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_.$][a-zA-Z0-9_$.@]*
75 AsmToken AsmLexer::LexIdentifier() {
76 while (isalnum(*CurPtr) || *CurPtr == '_' || *CurPtr == '$' ||
77 *CurPtr == '.' || *CurPtr == '@')
80 // Handle . as a special case.
81 if (CurPtr == TokStart+1)
82 if (TokStart[0] == '.')
83 return AsmToken(AsmToken::Dot, StringRef(TokStart, 1));
85 // Handle $ as a special case. $foo is an identifier, $42 is not.
86 if (TokStart[0] == '$' &&
87 (CurPtr-TokStart == 1 || isdigit(TokStart[1]) || TokStart[1] == '"')) {
89 return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
92 return AsmToken(AsmToken::Identifier, StringRef(TokStart, CurPtr - TokStart));
95 /// LexSlash: Slash: /
96 /// C-Style Comment: /* ... */
97 AsmToken AsmLexer::LexSlash() {
99 case '*': break; // C style comment.
100 case '/': return ++CurPtr, LexLineComment();
101 default: return AsmToken(AsmToken::Slash, StringRef(CurPtr, 1));
105 ++CurPtr; // skip the star.
107 int CurChar = getNextChar();
110 return ReturnError(TokStart, "unterminated comment");
112 // End of the comment?
113 if (CurPtr[0] != '/') break;
115 ++CurPtr; // End the */.
121 /// LexLineComment: Comment: #[^\n]*
123 AsmToken AsmLexer::LexLineComment() {
124 // FIXME: This is broken if we happen to a comment at the end of a file, which
125 // was .included, and which doesn't end with a newline.
126 int CurChar = getNextChar();
127 while (CurChar != '\n' && CurChar != '\n' && CurChar != EOF)
128 CurChar = getNextChar();
131 return AsmToken(AsmToken::Eof, StringRef(CurPtr, 0));
132 return AsmToken(AsmToken::EndOfStatement, StringRef(CurPtr, 0));
136 /// LexDigit: First character is [0-9].
137 /// Local Label: [0-9][:]
138 /// Forward/Backward Label: [0-9][fb]
139 /// Binary integer: 0b[01]+
140 /// Octal integer: 0[0-7]+
141 /// Hex integer: 0x[0-9a-fA-F]+
142 /// Decimal integer: [1-9][0-9]*
143 /// TODO: FP literal.
144 AsmToken AsmLexer::LexDigit() {
146 return ReturnError(TokStart, "FIXME: local label not implemented");
147 if (*CurPtr == 'f' || *CurPtr == 'b')
148 return ReturnError(TokStart, "FIXME: directional label not implemented");
150 // Decimal integer: [1-9][0-9]*
151 if (CurPtr[-1] != '0') {
152 while (isdigit(*CurPtr))
155 StringRef Result(TokStart, CurPtr - TokStart);
158 if (Result.getAsInteger(10, Value)) {
159 // We have to handle minint_as_a_positive_value specially, because
160 // - minint_as_a_positive_value = minint and it is valid.
161 if (Result == "9223372036854775808")
162 Value = -9223372036854775808ULL;
164 return ReturnError(TokStart, "Invalid decimal number");
166 return AsmToken(AsmToken::Integer, Result, Value);
169 if (*CurPtr == 'b') {
171 const char *NumStart = CurPtr;
172 while (CurPtr[0] == '0' || CurPtr[0] == '1')
175 // Requires at least one binary digit.
176 if (CurPtr == NumStart)
177 return ReturnError(TokStart, "Invalid binary number");
179 StringRef Result(TokStart, CurPtr - TokStart);
182 if (Result.getAsInteger(2, Value))
183 return ReturnError(TokStart, "Invalid binary number");
185 return AsmToken(AsmToken::Integer, Result, Value);
188 if (*CurPtr == 'x') {
190 const char *NumStart = CurPtr;
191 while (isxdigit(CurPtr[0]))
194 // Requires at least one hex digit.
195 if (CurPtr == NumStart)
196 return ReturnError(CurPtr-2, "Invalid hexadecimal number");
198 unsigned long long Result;
199 if (StringRef(TokStart, CurPtr - TokStart).getAsInteger(0, Result))
200 return ReturnError(TokStart, "Invalid hexadecimal number");
202 return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
206 // Must be an octal number, it starts with 0.
207 while (*CurPtr >= '0' && *CurPtr <= '7')
210 StringRef Result(TokStart, CurPtr - TokStart);
212 if (Result.getAsInteger(8, Value))
213 return ReturnError(TokStart, "Invalid octal number");
215 return AsmToken(AsmToken::Integer, Result, Value);
218 /// LexQuote: String: "..."
219 AsmToken AsmLexer::LexQuote() {
220 int CurChar = getNextChar();
221 // TODO: does gas allow multiline string constants?
222 while (CurChar != '"') {
223 if (CurChar == '\\') {
225 CurChar = getNextChar();
229 return ReturnError(TokStart, "unterminated string constant");
231 CurChar = getNextChar();
234 return AsmToken(AsmToken::String, StringRef(TokStart, CurPtr - TokStart));
237 StringRef AsmLexer::LexUntilEndOfStatement() {
240 while (!isAtStartOfComment(*CurPtr) && // Start of line comment.
241 *CurPtr != ';' && // End of statement marker.
244 (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd())) {
247 return StringRef(TokStart, CurPtr-TokStart);
250 bool AsmLexer::isAtStartOfComment(char Char) {
251 // FIXME: This won't work for multi-character comment indicators like "//".
252 return Char == *MAI.getCommentString();
255 AsmToken AsmLexer::LexToken() {
257 // This always consumes at least one character.
258 int CurChar = getNextChar();
260 if (isAtStartOfComment(CurChar))
261 return LexLineComment();
265 // Handle identifier: [a-zA-Z_.$][a-zA-Z0-9_$.@]*
266 if (isalpha(CurChar) || CurChar == '_' || CurChar == '.' || CurChar == '$')
267 return LexIdentifier();
269 // Unknown character, emit an error.
270 return ReturnError(TokStart, "invalid character in input");
271 case EOF: return AsmToken(AsmToken::Eof, StringRef(TokStart, 0));
275 // Ignore whitespace.
277 case '\n': // FALL THROUGH.
278 case '\r': // FALL THROUGH.
279 case ';': return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
280 case ':': return AsmToken(AsmToken::Colon, StringRef(TokStart, 1));
281 case '+': return AsmToken(AsmToken::Plus, StringRef(TokStart, 1));
282 case '-': return AsmToken(AsmToken::Minus, StringRef(TokStart, 1));
283 case '~': return AsmToken(AsmToken::Tilde, StringRef(TokStart, 1));
284 case '(': return AsmToken(AsmToken::LParen, StringRef(TokStart, 1));
285 case ')': return AsmToken(AsmToken::RParen, StringRef(TokStart, 1));
286 case '[': return AsmToken(AsmToken::LBrac, StringRef(TokStart, 1));
287 case ']': return AsmToken(AsmToken::RBrac, StringRef(TokStart, 1));
288 case '{': return AsmToken(AsmToken::LCurly, StringRef(TokStart, 1));
289 case '}': return AsmToken(AsmToken::RCurly, StringRef(TokStart, 1));
290 case '*': return AsmToken(AsmToken::Star, StringRef(TokStart, 1));
291 case ',': return AsmToken(AsmToken::Comma, StringRef(TokStart, 1));
294 return ++CurPtr, AsmToken(AsmToken::EqualEqual, StringRef(TokStart, 2));
295 return AsmToken(AsmToken::Equal, StringRef(TokStart, 1));
298 return ++CurPtr, AsmToken(AsmToken::PipePipe, StringRef(TokStart, 2));
299 return AsmToken(AsmToken::Pipe, StringRef(TokStart, 1));
300 case '^': return AsmToken(AsmToken::Caret, StringRef(TokStart, 1));
303 return ++CurPtr, AsmToken(AsmToken::AmpAmp, StringRef(TokStart, 2));
304 return AsmToken(AsmToken::Amp, StringRef(TokStart, 1));
307 return ++CurPtr, AsmToken(AsmToken::ExclaimEqual, StringRef(TokStart, 2));
308 return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
309 case '%': return AsmToken(AsmToken::Percent, StringRef(TokStart, 1));
310 case '/': return LexSlash();
311 case '#': return AsmToken(AsmToken::Hash, StringRef(TokStart, 1));
312 case '"': return LexQuote();
313 case '0': case '1': case '2': case '3': case '4':
314 case '5': case '6': case '7': case '8': case '9':
318 case '<': return ++CurPtr, AsmToken(AsmToken::LessLess,
319 StringRef(TokStart, 2));
320 case '=': return ++CurPtr, AsmToken(AsmToken::LessEqual,
321 StringRef(TokStart, 2));
322 case '>': return ++CurPtr, AsmToken(AsmToken::LessGreater,
323 StringRef(TokStart, 2));
324 default: return AsmToken(AsmToken::Less, StringRef(TokStart, 1));
328 case '>': return ++CurPtr, AsmToken(AsmToken::GreaterGreater,
329 StringRef(TokStart, 2));
330 case '=': return ++CurPtr, AsmToken(AsmToken::GreaterEqual,
331 StringRef(TokStart, 2));
332 default: return AsmToken(AsmToken::Greater, StringRef(TokStart, 1));
335 // TODO: Quoted identifiers (objc methods etc)
336 // local labels: [0-9][:]
337 // Forward/backward labels: [0-9][fb]
338 // Integers, fp constants, character constants.