1 |
#ifndef INC_Parser_hpp__ |
2 |
#define INC_Parser_hpp__ |
3 |
|
4 |
/* ANTLR Translator Generator |
5 |
* Project led by Terence Parr at http://www.jGuru.com |
6 |
* Software rights: http://www.antlr.org/license.html |
7 |
* |
8 |
* $Id$ |
9 |
*/ |
10 |
|
11 |
#include <antlr/config.hpp> |
12 |
|
13 |
#include <iostream> |
14 |
#include <exception> |
15 |
|
16 |
#include <antlr/BitSet.hpp> |
17 |
#include <antlr/TokenBuffer.hpp> |
18 |
#include <antlr/RecognitionException.hpp> |
19 |
#include <antlr/MismatchedTokenException.hpp> |
20 |
#include <antlr/ASTFactory.hpp> |
21 |
#include <antlr/ParserSharedInputState.hpp> |
22 |
|
23 |
#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE |
24 |
namespace antlr { |
25 |
#endif |
26 |
|
27 |
extern bool DEBUG_PARSER; |
28 |
|
29 |
/** A generic ANTLR parser (LL(k) for k>=1) containing a bunch of |
30 |
* utility routines useful at any lookahead depth. We distinguish between |
31 |
* the LL(1) and LL(k) parsers because of efficiency. This may not be |
32 |
* necessary in the near future. |
33 |
* |
34 |
* Each parser object contains the state of the parse including a lookahead |
35 |
* cache (the form of which is determined by the subclass), whether or |
36 |
* not the parser is in guess mode, where tokens come from, etc... |
37 |
* |
38 |
* <p> |
39 |
* During <b>guess</b> mode, the current lookahead token(s) and token type(s) |
40 |
* cache must be saved because the token stream may not have been informed |
41 |
* to save the token (via <tt>mark</tt>) before the <tt>try</tt> block. |
42 |
* Guessing is started by: |
43 |
* <ol> |
44 |
* <li>saving the lookahead cache. |
45 |
* <li>marking the current position in the TokenBuffer. |
46 |
* <li>increasing the guessing level. |
47 |
* </ol> |
48 |
* |
49 |
* After guessing, the parser state is restored by: |
50 |
* <ol> |
51 |
* <li>restoring the lookahead cache. |
52 |
* <li>rewinding the TokenBuffer. |
53 |
* <li>decreasing the guessing level. |
54 |
* </ol> |
55 |
* |
56 |
* @see antlr.Token |
57 |
* @see antlr.TokenBuffer |
58 |
* @see antlr.TokenStream |
59 |
* @see antlr.LL1Parser |
60 |
* @see antlr.LLkParser |
61 |
* |
62 |
* @todo add constructors with ASTFactory. |
63 |
*/ |
64 |
class ANTLR_API Parser { |
65 |
protected: |
66 |
Parser(TokenBuffer& input) |
67 |
: inputState(new ParserInputState(input)), astFactory(0), traceDepth(0) |
68 |
{ |
69 |
} |
70 |
Parser(TokenBuffer* input) |
71 |
: inputState(new ParserInputState(input)), astFactory(0), traceDepth(0) |
72 |
{ |
73 |
} |
74 |
Parser(const ParserSharedInputState& state) |
75 |
: inputState(state), astFactory(0), traceDepth(0) |
76 |
{ |
77 |
} |
78 |
public: |
79 |
virtual ~Parser() |
80 |
{ |
81 |
} |
82 |
|
83 |
/** Return the token type of the ith token of lookahead where i=1 |
84 |
* is the current token being examined by the parser (i.e., it |
85 |
* has not been matched yet). |
86 |
*/ |
87 |
virtual int LA(unsigned int i)=0; |
88 |
|
89 |
/// Return the i-th token of lookahead |
90 |
virtual RefToken LT(unsigned int i)=0; |
91 |
|
92 |
/** DEPRECATED! Specify the factory to be used during tree building. (Compulsory) |
93 |
* Setting the factory is nowadays compulsory. |
94 |
* @see setASTFactory |
95 |
*/ |
96 |
virtual void setASTNodeFactory( ASTFactory *factory ) |
97 |
{ |
98 |
astFactory = factory; |
99 |
} |
100 |
/** Specify the factory to be used during tree building. (Compulsory) |
101 |
* Setting the factory is nowadays compulsory. |
102 |
*/ |
103 |
virtual void setASTFactory( ASTFactory *factory ) |
104 |
{ |
105 |
astFactory = factory; |
106 |
} |
107 |
/** Return a pointer to the ASTFactory used. |
108 |
* So you might use it in subsequent treewalkers or to reload AST's |
109 |
* from disk. |
110 |
*/ |
111 |
virtual ASTFactory* getASTFactory() |
112 |
{ |
113 |
return astFactory; |
114 |
} |
115 |
/** Get the root AST node of the generated AST. When using a custom AST type |
116 |
* or heterogenous AST's, you'll have to convert it to the right type |
117 |
* yourself. |
118 |
*/ |
119 |
virtual RefAST getAST() = 0; |
120 |
|
121 |
/// Return the filename of the input file. |
122 |
virtual inline ANTLR_USE_NAMESPACE(std)string getFilename() const |
123 |
{ |
124 |
return inputState->filename; |
125 |
} |
126 |
/// Set the filename of the input file (used for error reporting). |
127 |
virtual void setFilename(const ANTLR_USE_NAMESPACE(std)string& f) |
128 |
{ |
129 |
inputState->filename = f; |
130 |
} |
131 |
|
132 |
virtual void setInputState(ParserSharedInputState state) |
133 |
{ |
134 |
inputState = state; |
135 |
} |
136 |
virtual inline ParserSharedInputState getInputState() const |
137 |
{ |
138 |
return inputState; |
139 |
} |
140 |
|
141 |
/// Get another token object from the token stream |
142 |
virtual void consume()=0; |
143 |
/// Consume tokens until one matches the given token |
144 |
virtual void consumeUntil(int tokenType) |
145 |
{ |
146 |
while (LA(1) != Token::EOF_TYPE && LA(1) != tokenType) |
147 |
consume(); |
148 |
} |
149 |
|
150 |
/// Consume tokens until one matches the given token set |
151 |
virtual void consumeUntil(const BitSet& set) |
152 |
{ |
153 |
while (LA(1) != Token::EOF_TYPE && !set.member(LA(1))) |
154 |
consume(); |
155 |
} |
156 |
|
157 |
/** Make sure current lookahead symbol matches token type <tt>t</tt>. |
158 |
* Throw an exception upon mismatch, which is catch by either the |
159 |
* error handler or by the syntactic predicate. |
160 |
*/ |
161 |
virtual void match(int t) |
162 |
{ |
163 |
if ( DEBUG_PARSER ) |
164 |
{ |
165 |
traceIndent(); |
166 |
ANTLR_USE_NAMESPACE(std)cout << "enter match(" << t << ") with LA(1)=" << LA(1) << ANTLR_USE_NAMESPACE(std)endl; |
167 |
} |
168 |
if ( LA(1) != t ) |
169 |
{ |
170 |
if ( DEBUG_PARSER ) |
171 |
{ |
172 |
traceIndent(); |
173 |
ANTLR_USE_NAMESPACE(std)cout << "token mismatch: " << LA(1) << "!=" << t << ANTLR_USE_NAMESPACE(std)endl; |
174 |
} |
175 |
throw MismatchedTokenException(getTokenNames(), getNumTokens(), LT(1), t, false, getFilename()); |
176 |
} |
177 |
else |
178 |
{ |
179 |
// mark token as consumed -- fetch next token deferred until LA/LT |
180 |
consume(); |
181 |
} |
182 |
} |
183 |
|
184 |
virtual void matchNot(int t) |
185 |
{ |
186 |
if ( LA(1)==t ) |
187 |
{ |
188 |
// Throws inverted-sense exception |
189 |
throw MismatchedTokenException(getTokenNames(), getNumTokens(), LT(1), t, true, getFilename()); |
190 |
} |
191 |
else |
192 |
{ |
193 |
// mark token as consumed -- fetch next token deferred until LA/LT |
194 |
consume(); |
195 |
} |
196 |
} |
197 |
|
198 |
/** Make sure current lookahead symbol matches the given set |
199 |
* Throw an exception upon mismatch, which is catch by either the |
200 |
* error handler or by the syntactic predicate. |
201 |
*/ |
202 |
virtual void match(const BitSet& b) |
203 |
{ |
204 |
if ( DEBUG_PARSER ) |
205 |
{ |
206 |
traceIndent(); |
207 |
ANTLR_USE_NAMESPACE(std)cout << "enter match(" << "bitset" /*b.toString()*/ |
208 |
<< ") with LA(1)=" << LA(1) << ANTLR_USE_NAMESPACE(std)endl; |
209 |
} |
210 |
if ( !b.member(LA(1)) ) |
211 |
{ |
212 |
if ( DEBUG_PARSER ) |
213 |
{ |
214 |
traceIndent(); |
215 |
ANTLR_USE_NAMESPACE(std)cout << "token mismatch: " << LA(1) << " not member of " |
216 |
<< "bitset" /*b.toString()*/ << ANTLR_USE_NAMESPACE(std)endl; |
217 |
} |
218 |
throw MismatchedTokenException(getTokenNames(), getNumTokens(), LT(1), b, false, getFilename()); |
219 |
} |
220 |
else |
221 |
{ |
222 |
// mark token as consumed -- fetch next token deferred until LA/LT |
223 |
consume(); |
224 |
} |
225 |
} |
226 |
|
227 |
/** Mark a spot in the input and return the position. |
228 |
* Forwarded to TokenBuffer. |
229 |
*/ |
230 |
virtual inline unsigned int mark() |
231 |
{ |
232 |
return inputState->getInput().mark(); |
233 |
} |
234 |
/// rewind to a previously marked position |
235 |
virtual inline void rewind(unsigned int pos) |
236 |
{ |
237 |
inputState->getInput().rewind(pos); |
238 |
} |
239 |
/** called by the generated parser to do error recovery, override to |
240 |
* customize the behaviour. |
241 |
*/ |
242 |
virtual void recover(const RecognitionException& ex, const BitSet& tokenSet) |
243 |
{ |
244 |
consume(); |
245 |
consumeUntil(tokenSet); |
246 |
} |
247 |
|
248 |
/// Parser error-reporting function can be overridden in subclass |
249 |
virtual void reportError(const RecognitionException& ex); |
250 |
/// Parser error-reporting function can be overridden in subclass |
251 |
virtual void reportError(const ANTLR_USE_NAMESPACE(std)string& s); |
252 |
/// Parser warning-reporting function can be overridden in subclass |
253 |
virtual void reportWarning(const ANTLR_USE_NAMESPACE(std)string& s); |
254 |
|
255 |
/// get the token name for the token number 'num' |
256 |
virtual const char* getTokenName(int num) const = 0; |
257 |
/// get a vector with all token names |
258 |
virtual const char* const* getTokenNames() const = 0; |
259 |
/** Get the number of tokens defined. |
260 |
* This one should be overridden in subclasses. |
261 |
*/ |
262 |
virtual int getNumTokens(void) const = 0; |
263 |
|
264 |
/** Set or change the input token buffer */ |
265 |
// void setTokenBuffer(TokenBuffer<Token>* t); |
266 |
|
267 |
virtual void traceIndent(); |
268 |
virtual void traceIn(const char* rname); |
269 |
virtual void traceOut(const char* rname); |
270 |
protected: |
271 |
// void setTokenNames(const char** tokenNames_); |
272 |
|
273 |
ParserSharedInputState inputState; |
274 |
|
275 |
// /// AST return value for a rule is squirreled away here |
276 |
// RefAST returnAST; |
277 |
|
278 |
/// AST support code; parser and treeparser delegate to this object |
279 |
ASTFactory *astFactory; |
280 |
|
281 |
// used to keep track of the indentation for the trace |
282 |
int traceDepth; |
283 |
|
284 |
/** Utility class which allows tracing to work even when exceptions are |
285 |
* thrown. |
286 |
*/ |
287 |
class Tracer { /*{{{*/ |
288 |
private: |
289 |
Parser* parser; |
290 |
const char* text; |
291 |
public: |
292 |
Tracer(Parser* p,const char * t) |
293 |
: parser(p), text(t) |
294 |
{ |
295 |
parser->traceIn(text); |
296 |
} |
297 |
~Tracer() |
298 |
{ |
299 |
#ifdef ANTLR_CXX_SUPPORTS_UNCAUGHT_EXCEPTION |
300 |
// Only give trace if there's no uncaught exception.. |
301 |
if(!ANTLR_USE_NAMESPACE(std)uncaught_exception()) |
302 |
#endif |
303 |
parser->traceOut(text); |
304 |
} |
305 |
private: |
306 |
Tracer(const Tracer&); // undefined |
307 |
const Tracer& operator=(const Tracer&); // undefined |
308 |
/*}}}*/ |
309 |
}; |
310 |
private: |
311 |
Parser(const Parser&); // undefined |
312 |
const Parser& operator=(const Parser&); // undefined |
313 |
}; |
314 |
|
315 |
#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE |
316 |
} |
317 |
#endif |
318 |
|
319 |
#endif //INC_Parser_hpp__ |