.isMacroID());
SourceLocation MacroBegin, MacroEnd;
if (isAtStartOfMacroExpansion(Begin, SM, LangOpts, &MacroBegin) &&
((Range.isTokenRange() && isAtEndOfMacroExpansion(End, SM, LangOpts,
&MacroEnd)) ||
(Range.isCharRange() && isAtStartOfMacroExpansion(End, SM, LangOpts,
&MacroEnd)))) {
Range.setBegin(MacroBegin);
Range.setEnd(MacroEnd);
return makeRangeFromFileLocs(Range, SM, LangOpts);
}
FileID FID;
unsigned BeginOffs;
llvm::tie(FID, BeginOffs) = SM.getDecomposedLoc(Begin);
if (FID.isInvalid())
return CharSourceRange();
unsigned EndOffs;
if (!SM.isInFileID(End, FID, &EndOffs) ||
BeginOffs > EndOffs)
return CharSourceRange();
const SrcMgr::SLocEntry *E = &SM.getSLocEntry(FID);
const SrcMgr::ExpansionInfo &Expansion = E->getExpansion();
if (Expansion.isMacroArgExpansion() &&
Expansion.getSpellingLoc().isFileID()) {
SourceLocation SpellLoc = Expansion.getSpellingLoc();
Range.setBegin(SpellLoc.getLocWithOffset(BeginOffs));
Range.setEnd(SpellLoc.getLocWithOffset(EndOffs));
return makeRangeFromFileLocs(Range, SM, LangOpts);
}
return CharSourceRange();
}
StringRef Lexer::getSourceText(CharSourceRange Range,
const SourceManager &SM,
const LangOptions &LangOpts,
bool *Invalid) {
Range = makeFileCharRange(Range, SM, LangOpts);
if (Range.isInvalid()) {
if (Invalid) *Invalid = true;
return StringRef();
}
// Break down the source location.
std::pair<FileID, unsigned> beginInfo = SM.getDecomposedLoc(Range.getBegin());
if (beginInfo.first.isInvalid()) {
if (Invalid) *Invalid = true;
return StringRef();
}
unsigned EndOffs;
if (!SM.isInFileID(Range.getEnd(), beginInfo.first, &EndOffs) ||
beginInfo.second > EndOffs) {
if (Invalid) *Invalid = true;
return StringRef();
}
// Try to the load the file buffer.
bool invalidTemp = false;
StringRef file = SM.getBufferData(beginInfo.first, &invalidTemp);
if (invalidTemp) {
if (Invalid) *Invalid = true;
return StringRef();
}
if (Invalid) *Invalid = false;
return file.substr(beginInfo.second, EndOffs - beginInfo.second);
}
StringRef Lexer::getImmediateMacroName(SourceLocation Loc,
const SourceManager &SM,
const LangOptions &LangOpts) {
assert(Loc.isMacroID() && "Only reasonble to call this on macros");
// Find the location of the immediate macro expansion.
while (1) {
FileID FID = SM.getFileID(Loc);
const SrcMgr::SLocEntry *E = &SM.getSLocEntry(FID);
const SrcMgr::ExpansionInfo &Expansion = E->getExpansion();
Loc = Expansion.getExpansionLocStart();
if (!Expansion.isMacroArgExpansion())
break;
// For macro arguments we need to check that the argument did not come
// from an inner macro, e.g: "MAC1( MAC2(foo) )"
// Loc points to the argument id of the macro definition, move to the
// macro expansion.
Loc = SM.getImmediateExpansionRange(Loc).first;
SourceLocation SpellLoc = Expansion.getSpellingLoc();
if (SpellLoc.isFileID())
break; // No inner macro.
// If spelling location resides in the same FileID as macro expansion
// location, it means there is no inner macro.
FileID MacroFID = SM.getFileID(Loc);
if (SM.isInFileID(SpellLoc, MacroFID))
break;
// Argument came from inner macro.
Loc = SpellLoc;
}
// Find the spelling location of the start of the non-argument expansion
// range. This is where the macro name was spelled in order to begin
// expanding this macro.
Loc = SM.getSpellingLoc(Loc);
// Dig out the buffer where the macro name was spelled and the extents of the
// name so that we can render it into the expansion note.
std::pair<FileID, unsigned> ExpansionInfo = SM.getDecomposedLoc(Loc);
unsigned MacroTokenLength = Lexer::MeasureTokenLength(Loc, SM, LangOpts);
StringRef ExpansionBuffer = SM.getBufferData(ExpansionInfo.first);
return ExpansionBuffer.substr(ExpansionInfo.second, MacroTokenLength);
}
//===----------------------------------------------------------------------===//
// Character information.
//===----------------------------------------------------------------------===//
enum {
CHAR_HORZ_WS = 0x01, // ' ', '\t', '\f', '\v'. Note, no '\0'
CHAR_VERT_WS = 0x02, // '\r', '\n'
CHAR_LETTER = 0x04, // a-z,A-Z
CHAR_NUMBER = 0x08, // 0-9
CHAR_UNDER = 0x10, // _
CHAR_PERIOD = 0x20, // .
CHAR_RAWDEL = 0x40 // {}[]#<>%:;?*+-/^&|~!=,"'
};
// Statically initialize CharInfo table based on ASCII character set
// Reference: FreeBSD 7.2 /usr/share/misc/ascii
static const unsigned char CharInfo[256] =
{
// 0 NUL 1 SOH 2 STX 3 ETX
// 4 EOT 5 ENQ 6 ACK 7 BEL
0 , 0 , 0 , 0 ,
0 , 0 , 0 , 0 ,
// 8 BS 9 HT 10 NL 11 VT
//12 NP 13 CR 14 SO 15 SI
0 , CHAR_HORZ_WS, CHAR_VERT_WS, CHAR_HORZ_WS,
CHAR_HORZ_WS, CHAR_VERT_WS, 0 , 0 ,
//16 DLE 17 DC1 18 DC2 19 DC3
//20 DC4 21 NAK 22 SYN 23 ETB
0 , 0 , 0 , 0 ,
0 , 0 , 0 , 0 ,
//24 CAN 25 EM 26 SUB 27 ESC
//28 FS 29 GS 30 RS 31 US
0 , 0 , 0 , 0 ,
0 , 0 , 0 , 0 ,
//32 SP 33 ! 34 " 35 #
//36 $ 37 % 38 & 39 '
CHAR_HORZ_WS, CHAR_RAWDEL , CHAR_RAWDEL , CHAR_RAWDEL ,
0 , CHAR_RAWDEL , CHAR_RAWDEL , CHAR_RAWDEL ,
//40 ( 41 ) 42 * 43 +
//44 , 45 - 46 . 47 /
0 , 0 , CHAR_RAWDEL , CHAR_RAWDEL ,
CHAR_RAWDEL , CHAR_RAWDEL , CHAR_PERIOD , CHAR_RAWDEL ,
//48 0 49 1 50 2 51 3
//52 4 53 5 54 6 55 7
CHAR_NUMBER , CHAR_NUMBER , CHAR_NUMBER , CHAR_NUMBER ,
CHAR_NUMBER , CHAR_NUMBER , CHAR_NUMBER , CHAR_NUMBER ,
//56 8 57 9 58 : 59 ;
//60 < 61 = 62 > 63 ?
CHAR_NUMBER , CHAR_NUMBER , CHAR_RAWDEL , CHAR_RAWDEL ,
CHAR_RAWDEL , CHAR_RAWDEL , CHAR_RAWDEL , CHAR_RAWDEL ,
//64 @ 65 A 66 B 67 C
//68 D 69 E 70 F 71 G
0 , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
//72 H 73 I 74 J 75 K
//76 L 77 M 78 N 79 O
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
//80 P 81 Q 82 R 83 S
//84 T 85 U 86 V 87 W
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
//88 X 89 Y 90 Z 91 [
//92 \ 93 ] 94 ^ 95 _
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_RAWDEL ,
0 , CHAR_RAWDEL , CHAR_RAWDEL , CHAR_UNDER ,
//96 ` 97 a 98 b 99 c
//100 d 101 e 102 f 103 g
0 , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
//104 h 105 i 106 j 107 k
//108 l 109 m 110 n 111 o
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
//112 p 113 q 114 r 115 s
//116 t 117 u 118 v 119 w
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_LETTER ,
//120 x 121 y 122 z 123 {
//124 | 125 } 126 ~ 127 DEL
CHAR_LETTER , CHAR_LETTER , CHAR_LETTER , CHAR_RAWDEL ,
CHAR_RAWDEL , CHAR_RAWDEL , CHAR_RAWDEL , 0
};
static void InitCharacterInfo() {
static bool isInited = false;
if (isInited) return;
// check the statically-initialized CharInfo table
assert(CHAR_HORZ_WS == CharInfo[(int)' ']);
assert(CHAR_HORZ_WS == CharInfo[(int)'\t']);
assert(CHAR_HORZ_WS == CharInfo[(int)'\f']);
assert(CHAR_HORZ_WS == CharInfo[(int)'\v']);
assert(CHAR_VERT_WS == CharInfo[(int)'\n']);
assert(CHAR_VERT_WS == CharInfo[(int)'\r']);
assert(CHAR_UNDER == CharInfo[(int)'_']);
assert(CHAR_PERIOD == CharInfo[(int)'.']);
for (unsigned i = 'a'; i <= 'z'; ++i) {
assert(CHAR_LETTER == CharInfo[i]);
assert(CHAR_LETTER == CharInfo[i+'A'-'a']);
}
for (unsigned i = '0'; i <= '9'; ++i)
assert(CHAR_NUMBER == CharInfo[i]);
isInited = true;
}
/// isIdentifierHead - Return true if this is the first character of an
/// identifier, which is [a-zA-Z_].
static inline bool isIdentifierHead(unsigned char c) {
return (CharInfo[c] & (CHAR_LETTER|CHAR_UNDER)) ? true : false;
}
/// isIdentifierBody - Return true if this is the body character of an
/// identifier, which is [a-zA-Z0-9_].
static inline bool isIdentifierBody(unsigned char c) {
return (CharInfo[c] & (CHAR_LETTER|CHAR_NUMBER|CHAR_UNDER)) ? true : false;
}
/// isHorizontalWhitespace - Return true if this character is horizontal
/// whitespace: ' ', '\t', '\f', '\v'. Note that this returns false for '\0'.
static inline bool isHorizontalWhitespace(unsigned char c) {
return (CharInfo[c] & CHAR_HORZ_WS) ? true : false;
}
/// isVerticalWhitespace - Return true if this character is vertical
/// whitespace: '\n', '\r'. Note that this returns false for '\0'.
static inline bool isVerticalWhitespace(unsigned char c) {
return (CharInfo[c] & CHAR_VERT_WS) ? true : false;
}
/// isWhitespace - Return true if this character is horizontal or vertical
/// whitespace: ' ', '\t', '\f', '\v', '\n', '\r'. Note that this returns false
/// for '\0'.
static inline bool isWhitespace(unsigned char c) {
return (CharInfo[c] & (CHAR_HORZ_WS|CHAR_VERT_WS)) ? true : false;
}
/// isNumberBody - Return true if this is the body character of an
/// preprocessing number, which is [a-zA-Z0-9_.].
static inline bool isNumberBody(unsigned char c) {
return (CharInfo[c] & (CHAR_LETTER|CHAR_NUMBER|CHAR_UNDER|CHAR_PERIOD)) ?
true : false;
}
/// isRawStringDelimBody - Return true if this is the body character of a
/// raw string delimiter.
static inline bool isRawStringDelimBody(unsigned char c) {
return (CharInfo[c] &
(CHAR_LETTER|CHAR_NUMBER|CHAR_UNDER|CHAR_PERIOD|CHAR_RAWDEL)) ?
true : false;
}
//===----------------------------------------------------------------------===//
// Diagnostics forwarding code.
//===----------------------------------------------------------------------===//
/// GetMappedTokenLoc - If lexing out of a 'mapped buffer', where we pretend the
/// lexer buffer was all expanded at a single point, perform the mapping.
/// This is currently only used for _Pragma implementation, so it is the slow
/// path of the hot getSourceLocation method. Do not allow it to be inlined.
static LLVM_ATTRIBUTE_NOINLINE SourceLocation GetMappedTokenLoc(
Preprocessor &PP, SourceLocation FileLoc, unsigned CharNo, unsigned TokLen);
static SourceLocation GetMappedTokenLoc(Preprocessor &PP,
SourceLocation FileLoc,
unsigned CharNo, unsigned TokLen) {
assert(FileLoc.isMacroID() && "Must be a macro expansion");
// Otherwise, we're lexing "mapped tokens". This is used for things like
// _Pragma handling. Combine the expansion location of FileLoc with the
// spelling location.
SourceManager &SM = PP.getSourceManager();
// Create a new SLoc which is expanded from Expansion(FileLoc) but whose
// characters come from spelling(FileLoc)+Offset.
SourceLocation SpellingLoc = SM.getSpellingLoc(FileLoc);
SpellingLoc = SpellingLoc.getLocWithOffset(CharNo);
// Figure out the expansion loc range, which is the range covered by the
// original _Pragma(...) sequence.
std::pair<SourceLocation,SourceLocation> II =
SM.getImmediateExpansionRange(FileLoc);
return SM.createExpansionLoc(SpellingLoc, II.first, II.second, TokLen);
}
/// getSourceLocation - Return a source location identifier for the specified
/// offset in the current file.
SourceLocation Lexer::getSourceLocation(const char *Loc,
unsigned TokLen) const {
assert(Loc >= BufferStart && Loc <= BufferEnd &&
"Location out of range for this buffer!");
// In the normal case, we're just lexing from a simple file buffer, return
// the file id from FileLoc with the offset specified.
unsigned CharNo = Loc-BufferStart;
if (FileLoc.isFileID())
return FileLoc.getLocWithOffset(CharNo);
// Otherwise, this is the _Pragma lexer case, which pretends that all of the
// tokens are lexed from where the _Pragma was defined.
assert(PP && "This doesn't work on raw lexers");
return GetMappedTokenLoc(*PP, FileLoc, CharNo, TokLen);
}
/// Diag - Forwarding function for diagnostics. This translate a source
/// position in the current buffer into a SourceLocation object for rendering.
DiagnosticBuilder Lexer::Diag(const char *Loc, unsigned DiagID) const {
return PP->Diag(getSourceLocation(Loc), DiagID);
}
//===----------------------------------------------------------------------===//
// Trigraph and Escaped Newline Handling Code.
//===----------------------------------------------------------------------===//
/// GetTrigraphCharForLetter - Given a character that occurs after a ?? pair,
/// return the decoded trigraph letter it corresponds to, or '\0' if nothing.
static char GetTrigraphCharForLetter(char Letter) {
switch (Letter) {
default: return 0;
case '=': return '#';
case ')': return ']';
case '(': return '[';
case '!': return '|';
case '\'': return '^';
case '>': return '}';
case '/': return '\\';
case '<': return '{';
case '-': return '~';
}
}
/// DecodeTrigraphChar - If the specified character is a legal trigraph when
/// prefixed with ??, emit a trigraph warning. If trigraphs are enabled,
/// return the result character. Finally, emit a warning about trigraph use
/// whether trigraphs are enabled or not.
static char DecodeTrigraphChar(const char *CP, Lexer *L) {
char Res = GetTrigraphCharForLetter(*CP);
if (!Res || !L) return Res;
if (!L->getLangOpts().Trigraphs) {
if (!L->isLexingRawMode())
L->Diag(CP-2, diag::trigraph_ignored);
return 0;
}
if (!L->isLexingRawMode())
L->Diag(CP-2, diag::trigraph_converted) << StringRef(&Res, 1);
return Res;
}
/// getEscapedNewLineSize - Return the size of the specified escaped newline,
/// or 0 if it is not an escaped newline. P[-1] is known to be a "\" or a
/// trigraph equivalent on entry to this function.
unsigned Lexer::getEscapedNewLineSize(const char *Ptr) {
unsigned Size = 0;
while (isWhitespace(Ptr[Size])) {
++Size;
if (Ptr[Size-1] != '\n' && Ptr[Size-1] != '\r')
continue;
// If this is a \r\n or \n\r, skip the other half.
if ((Ptr[Size] == '\r' || Ptr[Size] == '\n') &&
Ptr[Size-1] != Ptr[Size])
++Size;
return Size;
}
// Not an escaped newline, must be a \t or something else.
return 0;
}
/// SkipEscapedNewLines - If P points to an escaped newline (or a series of
/// them), skip over them and return the first non-escaped-newline found,
/// otherwise return P.
const char *Lexer::SkipEscapedNewLines(const char *P) {
while (1) {
const char *AfterEscape;
if (*P == '\\') {
AfterEscape = P+1;
} else if (*P == '?') {
// If not a trigraph for escape, bail out.
if (P[1] != '?' || P[2] != '/')
return P;
AfterEscape = P+3;
} else {
return P;
}
unsigned NewLineSize = Lexer::getEscapedNewLineSize(AfterEscape);
if (NewLineSize == 0) return P;
P = AfterEscape+NewLineSize;
}
}
/// \brief Checks that the given token is the first token that occurs after the
/// given location (this excludes comments and whitespace). Returns the location
/// immediately after the specified token. If the token is not found or the
/// location is inside a macro, the returned source location will be invalid.
SourceLocation Lexer::findLocationAfterToken(SourceLocation Loc,
tok::TokenKind TKind,
const SourceManager &SM,
const LangOptions &LangOpts,
bool SkipTrailingWhitespaceAndNewLine) {
if (Loc.isMacroID()) {
if (!Lexer::isAtEndOfMacroExpansion(Loc, SM, LangOpts, &Loc))
return SourceLocation();
}
Loc = Lexer::getLocForEndOfToken(Loc, 0, SM, LangOpts);
// Break down the source location.
std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
// Try to load the file buffer.
bool InvalidTemp = false;
llvm::StringRef File = SM.getBufferData(LocInfo.first, &InvalidTemp);
if (InvalidTemp)
return SourceLocation();
const char *TokenBegin = File.data() + LocInfo.second;
// Lex from the start of the given location.
Lexer lexer(SM.getLocForStartOfFile(LocInfo.first), LangOpts, File.begin(),
TokenBegin, File.end());
// Find the token.
Token Tok;
lexer.LexFromRawLexer(Tok);
if (Tok.isNot(TKind))
return SourceLocation();
SourceLocation TokenLoc = Tok.getLocation();
// Calculate how much whitespace needs to be skipped if any.
unsigned NumWhitespaceChars = 0;
if (SkipTrailingWhitespaceAndNewLine) {
const char *TokenEnd = SM.getCharacterData(TokenLoc) +
Tok.getLength();
unsigned char C = *TokenEnd;
while (isHorizontalWhitespace(C)) {
C = *(++TokenEnd);
NumWhitespaceChars++;
}
if (isVerticalWhitespace(C))
NumWhitespaceChars++;
}
return TokenLoc.getLocWithOffset(Tok.getLength() + NumWhitespaceChars);
}
/// getCharAndSizeSlow - Peek a single 'character' from the specified buffer,
/// get its size, and return it. This is tricky in several cases:
/// 1. If currently at the start of a trigraph, we warn about the trigraph,
/// then either return the trigraph (skipping 3 chars) or the '?',
/// depending on whether trigraphs are enabled or not.
/// 2. If this is an escaped newline (potentially with whitespace between
/// the backslash and newline), implicitly skip the newline and return
/// the char after it.
/// 3. If this is a UCN, return it. FIXME: C++ UCN's?
///
/// This handles the slow/uncommon case of the getCharAndSize method. Here we
/// know that we can accumulate into Size, and that we have already incremented
/// Ptr by Size bytes.
///
/// NOTE: When this method is updated, getCharAndSizeSlowNoWarn (below) should
/// be updated to match.
///
char Lexer::getCharAndSizeSlow(const char *Ptr, unsigned &Size,
Token *Tok) {
// If we have a slash, look for an escaped newline.
if (Ptr[0] == '\\') {
++Size;
++Ptr;
Slash:
// Common case, backslash-char where the char is not whitespace.
if (!isWhitespace(Ptr[0])) return '\\';
// See if we have optional whitespace characters between the slash and
// newline.
if (unsigned EscapedNewLineSize = getEscapedNewLineSize(Ptr)) {
// Remember that this token needs to be cleaned.
if (Tok) Tok->setFlag(Token::NeedsCleaning);
// Warn if there was whitespace between the backslash and newline.
if (Ptr[0] != '\n' && Ptr[0] != '\r' && Tok && !isLexingRawMode())
Diag(Ptr, diag::backslash_newline_space);
// Found backslash<whitespace><newline>. Parse the char after it.
Size += EscapedNewLineSize;
Ptr += EscapedNewLineSize;
// If the char that we finally got was a \n, then we must have had
// something like \<newline><newline>. We don't want to consume the
// second newline.
if (*Ptr == '\n' || *Ptr == '\r' || *Ptr == '\0')
return ' ';
// Use slow version to accumulate a correct size field.
return getCharAndSizeSlow(Ptr, Size, Tok);
}
// Otherwise, this is not an escaped newline, just return the slash.
return '\\';
}
// If this is a trigraph, process it.
if (Ptr[0] == '?' && Ptr[1] == '?') {
// If this is actually a legal trigraph (not something like "??x"), emit
// a trigraph warning. If so, and if trigraphs are enabled, return it.
if (char C = DecodeTrigraphChar(Ptr+2, Tok ? this : 0)) {
// Remember that this token needs to be cleaned.
if (Tok) Tok->setFlag(Token::NeedsCleaning);
Ptr += 3;
Size += 3;
if (C == '\\') goto Slash;
return C;
}
}
// If this is neither, return a single character.
++Size;
return *Ptr;
}
/// getCharAndSizeSlowNoWarn - Handle the slow/uncommon case of the
/// getCharAndSizeNoWarn method. Here we know that we can accumulate into Size,
/// and that we have already incremented Ptr by Size bytes.
///
/// NOTE: When this method is updated, getCharAndSizeSlow (above) should
/// be updated to match.
char Lexer::getCharAndSizeSlowNoWarn(const char *Ptr, unsigned &Size,
const LangOptions &LangOpts) {
// If we have a slash, look for an escaped newline.
if (Ptr[0] == '\\') {
++Size;
++Ptr;
Slash:
// Common case, backslash-char where the char is not whitespace.
if (!isWhitespace(Ptr[0])) return '\\';
// See if we have optional whitespace characters followed by a newline.
if (unsigned EscapedNewLineSize = getEscapedNewLineSize(Ptr)) {
// Found backslash<whitespace><newline>. Parse the char after it.
Size += EscapedNewLineSize;
Ptr += EscapedNewLineSize;
// If the char that we finally got was a \n, then we must have had
// something like \<newline><newline>. We don't want to consume the
// second newline.
if (*Ptr == '\n' || *Ptr == '\r' || *Ptr == '\0')
return ' ';
// Use slow version to accumulate a correct size field.
return getCharAndSizeSlowNoWarn(Ptr, Size, LangOpts);
}
// Otherwise, this is not an escaped newline, just return the slash.
return '\\';
}
// If this is a trigraph, process it.
if (LangOpts.Trigraphs && Ptr[0] == '?' && Ptr[1] == '?') {
// If this is actually a legal trigraph (not something like "??x"), return
// it.
if (char C = GetTrigraphCharForLetter(Ptr[2])) {
Ptr += 3;
Size += 3;
if (C == '\\') goto Slash;
return C;
}
}
// If this is neither, return a single character.
++Size;
return *Ptr;
}
//===----------------------------------------------------------------------===//
// Helper methods for lexing.
//===----------------------------------------------------------------------===//
/// \brief Routine that indiscriminately skips bytes in the source file.
void Lexer::SkipBytes(unsigned Bytes, bool StartOfLine) {
BufferPtr += Bytes;
if (BufferPtr > BufferEnd)
BufferPtr = BufferEnd;
IsAtStartOfLine = StartOfLine;
}
void Lexer::LexIdentifier(Token &Result, const char *CurPtr) {
// Match [_A-Za-z0-9]*, we have already matched [_A-Za-z$]
unsigned Size;
unsigned char C = *CurPtr++;
while (isIdentifierBody(C))
C = *CurPtr++;
--CurPtr; // Back up over the skipped character.
// Fast path, no $,\,? in identifier found. '\' might be an escaped newline
// or UCN, and ? might be a trigraph for '\', an escaped newline or UCN.
// FIXME: UCNs.
//
// TODO: Could merge these checks into a CharInfo flag to make the comparison
// cheaper
if (C != '\\' && C != '?' && (C != '$' || !LangOpts.DollarIdents)) {
FinishIdentifier:
const char *IdStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, tok::raw_identifier);
Result.setRawIdentifierData(IdStart);
// If we are in raw mode, return this identifier raw. There is no need to
// look up identifier information or attempt to macro expand it.
if (LexingRawMode)
return;
// Fill in Result.IdentifierInfo and update the token kind,
// looking up the identifier in the identifier table.
IdentifierInfo *II = PP->LookUpIdentifierInfo(Result);
// Finally, now that we know we have an identifier, pass this off to the
// preprocessor, which may macro expand it or something.
if (II->isHandleIdentifierCase())
PP->HandleIdentifier(Result);
return;
}
// Otherwise, $,\,? in identifier found. Enter slower path.
C = getCharAndSize(CurPtr, Size);
while (1) {
if (C == '$') {
// If we hit a $ and they are not supported in identifiers, we are done.
if (!LangOpts.DollarIdents) goto FinishIdentifier;
// Otherwise, emit a diagnostic and continue.
if (!isLexingRawMode())
Diag(CurPtr, diag::ext_dollar_in_identifier);
CurPtr = ConsumeChar(CurPtr, Size, Result);
C = getCharAndSize(CurPtr, Size);
continue;
} else if (!isIdentifierBody(C)) { // FIXME: UCNs.
// Found end of identifier.
goto FinishIdentifier;
}
// Otherwise, this character is good, consume it.
CurPtr = ConsumeChar(CurPtr, Size, Result);
C = getCharAndSize(CurPtr, Size);
while (isIdentifierBody(C)) { // FIXME: UCNs.
CurPtr = ConsumeChar(CurPtr, Size, Result);
C = getCharAndSize(CurPtr, Size);
}
}
}
/// isHexaLiteral - Return true if Start points to a hex constant.
/// in microsoft mode (where this is supposed to be several different tokens).
static bool isHexaLiteral(const char *Start, const LangOptions &LangOpts) {
unsigned Size;
char C1 = Lexer::getCharAndSizeNoWarn(Start, Size, LangOpts);
if (C1 != '0')
return false;
char C2 = Lexer::getCharAndSizeNoWarn(Start + Size, Size, LangOpts);
return (C2 == 'x' || C2 == 'X');
}
/// LexNumericConstant - Lex the remainder of a integer or floating point
/// constant. From[-1] is the first character lexed. Return the end of the
/// constant.
void Lexer::LexNumericConstant(Token &Result, const char *CurPtr) {
unsigned Size;
char C = getCharAndSize(CurPtr, Size);
char PrevCh = 0;
while (isNumberBody(C)) { // FIXME: UCNs.
CurPtr = ConsumeChar(CurPtr, Size, Result);
PrevCh = C;
C = getCharAndSize(CurPtr, Size);
}
// If we fell out, check for a sign, due to 1e+12. If we have one, continue.
if ((C == '-' || C == '+') && (PrevCh == 'E' || PrevCh == 'e')) {
// If we are in Microsoft mode, don't continue if the constant is hex.
// For example, MSVC will accept the following as 3 tokens: 0x1234567e+1
if (!LangOpts.MicrosoftExt || !isHexaLiteral(BufferPtr, LangOpts))
return LexNumericConstant(Result, ConsumeChar(CurPtr, Size, Result));
}
// If we have a hex FP constant, continue.
if ((C == '-' || C == '+') && (PrevCh == 'P' || PrevCh == 'p'))
return LexNumericConstant(Result, ConsumeChar(CurPtr, Size, Result));
// Update the location of token as well as BufferPtr.
const char *TokStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, tok::numeric_constant);
Result.setLiteralData(TokStart);
}
/// LexUDSuffix - Lex the ud-suffix production for user-defined literal suffixes
/// in C++11, or warn on a ud-suffix in C++98.
const char *Lexer::LexUDSuffix(Token &Result, const char *CurPtr) {
assert(getLangOpts().CPlusPlus);
// Maximally munch an identifier. FIXME: UCNs.
unsigned Size;
char C = getCharAndSize(CurPtr, Size);
if (isIdentifierHead(C)) {
if (!getLangOpts().CPlusPlus0x) {
if (!isLexingRawMode())
Diag(CurPtr,
C == '_' ? diag::warn_cxx11_compat_user_defined_literal
: diag::warn_cxx11_compat_reserved_user_defined_literal)
<< FixItHint::CreateInsertion(getSourceLocation(CurPtr), " ");
return CurPtr;
}
// C++11 [lex.ext]p10, [usrlit.suffix]p1: A program containing a ud-suffix
// that does not start with an underscore is ill-formed. As a conforming
// extension, we treat all such suffixes as if they had whitespace before
// them.
if (C != '_') {
if (!isLexingRawMode())
Diag(CurPtr, getLangOpts().MicrosoftMode ?
diag::ext_ms_reserved_user_defined_literal :
diag::ext_reserved_user_defined_literal)
<< FixItHint::CreateInsertion(getSourceLocation(CurPtr), " ");
return CurPtr;
}
Result.setFlag(Token::HasUDSuffix);
do {
CurPtr = ConsumeChar(CurPtr, Size, Result);
C = getCharAndSize(CurPtr, Size);
} while (isIdentifierBody(C));
}
return CurPtr;
}
/// LexStringLiteral - Lex the remainder of a string literal, after having lexed
/// either " or L" or u8" or u" or U".
void Lexer::LexStringLiteral(Token &Result, const char *CurPtr,
tok::TokenKind Kind) {
const char *NulCharacter = 0; // Does this string contain the \0 character?
if (!isLexingRawMode() &&
(Kind == tok::utf8_string_literal ||
Kind == tok::utf16_string_literal ||
Kind == tok::utf32_string_literal))
Diag(BufferPtr, diag::warn_cxx98_compat_unicode_literal);
char C = getAndAdvanceChar(CurPtr, Result);
while (C != '"') {
// Skip escaped characters. Escaped newlines will already be processed by
// getAndAdvanceChar.
if (C == '\\')
C = getAndAdvanceChar(CurPtr, Result);
if (C == '\n' || C == '\r' || // Newline.
(C == 0 && CurPtr-1 == BufferEnd)) { // End of file.
if (!isLexingRawMode() && !LangOpts.AsmPreprocessor)
Diag(BufferPtr, diag::warn_unterminated_string);
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
return;
}
if (C == 0) {
if (isCodeCompletionPoint(CurPtr-1)) {
PP->CodeCompleteNaturalLanguage();
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
return cutOffLexing();
}
NulCharacter = CurPtr-1;
}
C = getAndAdvanceChar(CurPtr, Result);
}
// If we are in C++11, lex the optional ud-suffix.
if (getLangOpts().CPlusPlus)
CurPtr = LexUDSuffix(Result, CurPtr);
// If a nul character existed in the string, warn about it.
if (NulCharacter && !isLexingRawMode())
Diag(NulCharacter, diag::null_in_string);
// Update the location of the token as well as the BufferPtr instance var.
const char *TokStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, Kind);
Result.setLiteralData(TokStart);
}
/// LexRawStringLiteral - Lex the remainder of a raw string literal, after
/// having lexed R", LR", u8R", uR", or UR".
void Lexer::LexRawStringLiteral(Token &Result, const char *CurPtr,
tok::TokenKind Kind) {
// This function doesn't use getAndAdvanceChar because C++0x [lex.pptoken]p3:
// Between the initial and final double quote characters of the raw string,
// any transformations performed in phases 1 and 2 (trigraphs,
// universal-character-names, and line splicing) are reverted.
if (!isLexingRawMode())
Diag(BufferPtr, diag::warn_cxx98_compat_raw_string_literal);
unsigned PrefixLen = 0;
while (PrefixLen != 16 && isRawStringDelimBody(CurPtr[PrefixLen]))
++PrefixLen;
// If the last character was not a '(', then we didn't lex a valid delimiter.
if (CurPtr[PrefixLen] != '(') {
if (!isLexingRawMode()) {
const char *PrefixEnd = &CurPtr[PrefixLen];
if (PrefixLen == 16) {
Diag(PrefixEnd, diag::err_raw_delim_too_long);
} else {
Diag(PrefixEnd, diag::err_invalid_char_raw_delim)
<< StringRef(PrefixEnd, 1);
}
}
// Search for the next '"' in hopes of salvaging the lexer. Unfortunately,
// it's possible the '"' was intended to be part of the raw string, but
// there's not much we can do about that.
while (1) {
char C = *CurPtr++;
if (C == '"')
break;
if (C == 0 && CurPtr-1 == BufferEnd) {
--CurPtr;
break;
}
}
FormTokenWithChars(Result, CurPtr, tok::unknown);
return;
}
// Save prefix and move CurPtr past it
const char *Prefix = CurPtr;
CurPtr += PrefixLen + 1; // skip over prefix and '('
while (1) {
char C = *CurPtr++;
if (C == ')') {
// Check for prefix match and closing quote.
if (strncmp(CurPtr, Prefix, PrefixLen) == 0 && CurPtr[PrefixLen] == '"') {
CurPtr += PrefixLen + 1; // skip over prefix and '"'
break;
}
} else if (C == 0 && CurPtr-1 == BufferEnd) { // End of file.
if (!isLexingRawMode())
Diag(BufferPtr, diag::err_unterminated_raw_string)
<< StringRef(Prefix, PrefixLen);
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
return;
}
}
// If we are in C++11, lex the optional ud-suffix.
if (getLangOpts().CPlusPlus)
CurPtr = LexUDSuffix(Result, CurPtr);
// Update the location of token as well as BufferPtr.
const char *TokStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, Kind);
Result.setLiteralData(TokStart);
}
/// LexAngledStringLiteral - Lex the remainder of an angled string literal,
/// after having lexed the '<' character. This is used for #include filenames.
void Lexer::LexAngledStringLiteral(Token &Result, const char *CurPtr) {
const char *NulCharacter = 0; // Does this string contain the \0 character?
const char *AfterLessPos = CurPtr;
char C = getAndAdvanceChar(CurPtr, Result);
while (C != '>') {
// Skip escaped characters.
if (C == '\\') {
// Skip the escaped character.
C = getAndAdvanceChar(CurPtr, Result);
} else if (C == '\n' || C == '\r' || // Newline.
(C == 0 && (CurPtr-1 == BufferEnd || // End of file.
isCodeCompletionPoint(CurPtr-1)))) {
// If the filename is unterminated, then it must just be a lone <
// character. Return this as such.
FormTokenWithChars(Result, AfterLessPos, tok::less);
return;
} else if (C == 0) {
NulCharacter = CurPtr-1;
}
C = getAndAdvanceChar(CurPtr, Result);
}
// If a nul character existed in the string, warn about it.
if (NulCharacter && !isLexingRawMode())
Diag(NulCharacter, diag::null_in_string);
// Update the location of token as well as BufferPtr.
const char *TokStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, tok::angle_string_literal);
Result.setLiteralData(TokStart);
}
/// LexCharConstant - Lex the remainder of a character constant, after having
/// lexed either ' or L' or u' or U'.
void Lexer::LexCharConstant(Token &Result, const char *CurPtr,
tok::TokenKind Kind) {
const char *NulCharacter = 0; // Does this character contain the \0 character?
if (!isLexingRawMode() &&
(Kind == tok::utf16_char_constant || Kind == tok::utf32_char_constant))
Diag(BufferPtr, diag::warn_cxx98_compat_unicode_literal);
char C = getAndAdvanceChar(CurPtr, Result);
if (C == '\'') {
if (!isLexingRawMode() && !LangOpts.AsmPreprocessor)
Diag(BufferPtr, diag::err_empty_character);
FormTokenWithChars(Result, CurPtr, tok::unknown);
return;
}
while (C != '\'') {
// Skip escaped characters.
if (C == '\\') {
// Skip the escaped character.
// FIXME: UCN's
C = getAndAdvanceChar(CurPtr, Result);
} else if (C == '\n' || C == '\r' || // Newline.
(C == 0 && CurPtr-1 == BufferEnd)) { // End of file.
if (!isLexingRawMode() && !LangOpts.AsmPreprocessor)
Diag(BufferPtr, diag::warn_unterminated_char);
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
return;
} else if (C == 0) {
if (isCodeCompletionPoint(CurPtr-1)) {
PP->CodeCompleteNaturalLanguage();
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
return cutOffLexing();
}
NulCharacter = CurPtr-1;
}
C = getAndAdvanceChar(CurPtr, Result);
}
// If we are in C++11, lex the optional ud-suffix.
if (getLangOpts().CPlusPlus)
CurPtr = LexUDSuffix(Result, CurPtr);
// If a nul character existed in the character, warn about it.
if (NulCharacter && !isLexingRawMode())
Diag(NulCharacter, diag::null_in_char);
// Update the location of token as well as BufferPtr.
const char *TokStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, Kind);
Result.setLiteralData(TokStart);
}
/// SkipWhitespace - Efficiently skip over a series of whitespace characters.
/// Update BufferPtr to point to the next non-whitespace character and return.
///
/// This method forms a token and returns true if KeepWhitespaceMode is enabled.
///
bool Lexer::SkipWhitespace(Token &Result, const char *CurPtr) {
// Whitespace - Skip it, then return the token after the whitespace.
unsigned char Char = *CurPtr; // Skip consequtive spaces efficiently.
while (1) {
// Skip horizontal whitespace very aggressively.
while (isHorizontalWhitespace(Char))
Char = *++CurPtr;
// Otherwise if we have something other than whitespace, we're done.
if (Char != '\n' && Char != '\r')
break;
if (ParsingPreprocessorDirective) {
// End of preprocessor directive line, let LexTokenInternal handle this.
BufferPtr = CurPtr;
return false;
}
// ok, but handle newline.
// The returned token is at the start of the line.
Result.setFlag(Token::StartOfLine);
// No leading whitespace seen so far.
Result.clearFlag(Token::LeadingSpace);
Char = *++CurPtr;
}
// If this isn't immediately after a newline, there is leading space.
char PrevChar = CurPtr[-1];
if (PrevChar != '\n' && PrevChar != '\r')
Result.setFlag(Token::LeadingSpace);
// If the client wants us to return whitespace, return it now.
if (isKeepWhitespaceMode()) {
FormTokenWithChars(Result, CurPtr, tok::unknown);
return true;
}
BufferPtr = CurPtr;
return false;
}
// SkipBCPLComment - We have just read the // characters from input. Skip until
// we find the newline character thats terminate the comment. Then update
/// BufferPtr and return.
///
/// If we're in KeepCommentMode or any CommentHandler has inserted
/// some tokens, this will store the first token and return true.
bool Lexer::SkipBCPLComment(Token &Result, const char *CurPtr) {
// If BCPL comments aren't explicitly enabled for this language, emit an
// extension warning.
if (!LangOpts.BCPLComment && !isLexingRawMode()) {
Diag(BufferPtr, diag::ext_bcpl_comment);
// Mark them enabled so we only emit one warning for this translation
// unit.
LangOpts.BCPLComment = true;
}
// Scan over the body of the comment. The common case, when scanning, is that
// the comment contains normal ascii characters with nothing interesting in
// them. As such, optimize for this case with the inner loop.
char C;
do {
C = *CurPtr;
// Skip over characters in the fast loop.
while (C != 0 && // Potentially EOF.
C != '\n' && C != '\r') // Newline or DOS-style newline.
C = *++CurPtr;
const char *NextLine = CurPtr;
if (C != 0) {
// We found a newline, see if it's escaped.
const char *EscapePtr = CurPtr-1;
while (isHorizontalWhitespace(*EscapePtr)) // Skip whitespace.
--EscapePtr;
if (*EscapePtr == '\\') // Escaped newline.
CurPtr = EscapePtr;
else if (EscapePtr[0] == '/' && EscapePtr[-1] == '?' &&
EscapePtr[-2] == '?') // Trigraph-escaped newline.
CurPtr = EscapePtr-2;
else
break; // This is a newline, we're done.
C = *CurPtr;
}
// Otherwise, this is a hard case. Fall back on getAndAdvanceChar to
// properly decode the character. Read it in raw mode to avoid emitting
// diagnostics about things like trigraphs. If we see an escaped newline,
// we'll handle it below.
const char *OldPtr = CurPtr;
bool OldRawMode = isLexingRawMode();
LexingRawMode = true;
C = getAndAdvanceChar(CurPtr, Result);
LexingRawMode = OldRawMode;
// If we only read only one character, then no special handling is needed.
// We're done and can skip forward to the newline.
if (C != 0 && CurPtr == OldPtr+1) {
CurPtr = NextLine;
break;
}
// If we read multiple characters, and one of those characters was a \r or
// \n, then we had an escaped newline within the comment. Emit diagnostic
// unless the next line is also a // comment.
if (CurPtr != OldPtr+1 && C != '/' && CurPtr[0] != '/') {
for (; OldPtr != CurPtr; ++OldPtr)
if (OldPtr[0] == '\n' || OldPtr[0] == '\r') {
// Okay, we found a // comment that ends in a newline, if the next
// line is also a // comment, but has spaces, don't emit a diagnostic.
if (isWhitespace(C)) {
const char *ForwardPtr = CurPtr;
while (isWhitespace(*ForwardPtr)) // Skip whitespace.
++ForwardPtr;
if (ForwardPtr[0] == '/' && ForwardPtr[1] == '/')
break;
}
if (!isLexingRawMode())
Diag(OldPtr-1, diag::ext_multi_line_bcpl_comment);
break;
}
}
if (CurPtr == BufferEnd+1) {
--CurPtr;
break;
}
if (C == '\0' && isCodeCompletionPoint(CurPtr-1)) {
PP->CodeCompleteNaturalLanguage();
cutOffLexing();
return false;
}
} while (C != '\n' && C != '\r');
// Found but did not consume the newline. Notify comment handlers about the
// comment unless we're in a #if 0 block.
if (PP && !isLexingRawMode() &&
PP->HandleComment(Result, SourceRange(getSourceLocation(BufferPtr),
getSourceLocation(CurPtr)))) {
BufferPtr = CurPtr;
return true; // A token has to be returned.
}
// If we are returning comments as tokens, return this comment as a token.
if (inKeepCommentMode())
return SaveBCPLComment(Result, CurPtr);
// If we are inside a preprocessor directive and we see the end of line,
// return immediately, so that the lexer can return this as an EOD token.
if (ParsingPreprocessorDirective || CurPtr == BufferEnd) {
BufferPtr = CurPtr;
return false;
}
// Otherwise, eat the \n character. We don't care if this is a \n\r or
// \r\n sequence. This is an efficiency hack (because we know the \n can't
// contribute to another token), it isn't needed for correctness. Note that
// this is ok even in KeepWhitespaceMode, because we would have returned the
/// comment above in that mode.
++CurPtr;
// The next returned token is at the start of the line.
Result.setFlag(Token::StartOfLine);
// No leading whitespace seen so far.
Result.clearFlag(Token::LeadingSpace);
BufferPtr = CurPtr;
return false;
}
/// SaveBCPLComment - If in save-comment mode, package up this BCPL comment in
/// an appropriate way and return it.
bool Lexer::SaveBCPLComment(Token &Result, const char *CurPtr) {
// If we're not in a preprocessor directive, just return the // comment
// directly.
FormTokenWithChars(Result, CurPtr, tok::comment);
if (!ParsingPreprocessorDirective)
return true;
// If this BCPL-style comment is in a macro definition, transmogrify it into
// a C-style block comment.
bool Invalid = false;
std::string Spelling = PP->getSpelling(Result, &Invalid);
if (Invalid)
return true;
assert(Spelling[0] == '/' && Spelling[1] == '/' && "Not bcpl comment?");
Spelling[1] = '*'; // Change prefix to "/*".
Spelling += "*/"; // add suffix.
Result.setKind(tok::comment);
PP->CreateString(&Spelling[0], Spelling.size(), Result,
Result.getLocation(), Result.getLocation());
return true;
}
/// isBlockCommentEndOfEscapedNewLine - Return true if the specified newline
/// character (either \n or \r) is part of an escaped newline sequence. Issue a
/// diagnostic if so. We know that the newline is inside of a block comment.
static bool isEndOfBlockCommentWithEscapedNewLine(const char *CurPtr,
Lexer *L) {
assert(CurPtr[0] == '\n' || CurPtr[0] == '\r');
// Back up off the newline.
--CurPtr;
// If this is a two-character newline sequence, skip the other character.
if (CurPtr[0] == '\n' || CurPtr[0] == '\r') {
// \n\n or \r\r -> not escaped newline.
if (CurPtr[0] == CurPtr[1])
return false;
// \n\r or \r\n -> skip the newline.
--CurPtr;
}
// If we have horizontal whitespace, skip over it. We allow whitespace
// between the slash and newline.
bool HasSpace = false;
while (isHorizontalWhitespace(*CurPtr) || *CurPtr == 0) {
--CurPtr;
HasSpace = true;
}
// If we have a slash, we know this is an escaped newline.
if (*CurPtr == '\\') {
if (CurPtr[-1] != '*') return false;
} else {
// It isn't a slash, is it the ?? / trigraph?
if (CurPtr[0] != '/' || CurPtr[-1] != '?' || CurPtr[-2] != '?' ||
CurPtr[-3] != '*')
return false;
// This is the trigraph ending the comment. Emit a stern warning!
CurPtr -= 2;
// If no trigraphs are enabled, warn that we ignored this trigraph and
// ignore this * character.
if (!L->getLangOpts().Trigraphs) {
if (!L->isLexingRawMode())
L->Diag(CurPtr, diag::trigraph_ignored_block_comment);
return false;
}
if (!L->isLexingRawMode())
L->Diag(CurPtr, diag::trigraph_ends_block_comment);
}
// Warn about having an escaped newline between the */ characters.
if (!L->isLexingRawMode())
L->Diag(CurPtr, diag::escaped_newline_block_comment_end);
// If there was space between the backslash and newline, warn about it.
if (HasSpace && !L->isLexingRawMode())
L->Diag(CurPtr, diag::backslash_newline_space);
return true;
}
#ifdef __SSE2__
#include <emmintrin.h>
#elif __ALTIVEC__
#include <altivec.h>
#undef bool
#endif
/// SkipBlockComment - We have just read the /* characters from input. Read
/// until we find the */ characters that terminate the comment. Note that we
/// don't bother decoding trigraphs or escaped newlines in block comments,
/// because they cannot cause the comment to end. The only thing that can
/// happen is the comment could end with an escaped newline between the */ end
/// of comment.
///
/// If we're in KeepCommentMode or any CommentHandler has inserted
/// some tokens, this will store the first token and return true.
bool Lexer::SkipBlockComment(Token &Result, const char *CurPtr) {
// Scan one character past where we should, looking for a '/' character. Once
// we find it, check to see if it was preceded by a *. This common
// optimization helps people who like to put a lot of * characters in their
// comments.
// The first character we get with newlines and trigraphs skipped to handle
// the degenerate /*/ case below correctly if the * has an escaped newline
// after it.
unsigned CharSize;
unsigned char C = getCharAndSize(CurPtr, CharSize);
CurPtr += CharSize;
if (C == 0 && CurPtr == BufferEnd+1) {
if (!isLexingRawMode())
Diag(BufferPtr, diag::err_unterminated_block_comment);
--CurPtr;
// KeepWhitespaceMode should return this broken comment as a token. Since
// it isn't a well formed comment, just return it as an 'unknown' token.
if (isKeepWhitespaceMode()) {
FormTokenWithChars(Result, CurPtr, tok::unknown);
return true;
}
BufferPtr = CurPtr;
return false;
}
// Check to see if the first character after the '/*' is another /. If so,
// then this slash does not end the block comment, it is part of it.
if (C == '/')
C = *CurPtr++;
while (1) {
// Skip over all non-interesting characters until we find end of buffer or a
// (probably ending) '/' character.
if (CurPtr + 24 < BufferEnd &&
// If there is a code-completion point avoid the fast scan because it
// doesn't check for '\0'.
!(PP && PP->getCodeCompletionFileLoc() == FileLoc)) {
// While not aligned to a 16-byte boundary.
while (C != '/' && ((intptr_t)CurPtr & 0x0F) != 0)
C = *CurPtr++;
if (C == '/') goto FoundSlash;
#ifdef __SSE2__
__m128i Slashes = _mm_set1_epi8('/');
while (CurPtr+16 <= BufferEnd) {
int cmp = _mm_movemask_epi8(_mm_cmpeq_epi8(*(__m128i*)CurPtr, Slashes));
if (cmp != 0) {
// Adjust the pointer to point directly after the first slash. It's
// not necessary to set C here, it will be overwritten at the end of
// the outer loop.
CurPtr += llvm::CountTrailingZeros_32(cmp) + 1;
goto FoundSlash;
}
CurPtr += 16;
}
#elif __ALTIVEC__
__vector unsigned char Slashes = {
'/', '/', '/', '/', '/', '/', '/', '/',
'/', '/', '/', '/', '/', '/', '/', '/'
};
while (CurPtr+16 <= BufferEnd &&
!vec_any_eq(*(vector unsigned char*)CurPtr, Slashes))
CurPtr += 16;
#else
// Scan for '/' quickly. Many block comments are very large.
while (CurPtr[0] != '/' &&
CurPtr[1] != '/' &&
CurPtr[2] != '/' &&
CurPtr[3] != '/' &&
CurPtr+4 < BufferEnd) {
CurPtr += 4;
}
#endif
// It has to be one of the bytes scanned, increment to it and read one.
C = *CurPtr++;
}
// Loop to scan the remainder.
while (C != '/' && C != '\0')
C = *CurPtr++;
if (C == '/') {
FoundSlash:
if (CurPtr[-2] == '*') // We found the final */. We're done!
break;
if ((CurPtr[-2] == '\n' || CurPtr[-2] == '\r')) {
if (isEndOfBlockCommentWithEscapedNewLine(CurPtr-2, this)) {
// We found the final */, though it had an escaped newline between the
// * and /. We're done!
break;
}
}
if (CurPtr[0] == '*' && CurPtr[1] != '/') {
// If this is a /* inside of the comment, emit a warning. Don't do this
// if this is a /*/, which will end the comment. This misses cases with
// embedded escaped newlines, but oh well.
if (!isLexingRawMode())
Diag(CurPtr-1, diag::warn_nested_block_comment);
}
} else if (C == 0 && CurPtr == BufferEnd+1) {
if (!isLexingRawMode())
Diag(BufferPtr, diag::err_unterminated_block_comment);
// Note: the user probably forgot a */. We could continue immediately
// after the /*, but this would involve lexing a lot of what really is the
// comment, which surely would confuse the parser.
--CurPtr;
// KeepWhitespaceMode should return this broken comment as a token. Since
// it isn't a well formed comment, just return it as an 'unknown' token.
if (isKeepWhitespaceMode()) {
FormTokenWithChars(Result, CurPtr, tok::unknown);
return true;
}
BufferPtr = CurPtr;
return false;
} else if (C == '\0' && isCodeCompletionPoint(CurPtr-1)) {
PP->CodeCompleteNaturalLanguage();
cutOffLexing();
return false;
}
C = *CurPtr++;
}
// Notify comment handlers about the comment unless we're in a #if 0 block.
if (PP && !isLexingRawMode() &&
PP->HandleComment(Result, SourceRange(getSourceLocation(BufferPtr),
getSourceLocation(CurPtr)))) {
BufferPtr = CurPtr;
return true; // A token has to be returned.
}
// If we are returning comments as tokens, return this comment as a token.
if (inKeepCommentMode()) {
FormTokenWithChars(Result, CurPtr, tok::comment);
return true;
}
// It is common for the tokens immediately after a /**/ comment to be
// whitespace. Instead of going through the big switch, handle it
// efficiently now. This is safe even in KeepWhitespaceMode because we would
// have already returned above with the comment as a token.
if (isHorizontalWhitespace(*CurPtr)) {
Result.setFlag(Token::LeadingSpace);
SkipWhitespace(Result, CurPtr+1);
return false;
}
// Otherwise, just return so that the next character will be lexed as a token.
BufferPtr = CurPtr;
Result.setFlag(Token::LeadingSpace);
return false;
}
//===----------------------------------------------------------------------===//
// Primary Lexing Entry Points
//===----------------------------------------------------------------------===//
/// ReadToEndOfLine - Read the rest of the current preprocessor line as an
/// uninterpreted string. This switches the lexer out of directive mode.
std::string Lexer::ReadToEndOfLine() {
assert(ParsingPreprocessorDirective && ParsingFilename == false &&
"Must be in a preprocessing directive!");
std::string Result;
Token Tmp;
// CurPtr - Cache BufferPtr in an automatic variable.
const char *CurPtr = BufferPtr;
while (1) {
char Char = getAndAdvanceChar(CurPtr, Tmp);
switch (Char) {
default:
Result += Char;
break;
case 0: // Null.
// Found end of file?
if (CurPtr-1 != BufferEnd) {
if (isCodeCompletionPoint(CurPtr-1)) {
PP->CodeCompleteNaturalLanguage();
cutOffLexing();
return Result;
}
// Nope, normal character, continue.
Result += Char;
break;
}
// FALL THROUGH.
case '\r':
case '\n':
// Okay, we found the end of the line. First, back up past the \0, \r, \n.
assert(CurPtr[-1] == Char && "Trigraphs for newline?");
BufferPtr = CurPtr-1;
// Next, lex the character, which should handle the EOD transition.
Lex(Tmp);
if (Tmp.is(tok::code_completion)) {
if (PP)
PP->CodeCompleteNaturalLanguage();
Lex(Tmp);
}
assert(Tmp.is(tok::eod) && "Unexpected token!");
// Finally, we're done, return the string we found.
return Result;
}
}
}
/// LexEndOfFile - CurPtr points to the end of this file. Handle this
/// condition, reporting diagnostics and handling other edge cases as required.
/// This returns true if Result contains a token, false if PP.Lex should be
/// called again.
bool Lexer::LexEndOfFile(Token &Result, const char *CurPtr) {
// If we hit the end of the file while parsing a preprocessor directive,
// end the preprocessor directive first. The next token returned will
// then be the end of file.
if (ParsingPreprocessorDirective) {
// Done parsing the "line".
ParsingPreprocessorDirective = false;
// Update the location of token as well as BufferPtr.
FormTokenWithChars(Result, CurPtr, tok::eod);
// Restore comment saving mode, in case it was disabled for directive.
SetCommentRetentionState(PP->getCommentRetentionState());
return true; // Have a token.
}
// If we are in raw mode, return this event as an EOF token. Let the caller
// that put us in raw mode handle the event.
if (isLexingRawMode()) {
Result.startToken();
BufferPtr = BufferEnd;
FormTokenWithChars(Result, BufferEnd, tok::eof);
return true;
}
// Issue diagnostics for unterminated #if and missing newline.
// If we are in a #if directive, emit an error.
while (!ConditionalStack.empty()) {
if (PP->getCodeCompletionFileLoc() != FileLoc)
PP->Diag(ConditionalStack.back().IfLoc,
diag::err_pp_unterminated_conditional);
ConditionalStack.pop_back();
}
// C99 5.1.1.2p2: If the file is non-empty and didn't end in a newline, issue
// a pedwarn.
if (CurPtr != BufferStart && (CurPtr[-1] != '\n' && CurPtr[-1] != '\r'))
Diag(BufferEnd, diag::ext_no_newline_eof)
<< FixItHint::CreateInsertion(getSourceLocation(BufferEnd), "\n");
BufferPtr = CurPtr;
// Finally, let the preprocessor handle this.
return PP->HandleEndOfFile(Result);
}
/// isNextPPTokenLParen - Return 1 if the next unexpanded token lexed from
/// the specified lexer will return a tok::l_paren token, 0 if it is something
/// else and 2 if there are no more tokens in the buffer controlled by the
/// lexer.
unsigned Lexer::isNextPPTokenLParen() {
assert(!LexingRawMode && "How can we expand a macro from a skipping buffer?");
// Switch to 'skipping' mode. This will ensure that we can lex a token
// without emitting diagnostics, disables macro expansion, and will cause EOF
// to return an EOF token instead of popping the include stack.
LexingRawMode = true;
// Save state that can be changed while lexing so that we can restore it.
const char *TmpBufferPtr = BufferPtr;
bool inPPDirectiveMode = ParsingPreprocessorDirective;
Token Tok;
Tok.startToken();
LexTokenInternal(Tok);
// Restore state that may have changed.
BufferPtr = TmpBufferPtr;
ParsingPreprocessorDirective = inPPDirectiveMode;
// Restore the lexer back to non-skipping mode.
LexingRawMode = false;
if (Tok.is(tok::eof))
return 2;
return Tok.is(tok::l_paren);
}
/// FindConflictEnd - Find the end of a version control conflict marker.
static const char *FindConflictEnd(const char *CurPtr, const char *BufferEnd,
ConflictMarkerKind CMK) {
const char *Terminator = CMK == CMK_Perforce ? "<<<<\n" : ">>>>>>>";
size_t TermLen = CMK == CMK_Perforce ? 5 : 7;
StringRef RestOfBuffer(CurPtr+TermLen, BufferEnd-CurPtr-TermLen);
size_t Pos = RestOfBuffer.find(Terminator);
while (Pos != StringRef::npos) {
// Must occur at start of line.
if (RestOfBuffer[Pos-1] != '\r' &&
RestOfBuffer[Pos-1] != '\n') {
RestOfBuffer = RestOfBuffer.substr(Pos+TermLen);
Pos = RestOfBuffer.find(Terminator);
continue;
}
return RestOfBuffer.data()+Pos;
}
return 0;
}
/// IsStartOfConflictMarker - If the specified pointer is the start of a version
/// control conflict marker like '<<<<<<<', recognize it as such, emit an error
/// and recover nicely. This returns true if it is a conflict marker and false
/// if not.
bool Lexer::IsStartOfConflictMarker(const char *CurPtr) {
// Only a conflict marker if it starts at the beginning of a line.
if (CurPtr != BufferStart &&
CurPtr[-1] != '\n' && CurPtr[-1] != '\r')
return false;
// Check to see if we have <<<<<<< or >>>>.
if ((BufferEnd-CurPtr < 8 || StringRef(CurPtr, 7) != "<<<<<<<") &&
(BufferEnd-CurPtr < 6 || StringRef(CurPtr, 5) != ">>>> "))
return false;
// If we have a situation where we don't care about conflict markers, ignore
// it.
if (CurrentConflictMarkerState || isLexingRawMode())
return false;
ConflictMarkerKind Kind = *CurPtr == '<' ? CMK_Normal : CMK_Perforce;
// Check to see if there is an ending marker somewhere in the buffer at the
// start of a line to terminate this conflict marker.
if (FindConflictEnd(CurPtr, BufferEnd, Kind)) {
// We found a match. We are really in a conflict marker.
// Diagnose this, and ignore to the end of line.
Diag(CurPtr, diag::err_conflict_marker);
CurrentConflictMarkerState = Kind;
// Skip ahead to the end of line. We know this exists because the
// end-of-conflict marker starts with \r or \n.
while (*CurPtr != '\r' && *CurPtr != '\n') {
assert(CurPtr != BufferEnd && "Didn't find end of line");
++CurPtr;
}
BufferPtr = CurPtr;
return true;
}
// No end of conflict marker found.
return false;
}
/// HandleEndOfConflictMarker - If this is a '====' or '||||' or '>>>>', or if
/// it is '<<<<' and the conflict marker started with a '>>>>' marker, then it
/// is the end of a conflict marker. Handle it by ignoring up until the end of
/// the line. This returns true if it is a conflict marker and false if not.
bool Lexer::HandleEndOfConflictMarker(const char *CurPtr) {
// Only a conflict marker if it starts at the beginning of a line.
if (CurPtr != BufferStart &&
CurPtr[-1] != '\n' && CurPtr[-1] != '\r')
return false;
// If we have a situation where we don't care about conflict markers, ignore
// it.
if (!CurrentConflictMarkerState || isLexingRawMode())
return false;
// Check to see if we have the marker (4 characters in a row).
for (unsigned i = 1; i != 4; ++i)
if (CurPtr[i] != CurPtr[0])
return false;
// If we do have it, search for the end of the conflict marker. This could
// fail if it got skipped with a '#if 0' or something. Note that CurPtr might
// be the end of conflict marker.
if (const char *End = FindConflictEnd(CurPtr, BufferEnd,
CurrentConflictMarkerState)) {
CurPtr = End;
// Skip ahead to the end of line.
while (CurPtr != BufferEnd && *CurPtr != '\r' && *CurPtr != '\n')
++CurPtr;
BufferPtr = CurPtr;
// No longer in the conflict marker.
CurrentConflictMarkerState = CMK_None;
return true;
}
return false;
}
bool Lexer::isCodeCompletionPoint(const char *CurPtr) const {
if (PP && PP->isCodeCompletionEnabled()) {
SourceLocation Loc = FileLoc.getLocWithOffset(CurPtr-BufferStart);
return Loc == PP->getCodeCompletionLoc();
}
return false;
}
/// LexTokenInternal - This implements a simple C family lexer. It is an
/// extremely performance critical piece of code. This assumes that the buffer
/// has a null character at the end of the file. This returns a preprocessing
/// token, not a normal token, as such, it is an internal interface. It assumes
/// that the Flags of result have been cleared before calling this.
void Lexer::LexTokenInternal(Token &Result) {
LexNextToken:
// New token, can't need cleaning yet.
Result.clearFlag(Token::NeedsCleaning);