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1grammar t033backtracking;
2options {
3    language=Python;
4    backtrack=true;
5    memoize=true;
6    k=2;
7}
8
9scope Symbols {
10	types;
11}
12
13@header {
14# compatibility stuff
15try:
16    set = set
17    frozenset = frozenset
18except NameError:
19    from sets import Set as set, ImmutableSet as frozenset
20
21
22try:
23    reversed = reversed
24except NameError:
25    def reversed(l):
26        l = l[:]
27        l.reverse()
28        return l
29
30}
31
32@members {
33    def isTypeName(self, name):
34        for scope in reversed(self.Symbols_stack):
35            if name in scope.types:
36                return True
37
38        return False
39
40}
41
42translation_unit
43scope Symbols; // entire file is a scope
44@init {
45  $Symbols::types = set()
46}
47	: external_declaration+
48	;
49
50/** Either a function definition or any other kind of C decl/def.
51 *  The LL(*) analysis algorithm fails to deal with this due to
52 *  recursion in the declarator rules.  I'm putting in a
53 *  manual predicate here so that we don't backtrack over
54 *  the entire function.  Further, you get a better error
55 *  as errors within the function itself don't make it fail
56 *  to predict that it's a function.  Weird errors previously.
57 *  Remember: the goal is to avoid backtrack like the plague
58 *  because it makes debugging, actions, and errors harder.
59 *
60 *  Note that k=1 results in a much smaller predictor for the
61 *  fixed lookahead; k=2 made a few extra thousand lines. ;)
62 *  I'll have to optimize that in the future.
63 */
64external_declaration
65options {k=1;}
66	: ( declaration_specifiers? declarator declaration* '{' )=> function_definition
67	| declaration
68	;
69
70function_definition
71scope Symbols; // put parameters and locals into same scope for now
72@init {
73  $Symbols::types = set()
74}
75	:	declaration_specifiers? declarator
76// 		(	declaration+ compound_statement	// K&R style
77// 		|	compound_statement				// ANSI style
78// 		)
79	;
80
81declaration
82scope {
83  isTypedef;
84}
85@init {
86  $declaration::isTypedef = False
87}
88	: 'typedef' declaration_specifiers? {$declaration::isTypedef = True}
89	  init_declarator_list ';' // special case, looking for typedef
90	| declaration_specifiers init_declarator_list? ';'
91	;
92
93declaration_specifiers
94	:   (   storage_class_specifier
95		|   type_specifier
96        |   type_qualifier
97        )+
98	;
99
100init_declarator_list
101	: init_declarator (',' init_declarator)*
102	;
103
104init_declarator
105	: declarator //('=' initializer)?
106	;
107
108storage_class_specifier
109	: 'extern'
110	| 'static'
111	| 'auto'
112	| 'register'
113	;
114
115type_specifier
116	: 'void'
117	| 'char'
118	| 'short'
119	| 'int'
120	| 'long'
121	| 'float'
122	| 'double'
123	| 'signed'
124	| 'unsigned'
125// 	| struct_or_union_specifier
126// 	| enum_specifier
127	| type_id
128	;
129
130type_id
131    :   {self.isTypeName(self.input.LT(1).getText())}? IDENTIFIER
132//    	{System.out.println($IDENTIFIER.text+" is a type");}
133    ;
134
135// struct_or_union_specifier
136// options {k=3;}
137// scope Symbols; // structs are scopes
138// @init {
139//   $Symbols::types = set()
140// }
141// 	: struct_or_union IDENTIFIER? '{' struct_declaration_list '}'
142// 	| struct_or_union IDENTIFIER
143// 	;
144
145// struct_or_union
146// 	: 'struct'
147// 	| 'union'
148// 	;
149
150// struct_declaration_list
151// 	: struct_declaration+
152// 	;
153
154// struct_declaration
155// 	: specifier_qualifier_list struct_declarator_list ';'
156// 	;
157
158// specifier_qualifier_list
159// 	: ( type_qualifier | type_specifier )+
160// 	;
161
162// struct_declarator_list
163// 	: struct_declarator (',' struct_declarator)*
164// 	;
165
166// struct_declarator
167// 	: declarator (':' constant_expression)?
168// 	| ':' constant_expression
169// 	;
170
171// enum_specifier
172// options {k=3;}
173// 	: 'enum' '{' enumerator_list '}'
174// 	| 'enum' IDENTIFIER '{' enumerator_list '}'
175// 	| 'enum' IDENTIFIER
176// 	;
177
178// enumerator_list
179// 	: enumerator (',' enumerator)*
180// 	;
181
182// enumerator
183// 	: IDENTIFIER ('=' constant_expression)?
184// 	;
185
186type_qualifier
187	: 'const'
188	| 'volatile'
189	;
190
191declarator
192	: pointer? direct_declarator
193	| pointer
194	;
195
196direct_declarator
197	:   (	IDENTIFIER
198			{
199			if len($declaration)>0 and $declaration::isTypedef:
200				$Symbols::types.add($IDENTIFIER.text)
201				print "define type "+$IDENTIFIER.text
202			}
203		|	'(' declarator ')'
204		)
205        declarator_suffix*
206	;
207
208declarator_suffix
209	:   /*'[' constant_expression ']'
210    |*/   '[' ']'
211//     |   '(' parameter_type_list ')'
212//     |   '(' identifier_list ')'
213    |   '(' ')'
214	;
215
216pointer
217	: '*' type_qualifier+ pointer?
218	| '*' pointer
219	| '*'
220	;
221
222// parameter_type_list
223// 	: parameter_list (',' '...')?
224// 	;
225
226// parameter_list
227// 	: parameter_declaration (',' parameter_declaration)*
228// 	;
229
230// parameter_declaration
231// 	: declaration_specifiers (declarator|abstract_declarator)*
232// 	;
233
234// identifier_list
235// 	: IDENTIFIER (',' IDENTIFIER)*
236// 	;
237
238// type_name
239// 	: specifier_qualifier_list abstract_declarator?
240// 	;
241
242// abstract_declarator
243// 	: pointer direct_abstract_declarator?
244// 	| direct_abstract_declarator
245// 	;
246
247// direct_abstract_declarator
248// 	:	( '(' abstract_declarator ')' | abstract_declarator_suffix ) abstract_declarator_suffix*
249// 	;
250
251// abstract_declarator_suffix
252// 	:	'[' ']'
253// 	|	'[' constant_expression ']'
254// 	|	'(' ')'
255// 	|	'(' parameter_type_list ')'
256// 	;
257
258// initializer
259// 	: assignment_expression
260// 	| '{' initializer_list ','? '}'
261// 	;
262
263// initializer_list
264// 	: initializer (',' initializer)*
265// 	;
266
267// // E x p r e s s i o n s
268
269// argument_expression_list
270// 	:   assignment_expression (',' assignment_expression)*
271// 	;
272
273// additive_expression
274// 	: (multiplicative_expression) ('+' multiplicative_expression | '-' multiplicative_expression)*
275// 	;
276
277// multiplicative_expression
278// 	: (cast_expression) ('*' cast_expression | '/' cast_expression | '%' cast_expression)*
279// 	;
280
281// cast_expression
282// 	: '(' type_name ')' cast_expression
283// 	| unary_expression
284// 	;
285
286// unary_expression
287// 	: postfix_expression
288// 	| '++' unary_expression
289// 	| '--' unary_expression
290// 	| unary_operator cast_expression
291// 	| 'sizeof' unary_expression
292// 	| 'sizeof' '(' type_name ')'
293// 	;
294
295// postfix_expression
296// 	:   primary_expression
297//         (   '[' expression ']'
298//         |   '(' ')'
299//         |   '(' argument_expression_list ')'
300//         |   '.' IDENTIFIER
301//         |   '*' IDENTIFIER
302//         |   '->' IDENTIFIER
303//         |   '++'
304//         |   '--'
305//         )*
306// 	;
307
308// unary_operator
309// 	: '&'
310// 	| '*'
311// 	| '+'
312// 	| '-'
313// 	| '~'
314// 	| '!'
315// 	;
316
317// primary_expression
318// 	: IDENTIFIER
319// 	| constant
320// 	| '(' expression ')'
321// 	;
322
323// constant
324//     :   HEX_LITERAL
325//     |   OCTAL_LITERAL
326//     |   DECIMAL_LITERAL
327//     |	CHARACTER_LITERAL
328// 	|	STRING_LITERAL
329//     |   FLOATING_POINT_LITERAL
330//     ;
331
332// /////
333
334// expression
335// 	: assignment_expression (',' assignment_expression)*
336// 	;
337
338// constant_expression
339// 	: conditional_expression
340// 	;
341
342// assignment_expression
343// 	: lvalue assignment_operator assignment_expression
344// 	| conditional_expression
345// 	;
346
347// lvalue
348// 	:	unary_expression
349// 	;
350
351// assignment_operator
352// 	: '='
353// 	| '*='
354// 	| '/='
355// 	| '%='
356// 	| '+='
357// 	| '-='
358// 	| '<<='
359// 	| '>>='
360// 	| '&='
361// 	| '^='
362// 	| '|='
363// 	;
364
365// conditional_expression
366// 	: logical_or_expression ('?' expression ':' conditional_expression)?
367// 	;
368
369// logical_or_expression
370// 	: logical_and_expression ('||' logical_and_expression)*
371// 	;
372
373// logical_and_expression
374// 	: inclusive_or_expression ('&&' inclusive_or_expression)*
375// 	;
376
377// inclusive_or_expression
378// 	: exclusive_or_expression ('|' exclusive_or_expression)*
379// 	;
380
381// exclusive_or_expression
382// 	: and_expression ('^' and_expression)*
383// 	;
384
385// and_expression
386// 	: equality_expression ('&' equality_expression)*
387// 	;
388// equality_expression
389// 	: relational_expression (('=='|'!=') relational_expression)*
390// 	;
391
392// relational_expression
393// 	: shift_expression (('<'|'>'|'<='|'>=') shift_expression)*
394// 	;
395
396// shift_expression
397// 	: additive_expression (('<<'|'>>') additive_expression)*
398// 	;
399
400// // S t a t e m e n t s
401
402// statement
403// 	: labeled_statement
404// 	| compound_statement
405// 	| expression_statement
406// 	| selection_statement
407// 	| iteration_statement
408// 	| jump_statement
409// 	;
410
411// labeled_statement
412// 	: IDENTIFIER ':' statement
413// 	| 'case' constant_expression ':' statement
414// 	| 'default' ':' statement
415// 	;
416
417// compound_statement
418// scope Symbols; // blocks have a scope of symbols
419// @init {
420//   $Symbols::types = {}
421// }
422// 	: '{' declaration* statement_list? '}'
423// 	;
424
425// statement_list
426// 	: statement+
427// 	;
428
429// expression_statement
430// 	: ';'
431// 	| expression ';'
432// 	;
433
434// selection_statement
435// 	: 'if' '(' expression ')' statement (options {k=1; backtrack=false;}:'else' statement)?
436// 	| 'switch' '(' expression ')' statement
437// 	;
438
439// iteration_statement
440// 	: 'while' '(' expression ')' statement
441// 	| 'do' statement 'while' '(' expression ')' ';'
442// 	| 'for' '(' expression_statement expression_statement expression? ')' statement
443// 	;
444
445// jump_statement
446// 	: 'goto' IDENTIFIER ';'
447// 	| 'continue' ';'
448// 	| 'break' ';'
449// 	| 'return' ';'
450// 	| 'return' expression ';'
451// 	;
452
453IDENTIFIER
454	:	LETTER (LETTER|'0'..'9')*
455	;
456
457fragment
458LETTER
459	:	'$'
460	|	'A'..'Z'
461	|	'a'..'z'
462	|	'_'
463	;
464
465CHARACTER_LITERAL
466    :   '\'' ( EscapeSequence | ~('\''|'\\') ) '\''
467    ;
468
469STRING_LITERAL
470    :  '"' ( EscapeSequence | ~('\\'|'"') )* '"'
471    ;
472
473HEX_LITERAL : '0' ('x'|'X') HexDigit+ IntegerTypeSuffix? ;
474
475DECIMAL_LITERAL : ('0' | '1'..'9' '0'..'9'*) IntegerTypeSuffix? ;
476
477OCTAL_LITERAL : '0' ('0'..'7')+ IntegerTypeSuffix? ;
478
479fragment
480HexDigit : ('0'..'9'|'a'..'f'|'A'..'F') ;
481
482fragment
483IntegerTypeSuffix
484	:	('u'|'U')? ('l'|'L')
485	|	('u'|'U')  ('l'|'L')?
486	;
487
488FLOATING_POINT_LITERAL
489    :   ('0'..'9')+ '.' ('0'..'9')* Exponent? FloatTypeSuffix?
490    |   '.' ('0'..'9')+ Exponent? FloatTypeSuffix?
491    |   ('0'..'9')+ Exponent FloatTypeSuffix?
492    |   ('0'..'9')+ Exponent? FloatTypeSuffix
493	;
494
495fragment
496Exponent : ('e'|'E') ('+'|'-')? ('0'..'9')+ ;
497
498fragment
499FloatTypeSuffix : ('f'|'F'|'d'|'D') ;
500
501fragment
502EscapeSequence
503    :   '\\' ('b'|'t'|'n'|'f'|'r'|'\"'|'\''|'\\')
504    |   OctalEscape
505    ;
506
507fragment
508OctalEscape
509    :   '\\' ('0'..'3') ('0'..'7') ('0'..'7')
510    |   '\\' ('0'..'7') ('0'..'7')
511    |   '\\' ('0'..'7')
512    ;
513
514fragment
515UnicodeEscape
516    :   '\\' 'u' HexDigit HexDigit HexDigit HexDigit
517    ;
518
519WS  :  (' '|'\r'|'\t'|'\u000C'|'\n') {$channel=HIDDEN;}
520    ;
521
522COMMENT
523    :   '/*' ( options {greedy=false;} : . )* '*/' {$channel=HIDDEN;}
524    ;
525
526LINE_COMMENT
527    : '//' ~('\n'|'\r')* '\r'? '\n' {$channel=HIDDEN;}
528    ;
529
530// ignore #line info for now
531LINE_COMMAND
532    : '#' ~('\n'|'\r')* '\r'? '\n' {$channel=HIDDEN;}
533    ;
534
535