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lex.ll @ 811466d

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprpthread-emulationqualifiedEnum

Last change on this file since 811466d was b6ad601, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago
start basetypeof, update loop control, remove unnecessary 0/1 check from parsing
Property mode set to `100644`
File size: 18.6 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 : Thu Nov 1 20:57:35 2018
13	* Update Count : 687
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 : "";
35	unsigned int column = 0; // position of the end of the last token parsed
36
37	#include <string>
38	#include <cstdio> // FILENAME_MAX
39	using namespace std;
40
41	#include "ParseNode.h"
42	#include "TypedefTable.h"
43
44	char *yyfilename;
45	string *strtext; // accumulate parts of character and string constant value
46
47	#define RETURN_LOCN(x) yylval.tok.loc.file = yyfilename; yylval.tok.loc.line = yylineno; return( x )
48	#define RETURN_VAL(x) yylval.tok.str = new string( yytext ); RETURN_LOCN( x )
49	#define RETURN_CHAR(x) yylval.tok.str = nullptr; RETURN_LOCN( x )
50	#define RETURN_STR(x) yylval.tok.str = strtext; RETURN_LOCN( x )
51
52	#define WHITE_RETURN(x) // do nothing
53	#define NEWLINE_RETURN() column = 0; WHITE_RETURN( '\n' )
54	#define ASCIIOP_RETURN() RETURN_CHAR( (int)yytext[0] ) // single character operator
55	#define NAMEDOP_RETURN(x) RETURN_CHAR( x ) // multichar operator, with a name
56	#define NUMERIC_RETURN(x) rm_underscore(); RETURN_VAL( x ) // numeric constant
57	#define KEYWORD_RETURN(x) RETURN_CHAR( x ) // keyword
58	#define QKEYWORD_RETURN(x) RETURN_VAL(x); // quasi-keyword
59	#define IDENTIFIER_RETURN() RETURN_VAL( typedefTable.isKind( yytext ) )
60	#define ATTRIBUTE_RETURN() RETURN_VAL( ATTR_IDENTIFIER )
61
62	void rm_underscore() {
63	// SKULLDUGGERY: remove underscores (ok to shorten?)
64	yyleng = 0;
65	for ( int i = 0; yytext[i] != '\0'; i += 1 ) { // copying non-underscore characters to front of string
66	if ( yytext[i] != '_' ) {
67	yytext[yyleng] = yytext[i];
68	yyleng += 1;
69	} // if
70	} // for
71	yytext[yyleng] = '\0';
72	} // rm_underscore
73
74	// Stop warning due to incorrectly generated flex code.
75	#pragma GCC diagnostic ignored "-Wsign-compare"
76	%}
77
78	binary [0-1]
79	octal [0-7]
80	nonzero [1-9]
81	decimal [0-9]
82	hex [0-9a-fA-F]
83	universal_char "\\"((u"_"?{hex_quad})\|(U"_"?{hex_quad}{2}))
84
85	// identifier, GCC: $ in identifier
86	identifier ([a-zA-Z_$]\|{universal_char})([0-9a-zA-Z_$]\|{universal_char})*
87
88	// attribute identifier, GCC: $ in identifier
89	attr_identifier "@"{identifier}
90
91	// numeric constants, CFA: '_' in constant
92	hex_quad {hex}("_"?{hex}){3}
93	size_opt (8\|16\|32\|64\|128)?
94	length ("ll"\|"LL"\|[lL]{size_opt})\|("hh"\|"HH"\|[hH])
95	integer_suffix_opt ("_"?(([uU]({length}?[iI]?)\|([iI]{length}))\|([iI]({length}?[uU]?)\|([uU]{length}))\|({length}([iI]?[uU]?)\|([uU][iI]))\|[zZ]))?
96
97	octal_digits ({octal})\|({octal}({octal}\|"_")*{octal})
98	octal_prefix "0""_"?
99	octal_constant (("0")\|({octal_prefix}{octal_digits})){integer_suffix_opt}
100
101	nonzero_digits ({nonzero})\|({nonzero}({decimal}\|"_")*{decimal})
102	decimal_constant {nonzero_digits}{integer_suffix_opt}
103
104	binary_digits ({binary})\|({binary}({binary}\|"_")*{binary})
105	binary_prefix "0"[bB]"_"?
106	binary_constant {binary_prefix}{binary_digits}{integer_suffix_opt}
107
108	hex_digits ({hex})\|({hex}({hex}\|"_")*{hex})
109	hex_prefix "0"[xX]"_"?
110	hex_constant {hex_prefix}{hex_digits}{integer_suffix_opt}
111
112	// GCC: D (double) and iI (imaginary) suffixes, and DL (long double)
113	exponent "_"?[eE]"_"?[+-]?{decimal_digits}
114	floating_size 32\|64\|80\|128
115	floating_length ([fFdDlL]\|[lL]{floating_size})
116	floating_suffix ({floating_length}?[iI]?)\|([iI]{floating_length})
117	floating_suffix_opt ("_"?({floating_suffix}\|"DL"))?
118	decimal_digits ({decimal})\|({decimal}({decimal}\|"_")*{decimal})
119	floating_decimal {decimal_digits}"."{exponent}?{floating_suffix_opt}
120	floating_fraction "."{decimal_digits}{exponent}?{floating_suffix_opt}
121	floating_constant ({decimal_digits}{exponent}{floating_suffix_opt})\|({decimal_digits}{floating_fraction})
122
123	binary_exponent "_"?[pP]"_"?[+-]?{decimal_digits}
124	hex_floating_suffix_opt ("_"?({floating_suffix}))?
125	hex_floating_fraction ({hex_digits}?"."{hex_digits})\|({hex_digits}".")
126	hex_floating_constant {hex_prefix}(({hex_floating_fraction}{binary_exponent})\|({hex_digits}{binary_exponent})){hex_floating_suffix_opt}
127
128	// character escape sequence, GCC: \e => esc character
129	simple_escape "\\"[abefnrtv'"?\\]
130	// ' stop editor highlighting
131	octal_escape "\\"{octal}("_"?{octal}){0,2}
132	hex_escape "\\""x""_"?{hex_digits}
133	escape_seq {simple_escape}\|{octal_escape}\|{hex_escape}\|{universal_char}
134	cwide_prefix "L"\|"U"\|"u"
135	swide_prefix {cwide_prefix}\|"u8"
136
137	// display/white-space characters
138	h_tab [\011]
139	form_feed [\014]
140	v_tab [\013]
141	c_return [\015]
142	h_white [ ]\|{h_tab}
143
144	// overloadable operators
145	op_unary_only "~"\|"!"
146	op_unary_binary "+"\|"-"\|"*"
147	op_unary_pre_post "++"\|"--"
148	op_unary {op_unary_only}\|{op_unary_binary}\|{op_unary_pre_post}
149
150	op_binary_only "/"\|"%"\|"\\"\|"^"\|"&"\|"\|"\|"<"\|">"\|"="\|"=="\|"!="\|"<<"\|">>"\|"<="\|">="\|"+="\|"-="\|"*="\|"/="\|"%="\|"\\="\|"&="\|"\|="\|"^="\|"<<="\|">>="
151	op_binary_over {op_unary_binary}\|{op_binary_only}
152	// op_binary_not_over "?"\|"->"\|"."\|"&&"\|"\|\|"\|"@="
153	// operator {op_unary_pre_post}\|{op_binary_over}\|{op_binary_not_over}
154
155	%x COMMENT
156	%x BKQUOTE
157	%x QUOTE
158	%x STRING
159
160	%%
161	/* line directives */
162	^{h_white}"#"{h_white}[0-9]+{h_white}["][^"\n]+["]."\n" {
163	/* " stop editor highlighting */
164	static char filename[FILENAME_MAX]; // temporarily store current source-file name
165	char *end_num;
166	char begin_string, end_string;
167	long lineno, length;
168	lineno = strtol( yytext + 1, &end_num, 0 );
169	begin_string = strchr( end_num, '"' );
170	if ( begin_string ) { // file name ?
171	end_string = strchr( begin_string + 1, '"' ); // look for ending delimiter
172	assert( end_string ); // closing quote ?
173	length = end_string - begin_string - 1; // file-name length without quotes or sentinel
174	assert( length < FILENAME_MAX ); // room for sentinel ?
175	memcpy( &filename, begin_string + 1, length ); // copy file name from yytext
176	filename[ length ] = '\0'; // terminate string with sentinel
177	//cout << "file " << filename << " line " << lineno << endl;
178	yylineno = lineno;
179	yyfilename = filename;
180	} // if
181	}
182
183	/* preprocessor-style directives */
184	^{h_white}"#"[^\n]"\n" { RETURN_VAL( DIRECTIVE ); }
185
186	/* ignore C style comments (ALSO HANDLED BY CPP) */
187	"/*" { BEGIN COMMENT; }
188	<COMMENT>.\|\n ;
189	<COMMENT>"*/" { BEGIN 0; }
190
191	/* ignore C++ style comments (ALSO HANDLED BY CPP) */
192	"//"[^\n]*"\n" ;
193
194	/* ignore whitespace */
195	{h_white}+ { WHITE_RETURN(' '); }
196	({v_tab}\|{c_return}\|{form_feed})+ { WHITE_RETURN(' '); }
197	({h_white}\|{v_tab}\|{c_return}\|{form_feed})*"\n" { NEWLINE_RETURN(); }
198
199	/* keywords */
200	_Alignas { KEYWORD_RETURN(ALIGNAS); } // C11
201	_Alignof { KEYWORD_RETURN(ALIGNOF); } // C11
202	__alignof { KEYWORD_RETURN(ALIGNOF); } // GCC
203	__alignof__ { KEYWORD_RETURN(ALIGNOF); } // GCC
204	asm { KEYWORD_RETURN(ASM); }
205	__asm { KEYWORD_RETURN(ASM); } // GCC
206	__asm__ { KEYWORD_RETURN(ASM); } // GCC
207	_Atomic { KEYWORD_RETURN(ATOMIC); } // C11
208	__attribute { KEYWORD_RETURN(ATTRIBUTE); } // GCC
209	__attribute__ { KEYWORD_RETURN(ATTRIBUTE); } // GCC
210	auto { KEYWORD_RETURN(AUTO); }
211	basetypeof { KEYWORD_RETURN(BASETYPEOF); } // CFA
212	_Bool { KEYWORD_RETURN(BOOL); } // C99
213	break { KEYWORD_RETURN(BREAK); }
214	case { KEYWORD_RETURN(CASE); }
215	catch { KEYWORD_RETURN(CATCH); } // CFA
216	catchResume { KEYWORD_RETURN(CATCHRESUME); } // CFA
217	char { KEYWORD_RETURN(CHAR); }
218	choose { KEYWORD_RETURN(CHOOSE); } // CFA
219	_Complex { KEYWORD_RETURN(COMPLEX); } // C99
220	__complex { KEYWORD_RETURN(COMPLEX); } // GCC
221	__complex__ { KEYWORD_RETURN(COMPLEX); } // GCC
222	const { KEYWORD_RETURN(CONST); }
223	__const { KEYWORD_RETURN(CONST); } // GCC
224	__const__ { KEYWORD_RETURN(CONST); } // GCC
225	continue { KEYWORD_RETURN(CONTINUE); }
226	coroutine { KEYWORD_RETURN(COROUTINE); } // CFA
227	default { KEYWORD_RETURN(DEFAULT); }
228	disable { KEYWORD_RETURN(DISABLE); } // CFA
229	do { KEYWORD_RETURN(DO); }
230	double { KEYWORD_RETURN(DOUBLE); }
231	dtype { KEYWORD_RETURN(DTYPE); } // CFA
232	else { KEYWORD_RETURN(ELSE); }
233	enable { KEYWORD_RETURN(ENABLE); } // CFA
234	enum { KEYWORD_RETURN(ENUM); }
235	__extension__ { KEYWORD_RETURN(EXTENSION); } // GCC
236	exception { KEYWORD_RETURN(EXCEPTION); } // CFA
237	extern { KEYWORD_RETURN(EXTERN); }
238	fallthrough { KEYWORD_RETURN(FALLTHROUGH); } // CFA
239	fallthru { KEYWORD_RETURN(FALLTHRU); } // CFA
240	finally { KEYWORD_RETURN(FINALLY); } // CFA
241	float { KEYWORD_RETURN(FLOAT); }
242	_Float32 { KEYWORD_RETURN(FLOAT); } // GCC
243	_Float32x { KEYWORD_RETURN(FLOAT); } // GCC
244	_Float64 { KEYWORD_RETURN(DOUBLE); } // GCC
245	_Float64x { KEYWORD_RETURN(DOUBLE); } // GCC
246	__float80 { KEYWORD_RETURN(FLOAT80); } // GCC
247	float80 { KEYWORD_RETURN(FLOAT80); } // GCC
248	_Float128 { KEYWORD_RETURN(FLOAT128); } // GCC
249	_Float128x { KEYWORD_RETURN(FLOAT128); } // GCC
250	__float128 { KEYWORD_RETURN(FLOAT128); } // GCC
251	float128 { KEYWORD_RETURN(FLOAT128); } // GCC
252	for { KEYWORD_RETURN(FOR); }
253	forall { KEYWORD_RETURN(FORALL); } // CFA
254	fortran { KEYWORD_RETURN(FORTRAN); }
255	ftype { KEYWORD_RETURN(FTYPE); } // CFA
256	_Generic { KEYWORD_RETURN(GENERIC); } // C11
257	goto { KEYWORD_RETURN(GOTO); }
258	if { KEYWORD_RETURN(IF); }
259	_Imaginary { KEYWORD_RETURN(IMAGINARY); } // C99
260	__imag { KEYWORD_RETURN(IMAGINARY); } // GCC
261	__imag__ { KEYWORD_RETURN(IMAGINARY); } // GCC
262	inline { KEYWORD_RETURN(INLINE); } // C99
263	__inline { KEYWORD_RETURN(INLINE); } // GCC
264	__inline__ { KEYWORD_RETURN(INLINE); } // GCC
265	int { KEYWORD_RETURN(INT); }
266	__int128 { KEYWORD_RETURN(INT128); } // GCC
267	int128 { KEYWORD_RETURN(INT128); } // GCC
268	__label__ { KEYWORD_RETURN(LABEL); } // GCC
269	long { KEYWORD_RETURN(LONG); }
270	monitor { KEYWORD_RETURN(MONITOR); } // CFA
271	mutex { KEYWORD_RETURN(MUTEX); } // CFA
272	_Noreturn { KEYWORD_RETURN(NORETURN); } // C11
273	__builtin_offsetof { KEYWORD_RETURN(OFFSETOF); } // GCC
274	one_t { NUMERIC_RETURN(ONE_T); } // CFA
275	or { QKEYWORD_RETURN(WOR); } // CFA
276	otype { KEYWORD_RETURN(OTYPE); } // CFA
277	register { KEYWORD_RETURN(REGISTER); }
278	restrict { KEYWORD_RETURN(RESTRICT); } // C99
279	__restrict { KEYWORD_RETURN(RESTRICT); } // GCC
280	__restrict__ { KEYWORD_RETURN(RESTRICT); } // GCC
281	return { KEYWORD_RETURN(RETURN); }
282	short { KEYWORD_RETURN(SHORT); }
283	signed { KEYWORD_RETURN(SIGNED); }
284	__signed { KEYWORD_RETURN(SIGNED); } // GCC
285	__signed__ { KEYWORD_RETURN(SIGNED); } // GCC
286	sizeof { KEYWORD_RETURN(SIZEOF); }
287	static { KEYWORD_RETURN(STATIC); }
288	_Static_assert { KEYWORD_RETURN(STATICASSERT); } // C11
289	struct { KEYWORD_RETURN(STRUCT); }
290	switch { KEYWORD_RETURN(SWITCH); }
291	thread { KEYWORD_RETURN(THREAD); } // C11
292	_Thread_local { KEYWORD_RETURN(THREADLOCAL); } // C11
293	throw { KEYWORD_RETURN(THROW); } // CFA
294	throwResume { KEYWORD_RETURN(THROWRESUME); } // CFA
295	timeout { QKEYWORD_RETURN(TIMEOUT); } // CFA
296	trait { KEYWORD_RETURN(TRAIT); } // CFA
297	try { KEYWORD_RETURN(TRY); } // CFA
298	ttype { KEYWORD_RETURN(TTYPE); } // CFA
299	typedef { KEYWORD_RETURN(TYPEDEF); }
300	typeof { KEYWORD_RETURN(TYPEOF); } // GCC
301	__typeof { KEYWORD_RETURN(TYPEOF); } // GCC
302	__typeof__ { KEYWORD_RETURN(TYPEOF); } // GCC
303	union { KEYWORD_RETURN(UNION); }
304	unsigned { KEYWORD_RETURN(UNSIGNED); }
305	__builtin_va_list { KEYWORD_RETURN(VALIST); } // GCC
306	virtual { KEYWORD_RETURN(VIRTUAL); } // CFA
307	void { KEYWORD_RETURN(VOID); }
308	volatile { KEYWORD_RETURN(VOLATILE); }
309	__volatile { KEYWORD_RETURN(VOLATILE); } // GCC
310	__volatile__ { KEYWORD_RETURN(VOLATILE); } // GCC
311	waitfor { KEYWORD_RETURN(WAITFOR); }
312	when { KEYWORD_RETURN(WHEN); }
313	while { KEYWORD_RETURN(WHILE); }
314	with { KEYWORD_RETURN(WITH); } // CFA
315	zero_t { NUMERIC_RETURN(ZERO_T); } // CFA
316
317	/* identifier */
318	{identifier} { IDENTIFIER_RETURN(); }
319	"`"{identifier}"`" { // CFA
320	yytext[yyleng - 1] = '\0'; yytext += 1; // SKULLDUGGERY: remove backquotes (ok to shorten?)
321	IDENTIFIER_RETURN();
322	}
323	{attr_identifier} { ATTRIBUTE_RETURN(); }
324
325	/* numeric constants */
326	{binary_constant} { NUMERIC_RETURN(INTEGERconstant); }
327	{octal_constant} { NUMERIC_RETURN(INTEGERconstant); }
328	{decimal_constant} { NUMERIC_RETURN(INTEGERconstant); }
329	{hex_constant} { NUMERIC_RETURN(INTEGERconstant); }
330	{floating_decimal} { NUMERIC_RETURN(FLOATING_DECIMALconstant); } // must appear before floating_constant
331	{floating_fraction} { NUMERIC_RETURN(FLOATING_FRACTIONconstant); } // must appear before floating_constant
332	{floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
333	{hex_floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
334
335	/* character constant, allows empty value */
336	({cwide_prefix}[_]?)?['] { BEGIN QUOTE; rm_underscore(); strtext = new string( yytext, yyleng ); }
337	<QUOTE>[^'\\\n]* { strtext->append( yytext, yyleng ); }
338	<QUOTE>['\n] { BEGIN 0; strtext->append( yytext, yyleng ); RETURN_STR(CHARACTERconstant); }
339	/* ' stop editor highlighting */
340
341	/* string constant */
342	({swide_prefix}[_]?)?["] { BEGIN STRING; rm_underscore(); strtext = new string( yytext, yyleng ); }
343	<STRING>[^"\\\n]* { strtext->append( yytext, yyleng ); }
344	<STRING>["\n] { BEGIN 0; strtext->append( yytext, yyleng ); RETURN_STR(STRINGliteral); }
345	/* " stop editor highlighting */
346
347	/* common character/string constant */
348	<QUOTE,STRING>{escape_seq} { rm_underscore(); strtext->append( yytext, yyleng ); }
349	<QUOTE,STRING>"\\"{h_white}*"\n" {} // continuation (ALSO HANDLED BY CPP)
350	<QUOTE,STRING>"\\" { strtext->append( yytext, yyleng ); } // unknown escape character
351
352	/* punctuation */
353	"@" { ASCIIOP_RETURN(); }
354	"`" { ASCIIOP_RETURN(); }
355	"[" { ASCIIOP_RETURN(); }
356	"]" { ASCIIOP_RETURN(); }
357	"(" { ASCIIOP_RETURN(); }
358	")" { ASCIIOP_RETURN(); }
359	"{" { ASCIIOP_RETURN(); }
360	"}" { ASCIIOP_RETURN(); }
361	"," { ASCIIOP_RETURN(); } // also operator
362	":" { ASCIIOP_RETURN(); }
363	";" { ASCIIOP_RETURN(); }
364	"." { ASCIIOP_RETURN(); } // also operator
365	"..." { NAMEDOP_RETURN(ELLIPSIS); }
366
367	/* alternative C99 brackets, "<:" & "<:<:" handled by preprocessor */
368	"<:" { RETURN_VAL('['); }
369	":>" { RETURN_VAL(']'); }
370	"<%" { RETURN_VAL('{'); }
371	"%>" { RETURN_VAL('}'); }
372
373	/* operators */
374	"!" { ASCIIOP_RETURN(); }
375	"+" { ASCIIOP_RETURN(); }
376	"-" { ASCIIOP_RETURN(); }
377	"*" { ASCIIOP_RETURN(); }
378	"\\" { ASCIIOP_RETURN(); } // CFA, exponentiation
379	"/" { ASCIIOP_RETURN(); }
380	"%" { ASCIIOP_RETURN(); }
381	"^" { ASCIIOP_RETURN(); }
382	"~" { ASCIIOP_RETURN(); }
383	"&" { ASCIIOP_RETURN(); }
384	"\|" { ASCIIOP_RETURN(); }
385	"<" { ASCIIOP_RETURN(); }
386	">" { ASCIIOP_RETURN(); }
387	"=" { ASCIIOP_RETURN(); }
388	"?" { ASCIIOP_RETURN(); }
389
390	"++" { NAMEDOP_RETURN(ICR); }
391	"--" { NAMEDOP_RETURN(DECR); }
392	"==" { NAMEDOP_RETURN(EQ); }
393	"!=" { NAMEDOP_RETURN(NE); }
394	"<<" { NAMEDOP_RETURN(LS); }
395	">>" { NAMEDOP_RETURN(RS); }
396	"<=" { NAMEDOP_RETURN(LE); }
397	">=" { NAMEDOP_RETURN(GE); }
398	"&&" { NAMEDOP_RETURN(ANDAND); }
399	"\|\|" { NAMEDOP_RETURN(OROR); }
400	"->" { NAMEDOP_RETURN(ARROW); }
401	"+=" { NAMEDOP_RETURN(PLUSassign); }
402	"-=" { NAMEDOP_RETURN(MINUSassign); }
403	"\\=" { NAMEDOP_RETURN(EXPassign); } // CFA, exponentiation
404	"*=" { NAMEDOP_RETURN(MULTassign); }
405	"/=" { NAMEDOP_RETURN(DIVassign); }
406	"%=" { NAMEDOP_RETURN(MODassign); }
407	"&=" { NAMEDOP_RETURN(ANDassign); }
408	"\|=" { NAMEDOP_RETURN(ORassign); }
409	"^=" { NAMEDOP_RETURN(ERassign); }
410	"<<=" { NAMEDOP_RETURN(LSassign); }
411	">>=" { NAMEDOP_RETURN(RSassign); }
412
413	"@=" { NAMEDOP_RETURN(ATassign); } // CFA
414	"~=" { NAMEDOP_RETURN(ErangeUpEq); } // CFA
415	"-~" { NAMEDOP_RETURN(ErangeDown); } // CFA
416	"-~=" { NAMEDOP_RETURN(ErangeDownEq); } // CFA
417
418	/* CFA, operator identifier */
419	{op_unary}"?" { IDENTIFIER_RETURN(); } // unary
420	"?"({op_unary_pre_post}\|"()"\|"[?]"\|"{}") { IDENTIFIER_RETURN(); }
421	"^?{}" { IDENTIFIER_RETURN(); }
422	"?`"{identifier} { IDENTIFIER_RETURN(); } // postfix operator
423	"?"{op_binary_over}"?" { IDENTIFIER_RETURN(); } // binary
424	/*
425	This rule handles ambiguous cases with operator identifiers, e.g., "int ??()", where the string "??" can be
426	lexed as "?"/"?" or ""/"??". Since it is common practise to put a unary operator juxtaposed to an identifier,
427	e.g., "*i", users will be annoyed if they cannot do this with respect to operator identifiers. Therefore, there is
428	a lexical look-ahead for the second case, with backtracking to return the leading unary operator and then
429	reparsing the trailing operator identifier. Otherwise a space is needed between the unary operator and operator
430	identifier to disambiguate this common case.
431
432	A similar issue occurs with the dereference, *?(...), and routine-call, ?()(...) identifiers. The ambiguity
433	occurs when the deference operator has no parameters, ?() and ?()(...), requiring arbitrary whitespace
434	look-ahead for the routine-call parameter-list to disambiguate. However, the dereference operator must have a
435	parameter/argument to dereference ?(...). Hence, always interpreting the string ?() as * ?() does not preclude
436	any meaningful program.
437
438	The remaining cases are with the increment/decrement operators and conditional expression:
439
440	i++? ...(...);
441	i?++ ...(...);
442
443	requiring arbitrary whitespace look-ahead for the operator parameter-list, even though that interpretation is an
444	incorrect expression (juxtaposed identifiers). Therefore, it is necessary to disambiguate these cases with a
445	space:
446
447	i++ ? i : 0;
448	i? ++i : 0;
449	*/
450	{op_unary}"?"({op_unary_pre_post}\|"()"\|"[?]"\|{op_binary_over}"?") {
451	// 1 or 2 character unary operator ?
452	int i = yytext[1] == '?' ? 1 : 2;
453	yyless( i ); // put back characters up to first '?'
454	if ( i > 1 ) {
455	NAMEDOP_RETURN( yytext[0] == '+' ? ICR : DECR );
456	} else {
457	ASCIIOP_RETURN();
458	} // if
459	}
460
461	/* unknown character */
462	. { yyerror( "unknown character" ); }
463
464	%%
465
466	// ----end of lexer----
467
468	void yyerror( const char * errmsg ) {
469	SemanticErrorThrow = true;
470	cerr << (yyfilename ? yyfilename : "unknown file") << ':' << yylineno << ':' << column - yyleng + 1
471	<< ": " << ErrorHelpers::error_str() << errmsg << " at token \"" << (yytext[0] == '\0' ? "EOF" : yytext) << '"' << endl;
472	}
473
474	// Local Variables: //
475	// mode: c++ //
476	// tab-width: 4 //
477	// compile-command: "make install" //
478	// End: //

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