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"
23 AsmLexer::AsmLexer(const MCAsmInfo &_MAI) : MAI(_MAI) {
29 AsmLexer::~AsmLexer() {
32 void AsmLexer::setBuffer(const MemoryBuffer *buf, const char *ptr) {
38 CurPtr = CurBuf->getBufferStart();
43 SMLoc AsmLexer::getLoc() const {
44 return SMLoc::getFromPointer(TokStart);
47 /// ReturnError - Set the error to the specified string at the specified
48 /// location. This is defined to always return AsmToken::Error.
49 AsmToken AsmLexer::ReturnError(const char *Loc, const std::string &Msg) {
50 SetError(SMLoc::getFromPointer(Loc), Msg);
52 return AsmToken(AsmToken::Error, StringRef(Loc, 0));
55 int AsmLexer::getNextChar() {
56 char CurChar = *CurPtr++;
59 return (unsigned char)CurChar;
61 // A nul character in the stream is either the end of the current buffer or
62 // a random nul in the file. Disambiguate that here.
63 if (CurPtr-1 != CurBuf->getBufferEnd())
64 return 0; // Just whitespace.
66 // Otherwise, return end of file.
67 --CurPtr; // Another call to lex will return EOF again.
72 /// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
73 AsmToken AsmLexer::LexIdentifier() {
74 while (isalnum(*CurPtr) || *CurPtr == '_' || *CurPtr == '$' ||
75 *CurPtr == '.' || *CurPtr == '@')
78 // Handle . as a special case.
79 if (CurPtr == TokStart+1 && TokStart[0] == '.')
80 return AsmToken(AsmToken::Dot, StringRef(TokStart, 1));
82 return AsmToken(AsmToken::Identifier, StringRef(TokStart, CurPtr - TokStart));
85 /// LexSlash: Slash: /
86 /// C-Style Comment: /* ... */
87 AsmToken AsmLexer::LexSlash() {
89 case '*': break; // C style comment.
90 case '/': return ++CurPtr, LexLineComment();
91 default: return AsmToken(AsmToken::Slash, StringRef(CurPtr, 1));
95 ++CurPtr; // skip the star.
97 int CurChar = getNextChar();
100 return ReturnError(TokStart, "unterminated comment");
102 // End of the comment?
103 if (CurPtr[0] != '/') break;
105 ++CurPtr; // End the */.
111 /// LexLineComment: Comment: #[^\n]*
113 AsmToken AsmLexer::LexLineComment() {
114 // FIXME: This is broken if we happen to a comment at the end of a file, which
115 // was .included, and which doesn't end with a newline.
116 int CurChar = getNextChar();
117 while (CurChar != '\n' && CurChar != '\n' && CurChar != EOF)
118 CurChar = getNextChar();
121 return AsmToken(AsmToken::Eof, StringRef(CurPtr, 0));
122 return AsmToken(AsmToken::EndOfStatement, StringRef(CurPtr, 0));
126 /// LexDigit: First character is [0-9].
127 /// Local Label: [0-9][:]
128 /// Forward/Backward Label: [0-9][fb]
129 /// Binary integer: 0b[01]+
130 /// Octal integer: 0[0-7]+
131 /// Hex integer: 0x[0-9a-fA-F]+
132 /// Decimal integer: [1-9][0-9]*
133 /// TODO: FP literal.
134 AsmToken AsmLexer::LexDigit() {
135 // Decimal integer: [1-9][0-9]*
136 if (CurPtr[-1] != '0') {
137 while (isdigit(*CurPtr))
140 StringRef Result(TokStart, CurPtr - TokStart);
143 if (Result.getAsInteger(10, Value)) {
144 // We have to handle minint_as_a_positive_value specially, because
145 // - minint_as_a_positive_value = minint and it is valid.
146 if (Result == "9223372036854775808")
147 Value = -9223372036854775808ULL;
149 return ReturnError(TokStart, "Invalid decimal number");
151 return AsmToken(AsmToken::Integer, Result, Value);
154 if (*CurPtr == 'b') {
156 // See if we actually have "0b" as part of something like "jmp 0b\n"
157 if (CurPtr[0] == '\n') {
159 StringRef Result(TokStart, CurPtr - TokStart);
160 return AsmToken(AsmToken::Integer, Result, 0);
162 const char *NumStart = CurPtr;
163 while (CurPtr[0] == '0' || CurPtr[0] == '1')
166 // Requires at least one binary digit.
167 if (CurPtr == NumStart)
168 return ReturnError(TokStart, "Invalid binary number");
170 StringRef Result(TokStart, CurPtr - TokStart);
173 if (Result.getAsInteger(2, Value))
174 return ReturnError(TokStart, "Invalid binary number");
176 return AsmToken(AsmToken::Integer, Result, Value);
179 if (*CurPtr == 'x') {
181 const char *NumStart = CurPtr;
182 while (isxdigit(CurPtr[0]))
185 // Requires at least one hex digit.
186 if (CurPtr == NumStart)
187 return ReturnError(CurPtr-2, "Invalid hexadecimal number");
189 unsigned long long Result;
190 if (StringRef(TokStart, CurPtr - TokStart).getAsInteger(0, Result))
191 return ReturnError(TokStart, "Invalid hexadecimal number");
193 return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
197 // Must be an octal number, it starts with 0.
198 while (*CurPtr >= '0' && *CurPtr <= '7')
201 StringRef Result(TokStart, CurPtr - TokStart);
203 if (Result.getAsInteger(8, Value))
204 return ReturnError(TokStart, "Invalid octal number");
206 return AsmToken(AsmToken::Integer, Result, Value);
209 /// LexQuote: String: "..."
210 AsmToken AsmLexer::LexQuote() {
211 int CurChar = getNextChar();
212 // TODO: does gas allow multiline string constants?
213 while (CurChar != '"') {
214 if (CurChar == '\\') {
216 CurChar = getNextChar();
220 return ReturnError(TokStart, "unterminated string constant");
222 CurChar = getNextChar();
225 return AsmToken(AsmToken::String, StringRef(TokStart, CurPtr - TokStart));
228 StringRef AsmLexer::LexUntilEndOfStatement() {
231 while (!isAtStartOfComment(*CurPtr) && // Start of line comment.
232 *CurPtr != ';' && // End of statement marker.
235 (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd())) {
238 return StringRef(TokStart, CurPtr-TokStart);
241 bool AsmLexer::isAtStartOfComment(char Char) {
242 // FIXME: This won't work for multi-character comment indicators like "//".
243 return Char == *MAI.getCommentString();
246 AsmToken AsmLexer::LexToken() {
248 // This always consumes at least one character.
249 int CurChar = getNextChar();
251 if (isAtStartOfComment(CurChar))
252 return LexLineComment();
256 // Handle identifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
257 if (isalpha(CurChar) || CurChar == '_' || CurChar == '.')
258 return LexIdentifier();
260 // Unknown character, emit an error.
261 return ReturnError(TokStart, "invalid character in input");
262 case EOF: return AsmToken(AsmToken::Eof, StringRef(TokStart, 0));
266 // Ignore whitespace.
268 case '\n': // FALL THROUGH.
269 case '\r': // FALL THROUGH.
270 case ';': return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
271 case ':': return AsmToken(AsmToken::Colon, StringRef(TokStart, 1));
272 case '+': return AsmToken(AsmToken::Plus, StringRef(TokStart, 1));
273 case '-': return AsmToken(AsmToken::Minus, StringRef(TokStart, 1));
274 case '~': return AsmToken(AsmToken::Tilde, StringRef(TokStart, 1));
275 case '(': return AsmToken(AsmToken::LParen, StringRef(TokStart, 1));
276 case ')': return AsmToken(AsmToken::RParen, StringRef(TokStart, 1));
277 case '[': return AsmToken(AsmToken::LBrac, StringRef(TokStart, 1));
278 case ']': return AsmToken(AsmToken::RBrac, StringRef(TokStart, 1));
279 case '{': return AsmToken(AsmToken::LCurly, StringRef(TokStart, 1));
280 case '}': return AsmToken(AsmToken::RCurly, StringRef(TokStart, 1));
281 case '*': return AsmToken(AsmToken::Star, StringRef(TokStart, 1));
282 case ',': return AsmToken(AsmToken::Comma, StringRef(TokStart, 1));
283 case '$': return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
286 return ++CurPtr, AsmToken(AsmToken::EqualEqual, StringRef(TokStart, 2));
287 return AsmToken(AsmToken::Equal, StringRef(TokStart, 1));
290 return ++CurPtr, AsmToken(AsmToken::PipePipe, StringRef(TokStart, 2));
291 return AsmToken(AsmToken::Pipe, StringRef(TokStart, 1));
292 case '^': return AsmToken(AsmToken::Caret, StringRef(TokStart, 1));
295 return ++CurPtr, AsmToken(AsmToken::AmpAmp, StringRef(TokStart, 2));
296 return AsmToken(AsmToken::Amp, StringRef(TokStart, 1));
299 return ++CurPtr, AsmToken(AsmToken::ExclaimEqual, StringRef(TokStart, 2));
300 return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
301 case '%': return AsmToken(AsmToken::Percent, StringRef(TokStart, 1));
302 case '/': return LexSlash();
303 case '#': return AsmToken(AsmToken::Hash, StringRef(TokStart, 1));
304 case '"': return LexQuote();
305 case '0': case '1': case '2': case '3': case '4':
306 case '5': case '6': case '7': case '8': case '9':
310 case '<': return ++CurPtr, AsmToken(AsmToken::LessLess,
311 StringRef(TokStart, 2));
312 case '=': return ++CurPtr, AsmToken(AsmToken::LessEqual,
313 StringRef(TokStart, 2));
314 case '>': return ++CurPtr, AsmToken(AsmToken::LessGreater,
315 StringRef(TokStart, 2));
316 default: return AsmToken(AsmToken::Less, StringRef(TokStart, 1));
320 case '>': return ++CurPtr, AsmToken(AsmToken::GreaterGreater,
321 StringRef(TokStart, 2));
322 case '=': return ++CurPtr, AsmToken(AsmToken::GreaterEqual,
323 StringRef(TokStart, 2));
324 default: return AsmToken(AsmToken::Greater, StringRef(TokStart, 1));
327 // TODO: Quoted identifiers (objc methods etc)
328 // local labels: [0-9][:]
329 // Forward/backward labels: [0-9][fb]
330 // Integers, fp constants, character constants.