1 //===- AsmLexer.cpp - Lexer for Assembly Files ----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This class implements the lexer for assembly files.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/MC/MCParser/AsmLexer.h"
15 #include "llvm/Support/SMLoc.h"
16 #include "llvm/Support/MemoryBuffer.h"
17 #include "llvm/MC/MCAsmInfo.h"
24 AsmLexer::AsmLexer(const MCAsmInfo &_MAI) : MAI(_MAI) {
27 isAtStartOfLine = true;
30 AsmLexer::~AsmLexer() {
33 void AsmLexer::setBuffer(const MemoryBuffer *buf, const char *ptr) {
39 CurPtr = CurBuf->getBufferStart();
44 /// ReturnError - Set the error to the specified string at the specified
45 /// location. This is defined to always return AsmToken::Error.
46 AsmToken AsmLexer::ReturnError(const char *Loc, const std::string &Msg) {
47 SetError(SMLoc::getFromPointer(Loc), Msg);
49 return AsmToken(AsmToken::Error, StringRef(Loc, 0));
52 int AsmLexer::getNextChar() {
53 char CurChar = *CurPtr++;
56 return (unsigned char)CurChar;
58 // A nul character in the stream is either the end of the current buffer or
59 // a random nul in the file. Disambiguate that here.
60 if (CurPtr-1 != CurBuf->getBufferEnd())
61 return 0; // Just whitespace.
63 // Otherwise, return end of file.
64 --CurPtr; // Another call to lex will return EOF again.
69 /// LexFloatLiteral: [0-9]*[.][0-9]*([eE][+-]?[0-9]*)?
71 /// The leading integral digit sequence and dot should have already been
72 /// consumed, some or all of the fractional digit sequence *can* have been
74 AsmToken AsmLexer::LexFloatLiteral() {
75 // Skip the fractional digit sequence.
76 while (isdigit(*CurPtr))
79 // Check for exponent; we intentionally accept a slighlty wider set of
80 // literals here and rely on the upstream client to reject invalid ones (e.g.,
82 if (*CurPtr == 'e' || *CurPtr == 'E') {
84 if (*CurPtr == '-' || *CurPtr == '+')
86 while (isdigit(*CurPtr))
90 return AsmToken(AsmToken::Real,
91 StringRef(TokStart, CurPtr - TokStart));
94 /// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
95 static bool IsIdentifierChar(char c) {
96 return isalnum(c) || c == '_' || c == '$' || c == '.' || c == '@';
98 AsmToken AsmLexer::LexIdentifier() {
99 // Check for floating point literals.
100 if (CurPtr[-1] == '.' && isdigit(*CurPtr)) {
101 // Disambiguate a .1243foo identifier from a floating literal.
102 while (isdigit(*CurPtr))
104 if (*CurPtr == 'e' || *CurPtr == 'E' || !IsIdentifierChar(*CurPtr))
105 return LexFloatLiteral();
108 while (IsIdentifierChar(*CurPtr))
111 // Handle . as a special case.
112 if (CurPtr == TokStart+1 && TokStart[0] == '.')
113 return AsmToken(AsmToken::Dot, StringRef(TokStart, 1));
115 return AsmToken(AsmToken::Identifier, StringRef(TokStart, CurPtr - TokStart));
118 /// LexSlash: Slash: /
119 /// C-Style Comment: /* ... */
120 AsmToken AsmLexer::LexSlash() {
122 case '*': break; // C style comment.
123 case '/': return ++CurPtr, LexLineComment();
124 default: return AsmToken(AsmToken::Slash, StringRef(CurPtr-1, 1));
128 ++CurPtr; // skip the star.
130 int CurChar = getNextChar();
133 return ReturnError(TokStart, "unterminated comment");
135 // End of the comment?
136 if (CurPtr[0] != '/') break;
138 ++CurPtr; // End the */.
144 /// LexLineComment: Comment: #[^\n]*
146 AsmToken AsmLexer::LexLineComment() {
147 // FIXME: This is broken if we happen to a comment at the end of a file, which
148 // was .included, and which doesn't end with a newline.
149 int CurChar = getNextChar();
150 while (CurChar != '\n' && CurChar != '\r' && CurChar != EOF)
151 CurChar = getNextChar();
154 return AsmToken(AsmToken::Eof, StringRef(CurPtr, 0));
155 return AsmToken(AsmToken::EndOfStatement, StringRef(CurPtr, 0));
158 static void SkipIgnoredIntegerSuffix(const char *&CurPtr) {
159 if (CurPtr[0] == 'L' && CurPtr[1] == 'L')
161 if (CurPtr[0] == 'U' && CurPtr[1] == 'L' && CurPtr[2] == 'L')
165 /// LexDigit: First character is [0-9].
166 /// Local Label: [0-9][:]
167 /// Forward/Backward Label: [0-9][fb]
168 /// Binary integer: 0b[01]+
169 /// Octal integer: 0[0-7]+
170 /// Hex integer: 0x[0-9a-fA-F]+
171 /// Decimal integer: [1-9][0-9]*
172 AsmToken AsmLexer::LexDigit() {
173 // Decimal integer: [1-9][0-9]*
174 if (CurPtr[-1] != '0' || CurPtr[0] == '.') {
175 while (isdigit(*CurPtr))
178 // Check for floating point literals.
179 if (*CurPtr == '.' || *CurPtr == 'e') {
181 return LexFloatLiteral();
184 StringRef Result(TokStart, CurPtr - TokStart);
187 if (Result.getAsInteger(10, Value)) {
188 // Allow positive values that are too large to fit into a signed 64-bit
189 // integer, but that do fit in an unsigned one, we just convert them over.
190 unsigned long long UValue;
191 if (Result.getAsInteger(10, UValue))
192 return ReturnError(TokStart, "invalid decimal number");
193 Value = (long long)UValue;
196 // The darwin/x86 (and x86-64) assembler accepts and ignores ULL and LL
197 // suffixes on integer literals.
198 SkipIgnoredIntegerSuffix(CurPtr);
200 return AsmToken(AsmToken::Integer, Result, Value);
203 if (*CurPtr == 'b') {
205 // See if we actually have "0b" as part of something like "jmp 0b\n"
206 if (!isdigit(CurPtr[0])) {
208 StringRef Result(TokStart, CurPtr - TokStart);
209 return AsmToken(AsmToken::Integer, Result, 0);
211 const char *NumStart = CurPtr;
212 while (CurPtr[0] == '0' || CurPtr[0] == '1')
215 // Requires at least one binary digit.
216 if (CurPtr == NumStart)
217 return ReturnError(TokStart, "invalid binary number");
219 StringRef Result(TokStart, CurPtr - TokStart);
222 if (Result.substr(2).getAsInteger(2, Value))
223 return ReturnError(TokStart, "invalid binary number");
225 // The darwin/x86 (and x86-64) assembler accepts and ignores ULL and LL
226 // suffixes on integer literals.
227 SkipIgnoredIntegerSuffix(CurPtr);
229 return AsmToken(AsmToken::Integer, Result, Value);
232 if (*CurPtr == 'x') {
234 const char *NumStart = CurPtr;
235 while (isxdigit(CurPtr[0]))
238 // Requires at least one hex digit.
239 if (CurPtr == NumStart)
240 return ReturnError(CurPtr-2, "invalid hexadecimal number");
242 unsigned long long Result;
243 if (StringRef(TokStart, CurPtr - TokStart).getAsInteger(0, Result))
244 return ReturnError(TokStart, "invalid hexadecimal number");
246 // The darwin/x86 (and x86-64) assembler accepts and ignores ULL and LL
247 // suffixes on integer literals.
248 SkipIgnoredIntegerSuffix(CurPtr);
250 return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
254 // Must be an octal number, it starts with 0.
255 while (*CurPtr >= '0' && *CurPtr <= '9')
258 StringRef Result(TokStart, CurPtr - TokStart);
260 if (Result.getAsInteger(8, Value))
261 return ReturnError(TokStart, "invalid octal number");
263 // The darwin/x86 (and x86-64) assembler accepts and ignores ULL and LL
264 // suffixes on integer literals.
265 SkipIgnoredIntegerSuffix(CurPtr);
267 return AsmToken(AsmToken::Integer, Result, Value);
270 /// LexSingleQuote: Integer: 'b'
271 AsmToken AsmLexer::LexSingleQuote() {
272 int CurChar = getNextChar();
275 CurChar = getNextChar();
278 return ReturnError(TokStart, "unterminated single quote");
280 CurChar = getNextChar();
283 return ReturnError(TokStart, "single quote way too long");
285 // The idea here being that 'c' is basically just an integral
287 StringRef Res = StringRef(TokStart,CurPtr - TokStart);
290 if (Res.startswith("\'\\")) {
291 char theChar = Res[2];
293 default: Value = theChar; break;
294 case '\'': Value = '\''; break;
295 case 't': Value = '\t'; break;
296 case 'n': Value = '\n'; break;
297 case 'b': Value = '\b'; break;
302 return AsmToken(AsmToken::Integer, Res, Value);
306 /// LexQuote: String: "..."
307 AsmToken AsmLexer::LexQuote() {
308 int CurChar = getNextChar();
309 // TODO: does gas allow multiline string constants?
310 while (CurChar != '"') {
311 if (CurChar == '\\') {
313 CurChar = getNextChar();
317 return ReturnError(TokStart, "unterminated string constant");
319 CurChar = getNextChar();
322 return AsmToken(AsmToken::String, StringRef(TokStart, CurPtr - TokStart));
325 StringRef AsmLexer::LexUntilEndOfStatement() {
328 while (!isAtStartOfComment(*CurPtr) && // Start of line comment.
329 !isAtStatementSeparator(CurPtr) && // End of statement marker.
332 (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd())) {
335 return StringRef(TokStart, CurPtr-TokStart);
338 StringRef AsmLexer::LexUntilEndOfLine() {
341 while (*CurPtr != '\n' &&
343 (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd())) {
346 return StringRef(TokStart, CurPtr-TokStart);
349 bool AsmLexer::isAtStartOfComment(char Char) {
350 // FIXME: This won't work for multi-character comment indicators like "//".
351 return Char == *MAI.getCommentString();
354 bool AsmLexer::isAtStatementSeparator(const char *Ptr) {
355 return strncmp(Ptr, MAI.getSeparatorString(),
356 strlen(MAI.getSeparatorString())) == 0;
359 AsmToken AsmLexer::LexToken() {
361 // This always consumes at least one character.
362 int CurChar = getNextChar();
364 if (isAtStartOfComment(CurChar)) {
365 // If this comment starts with a '#', then return the Hash token and let
366 // the assembler parser see if it can be parsed as a cpp line filename
367 // comment. We do this only if we are at the start of a line.
368 if (CurChar == '#' && isAtStartOfLine)
369 return AsmToken(AsmToken::Hash, StringRef(TokStart, 1));
370 isAtStartOfLine = true;
371 return LexLineComment();
373 if (isAtStatementSeparator(TokStart)) {
374 CurPtr += strlen(MAI.getSeparatorString()) - 1;
375 return AsmToken(AsmToken::EndOfStatement,
376 StringRef(TokStart, strlen(MAI.getSeparatorString())));
379 // If we're missing a newline at EOF, make sure we still get an
380 // EndOfStatement token before the Eof token.
381 if (CurChar == EOF && !isAtStartOfLine) {
382 isAtStartOfLine = true;
383 return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
386 isAtStartOfLine = false;
389 // Handle identifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
390 if (isalpha(CurChar) || CurChar == '_' || CurChar == '.')
391 return LexIdentifier();
393 // Unknown character, emit an error.
394 return ReturnError(TokStart, "invalid character in input");
395 case EOF: return AsmToken(AsmToken::Eof, StringRef(TokStart, 0));
399 // Ignore whitespace.
401 case '\n': // FALL THROUGH.
403 isAtStartOfLine = true;
404 return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
405 case ':': return AsmToken(AsmToken::Colon, StringRef(TokStart, 1));
406 case '+': return AsmToken(AsmToken::Plus, StringRef(TokStart, 1));
407 case '-': return AsmToken(AsmToken::Minus, StringRef(TokStart, 1));
408 case '~': return AsmToken(AsmToken::Tilde, StringRef(TokStart, 1));
409 case '(': return AsmToken(AsmToken::LParen, StringRef(TokStart, 1));
410 case ')': return AsmToken(AsmToken::RParen, StringRef(TokStart, 1));
411 case '[': return AsmToken(AsmToken::LBrac, StringRef(TokStart, 1));
412 case ']': return AsmToken(AsmToken::RBrac, StringRef(TokStart, 1));
413 case '{': return AsmToken(AsmToken::LCurly, StringRef(TokStart, 1));
414 case '}': return AsmToken(AsmToken::RCurly, StringRef(TokStart, 1));
415 case '*': return AsmToken(AsmToken::Star, StringRef(TokStart, 1));
416 case ',': return AsmToken(AsmToken::Comma, StringRef(TokStart, 1));
417 case '$': return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
418 case '@': return AsmToken(AsmToken::At, StringRef(TokStart, 1));
419 case '\\': return AsmToken(AsmToken::BackSlash, StringRef(TokStart, 1));
422 return ++CurPtr, AsmToken(AsmToken::EqualEqual, StringRef(TokStart, 2));
423 return AsmToken(AsmToken::Equal, StringRef(TokStart, 1));
426 return ++CurPtr, AsmToken(AsmToken::PipePipe, StringRef(TokStart, 2));
427 return AsmToken(AsmToken::Pipe, StringRef(TokStart, 1));
428 case '^': return AsmToken(AsmToken::Caret, StringRef(TokStart, 1));
431 return ++CurPtr, AsmToken(AsmToken::AmpAmp, StringRef(TokStart, 2));
432 return AsmToken(AsmToken::Amp, StringRef(TokStart, 1));
435 return ++CurPtr, AsmToken(AsmToken::ExclaimEqual, StringRef(TokStart, 2));
436 return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
437 case '%': return AsmToken(AsmToken::Percent, StringRef(TokStart, 1));
438 case '/': return LexSlash();
439 case '#': return AsmToken(AsmToken::Hash, StringRef(TokStart, 1));
440 case '\'': return LexSingleQuote();
441 case '"': return LexQuote();
442 case '0': case '1': case '2': case '3': case '4':
443 case '5': case '6': case '7': case '8': case '9':
447 case '<': return ++CurPtr, AsmToken(AsmToken::LessLess,
448 StringRef(TokStart, 2));
449 case '=': return ++CurPtr, AsmToken(AsmToken::LessEqual,
450 StringRef(TokStart, 2));
451 case '>': return ++CurPtr, AsmToken(AsmToken::LessGreater,
452 StringRef(TokStart, 2));
453 default: return AsmToken(AsmToken::Less, StringRef(TokStart, 1));
457 case '>': return ++CurPtr, AsmToken(AsmToken::GreaterGreater,
458 StringRef(TokStart, 2));
459 case '=': return ++CurPtr, AsmToken(AsmToken::GreaterEqual,
460 StringRef(TokStart, 2));
461 default: return AsmToken(AsmToken::Greater, StringRef(TokStart, 1));
464 // TODO: Quoted identifiers (objc methods etc)
465 // local labels: [0-9][:]
466 // Forward/backward labels: [0-9][fb]
467 // Integers, fp constants, character constants.