source: src/Parser/lex.ll@ 8f55e8e9

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 8f55e8e9 was 0a616e0, checked in by Peter A. Buhr <pabuhr@…>, 7 years ago

clean up constant code and add pointer suffix

  • Property mode set to 100644
File size: 19.0 KB
Line 
1/*
2 * Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3 *
4 * The contents of this file are covered under the licence agreement in the
5 * file "LICENCE" distributed with Cforall.
6 *
7 * lex.ll --
8 *
9 * Author : Peter A. Buhr
10 * Created On : Sat Sep 22 08:58:10 2001
11 * Last Modified By : Peter A. Buhr
12 * Last Modified On : Sun Mar 10 09:13:09 2019
13 * Update Count : 706
14 */
15
16%option yylineno
17%option noyywrap
18%option nounput
19
20%{
21// The lexer assumes the program has been preprocessed by cpp. Hence, all user level preprocessor directive have been
22// performed and removed from the source. The only exceptions are preprocessor directives passed to the compiler (e.g.,
23// line-number directives) and C/C++ style comments, which are ignored.
24
25//**************************** Includes and Defines ****************************
26
27// trigger before each matching rule's action
28#define YY_USER_ACTION \
29 yylloc.first_line = yylineno; \
30 yylloc.first_column = column; \
31 column += yyleng; \
32 yylloc.last_column = column; \
33 yylloc.last_line = yylineno; \
34 yylloc.filename = yyfilename ? yyfilename : "";
35unsigned int column = 0; // position of the end of the last token parsed
36
37#include <string>
38#include <cstdio> // FILENAME_MAX
39using namespace std;
40
41#include "config.h" // configure info
42#include "ParseNode.h"
43#include "TypedefTable.h"
44
45char *yyfilename;
46string *strtext; // accumulate parts of character and string constant value
47
48#define RETURN_LOCN(x) yylval.tok.loc.file = yyfilename; yylval.tok.loc.line = yylineno; return( x )
49#define RETURN_VAL(x) yylval.tok.str = new string( yytext ); RETURN_LOCN( x )
50#define RETURN_CHAR(x) yylval.tok.str = nullptr; RETURN_LOCN( x )
51#define RETURN_STR(x) yylval.tok.str = strtext; RETURN_LOCN( x )
52
53#define WHITE_RETURN(x) // do nothing
54#define NEWLINE_RETURN() column = 0; WHITE_RETURN( '\n' )
55#define ASCIIOP_RETURN() RETURN_CHAR( (int)yytext[0] ) // single character operator
56#define NAMEDOP_RETURN(x) RETURN_CHAR( x ) // multichar operator, with a name
57#define NUMERIC_RETURN(x) rm_underscore(); RETURN_VAL( x ) // numeric constant
58#define KEYWORD_RETURN(x) RETURN_CHAR( x ) // keyword
59#define QKEYWORD_RETURN(x) RETURN_VAL(x); // quasi-keyword
60#define IDENTIFIER_RETURN() RETURN_VAL( typedefTable.isKind( yytext ) )
61#define ATTRIBUTE_RETURN() RETURN_VAL( ATTR_IDENTIFIER )
62
63#ifdef HAVE_KEYWORDS_FLOATXX // GCC >= 7 => keyword, otherwise typedef
64#define FLOATXX(v) KEYWORD_RETURN(v);
65#else
66#define FLOATXX(v) IDENTIFIER_RETURN();
67#endif // HAVE_KEYWORDS_FLOATXX
68
69void rm_underscore() {
70 // SKULLDUGGERY: remove underscores (ok to shorten?)
71 yyleng = 0;
72 for ( int i = 0; yytext[i] != '\0'; i += 1 ) { // copying non-underscore characters to front of string
73 if ( yytext[i] != '_' ) {
74 yytext[yyleng] = yytext[i];
75 yyleng += 1;
76 } // if
77 } // for
78 yytext[yyleng] = '\0';
79} // rm_underscore
80
81// Stop warning due to incorrectly generated flex code.
82#pragma GCC diagnostic ignored "-Wsign-compare"
83%}
84
85binary [0-1]
86octal [0-7]
87nonzero [1-9]
88decimal [0-9]
89hex [0-9a-fA-F]
90universal_char "\\"((u"_"?{hex_quad})|(U"_"?{hex_quad}{2}))
91
92 // identifier, GCC: $ in identifier
93identifier ([a-zA-Z_$]|{universal_char})([0-9a-zA-Z_$]|{universal_char})*
94
95 // attribute identifier, GCC: $ in identifier
96attr_identifier "@"{identifier}
97
98 // numeric constants, CFA: '_' in constant
99hex_quad {hex}("_"?{hex}){3}
100size_opt (8|16|32|64|128)?
101 // CFA: explicit l8/l16/l32/l64/l128, char 'hh', short 'h', int 'n'
102length ("ll"|"LL"|[lL]{size_opt})|("hh"|"HH"|[hHnN])
103 // CFA: size_t 'z', pointer 'p', which define a sign and length
104integer_suffix_opt ("_"?(([uU]({length}?[iI]?)|([iI]{length}))|([iI]({length}?[uU]?)|([uU]{length}))|({length}([iI]?[uU]?)|([uU][iI]))|[zZ]|[pP]))?
105
106octal_digits ({octal})|({octal}({octal}|"_")*{octal})
107octal_prefix "0""_"?
108octal_constant (("0")|({octal_prefix}{octal_digits})){integer_suffix_opt}
109
110nonzero_digits ({nonzero})|({nonzero}({decimal}|"_")*{decimal})
111decimal_constant {nonzero_digits}{integer_suffix_opt}
112
113binary_digits ({binary})|({binary}({binary}|"_")*{binary})
114binary_prefix "0"[bB]"_"?
115binary_constant {binary_prefix}{binary_digits}{integer_suffix_opt}
116
117hex_digits ({hex})|({hex}({hex}|"_")*{hex})
118hex_prefix "0"[xX]"_"?
119hex_constant {hex_prefix}{hex_digits}{integer_suffix_opt}
120
121 // GCC: D (double) and iI (imaginary) suffixes, and DL (long double)
122exponent "_"?[eE]"_"?[+-]?{decimal_digits}
123floating_size 16|32|32x|64|64x|80|128|128x
124floating_length ([fFdDlLwWqQ]|[fF]{floating_size})
125floating_suffix ({floating_length}?[iI]?)|([iI]{floating_length})
126floating_suffix_opt ("_"?({floating_suffix}|"DL"))?
127decimal_digits ({decimal})|({decimal}({decimal}|"_")*{decimal})
128floating_decimal {decimal_digits}"."{exponent}?{floating_suffix_opt}
129floating_fraction "."{decimal_digits}{exponent}?{floating_suffix_opt}
130floating_constant ({decimal_digits}{exponent}{floating_suffix_opt})|({decimal_digits}{floating_fraction})
131
132binary_exponent "_"?[pP]"_"?[+-]?{decimal_digits}
133hex_floating_suffix_opt ("_"?({floating_suffix}))?
134hex_floating_fraction ({hex_digits}?"."{hex_digits})|({hex_digits}".")
135hex_floating_constant {hex_prefix}(({hex_floating_fraction}{binary_exponent})|({hex_digits}{binary_exponent})){hex_floating_suffix_opt}
136
137 // character escape sequence, GCC: \e => esc character
138simple_escape "\\"[abefnrtv'"?\\]
139 // ' stop editor highlighting
140octal_escape "\\"{octal}("_"?{octal}){0,2}
141hex_escape "\\""x""_"?{hex_digits}
142escape_seq {simple_escape}|{octal_escape}|{hex_escape}|{universal_char}
143cwide_prefix "L"|"U"|"u"
144swide_prefix {cwide_prefix}|"u8"
145
146 // display/white-space characters
147h_tab [\011]
148form_feed [\014]
149v_tab [\013]
150c_return [\015]
151h_white [ ]|{h_tab}
152
153 // overloadable operators
154op_unary_only "~"|"!"
155op_unary_binary "+"|"-"|"*"
156op_unary_pre_post "++"|"--"
157op_unary {op_unary_only}|{op_unary_binary}|{op_unary_pre_post}
158
159op_binary_only "/"|"%"|"\\"|"^"|"&"|"|"|"<"|">"|"="|"=="|"!="|"<<"|">>"|"<="|">="|"+="|"-="|"*="|"/="|"%="|"\\="|"&="|"|="|"^="|"<<="|">>="
160op_binary_over {op_unary_binary}|{op_binary_only}
161 // op_binary_not_over "?"|"->"|"."|"&&"|"||"|"@="
162 // operator {op_unary_pre_post}|{op_binary_over}|{op_binary_not_over}
163
164%x COMMENT
165%x BKQUOTE
166%x QUOTE
167%x STRING
168
169%%
170 /* line directives */
171^{h_white}*"#"{h_white}*[0-9]+{h_white}*["][^"\n]+["].*"\n" {
172 /* " stop editor highlighting */
173 static char filename[FILENAME_MAX]; // temporarily store current source-file name
174 char *end_num;
175 char *begin_string, *end_string;
176 long lineno, length;
177 lineno = strtol( yytext + 1, &end_num, 0 );
178 begin_string = strchr( end_num, '"' );
179 if ( begin_string ) { // file name ?
180 end_string = strchr( begin_string + 1, '"' ); // look for ending delimiter
181 assert( end_string ); // closing quote ?
182 length = end_string - begin_string - 1; // file-name length without quotes or sentinel
183 assert( length < FILENAME_MAX ); // room for sentinel ?
184 memcpy( &filename, begin_string + 1, length ); // copy file name from yytext
185 filename[ length ] = '\0'; // terminate string with sentinel
186 //cout << "file " << filename << " line " << lineno << endl;
187 yylineno = lineno;
188 yyfilename = filename;
189 } // if
190}
191
192 /* preprocessor-style directives */
193^{h_white}*"#"[^\n]*"\n" { RETURN_VAL( DIRECTIVE ); }
194
195 /* ignore C style comments (ALSO HANDLED BY CPP) */
196"/*" { BEGIN COMMENT; }
197<COMMENT>.|\n ;
198<COMMENT>"*/" { BEGIN 0; }
199
200 /* ignore C++ style comments (ALSO HANDLED BY CPP) */
201"//"[^\n]*"\n" ;
202
203 /* ignore whitespace */
204{h_white}+ { WHITE_RETURN(' '); }
205({v_tab}|{c_return}|{form_feed})+ { WHITE_RETURN(' '); }
206({h_white}|{v_tab}|{c_return}|{form_feed})*"\n" { NEWLINE_RETURN(); }
207
208 /* keywords */
209_Alignas { KEYWORD_RETURN(ALIGNAS); } // C11
210_Alignof { KEYWORD_RETURN(ALIGNOF); } // C11
211__alignof { KEYWORD_RETURN(ALIGNOF); } // GCC
212__alignof__ { KEYWORD_RETURN(ALIGNOF); } // GCC
213asm { KEYWORD_RETURN(ASM); }
214__asm { KEYWORD_RETURN(ASM); } // GCC
215__asm__ { KEYWORD_RETURN(ASM); } // GCC
216_Atomic { KEYWORD_RETURN(ATOMIC); } // C11
217__attribute { KEYWORD_RETURN(ATTRIBUTE); } // GCC
218__attribute__ { KEYWORD_RETURN(ATTRIBUTE); } // GCC
219auto { KEYWORD_RETURN(AUTO); }
220basetypeof { KEYWORD_RETURN(BASETYPEOF); } // CFA
221_Bool { KEYWORD_RETURN(BOOL); } // C99
222break { KEYWORD_RETURN(BREAK); }
223case { KEYWORD_RETURN(CASE); }
224catch { KEYWORD_RETURN(CATCH); } // CFA
225catchResume { KEYWORD_RETURN(CATCHRESUME); } // CFA
226char { KEYWORD_RETURN(CHAR); }
227choose { KEYWORD_RETURN(CHOOSE); } // CFA
228_Complex { KEYWORD_RETURN(COMPLEX); } // C99
229__complex { KEYWORD_RETURN(COMPLEX); } // GCC
230__complex__ { KEYWORD_RETURN(COMPLEX); } // GCC
231const { KEYWORD_RETURN(CONST); }
232__const { KEYWORD_RETURN(CONST); } // GCC
233__const__ { KEYWORD_RETURN(CONST); } // GCC
234continue { KEYWORD_RETURN(CONTINUE); }
235coroutine { KEYWORD_RETURN(COROUTINE); } // CFA
236default { KEYWORD_RETURN(DEFAULT); }
237disable { KEYWORD_RETURN(DISABLE); } // CFA
238do { KEYWORD_RETURN(DO); }
239double { KEYWORD_RETURN(DOUBLE); }
240dtype { KEYWORD_RETURN(DTYPE); } // CFA
241else { KEYWORD_RETURN(ELSE); }
242enable { KEYWORD_RETURN(ENABLE); } // CFA
243enum { KEYWORD_RETURN(ENUM); }
244__extension__ { KEYWORD_RETURN(EXTENSION); } // GCC
245exception { KEYWORD_RETURN(EXCEPTION); } // CFA
246extern { KEYWORD_RETURN(EXTERN); }
247fallthrough { KEYWORD_RETURN(FALLTHROUGH); } // CFA
248fallthru { KEYWORD_RETURN(FALLTHRU); } // CFA
249finally { KEYWORD_RETURN(FINALLY); } // CFA
250float { KEYWORD_RETURN(FLOAT); }
251__float80 { KEYWORD_RETURN(uuFLOAT80); } // GCC
252float80 { KEYWORD_RETURN(uuFLOAT80); } // GCC
253__float128 { KEYWORD_RETURN(uuFLOAT128); } // GCC
254float128 { KEYWORD_RETURN(uuFLOAT128); } // GCC
255_Float16 { FLOATXX(uFLOAT16); } // GCC
256_Float32 { FLOATXX(uFLOAT32); } // GCC
257_Float32x { FLOATXX(uFLOAT32X); } // GCC
258_Float64 { FLOATXX(uFLOAT64); } // GCC
259_Float64x { FLOATXX(uFLOAT64X); } // GCC
260_Float128 { FLOATXX(uFLOAT128); } // GCC
261_Float128x { FLOATXX(uFLOAT128); } // GCC
262for { KEYWORD_RETURN(FOR); }
263forall { KEYWORD_RETURN(FORALL); } // CFA
264fortran { KEYWORD_RETURN(FORTRAN); }
265ftype { KEYWORD_RETURN(FTYPE); } // CFA
266_Generic { KEYWORD_RETURN(GENERIC); } // C11
267goto { KEYWORD_RETURN(GOTO); }
268if { KEYWORD_RETURN(IF); }
269_Imaginary { KEYWORD_RETURN(IMAGINARY); } // C99
270__imag { KEYWORD_RETURN(IMAGINARY); } // GCC
271__imag__ { KEYWORD_RETURN(IMAGINARY); } // GCC
272inline { KEYWORD_RETURN(INLINE); } // C99
273__inline { KEYWORD_RETURN(INLINE); } // GCC
274__inline__ { KEYWORD_RETURN(INLINE); } // GCC
275int { KEYWORD_RETURN(INT); }
276__int128 { KEYWORD_RETURN(INT128); } // GCC
277int128 { KEYWORD_RETURN(INT128); } // GCC
278__label__ { KEYWORD_RETURN(LABEL); } // GCC
279long { KEYWORD_RETURN(LONG); }
280monitor { KEYWORD_RETURN(MONITOR); } // CFA
281mutex { KEYWORD_RETURN(MUTEX); } // CFA
282_Noreturn { KEYWORD_RETURN(NORETURN); } // C11
283__builtin_offsetof { KEYWORD_RETURN(OFFSETOF); } // GCC
284one_t { NUMERIC_RETURN(ONE_T); } // CFA
285or { QKEYWORD_RETURN(WOR); } // CFA
286otype { KEYWORD_RETURN(OTYPE); } // CFA
287register { KEYWORD_RETURN(REGISTER); }
288restrict { KEYWORD_RETURN(RESTRICT); } // C99
289__restrict { KEYWORD_RETURN(RESTRICT); } // GCC
290__restrict__ { KEYWORD_RETURN(RESTRICT); } // GCC
291return { KEYWORD_RETURN(RETURN); }
292short { KEYWORD_RETURN(SHORT); }
293signed { KEYWORD_RETURN(SIGNED); }
294__signed { KEYWORD_RETURN(SIGNED); } // GCC
295__signed__ { KEYWORD_RETURN(SIGNED); } // GCC
296sizeof { KEYWORD_RETURN(SIZEOF); }
297static { KEYWORD_RETURN(STATIC); }
298_Static_assert { KEYWORD_RETURN(STATICASSERT); } // C11
299struct { KEYWORD_RETURN(STRUCT); }
300switch { KEYWORD_RETURN(SWITCH); }
301thread { KEYWORD_RETURN(THREAD); } // C11
302_Thread_local { KEYWORD_RETURN(THREADLOCAL); } // C11
303throw { KEYWORD_RETURN(THROW); } // CFA
304throwResume { KEYWORD_RETURN(THROWRESUME); } // CFA
305timeout { QKEYWORD_RETURN(TIMEOUT); } // CFA
306trait { KEYWORD_RETURN(TRAIT); } // CFA
307try { KEYWORD_RETURN(TRY); } // CFA
308ttype { KEYWORD_RETURN(TTYPE); } // CFA
309typedef { KEYWORD_RETURN(TYPEDEF); }
310typeof { KEYWORD_RETURN(TYPEOF); } // GCC
311__typeof { KEYWORD_RETURN(TYPEOF); } // GCC
312__typeof__ { KEYWORD_RETURN(TYPEOF); } // GCC
313union { KEYWORD_RETURN(UNION); }
314unsigned { KEYWORD_RETURN(UNSIGNED); }
315__builtin_va_list { KEYWORD_RETURN(VALIST); } // GCC
316virtual { KEYWORD_RETURN(VIRTUAL); } // CFA
317void { KEYWORD_RETURN(VOID); }
318volatile { KEYWORD_RETURN(VOLATILE); }
319__volatile { KEYWORD_RETURN(VOLATILE); } // GCC
320__volatile__ { KEYWORD_RETURN(VOLATILE); } // GCC
321waitfor { KEYWORD_RETURN(WAITFOR); }
322when { KEYWORD_RETURN(WHEN); }
323while { KEYWORD_RETURN(WHILE); }
324with { KEYWORD_RETURN(WITH); } // CFA
325zero_t { NUMERIC_RETURN(ZERO_T); } // CFA
326
327 /* identifier */
328{identifier} { IDENTIFIER_RETURN(); }
329"`"{identifier}"`" { // CFA
330 yytext[yyleng - 1] = '\0'; yytext += 1; // SKULLDUGGERY: remove backquotes (ok to shorten?)
331 IDENTIFIER_RETURN();
332}
333{attr_identifier} { ATTRIBUTE_RETURN(); }
334
335 /* numeric constants */
336{binary_constant} { NUMERIC_RETURN(INTEGERconstant); }
337{octal_constant} { NUMERIC_RETURN(INTEGERconstant); }
338{decimal_constant} { NUMERIC_RETURN(INTEGERconstant); }
339{hex_constant} { NUMERIC_RETURN(INTEGERconstant); }
340{floating_decimal} { NUMERIC_RETURN(FLOATING_DECIMALconstant); } // must appear before floating_constant
341{floating_fraction} { NUMERIC_RETURN(FLOATING_FRACTIONconstant); } // must appear before floating_constant
342{floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
343{hex_floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
344
345 /* character constant, allows empty value */
346({cwide_prefix}[_]?)?['] { BEGIN QUOTE; rm_underscore(); strtext = new string( yytext, yyleng ); }
347<QUOTE>[^'\\\n]* { strtext->append( yytext, yyleng ); }
348<QUOTE>['\n] { BEGIN 0; strtext->append( yytext, yyleng ); RETURN_STR(CHARACTERconstant); }
349 /* ' stop editor highlighting */
350
351 /* string constant */
352({swide_prefix}[_]?)?["] { BEGIN STRING; rm_underscore(); strtext = new string( yytext, yyleng ); }
353<STRING>[^"\\\n]* { strtext->append( yytext, yyleng ); }
354<STRING>["\n] { BEGIN 0; strtext->append( yytext, yyleng ); RETURN_STR(STRINGliteral); }
355 /* " stop editor highlighting */
356
357 /* common character/string constant */
358<QUOTE,STRING>{escape_seq} { rm_underscore(); strtext->append( yytext, yyleng ); }
359<QUOTE,STRING>"\\"{h_white}*"\n" {} // continuation (ALSO HANDLED BY CPP)
360<QUOTE,STRING>"\\" { strtext->append( yytext, yyleng ); } // unknown escape character
361
362 /* punctuation */
363"@" { ASCIIOP_RETURN(); }
364"`" { ASCIIOP_RETURN(); }
365"[" { ASCIIOP_RETURN(); }
366"]" { ASCIIOP_RETURN(); }
367"(" { ASCIIOP_RETURN(); }
368")" { ASCIIOP_RETURN(); }
369"{" { ASCIIOP_RETURN(); }
370"}" { ASCIIOP_RETURN(); }
371"," { ASCIIOP_RETURN(); } // also operator
372":" { ASCIIOP_RETURN(); }
373";" { ASCIIOP_RETURN(); }
374"." { ASCIIOP_RETURN(); } // also operator
375"..." { NAMEDOP_RETURN(ELLIPSIS); }
376
377 /* alternative C99 brackets, "<:" & "<:<:" handled by preprocessor */
378"<:" { RETURN_VAL('['); }
379":>" { RETURN_VAL(']'); }
380"<%" { RETURN_VAL('{'); }
381"%>" { RETURN_VAL('}'); }
382
383 /* operators */
384"!" { ASCIIOP_RETURN(); }
385"+" { ASCIIOP_RETURN(); }
386"-" { ASCIIOP_RETURN(); }
387"*" { ASCIIOP_RETURN(); }
388"\\" { ASCIIOP_RETURN(); } // CFA, exponentiation
389"/" { ASCIIOP_RETURN(); }
390"%" { ASCIIOP_RETURN(); }
391"^" { ASCIIOP_RETURN(); }
392"~" { ASCIIOP_RETURN(); }
393"&" { ASCIIOP_RETURN(); }
394"|" { ASCIIOP_RETURN(); }
395"<" { ASCIIOP_RETURN(); }
396">" { ASCIIOP_RETURN(); }
397"=" { ASCIIOP_RETURN(); }
398"?" { ASCIIOP_RETURN(); }
399
400"++" { NAMEDOP_RETURN(ICR); }
401"--" { NAMEDOP_RETURN(DECR); }
402"==" { NAMEDOP_RETURN(EQ); }
403"!=" { NAMEDOP_RETURN(NE); }
404"<<" { NAMEDOP_RETURN(LS); }
405">>" { NAMEDOP_RETURN(RS); }
406"<=" { NAMEDOP_RETURN(LE); }
407">=" { NAMEDOP_RETURN(GE); }
408"&&" { NAMEDOP_RETURN(ANDAND); }
409"||" { NAMEDOP_RETURN(OROR); }
410"->" { NAMEDOP_RETURN(ARROW); }
411"+=" { NAMEDOP_RETURN(PLUSassign); }
412"-=" { NAMEDOP_RETURN(MINUSassign); }
413"\\=" { NAMEDOP_RETURN(EXPassign); } // CFA, exponentiation
414"*=" { NAMEDOP_RETURN(MULTassign); }
415"/=" { NAMEDOP_RETURN(DIVassign); }
416"%=" { NAMEDOP_RETURN(MODassign); }
417"&=" { NAMEDOP_RETURN(ANDassign); }
418"|=" { NAMEDOP_RETURN(ORassign); }
419"^=" { NAMEDOP_RETURN(ERassign); }
420"<<=" { NAMEDOP_RETURN(LSassign); }
421">>=" { NAMEDOP_RETURN(RSassign); }
422
423"@=" { NAMEDOP_RETURN(ATassign); } // CFA
424"~=" { NAMEDOP_RETURN(ErangeUpEq); } // CFA
425"-~" { NAMEDOP_RETURN(ErangeDown); } // CFA
426"-~=" { NAMEDOP_RETURN(ErangeDownEq); } // CFA
427
428 /* CFA, operator identifier */
429{op_unary}"?" { IDENTIFIER_RETURN(); } // unary
430"?"({op_unary_pre_post}|"()"|"[?]"|"{}") { IDENTIFIER_RETURN(); }
431"^?{}" { IDENTIFIER_RETURN(); }
432"?`"{identifier} { IDENTIFIER_RETURN(); } // postfix operator
433"?"{op_binary_over}"?" { IDENTIFIER_RETURN(); } // binary
434 /*
435 This rule handles ambiguous cases with operator identifiers, e.g., "int *?*?()", where the string "*?*?" can be
436 lexed as "*?"/"*?" or "*"/"?*?". Since it is common practise to put a unary operator juxtaposed to an identifier,
437 e.g., "*i", users will be annoyed if they cannot do this with respect to operator identifiers. Therefore, there is
438 a lexical look-ahead for the second case, with backtracking to return the leading unary operator and then
439 reparsing the trailing operator identifier. Otherwise a space is needed between the unary operator and operator
440 identifier to disambiguate this common case.
441
442 A similar issue occurs with the dereference, *?(...), and routine-call, ?()(...) identifiers. The ambiguity
443 occurs when the deference operator has no parameters, *?() and *?()(...), requiring arbitrary whitespace
444 look-ahead for the routine-call parameter-list to disambiguate. However, the dereference operator must have a
445 parameter/argument to dereference *?(...). Hence, always interpreting the string *?() as * ?() does not preclude
446 any meaningful program.
447
448 The remaining cases are with the increment/decrement operators and conditional expression:
449
450 i++? ...(...);
451 i?++ ...(...);
452
453 requiring arbitrary whitespace look-ahead for the operator parameter-list, even though that interpretation is an
454 incorrect expression (juxtaposed identifiers). Therefore, it is necessary to disambiguate these cases with a
455 space:
456
457 i++ ? i : 0;
458 i? ++i : 0;
459 */
460{op_unary}"?"({op_unary_pre_post}|"()"|"[?]"|{op_binary_over}"?") {
461 // 1 or 2 character unary operator ?
462 int i = yytext[1] == '?' ? 1 : 2;
463 yyless( i ); // put back characters up to first '?'
464 if ( i > 1 ) {
465 NAMEDOP_RETURN( yytext[0] == '+' ? ICR : DECR );
466 } else {
467 ASCIIOP_RETURN();
468 } // if
469}
470
471 /* unknown character */
472. { yyerror( "unknown character" ); }
473
474%%
475
476// ----end of lexer----
477
478void yyerror( const char * errmsg ) {
479 SemanticErrorThrow = true;
480 cerr << (yyfilename ? yyfilename : "*unknown file*") << ':' << yylineno << ':' << column - yyleng + 1
481 << ": " << ErrorHelpers::error_str() << errmsg << " at token \"" << (yytext[0] == '\0' ? "EOF" : yytext) << '"' << endl;
482}
483
484// Local Variables: //
485// mode: c++ //
486// tab-width: 4 //
487// compile-command: "make install" //
488// End: //
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