Context Navigation

lex.ll @ bdad1679

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsctordeferred_resndemanglerenumforall-pointer-decaygc_noraiijacob/cs343-translationjenkins-sandboxmemorynew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newstringwith_gc

Last change on this file since bdad1679 was 90c3b1c, checked in by Peter A. Buhr <pabuhr@…>, 8 years ago
compile CFA with C++11, further update refrat with lstlisting macros, support varags, enumeration initialization, add implicit separators to output streams, update example programs that print
Property mode set to `100644`
File size: 15.2 KB

Rev	Line
[b87a5ed]	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.
[51b7345]	6	*
	7	* lex.l --
	8	*
	9	* Author : Peter A. Buhr
	10	* Created On : Sat Sep 22 08:58:10 2001
	11	* Last Modified By : Peter A. Buhr
[90c3b1c]	12	* Last Modified On : Thu Feb 25 16:18:14 2016
	13	* Update Count : 427
[51b7345]	14	*/
	15
	16	%option yylineno
[5f2f2d7]	17	%option nounput
[51b7345]	18
	19	%{
[de62360d]	20	// This lexer assumes the program has been preprocessed by cpp. Hence, all user level preprocessor directive have been
	21	// performed and removed from the source. The only exceptions are preprocessor directives passed to the compiler (e.g.,
	22	// line-number directives) and C/C++ style comments, which are ignored.
[51b7345]	23
[8c17ab0]	24	//************************** Includes and Defines **************************
[51b7345]	25
	26	#include <string>
	27
	28	#include "lex.h"
	29	#include "ParseNode.h"
[59db689]	30	#include "parser.h" // YACC generated definitions based on C++ grammar
[51b7345]	31
	32	char *yyfilename;
[b87a5ed]	33	std::string *strtext; // accumulate parts of character and string constant value
[51b7345]	34
[de62360d]	35	#define RETURN_LOCN(x) yylval.tok.loc.file = yyfilename; yylval.tok.loc.line = yylineno; return( x )
	36	#define RETURN_VAL(x) yylval.tok.str = new std::string( yytext ); RETURN_LOCN( x )
	37	#define RETURN_CHAR(x) yylval.tok.str = NULL; RETURN_LOCN( x )
	38	#define RETURN_STR(x) yylval.tok.str = strtext; RETURN_LOCN( x )
[5f2f2d7]	39
[b87a5ed]	40	#define WHITE_RETURN(x) // do nothing
[de62360d]	41	#define NEWLINE_RETURN() WHITE_RETURN( '\n' )
	42	#define ASCIIOP_RETURN() RETURN_CHAR( (int)yytext[0] ) // single character operator
	43	#define NAMEDOP_RETURN(x) RETURN_VAL( x ) // multichar operator, with a name
	44	#define NUMERIC_RETURN(x) rm_underscore(); RETURN_VAL( x ) // numeric constant
	45	#define KEYWORD_RETURN(x) RETURN_CHAR( x ) // keyword
	46	#define IDENTIFIER_RETURN() RETURN_VAL( (typedefTable.isIdentifier( yytext ) ? IDENTIFIER : typedefTable.isTypedef( yytext ) ? TYPEDEFname : TYPEGENname ) )
	47	#define ATTRIBUTE_RETURN() RETURN_VAL( ATTR_IDENTIFIER )
[51b7345]	48
[3848e0e]	49	void rm_underscore() {
[b87a5ed]	50	// remove underscores in numeric constant
	51	int j = 0;
	52	for ( int i = 0; yytext[i] != '\0'; i += 1 ) {
	53	if ( yytext[i] != '_' ) {
	54	yytext[j] = yytext[i];
	55	j += 1;
	56	} // if
	57	} // for
	58	yyleng = j;
	59	yytext[yyleng] = '\0';
[51b7345]	60	}
	61
	62	%}
	63
	64	octal [0-7]
	65	nonzero [1-9]
	66	decimal [0-9]
	67	hex [0-9a-fA-F]
[3848e0e]	68	universal_char "\\"((u"_"?{hex_quad})\|(U"_"?{hex_quad}{2}))
[51b7345]	69
[b87a5ed]	70	// identifier, GCC: $ in identifier
[51b7345]	71	identifier ([a-zA-Z_$]\|{universal_char})([0-9a-zA-Z_$]\|{universal_char})*
	72
[b87a5ed]	73	// quoted identifier
[8c17ab0]	74	quoted_identifier "`"{identifier}"`"
	75
[b87a5ed]	76	// attribute identifier, GCC: $ in identifier
[51b7345]	77	attr_identifier "@"{identifier}
	78
[b87a5ed]	79	// numeric constants, CFA: '_' in constant
[3848e0e]	80	hex_quad {hex}("_"?{hex}){3}
[51b7345]	81	integer_suffix "_"?(([uU][lL]?)\|([uU]("ll"\|"LL")?)\|([lL][uU]?)\|("ll"\|"LL")[uU]?)
	82
	83	octal_digits ({octal})\|({octal}({octal}\|"_")*{octal})
	84	octal_prefix "0""_"?
	85	octal_constant (("0")\|({octal_prefix}{octal_digits})){integer_suffix}?
	86
	87	nonzero_digits ({nonzero})\|({nonzero}({decimal}\|"_")*{decimal})
	88	decimal_constant {nonzero_digits}{integer_suffix}?
	89
	90	hex_digits ({hex})\|({hex}({hex}\|"_")*{hex})
	91	hex_prefix "0"[xX]"_"?
	92	hex_constant {hex_prefix}{hex_digits}{integer_suffix}?
	93
	94	decimal_digits ({decimal})\|({decimal}({decimal}\|"_")*{decimal})
	95	fractional_constant ({decimal_digits}?"."{decimal_digits})\|({decimal_digits}".")
	96	exponent "_"?[eE]"_"?[+-]?{decimal_digits}
[7ee14bb7]	97	// GCC: D (double), LD (long double) and iI (imaginary) suffixes
[5721a6d]	98	floating_suffix "_"?([fFdD]?\|([lL]?)\|([iI][lLfFdD]?)\|([lLfFdD][iI]))
[51b7345]	99	floating_constant (({fractional_constant}{exponent}?)\|({decimal_digits}{exponent})){floating_suffix}?
	100
	101	binary_exponent "_"?[pP]"_"?[+-]?{decimal_digits}
	102	hex_fractional_constant ({hex_digits}?"."{hex_digits})\|({hex_digits}".")
	103	hex_floating_constant {hex_prefix}(({hex_fractional_constant}{binary_exponent})\|({hex_digits}{binary_exponent})){floating_suffix}?
	104
[b87a5ed]	105	// character escape sequence, GCC: \e => esc character
[51b7345]	106	simple_escape "\\"[abefnrtv'"?\\]
[b87a5ed]	107	// ' stop highlighting
[3848e0e]	108	octal_escape "\\"{octal}("_"?{octal}){0,2}
	109	hex_escape "\\""x""_"?{hex_digits}
[51b7345]	110	escape_seq {simple_escape}\|{octal_escape}\|{hex_escape}\|{universal_char}
[59db689]	111	cwide_prefix "L"\|"U"\|"u"
	112	swide_prefix {cwide_prefix}\|"u8"
[51b7345]	113
[b87a5ed]	114	// display/white-space characters
[51b7345]	115	h_tab [\011]
	116	form_feed [\014]
	117	v_tab [\013]
	118	c_return [\015]
	119	h_white [ ]\|{h_tab}
	120
[b87a5ed]	121	// operators
[51b7345]	122	op_unary_only "~"\|"!"
	123	op_unary_binary "+"\|"-"\|"*"
	124	op_unary_pre_post "++"\|"--"
	125	op_unary {op_unary_only}\|{op_unary_binary}\|{op_unary_pre_post}
	126
	127	op_binary_only "/"\|"%"\|"^"\|"&"\|"\|"\|"<"\|">"\|"="\|"=="\|"!="\|"<<"\|">>"\|"<="\|">="\|"+="\|"-="\|"*="\|"/="\|"%="\|"&="\|"\|="\|"^="\|"<<="\|">>="
	128	op_binary_over {op_unary_binary}\|{op_binary_only}
	129	op_binary_not_over "?"\|"->"\|"&&"\|"\|\|"
	130	operator {op_unary_pre_post}\|{op_binary_over}\|{op_binary_not_over}
	131
	132	%x COMMENT
[3848e0e]	133	%x BKQUOTE
	134	%x QUOTE
	135	%x STRING
[51b7345]	136
	137	%%
[b87a5ed]	138	/* line directives */
[51b7345]	139	^{h_white}"#"{h_white}[0-9]+{h_white}["][^"\n]+["][^\n]"\n" {
[8c17ab0]	140	/* " stop highlighting */
[51b7345]	141	char *end_num;
	142	char begin_string, end_string;
	143	char *filename;
	144	long lineno, length;
	145	lineno = strtol( yytext + 1, &end_num, 0 );
	146	begin_string = strchr( end_num, '"' );
[3848e0e]	147	if ( begin_string ) {
[b87a5ed]	148	end_string = strchr( begin_string + 1, '"' );
	149	if ( end_string ) {
	150	length = end_string - begin_string - 1;
	151	filename = new char[ length + 1 ];
	152	memcpy( filename, begin_string + 1, length );
	153	filename[ length ] = '\0';
	154	//std::cout << "file " << filename << " line " << lineno << std::endl;
	155	yylineno = lineno;
	156	yyfilename = filename;
	157	} // if
	158	} // if
[51b7345]	159	}
	160
[b87a5ed]	161	/* ignore preprocessor directives (for now) */
[51b7345]	162	^{h_white}"#"[^\n]"\n" ;
	163
[cd623a4]	164	/* ignore C style comments (ALSO HANDLED BY CPP) */
[3848e0e]	165	"/*" { BEGIN COMMENT; }
[cd623a4]	166	<COMMENT>.\|\n ;
	167	<COMMENT>"*/" { BEGIN 0; }
[51b7345]	168
[cd623a4]	169	/* ignore C++ style comments (ALSO HANDLED BY CPP) */
	170	"//"[^\n]*"\n" ;
[51b7345]	171
[b87a5ed]	172	/* ignore whitespace */
[3848e0e]	173	{h_white}+ { WHITE_RETURN(' '); }
	174	({v_tab}\|{c_return}\|{form_feed})+ { WHITE_RETURN(' '); }
	175	({h_white}\|{v_tab}\|{c_return}\|{form_feed})*"\n" { NEWLINE_RETURN(); }
[51b7345]	176
[b87a5ed]	177	/* keywords */
	178	_Alignas { KEYWORD_RETURN(ALIGNAS); } // C11
	179	_Alignof { KEYWORD_RETURN(ALIGNOF); } // C11
	180	__alignof { KEYWORD_RETURN(ALIGNOF); } // GCC
	181	__alignof__ { KEYWORD_RETURN(ALIGNOF); } // GCC
	182	asm { KEYWORD_RETURN(ASM); }
	183	__asm { KEYWORD_RETURN(ASM); } // GCC
	184	__asm__ { KEYWORD_RETURN(ASM); } // GCC
[02e5ab6]	185	_At { KEYWORD_RETURN(AT); } // CFA
[b87a5ed]	186	_Atomic { KEYWORD_RETURN(ATOMIC); } // C11
	187	__attribute { KEYWORD_RETURN(ATTRIBUTE); } // GCC
	188	__attribute__ { KEYWORD_RETURN(ATTRIBUTE); } // GCC
[3848e0e]	189	auto { KEYWORD_RETURN(AUTO); }
[b87a5ed]	190	_Bool { KEYWORD_RETURN(BOOL); } // C99
[3848e0e]	191	break { KEYWORD_RETURN(BREAK); }
	192	case { KEYWORD_RETURN(CASE); }
[b87a5ed]	193	catch { KEYWORD_RETURN(CATCH); } // CFA
[02e5ab6]	194	catchResume { KEYWORD_RETURN(CATCHRESUME); } // CFA
[3848e0e]	195	char { KEYWORD_RETURN(CHAR); }
[b87a5ed]	196	choose { KEYWORD_RETURN(CHOOSE); } // CFA
	197	_Complex { KEYWORD_RETURN(COMPLEX); } // C99
	198	__complex { KEYWORD_RETURN(COMPLEX); } // GCC
	199	__complex__ { KEYWORD_RETURN(COMPLEX); } // GCC
[3848e0e]	200	const { KEYWORD_RETURN(CONST); }
[b87a5ed]	201	__const { KEYWORD_RETURN(CONST); } // GCC
	202	__const__ { KEYWORD_RETURN(CONST); } // GCC
	203	context { KEYWORD_RETURN(CONTEXT); } // CFA
[3848e0e]	204	continue { KEYWORD_RETURN(CONTINUE); }
	205	default { KEYWORD_RETURN(DEFAULT); }
[02e5ab6]	206	disable { KEYWORD_RETURN(DISABLE); } // CFA
[b87a5ed]	207	do { KEYWORD_RETURN(DO); }
[3848e0e]	208	double { KEYWORD_RETURN(DOUBLE); }
[b87a5ed]	209	dtype { KEYWORD_RETURN(DTYPE); } // CFA
[3848e0e]	210	else { KEYWORD_RETURN(ELSE); }
[02e5ab6]	211	enable { KEYWORD_RETURN(ENABLE); } // CFA
[3848e0e]	212	enum { KEYWORD_RETURN(ENUM); }
[b87a5ed]	213	__extension__ { KEYWORD_RETURN(EXTENSION); } // GCC
[3848e0e]	214	extern { KEYWORD_RETURN(EXTERN); }
[b87a5ed]	215	fallthru { KEYWORD_RETURN(FALLTHRU); } // CFA
	216	finally { KEYWORD_RETURN(FINALLY); } // CFA
[3848e0e]	217	float { KEYWORD_RETURN(FLOAT); }
[b87a5ed]	218	__float128 { KEYWORD_RETURN(FLOAT); } // GCC
	219	for { KEYWORD_RETURN(FOR); }
	220	forall { KEYWORD_RETURN(FORALL); } // CFA
[3848e0e]	221	fortran { KEYWORD_RETURN(FORTRAN); }
[b87a5ed]	222	ftype { KEYWORD_RETURN(FTYPE); } // CFA
	223	_Generic { KEYWORD_RETURN(GENERIC); } // C11
[3848e0e]	224	goto { KEYWORD_RETURN(GOTO); }
[b87a5ed]	225	if { KEYWORD_RETURN(IF); }
	226	_Imaginary { KEYWORD_RETURN(IMAGINARY); } // C99
	227	__imag { KEYWORD_RETURN(IMAGINARY); } // GCC
	228	__imag__ { KEYWORD_RETURN(IMAGINARY); } // GCC
	229	inline { KEYWORD_RETURN(INLINE); } // C99
	230	__inline { KEYWORD_RETURN(INLINE); } // GCC
	231	__inline__ { KEYWORD_RETURN(INLINE); } // GCC
	232	int { KEYWORD_RETURN(INT); }
	233	__int128 { KEYWORD_RETURN(INT); } // GCC
	234	__label__ { KEYWORD_RETURN(LABEL); } // GCC
[3848e0e]	235	long { KEYWORD_RETURN(LONG); }
[b87a5ed]	236	lvalue { KEYWORD_RETURN(LVALUE); } // CFA
	237	_Noreturn { KEYWORD_RETURN(NORETURN); } // C11
[5721a6d]	238	__builtin_offsetof { KEYWORD_RETURN(OFFSETOF); } // GCC
[3848e0e]	239	register { KEYWORD_RETURN(REGISTER); }
[b87a5ed]	240	restrict { KEYWORD_RETURN(RESTRICT); } // C99
	241	__restrict { KEYWORD_RETURN(RESTRICT); } // GCC
	242	__restrict__ { KEYWORD_RETURN(RESTRICT); } // GCC
[3848e0e]	243	return { KEYWORD_RETURN(RETURN); }
	244	short { KEYWORD_RETURN(SHORT); }
	245	signed { KEYWORD_RETURN(SIGNED); }
[b87a5ed]	246	__signed { KEYWORD_RETURN(SIGNED); } // GCC
	247	__signed__ { KEYWORD_RETURN(SIGNED); } // GCC
[3848e0e]	248	sizeof { KEYWORD_RETURN(SIZEOF); }
	249	static { KEYWORD_RETURN(STATIC); }
[b87a5ed]	250	_Static_assert { KEYWORD_RETURN(STATICASSERT); } // C11
[3848e0e]	251	struct { KEYWORD_RETURN(STRUCT); }
	252	switch { KEYWORD_RETURN(SWITCH); }
[b87a5ed]	253	_Thread_local { KEYWORD_RETURN(THREADLOCAL); } // C11
	254	throw { KEYWORD_RETURN(THROW); } // CFA
[02e5ab6]	255	throwResume { KEYWORD_RETURN(THROWRESUME); } // CFA
[b87a5ed]	256	try { KEYWORD_RETURN(TRY); } // CFA
	257	type { KEYWORD_RETURN(TYPE); } // CFA
[3848e0e]	258	typedef { KEYWORD_RETURN(TYPEDEF); }
[b87a5ed]	259	typeof { KEYWORD_RETURN(TYPEOF); } // GCC
	260	__typeof { KEYWORD_RETURN(TYPEOF); } // GCC
	261	__typeof__ { KEYWORD_RETURN(TYPEOF); } // GCC
[3848e0e]	262	union { KEYWORD_RETURN(UNION); }
	263	unsigned { KEYWORD_RETURN(UNSIGNED); }
[90c3b1c]	264	__builtin_va_list { KEYWORD_RETURN(VALIST); } // GCC
[3848e0e]	265	void { KEYWORD_RETURN(VOID); }
	266	volatile { KEYWORD_RETURN(VOLATILE); }
[b87a5ed]	267	__volatile { KEYWORD_RETURN(VOLATILE); } // GCC
	268	__volatile__ { KEYWORD_RETURN(VOLATILE); } // GCC
[3848e0e]	269	while { KEYWORD_RETURN(WHILE); }
[51b7345]	270
[b87a5ed]	271	/* identifier */
	272	{identifier} { IDENTIFIER_RETURN(); }
	273	{attr_identifier} { ATTRIBUTE_RETURN(); }
[3848e0e]	274	"`" { BEGIN BKQUOTE; }
[b87a5ed]	275	<BKQUOTE>{identifier} { IDENTIFIER_RETURN(); }
	276	<BKQUOTE>"`" { BEGIN 0; }
[51b7345]	277
[b87a5ed]	278	/* numeric constants */
	279	"0" { NUMERIC_RETURN(ZERO); } // CFA
	280	"1" { NUMERIC_RETURN(ONE); } // CFA
[59db689]	281	{decimal_constant} { NUMERIC_RETURN(INTEGERconstant); }
	282	{octal_constant} { NUMERIC_RETURN(INTEGERconstant); }
	283	{hex_constant} { NUMERIC_RETURN(INTEGERconstant); }
[3848e0e]	284	{floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
	285	{hex_floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
[51b7345]	286
[b87a5ed]	287	/* character constant, allows empty value */
[59db689]	288	({cwide_prefix}[_]?)?['] { BEGIN QUOTE; rm_underscore(); strtext = new std::string; *strtext += std::string( yytext ); }
[b87a5ed]	289	<QUOTE>[^'\\\n]* { *strtext += std::string( yytext ); }
	290	<QUOTE>['\n] { BEGIN 0; *strtext += std::string( yytext); RETURN_STR(CHARACTERconstant); }
	291	/* ' stop highlighting */
[51b7345]	292
[b87a5ed]	293	/* string constant */
[59db689]	294	({swide_prefix}[_]?)?["] { BEGIN STRING; rm_underscore(); strtext = new std::string; *strtext += std::string( yytext ); }
[b87a5ed]	295	<STRING>[^"\\\n]* { *strtext += std::string( yytext ); }
[59db689]	296	<STRING>["\n] { BEGIN 0; *strtext += std::string( yytext ); RETURN_STR(STRINGliteral); }
[b87a5ed]	297	/* " stop highlighting */
[51b7345]	298
[59db689]	299	/* common character/string constant */
[3848e0e]	300	<QUOTE,STRING>{escape_seq} { rm_underscore(); *strtext += std::string( yytext ); }
[cd623a4]	301	<QUOTE,STRING>"\\"{h_white}*"\n" {} // continuation (ALSO HANDLED BY CPP)
[59db689]	302	<QUOTE,STRING>"\\" { *strtext += std::string( yytext ); } // unknown escape character
[3848e0e]	303
[b87a5ed]	304	/* punctuation */
	305	"[" { ASCIIOP_RETURN(); }
	306	"]" { ASCIIOP_RETURN(); }
	307	"(" { ASCIIOP_RETURN(); }
	308	")" { ASCIIOP_RETURN(); }
	309	"{" { ASCIIOP_RETURN(); }
	310	"}" { ASCIIOP_RETURN(); }
	311	"," { ASCIIOP_RETURN(); } // also operator
	312	":" { ASCIIOP_RETURN(); }
	313	";" { ASCIIOP_RETURN(); }
	314	"." { ASCIIOP_RETURN(); } // also operator
[3848e0e]	315	"..." { NAMEDOP_RETURN(ELLIPSIS); }
	316
[b87a5ed]	317	/* alternative C99 brackets, "<:" & "<:<:" handled by preprocessor */
[3848e0e]	318	"<:" { RETURN_VAL('['); }
	319	":>" { RETURN_VAL(']'); }
	320	"<%" { RETURN_VAL('{'); }
	321	"%>" { RETURN_VAL('}'); }
[51b7345]	322
[b87a5ed]	323	/* operators */
	324	"!" { ASCIIOP_RETURN(); }
	325	"+" { ASCIIOP_RETURN(); }
	326	"-" { ASCIIOP_RETURN(); }
	327	"*" { ASCIIOP_RETURN(); }
	328	"/" { ASCIIOP_RETURN(); }
	329	"%" { ASCIIOP_RETURN(); }
	330	"^" { ASCIIOP_RETURN(); }
	331	"~" { ASCIIOP_RETURN(); }
	332	"&" { ASCIIOP_RETURN(); }
	333	"\|" { ASCIIOP_RETURN(); }
	334	"<" { ASCIIOP_RETURN(); }
	335	">" { ASCIIOP_RETURN(); }
	336	"=" { ASCIIOP_RETURN(); }
	337	"?" { ASCIIOP_RETURN(); }
[3848e0e]	338
	339	"++" { NAMEDOP_RETURN(ICR); }
	340	"--" { NAMEDOP_RETURN(DECR); }
	341	"==" { NAMEDOP_RETURN(EQ); }
	342	"!=" { NAMEDOP_RETURN(NE); }
	343	"<<" { NAMEDOP_RETURN(LS); }
	344	">>" { NAMEDOP_RETURN(RS); }
	345	"<=" { NAMEDOP_RETURN(LE); }
	346	">=" { NAMEDOP_RETURN(GE); }
	347	"&&" { NAMEDOP_RETURN(ANDAND); }
	348	"\|\|" { NAMEDOP_RETURN(OROR); }
	349	"->" { NAMEDOP_RETURN(ARROW); }
	350	"+=" { NAMEDOP_RETURN(PLUSassign); }
	351	"-=" { NAMEDOP_RETURN(MINUSassign); }
	352	"*=" { NAMEDOP_RETURN(MULTassign); }
	353	"/=" { NAMEDOP_RETURN(DIVassign); }
	354	"%=" { NAMEDOP_RETURN(MODassign); }
	355	"&=" { NAMEDOP_RETURN(ANDassign); }
	356	"\|=" { NAMEDOP_RETURN(ORassign); }
	357	"^=" { NAMEDOP_RETURN(ERassign); }
	358	"<<=" { NAMEDOP_RETURN(LSassign); }
	359	">>=" { NAMEDOP_RETURN(RSassign); }
[51b7345]	360
[097e2b0]	361	"@=" { NAMEDOP_RETURN(ATassign); }
	362
[b87a5ed]	363	/* CFA, operator identifier */
	364	{op_unary}"?" { IDENTIFIER_RETURN(); } // unary
[a61fea9a]	365	"?"({op_unary_pre_post}\|"()"\|"[?]"\|"{}") { IDENTIFIER_RETURN(); }
[02e5ab6]	366	"^?{}" { IDENTIFIER_RETURN(); }
[b87a5ed]	367	"?"{op_binary_over}"?" { IDENTIFIER_RETURN(); } // binary
[51b7345]	368	/*
[b87a5ed]	369	This rule handles ambiguous cases with operator identifiers, e.g., "int ??()", where the string "??"
	370	can be lexed as ""/"??" or "?"/"?". Since it is common practise to put a unary operator juxtaposed
	371	to an identifier, e.g., "*i", users will be annoyed if they cannot do this with respect to operator
	372	identifiers. Even with this special hack, there are 5 general cases that cannot be handled. The first
	373	case is for the function-call identifier "?()":
[51b7345]	374
	375	int * ?()(); // declaration: space required after '*'
	376	* ?()(); // expression: space required after '*'
	377
[b87a5ed]	378	Without the space, the string "*?()" is ambiguous without N character look ahead; it requires scanning
	379	ahead to determine if there is a '(', which is the start of an argument/parameter list.
[51b7345]	380
	381	The 4 remaining cases occur in expressions:
	382
	383	i++?i:0; // space required before '?'
	384	i--?i:0; // space required before '?'
	385	i?++i:0; // space required after '?'
	386	i?--i:0; // space required after '?'
	387
[b87a5ed]	388	In the first two cases, the string "i++?" is ambiguous, where this string can be lexed as "i"/"++?" or
	389	"i++"/"?"; it requires scanning ahead to determine if there is a '(', which is the start of an argument
	390	list. In the second two cases, the string "?++x" is ambiguous, where this string can be lexed as
	391	"?++"/"x" or "?"/"++x"; it requires scanning ahead to determine if there is a '(', which is the start of
	392	an argument list.
[51b7345]	393	*/
[02e5ab6]	394	{op_unary}"?"({op_unary_pre_post}\|"[?]"\|{op_binary_over}"?") {
[b87a5ed]	395	// 1 or 2 character unary operator ?
	396	int i = yytext[1] == '?' ? 1 : 2;
	397	yyless( i ); // put back characters up to first '?'
	398	if ( i > 1 ) {
	399	NAMEDOP_RETURN( yytext[0] == '+' ? ICR : DECR );
	400	} else {
	401	ASCIIOP_RETURN();
	402	} // if
	403	}
	404
	405	/* unknown characters */
[3848e0e]	406	. { printf("unknown character(s):\"%s\" on line %d\n", yytext, yylineno); }
[51b7345]	407
	408	%%
	409
[b87a5ed]	410	// Local Variables: //
	411	// mode: c++ //
[de62360d]	412	// tab-width: 4 //
[b87a5ed]	413	// compile-command: "make install" //
	414	// End: //

Note: See TracBrowser for help on using the repository browser.

Download in other formats:

Original Format