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clang-1
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clang-1/lib/Lex/Lexer.cpp

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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/Basic/SourceManager.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cctype>
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::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!");
Is_PragmaLexer = false;
IsEofCodeCompletion = false;
// 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, Preprocessor &PP)
: PreprocessorLexer(&PP, FID),
FileLoc(PP.getSourceManager().getLocForStartOfFile(FID)),
Features(PP.getLangOptions()) {
const llvm::MemoryBuffer *InputFile = PP.getSourceManager().getBuffer(FID);
InitLexer(InputFile->getBufferStart(), InputFile->getBufferStart(),
InputFile->getBufferEnd());
// Default to keeping comments if the preprocessor wants them.
SetCommentRetentionState(PP.getCommentRetentionState());
// If the input file is truncated, the EOF is a code-completion token.
if (PP.getSourceManager().isTruncatedFile(FID))
IsEofCodeCompletion = 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(SourceLocation fileloc, const LangOptions &features,
const char *BufStart, const char *BufPtr, const char *BufEnd)
: FileLoc(fileloc), Features(features) {
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 SourceManager &SM, const LangOptions &features)
: FileLoc(SM.getLocForStartOfFile(FID)), Features(features) {
const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
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
/// instantiation 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 InstantiationLocStart,
SourceLocation InstantiationLocEnd,
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);
Lexer *L = new Lexer(SpellingFID, 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.createInstantiationLoc(SM.getLocForStartOfFile(SpellingFID),
InstantiationLocStart,
InstantiationLocEnd, TokLen);
// Ensure that the lexer thinks it is inside a directive, so that end \n will
// return an EOM 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(llvm::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;
}
}
}
/// 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.getInstantiationLoc(Loc);
std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
std::pair<const char *,const char *> Buffer = SM.getBufferData(LocInfo.first);
const char *StrData = Buffer.first+LocInfo.second;
// Create a lexer starting at the beginning of this token.
Lexer TheLexer(Loc, LangOpts, Buffer.first, StrData, Buffer.second);
TheLexer.SetCommentRetentionState(true);
Token TheTok;
TheLexer.LexFromRawLexer(TheTok);
return TheTok.getLength();
}
//===----------------------------------------------------------------------===//
// 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 // .
};
// 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, 0 , 0 , 0 ,
0 , 0 , 0 , 0 ,
//40 ( 41 ) 42 * 43 +
//44 , 45 - 46 . 47 /
0 , 0 , 0 , 0 ,
0 , 0 , CHAR_PERIOD , 0 ,
//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 , 0 , 0 ,
0 , 0 , 0 , 0 ,
//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 , 0 ,
0 , 0 , 0 , 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 , 0 ,
0 , 0 , 0 , 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;
}
/// 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;
}
/// 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;
}
//===----------------------------------------------------------------------===//
// Diagnostics forwarding code.
//===----------------------------------------------------------------------===//
/// GetMappedTokenLoc - If lexing out of a 'mapped buffer', where we pretend the
/// lexer buffer was all instantiated 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 DISABLE_INLINE 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 an instantiation");
// Otherwise, we're lexing "mapped tokens". This is used for things like
// _Pragma handling. Combine the instantiation location of FileLoc with the
// spelling location.
SourceManager &SM = PP.getSourceManager();
// Create a new SLoc which is expanded from Instantiation(FileLoc) but whose
// characters come from spelling(FileLoc)+Offset.
SourceLocation SpellingLoc = SM.getSpellingLoc(FileLoc);
SpellingLoc = SpellingLoc.getFileLocWithOffset(CharNo);
// Figure out the expansion loc range, which is the range covered by the
// original _Pragma(...) sequence.
std::pair<SourceLocation,SourceLocation> II =
SM.getImmediateInstantiationRange(FileLoc);
return SM.createInstantiationLoc(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.getFileLocWithOffset(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->getFeatures().Trigraphs) {
if (!L->isLexingRawMode())
L->Diag(CP-2, diag::trigraph_ignored);
return 0;
}
if (!L->isLexingRawMode())
L->Diag(CP-2, diag::trigraph_converted) << std::string()+Res;
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;
}
}
/// 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;
// 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 &Features) {
// 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;
// Use slow version to accumulate a correct size field.
return getCharAndSizeSlowNoWarn(Ptr, Size, Features);
}
// Otherwise, this is not an escaped newline, just return the slash.
return '\\';
}
// If this is a trigraph, process it.
if (Features.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.
//===----------------------------------------------------------------------===//
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 $,\,? in identifier found. '\' might be an escaped newline
// or UCN, and ? might be a trigraph for '\', an escaped newline or UCN.
// FIXME: UCNs.
if (C != '\\' && C != '?' && (C != '$' || !Features.DollarIdents)) {
FinishIdentifier:
const char *IdStart = BufferPtr;
FormTokenWithChars(Result, CurPtr, tok::identifier);
// 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, looking up the identifier in the
// identifier table.
IdentifierInfo *II = PP->LookUpIdentifierInfo(Result, IdStart);
// Change the kind of this identifier to the appropriate token kind, e.g.
// turning "for" into a keyword.
Result.setKind(II->getTokenID());
// 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 (!Features.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);
}
}
}
/// 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'))
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);
}
/// LexStringLiteral - Lex the remainder of a string literal, after having lexed
/// either " or L".
void Lexer::LexStringLiteral(Token &Result, const char *CurPtr, bool Wide) {
const char *NulCharacter = 0; // Does this string contain the \0 character?
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.
if (!isLexingRawMode() && !Features.AsmPreprocessor)
Diag(BufferPtr, diag::err_unterminated_string);
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
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 the token as well as the BufferPtr instance var.
const char *TokStart = BufferPtr;
FormTokenWithChars(Result, CurPtr,
Wide ? tok::wide_string_literal : tok::string_literal);
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.
// 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'.
void Lexer::LexCharConstant(Token &Result, const char *CurPtr) {
const char *NulCharacter = 0; // Does this character contain the \0 character?
// Handle the common case of 'x' and '\y' efficiently.
char C = getAndAdvanceChar(CurPtr, Result);
if (C == '\'') {
if (!isLexingRawMode() && !Features.AsmPreprocessor)
Diag(BufferPtr, diag::err_empty_character);
FormTokenWithChars(Result, CurPtr, tok::unknown);
return;
} else if (C == '\\') {
// Skip the escaped character.
// FIXME: UCN's.
C = getAndAdvanceChar(CurPtr, Result);
}
if (C && C != '\n' && C != '\r' && CurPtr[0] == '\'') {
++CurPtr;
} else {
// Fall back on generic code for embedded nulls, newlines, wide chars.
do {
// 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.
if (!isLexingRawMode() && !Features.AsmPreprocessor)
Diag(BufferPtr, diag::err_unterminated_char);
FormTokenWithChars(Result, CurPtr-1, tok::unknown);
return;
} else if (C == 0) {
NulCharacter = CurPtr-1;
}
C = getAndAdvanceChar(CurPtr, Result);
} while (C != '\'');
}
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, tok::char_constant);
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, this will form the 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 (!Features.BCPLComment && !isLexingRawMode()) {
Diag(BufferPtr, diag::ext_bcpl_comment);
// Mark them enabled so we only emit one warning for this translation
// unit.
Features.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;
// FIXME: Speedup BCPL comment lexing. Just scan for a \n or \r character.
// If we find a \n character, scan backwards, checking to see if it's an
// escaped newline, like we do for block comments.
// Skip over characters in the fast loop.
while (C != 0 && // Potentially EOF.
C != '\\' && // Potentially escaped newline.
C != '?' && // Potentially trigraph.
C != '\n' && C != '\r') // Newline or DOS-style newline.
C = *++CurPtr;
// If this is a newline, we're done.
if (C == '\n' || C == '\r')
break; // Found the newline? Break out!
// 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 the char that we finally got was a \n, then we must have had something
// like \<newline><newline>. We don't want to have consumed the second
// newline, we want CurPtr, to end up pointing to it down below.
if (C == '\n' || C == '\r') {
--CurPtr;
C = 'x'; // doesn't matter what this is.
}
// 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 (isspace(C)) {
const char *ForwardPtr = CurPtr;
while (isspace(*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; }
} while (C != '\n' && C != '\r');
// Found but did not consume the newline.
if (PP)
PP->HandleComment(SourceRange(getSourceLocation(BufferPtr),
getSourceLocation(CurPtr)));
// 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 EOM 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.
std::string Spelling = PP->getSpelling(Result);
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());
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->getFeatures().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 KeepCommentMode is enabled, this forms a token from the comment and
/// returns 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 preceeded 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) {
// 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_set_epi8('/', '/', '/', '/', '/', '/', '/', '/',
'/', '/', '/', '/', '/', '/', '/', '/');
while (CurPtr+16 <= BufferEnd &&
_mm_movemask_epi8(_mm_cmpeq_epi8(*(__m128i*)CurPtr, Slashes)) == 0)
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++;
FoundSlash:
if (C == '/') {
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;
}
C = *CurPtr++;
}
if (PP)
PP->HandleComment(SourceRange(getSourceLocation(BufferPtr),
getSourceLocation(CurPtr)));
// 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) {
// 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 EOM transition.
Lex(Tmp);
assert(Tmp.is(tok::eom) && "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::eom);
// 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;
}
// Otherwise, check if we are code-completing, then issue diagnostics for
// unterminated #if and missing newline.
if (IsEofCodeCompletion) {
bool isIntendedFile = true;
if (PP && FileLoc.isFileID()) {
SourceManager &SM = PP->getSourceManager();
isIntendedFile = SM.isTruncatedFile(SM.getFileID(FileLoc));
}
if (isIntendedFile) {
// We're at the end of the file, but we've been asked to consider the
// end of the file to be a code-completion token. Return the
// code-completion token.
Result.startToken();
FormTokenWithChars(Result, CurPtr, tok::code_completion);
// Only do the eof -> code_completion translation once.
IsEofCodeCompletion = false;
return true;
}
}
// If we are in a #if directive, emit an error.
while (!ConditionalStack.empty()) {
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)
<< CodeModificationHint::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);
}
/// 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);
Result.setIdentifierInfo(0);
// CurPtr - Cache BufferPtr in an automatic variable.
const char *CurPtr = BufferPtr;
// Small amounts of horizontal whitespace is very common between tokens.
if ((*CurPtr == ' ') || (*CurPtr == '\t')) {
++CurPtr;
while ((*CurPtr == ' ') || (*CurPtr == '\t'))
++CurPtr;
// If we are keeping whitespace and other tokens, just return what we just
// skipped. The next lexer invocation will return the token after the
// whitespace.
if (isKeepWhitespaceMode()) {
FormTokenWithChars(Result, CurPtr, tok::unknown);
return;
}
BufferPtr = CurPtr;
Result.setFlag(Token::LeadingSpace);
}
unsigned SizeTmp, SizeTmp2; // Temporaries for use in cases below.
// Read a character, advancing over it.
char Char = getAndAdvanceChar(CurPtr, Result);
tok::TokenKind Kind;
switch (Char) {
case 0: // Null.
// Found end of file?
if (CurPtr-1 == BufferEnd) {
// Read the PP instance variable into an automatic variable, because
// LexEndOfFile will often delete 'this'.
Preprocessor *PPCache = PP;
if (LexEndOfFile(Result, CurPtr-1)) // Retreat back into the file.
return; // Got a token to return.
assert(PPCache && "Raw buffer::LexEndOfFile should return a token");
return PPCache->Lex(Result);
}
if (!isLexingRawMode())
Diag(CurPtr-1, diag::null_in_file);
Result.setFlag(Token::LeadingSpace);
if (SkipWhitespace(Result, CurPtr))
return; // KeepWhitespaceMode
goto LexNextToken; // GCC isn't tail call eliminating.
case '\n':
case '\r':
// If we are inside a preprocessor directive and we see the end of line,
// we know we are done with the directive, so return an EOM token.
if (ParsingPreprocessorDirective) {
// Done parsing the "line".
ParsingPreprocessorDirective = false;
// Restore comment saving mode, in case it was disabled for directive.
SetCommentRetentionState(PP->getCommentRetentionState());
// Since we consumed a newline, we are back at the start of a line.
IsAtStartOfLine = true;
Kind = tok::eom;
break;
}
// The returned token is at the start of the line.
Result.setFlag(Token::StartOfLine);
// No leading whitespace seen so far.
Result.clearFlag(Token::LeadingSpace);
if (SkipWhitespace(Result, CurPtr))
return; // KeepWhitespaceMode
goto LexNextToken; // GCC isn't tail call eliminating.
case ' ':
case '\t':
case '\f':
case '\v':
SkipHorizontalWhitespace:
Result.setFlag(Token::LeadingSpace);
if (SkipWhitespace(Result, CurPtr))
return; // KeepWhitespaceMode
SkipIgnoredUnits:
CurPtr = BufferPtr;
// If the next token is obviously a // or /* */ comment, skip it efficiently
// too (without going through the big switch stmt).
if (CurPtr[0] == '/' && CurPtr[1] == '/' && !inKeepCommentMode() &&
Features.BCPLComment) {
SkipBCPLComment(Result, CurPtr+2);
goto SkipIgnoredUnits;
} else if (CurPtr[0] == '/' && CurPtr[1] == '*' && !inKeepCommentMode()) {
SkipBlockComment(Result, CurPtr+2);
goto SkipIgnoredUnits;
} else if (isHorizontalWhitespace(*CurPtr)) {
goto SkipHorizontalWhitespace;
}
goto LexNextToken; // GCC isn't tail call eliminating.
// C99 6.4.4.1: Integer Constants.
// C99 6.4.4.2: Floating Constants.
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
return LexNumericConstant(Result, CurPtr);
case 'L': // Identifier (Loony) or wide literal (L'x' or L"xyz").
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
Char = getCharAndSize(CurPtr, SizeTmp);
// Wide string literal.
if (Char == '"')
return LexStringLiteral(Result, ConsumeChar(CurPtr, SizeTmp, Result),
true);
// Wide character constant.
if (Char == '\'')
return LexCharConstant(Result, ConsumeChar(CurPtr, SizeTmp, Result));
// FALL THROUGH, treating L like the start of an identifier.
// C99 6.4.2: Identifiers.
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
case 'H': case 'I': case 'J': case 'K': /*'L'*/case 'M': case 'N':
case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
case 'V': case 'W': case 'X': case 'Y': case 'Z':
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
case 'v': case 'w': case 'x': case 'y': case 'z':
case '_':
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
return LexIdentifier(Result, CurPtr);
case '$': // $ in identifiers.
if (Features.DollarIdents) {
if (!isLexingRawMode())
Diag(CurPtr-1, diag::ext_dollar_in_identifier);
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
return LexIdentifier(Result, CurPtr);
}
Kind = tok::unknown;
break;
// C99 6.4.4: Character Constants.
case '\'':
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
return LexCharConstant(Result, CurPtr);
// C99 6.4.5: String Literals.
case '"':
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
return LexStringLiteral(Result, CurPtr, false);
// C99 6.4.6: Punctuators.
case '?':
Kind = tok::question;
break;
case '[':
Kind = tok::l_square;
break;
case ']':
Kind = tok::r_square;
break;
case '(':
Kind = tok::l_paren;
break;
case ')':
Kind = tok::r_paren;
break;
case '{':
Kind = tok::l_brace;
break;
case '}':
Kind = tok::r_brace;
break;
case '.':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char >= '0' && Char <= '9') {
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
return LexNumericConstant(Result, ConsumeChar(CurPtr, SizeTmp, Result));
} else if (Features.CPlusPlus && Char == '*') {
Kind = tok::periodstar;
CurPtr += SizeTmp;
} else if (Char == '.' &&
getCharAndSize(CurPtr+SizeTmp, SizeTmp2) == '.') {
Kind = tok::ellipsis;
CurPtr = ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result);
} else {
Kind = tok::period;
}
break;
case '&':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '&') {
Kind = tok::ampamp;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else if (Char == '=') {
Kind = tok::ampequal;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
Kind = tok::amp;
}
break;
case '*':
if (getCharAndSize(CurPtr, SizeTmp) == '=') {
Kind = tok::starequal;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
Kind = tok::star;
}
break;
case '+':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '+') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::plusplus;
} else if (Char == '=') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::plusequal;
} else {
Kind = tok::plus;
}
break;
case '-':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '-') { // --
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::minusminus;
} else if (Char == '>' && Features.CPlusPlus &&
getCharAndSize(CurPtr+SizeTmp, SizeTmp2) == '*') { // C++ ->*
CurPtr = ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result);
Kind = tok::arrowstar;
} else if (Char == '>') { // ->
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::arrow;
} else if (Char == '=') { // -=
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::minusequal;
} else {
Kind = tok::minus;
}
break;
case '~':
Kind = tok::tilde;
break;
case '!':
if (getCharAndSize(CurPtr, SizeTmp) == '=') {
Kind = tok::exclaimequal;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
Kind = tok::exclaim;
}
break;
case '/':
// 6.4.9: Comments
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '/') { // BCPL comment.
// Even if BCPL comments are disabled (e.g. in C89 mode), we generally
// want to lex this as a comment. There is one problem with this though,
// that in one particular corner case, this can change the behavior of the
// resultant program. For example, In "foo //**/ bar", C89 would lex
// this as "foo / bar" and langauges with BCPL comments would lex it as
// "foo". Check to see if the character after the second slash is a '*'.
// If so, we will lex that as a "/" instead of the start of a comment.
if (Features.BCPLComment ||
getCharAndSize(CurPtr+SizeTmp, SizeTmp2) != '*') {
if (SkipBCPLComment(Result, ConsumeChar(CurPtr, SizeTmp, Result)))
return; // KeepCommentMode
// It is common for the tokens immediately after a // comment to be
// whitespace (indentation for the next line). Instead of going through
// the big switch, handle it efficiently now.
goto SkipIgnoredUnits;
}
}
if (Char == '*') { // /**/ comment.
if (SkipBlockComment(Result, ConsumeChar(CurPtr, SizeTmp, Result)))
return; // KeepCommentMode
goto LexNextToken; // GCC isn't tail call eliminating.
}
if (Char == '=') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::slashequal;
} else {
Kind = tok::slash;
}
break;
case '%':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '=') {
Kind = tok::percentequal;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else if (Features.Digraphs && Char == '>') {
Kind = tok::r_brace; // '%>' -> '}'
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else if (Features.Digraphs && Char == ':') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '%' && getCharAndSize(CurPtr+SizeTmp, SizeTmp2) == ':') {
Kind = tok::hashhash; // '%:%:' -> '##'
CurPtr = ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result);
} else if (Char == '@' && Features.Microsoft) { // %:@ -> #@ -> Charize
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
if (!isLexingRawMode())
Diag(BufferPtr, diag::charize_microsoft_ext);
Kind = tok::hashat;
} else { // '%:' -> '#'
// We parsed a # character. If this occurs at the start of the line,
// it's actually the start of a preprocessing directive. Callback to
// the preprocessor to handle it.
// FIXME: -fpreprocessed mode??
if (Result.isAtStartOfLine() && !LexingRawMode && !Is_PragmaLexer) {
FormTokenWithChars(Result, CurPtr, tok::hash);
PP->HandleDirective(Result);
// As an optimization, if the preprocessor didn't switch lexers, tail
// recurse.
if (PP->isCurrentLexer(this)) {
// Start a new token. If this is a #include or something, the PP may
// want us starting at the beginning of the line again. If so, set
// the StartOfLine flag.
if (IsAtStartOfLine) {
Result.setFlag(Token::StartOfLine);
IsAtStartOfLine = false;
}
goto LexNextToken; // GCC isn't tail call eliminating.
}
return PP->Lex(Result);
}
Kind = tok::hash;
}
} else {
Kind = tok::percent;
}
break;
case '<':
Char = getCharAndSize(CurPtr, SizeTmp);
if (ParsingFilename) {
return LexAngledStringLiteral(Result, CurPtr);
} else if (Char == '<' &&
getCharAndSize(CurPtr+SizeTmp, SizeTmp2) == '=') {
Kind = tok::lesslessequal;
CurPtr = ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result);
} else if (Char == '<') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::lessless;
} else if (Char == '=') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::lessequal;
} else if (Features.Digraphs && Char == ':') { // '<:' -> '['
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::l_square;
} else if (Features.Digraphs && Char == '%') { // '<%' -> '{'
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::l_brace;
} else {
Kind = tok::less;
}
break;
case '>':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '=') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::greaterequal;
} else if (Char == '>' &&
getCharAndSize(CurPtr+SizeTmp, SizeTmp2) == '=') {
CurPtr = ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
SizeTmp2, Result);
Kind = tok::greatergreaterequal;
} else if (Char == '>') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::greatergreater;
} else {
Kind = tok::greater;
}
break;
case '^':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '=') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::caretequal;
} else {
Kind = tok::caret;
}
break;
case '|':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '=') {
Kind = tok::pipeequal;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else if (Char == '|') {
Kind = tok::pipepipe;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
Kind = tok::pipe;
}
break;
case ':':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Features.Digraphs && Char == '>') {
Kind = tok::r_square; // ':>' -> ']'
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else if (Features.CPlusPlus && Char == ':') {
Kind = tok::coloncolon;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
Kind = tok::colon;
}
break;
case ';':
Kind = tok::semi;
break;
case '=':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '=') {
Kind = tok::equalequal;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
Kind = tok::equal;
}
break;
case ',':
Kind = tok::comma;
break;
case '#':
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '#') {
Kind = tok::hashhash;
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else if (Char == '@' && Features.Microsoft) { // #@ -> Charize
Kind = tok::hashat;
if (!isLexingRawMode())
Diag(BufferPtr, diag::charize_microsoft_ext);
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
} else {
// We parsed a # character. If this occurs at the start of the line,
// it's actually the start of a preprocessing directive. Callback to
// the preprocessor to handle it.
// FIXME: -fpreprocessed mode??
if (Result.isAtStartOfLine() && !LexingRawMode && !Is_PragmaLexer) {
FormTokenWithChars(Result, CurPtr, tok::hash);
PP->HandleDirective(Result);
// As an optimization, if the preprocessor didn't switch lexers, tail
// recurse.
if (PP->isCurrentLexer(this)) {
// Start a new token. If this is a #include or something, the PP may
// want us starting at the beginning of the line again. If so, set
// the StartOfLine flag.
if (IsAtStartOfLine) {
Result.setFlag(Token::StartOfLine);
IsAtStartOfLine = false;
}
goto LexNextToken; // GCC isn't tail call eliminating.
}
return PP->Lex(Result);
}
Kind = tok::hash;
}
break;
case '@':
// Objective C support.
if (CurPtr[-1] == '@' && Features.ObjC1)
Kind = tok::at;
else
Kind = tok::unknown;
break;
case '\\':
// FIXME: UCN's.
// FALL THROUGH.
default:
Kind = tok::unknown;
break;
}
// Notify MIOpt that we read a non-whitespace/non-comment token.
MIOpt.ReadToken();
// Update the location of token as well as BufferPtr.
FormTokenWithChars(Result, CurPtr, Kind);
}
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