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 == '@')
77 return AsmToken(AsmToken::Identifier, StringRef(TokStart, CurPtr - TokStart));
80 /// LexSlash: Slash: /
81 /// C-Style Comment: /* ... */
82 AsmToken AsmLexer::LexSlash() {
84 case '*': break; // C style comment.
85 case '/': return ++CurPtr, LexLineComment();
86 default: return AsmToken(AsmToken::Slash, StringRef(CurPtr, 1));
90 ++CurPtr; // skip the star.
92 int CurChar = getNextChar();
95 return ReturnError(TokStart, "unterminated comment");
97 // End of the comment?
98 if (CurPtr[0] != '/') break;
100 ++CurPtr; // End the */.
106 /// LexLineComment: Comment: #[^\n]*
108 AsmToken AsmLexer::LexLineComment() {
109 // FIXME: This is broken if we happen to a comment at the end of a file, which
110 // was .included, and which doesn't end with a newline.
111 int CurChar = getNextChar();
112 while (CurChar != '\n' && CurChar != '\n' && CurChar != EOF)
113 CurChar = getNextChar();
116 return AsmToken(AsmToken::Eof, StringRef(CurPtr, 0));
117 return AsmToken(AsmToken::EndOfStatement, StringRef(CurPtr, 0));
121 /// LexDigit: First character is [0-9].
122 /// Local Label: [0-9][:]
123 /// Forward/Backward Label: [0-9][fb]
124 /// Binary integer: 0b[01]+
125 /// Octal integer: 0[0-7]+
126 /// Hex integer: 0x[0-9a-fA-F]+
127 /// Decimal integer: [1-9][0-9]*
128 /// TODO: FP literal.
129 AsmToken AsmLexer::LexDigit() {
131 return ReturnError(TokStart, "FIXME: local label not implemented");
132 if (*CurPtr == 'f' || *CurPtr == 'b')
133 return ReturnError(TokStart, "FIXME: directional label not implemented");
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 return ReturnError(TokStart, "Invalid decimal number");
145 return AsmToken(AsmToken::Integer, Result, Value);
148 if (*CurPtr == 'b') {
150 const char *NumStart = CurPtr;
151 while (CurPtr[0] == '0' || CurPtr[0] == '1')
154 // Requires at least one binary digit.
155 if (CurPtr == NumStart)
156 return ReturnError(TokStart, "Invalid binary number");
158 StringRef Result(TokStart, CurPtr - TokStart);
161 if (Result.getAsInteger(2, Value))
162 return ReturnError(TokStart, "Invalid binary number");
164 return AsmToken(AsmToken::Integer, Result, Value);
167 if (*CurPtr == 'x') {
169 const char *NumStart = CurPtr;
170 while (isxdigit(CurPtr[0]))
173 // Requires at least one hex digit.
174 if (CurPtr == NumStart)
175 return ReturnError(CurPtr-2, "Invalid hexadecimal number");
177 unsigned long long Result;
178 if (StringRef(TokStart, CurPtr - TokStart).getAsInteger(0, Result))
179 return ReturnError(TokStart, "Invalid hexadecimal number");
181 return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
185 // Must be an octal number, it starts with 0.
186 while (*CurPtr >= '0' && *CurPtr <= '7')
189 StringRef Result(TokStart, CurPtr - TokStart);
191 if (Result.getAsInteger(8, Value))
192 return ReturnError(TokStart, "Invalid octal number");
194 return AsmToken(AsmToken::Integer, Result, Value);
197 /// LexQuote: String: "..."
198 AsmToken AsmLexer::LexQuote() {
199 int CurChar = getNextChar();
200 // TODO: does gas allow multiline string constants?
201 while (CurChar != '"') {
202 if (CurChar == '\\') {
204 CurChar = getNextChar();
208 return ReturnError(TokStart, "unterminated string constant");
210 CurChar = getNextChar();
213 return AsmToken(AsmToken::String, StringRef(TokStart, CurPtr - TokStart));
216 StringRef AsmLexer::LexUntilEndOfStatement() {
219 while (!isAtStartOfComment(*CurPtr) && // Start of line comment.
220 *CurPtr != ';' && // End of statement marker.
223 (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd())) {
226 return StringRef(TokStart, CurPtr-TokStart);
229 bool AsmLexer::isAtStartOfComment(char Char) {
230 // FIXME: This won't work for multi-character comment indicators like "//".
231 return Char == *MAI.getCommentString();
234 AsmToken AsmLexer::LexToken() {
236 // This always consumes at least one character.
237 int CurChar = getNextChar();
239 if (isAtStartOfComment(CurChar))
240 return LexLineComment();
244 // Handle identifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
245 if (isalpha(CurChar) || CurChar == '_' || CurChar == '.')
246 return LexIdentifier();
248 // Unknown character, emit an error.
249 return ReturnError(TokStart, "invalid character in input");
250 case EOF: return AsmToken(AsmToken::Eof, StringRef(TokStart, 0));
254 // Ignore whitespace.
256 case '\n': // FALL THROUGH.
257 case '\r': // FALL THROUGH.
258 case ';': return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
259 case ':': return AsmToken(AsmToken::Colon, StringRef(TokStart, 1));
260 case '+': return AsmToken(AsmToken::Plus, StringRef(TokStart, 1));
261 case '-': return AsmToken(AsmToken::Minus, StringRef(TokStart, 1));
262 case '~': return AsmToken(AsmToken::Tilde, StringRef(TokStart, 1));
263 case '(': return AsmToken(AsmToken::LParen, StringRef(TokStart, 1));
264 case ')': return AsmToken(AsmToken::RParen, StringRef(TokStart, 1));
265 case '[': return AsmToken(AsmToken::LBrac, StringRef(TokStart, 1));
266 case ']': return AsmToken(AsmToken::RBrac, StringRef(TokStart, 1));
267 case '{': return AsmToken(AsmToken::LCurly, StringRef(TokStart, 1));
268 case '}': return AsmToken(AsmToken::RCurly, StringRef(TokStart, 1));
269 case '*': return AsmToken(AsmToken::Star, StringRef(TokStart, 1));
270 case ',': return AsmToken(AsmToken::Comma, StringRef(TokStart, 1));
271 case '$': return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
274 return ++CurPtr, AsmToken(AsmToken::EqualEqual, StringRef(TokStart, 2));
275 return AsmToken(AsmToken::Equal, StringRef(TokStart, 1));
278 return ++CurPtr, AsmToken(AsmToken::PipePipe, StringRef(TokStart, 2));
279 return AsmToken(AsmToken::Pipe, StringRef(TokStart, 1));
280 case '^': return AsmToken(AsmToken::Caret, StringRef(TokStart, 1));
283 return ++CurPtr, AsmToken(AsmToken::AmpAmp, StringRef(TokStart, 2));
284 return AsmToken(AsmToken::Amp, StringRef(TokStart, 1));
287 return ++CurPtr, AsmToken(AsmToken::ExclaimEqual, StringRef(TokStart, 2));
288 return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
289 case '%': return AsmToken(AsmToken::Percent, StringRef(TokStart, 1));
290 case '/': return LexSlash();
291 case '#': return AsmToken(AsmToken::Hash, StringRef(TokStart, 1));
292 case '"': return LexQuote();
293 case '0': case '1': case '2': case '3': case '4':
294 case '5': case '6': case '7': case '8': case '9':
298 case '<': return ++CurPtr, AsmToken(AsmToken::LessLess,
299 StringRef(TokStart, 2));
300 case '=': return ++CurPtr, AsmToken(AsmToken::LessEqual,
301 StringRef(TokStart, 2));
302 case '>': return ++CurPtr, AsmToken(AsmToken::LessGreater,
303 StringRef(TokStart, 2));
304 default: return AsmToken(AsmToken::Less, StringRef(TokStart, 1));
308 case '>': return ++CurPtr, AsmToken(AsmToken::GreaterGreater,
309 StringRef(TokStart, 2));
310 case '=': return ++CurPtr, AsmToken(AsmToken::GreaterEqual,
311 StringRef(TokStart, 2));
312 default: return AsmToken(AsmToken::Greater, StringRef(TokStart, 1));
315 // TODO: Quoted identifiers (objc methods etc)
316 // local labels: [0-9][:]
317 // Forward/backward labels: [0-9][fb]
318 // Integers, fp constants, character constants.