path: root/src/scanner.l

%{
/*===========================================================================
 Copyright (c) 1998-2000, The Santa Cruz Operation 
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

 *Redistributions of source code must retain the above copyright notice,
 this list of conditions and the following disclaimer.

 *Redistributions in binary form must reproduce the above copyright notice,
 this list of conditions and the following disclaimer in the documentation
 and/or other materials provided with the distribution.

 *Neither name of The Santa Cruz Operation nor the names of its contributors
 may be used to endorse or promote products derived from this software
 without specific prior written permission. 

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
 IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 DAMAGE. 
 =========================================================================*/

/*	cscope - interactive C symbol cross-reference
 *
 *	C symbol scanner
 */
#include "global.h"
#include "scanner.h"
#include "lookup.h"

/* the line counting has been moved from character reading for speed */
/* comments are discarded */

#define	IFLEVELINC	5	/* #if nesting level size increment */

static char const rcsid[] = "$Id: scanner.l,v 1.8 2007/03/09 23:54:34 broeker Exp $";

int	first;	/* buffer index for first char of symbol */
int	last;	/* buffer index for last char of symbol */
int	lineno;	/* symbol line number */
int	myylineno = 1;

static	BOOL	arraydimension;		/* inside array dimension declaration */
static	BOOL	bplisting;		/* breakpoint listing */
static	int	braces;			/* unmatched left brace count */
static	BOOL	classdef;		/* c++ class definition */
static	BOOL	elseelif;		/* #else or #elif found */
static	BOOL	esudef;			/* enum/struct/union global definition */
static	BOOL	external;		/* external definition */
static	int	externalbraces;		/* external definition outer brace count */
static	BOOL	fcndef;			/* function definition */
static	BOOL	global;			/* file global scope (outside functions) */
static	int	iflevel;		/* #if nesting level */
static	BOOL	initializer;		/* data initializer */
static	int	initializerbraces;	/* data initializer outer brace count */
static	BOOL	lex;			/* lex file */
static	int	miflevel = IFLEVELINC;	/* maximum #if nesting level */
static	int	*maxifbraces;		/* maximum brace count within #if */
static	int	*preifbraces;		/* brace count before #if */
static	int	parens;			/* unmatched left parenthesis count */
static	BOOL	ppdefine;		/* preprocessor define statement */
static	BOOL	pseudoelif;		/* pseudo-#elif */
static	BOOL	oldtype;		/* next identifier is an old type */
static	BOOL	rules;			/* lex/yacc rules */
static	BOOL	sdl;			/* sdl file */
static	BOOL	structfield;		/* structure field declaration */
static	int	tagdef;			/* class/enum/struct/union tag definition */
static	BOOL	template;		/* function template */
static	int	templateparens;		/* function template outer parentheses count */
static	int	typedefbraces = -1;	/* initial typedef brace count */
static	int	token;			/* token found */


void	multicharconstant(char terminator);
int	skipcomment_input(void);
int	comment(void);

#ifdef FLEX_SCANNER
#define YY_INPUT(buf,result,max_size) \
	{\
		int c = skipcomment_input (); \
		result = (c == EOF) ? YY_NULL : (buf[0] = c, 1); \
	}
#else
/* Assume this is the AT&T/SCO style lex */
#undef	input
#define input()  ((yytchar=(yytchar=yysptr>yysbuf?*(unsigned char *)--yysptr:getc(yyin))=='/'?comment():yytchar)==EOF?LEXEOF:yytchar)
#define noncommentinput()  ((yytchar=yysptr>yysbuf?*--yysptr:getc(yyin))==EOF?LEXEOF:yytchar)
#undef	unput
#define unput(c) (*yysptr++=(c))

#endif

%}

ws		[ \t\r\v\f]
wsnl		[ \t\r\v\f\n]
identifier	[a-zA-Z_$][a-zA-Z_0-9$]*
number		\.?[0-9][.0-9a-fA-FlLuUxX]*

%start SDL
%a 12000
%o 7000
%%
%\{		{	/* lex/yacc C declarations/definitions */
			global = YES;
			goto more;
			/* NOTREACHED */
		}
%\}		{
			global = NO;
			goto more;
			/* NOTREACHED */
		}
^%%		{	/* lex/yacc rules delimiter */
			braces = 0;
			if (rules == NO) {
				rules = YES;
				
				/* simulate a yylex() or yyparse() definition */
				(void) strcat(yytext, " /* ");
				first = strlen(yytext);
				if (lex == YES) {
					(void) strcat(yytext, "yylex");
				}
				else {	/* yacc: yyparse implicitly calls yylex */
					char *s = " yylex()";
					char *cp = s + strlen(s);
					while (--cp >= s) {
						unput(*cp);
					}
					(void) strcat(yytext, "yyparse");
				}
				last = strlen(yytext);
				(void) strcat(yytext, " */");
				yyleng = strlen(yytext);
				yymore();
				return(FCNDEF);
			}
			else {
				rules = NO;
				global = YES;
				last = first;
				yymore();
				return(FCNEND);
				/* NOTREACHED */
			}
		}
<SDL>STATE{ws}+({identifier}|\*)	{ /* sdl state, treat as function def */
			braces = 1;
			fcndef = YES;
			token = FCNDEF;
			goto findident;
			/* NOTREACHED */
		}
<SDL>ENDSTATE{ws}	{ /* end of an sdl state, treat as end of a function */
			goto endstate;
			/* NOTREACHED */
		}
\{		{	/* count unmatched left braces for fcn def detection */
			++braces;
			
			/* mark an untagged enum/struct/union so its beginning
			   can be found */
			if (tagdef) {
				if (braces == 1) {
					esudef = YES;
				}
				token = tagdef;
				tagdef = '\0';
				last = first;
				yymore();
				return(token);
			}
			goto more;
			/* NOTREACHED */
		}
\#{ws}*endif/.*\n{wsnl}*#{ws}*if	{
			/* attempt to correct erroneous brace count caused by:
			 * 
			 * #if ...
			 * 	... {
			 * #endif
			 * #if ...
			 * 	... {
			 * #endif
			 */
			/* the current #if must not have an #else or #elif */
			if (elseelif == YES) {
				goto endif;
				/* NOTREACHED */
			}
			pseudoelif = YES;
			goto more;
			/* NOTREACHED */
		}
\#{ws}*ifn?(def)?	{ /* #if, #ifdef or #ifndef */
			elseelif = NO;
			if (pseudoelif == YES) {
				pseudoelif = NO;
				goto elif;
				/* NOTREACHED */
			}
			/* make sure there is room for the current brace count */
			if (iflevel == miflevel) {
				miflevel += IFLEVELINC;
				maxifbraces = myrealloc(maxifbraces, miflevel * sizeof(int));
				preifbraces = myrealloc(preifbraces, miflevel * sizeof(int));
			}
			/* push the current brace count */
			preifbraces[iflevel] = braces;
			maxifbraces[iflevel++] = 0;
			goto more;
			/* NOTREACHED */
		}
\#{ws}*el(se|if)	{ /* #elif or #else */
			elseelif = YES;
		elif:
			if (iflevel > 0) {
				
				/* save the maximum brace count for this #if */
				if (braces > maxifbraces[iflevel - 1]) {
					maxifbraces[iflevel - 1] = braces;
				}
				/* restore the brace count to before the #if */
				braces = preifbraces[iflevel - 1];
			}
			goto more;
			/* NOTREACHED */
		}
\#{ws}*endif	{	/* #endif */
		endif:
			if (iflevel > 0) {
				
				/* get the maximum brace count for this #if */
				if (braces < maxifbraces[--iflevel]) {
					braces = maxifbraces[iflevel];
				}
			}
			goto more;
			/* NOTREACHED */
		}
\}		{
			/* could be the last enum member initializer */
			if (braces == initializerbraces) {
				initializerbraces = -1;
				initializer = NO;
			}
			if (--braces <= 0) {
		endstate:
				braces = 0;
				classdef = NO;
			}
			if (braces == 0 || (braces == 1 && classdef == YES)) {

				/* if the end of an enum/struct/union definition */
				if (esudef == YES) {
					esudef = NO;
				}
				/* if the end of the function */
				else if (fcndef == YES) {
					fcndef = NO;
					last = first;
					yymore();
					return(FCNEND);
				}
			}
			goto more;
			/* NOTREACHED */
		}
\(		{	/* count unmatched left parentheses for function templates */
			++parens;
			goto more;
			/* NOTREACHED */
		}
\)		{
			if (--parens <= 0) {
				parens = 0;
			}
			/* if the end of a function template */
			if (parens == templateparens) {
				templateparens = -1;
				template = NO;
			}
			goto more;
			/* NOTREACHED */
		}
=		{	/* if a global definition initializer */
			if (global == YES && ppdefine == NO && yytext[0] != '#') {
				initializerbraces = braces;
				initializer = YES;
			}
			goto more;
			/* NOTREACHED */
		}
:		{	/* a if global structure field */
			if (global == YES && ppdefine == NO && yytext[0] != '#') {
				structfield = YES;
			}
			goto more;
			/* NOTREACHED */
		}
\,		{
			if (braces == initializerbraces) {
				initializerbraces = -1;
				initializer = NO;
			}
			structfield = NO;
			goto more;
			/* NOTREACHED */
		}
;		{	/* if the enum/struct/union was not a definition */
			if (braces == 0) {
				esudef = NO;
			}
			/* if the end of a typedef */
			if (braces == typedefbraces) {
				typedefbraces = -1;
			}
			/* if the end of a external definition */
			if (braces == externalbraces) {
				externalbraces = -1;
				external = NO;
			}
			structfield = NO;
			initializer = NO;
			goto more;
			/* NOTREACHED */
		}
\#{ws}*define{ws}+{identifier}	{
				
			/* preprocessor macro or constant definition */
			ppdefine = YES;
			token = DEFINE;
			if (compress == YES) {
				yytext[0] = '\1';	/* compress the keyword */
			}
		findident:
			first = yyleng - 1;
			while (yytext[first] != ' ' && yytext[first] != '\t') {
				--first;
			}
			++first;
			goto fcn;
			/* NOTREACHED */
		}
class{ws}+{identifier}({wsnl}|[a-zA-Z0-9_():])*\{	{	/* class definition */
			classdef = YES;
			tagdef =  'c';
			REJECT;
			/* NOTREACHED */
		}
(enum|struct|union)/({wsnl}+{identifier}){wsnl}*\{	{ /* enum/struct/union definition */
			tagdef = *(yytext + first);
			goto ident;
			/* NOTREACHED */
		}
(enum|struct|union)/{wsnl}*\{		{ /* tag-less e/s/u definition */
			tagdef = yytext[first];
			if (braces == 0) {
				esudef = YES;
			}
			last = first;
			tagdef = '\0';
			goto more;
		}  			
{identifier}/{ws}*\(({wsnl}|a-zA-Z0-9_*&[\]=,.])*\)({wsnl}|[()])*[:a-zA-Z_#{]	{
			
			/* warning: "if (...)" must not overflow yytext, so the content
			   of function argument definitions is restricted, in particular
			   parentheses are not allowed */

			/* if a function definition */
			/* note: "#define a (b) {" and "#if defined(a)\n#" are not */
			if ((braces == 0 && ppdefine == NO && yytext[0] != '#' && rules == NO) ||
			    (braces == 1 && classdef == YES)) {
				fcndef = YES;
				token = FCNDEF;
				goto fcn;
				/* NOTREACHED */
			}
			goto fcncal;
			/* NOTREACHED */
		}
{identifier}/{ws}*\(	{ /* if a function call */
		fcncal:	if (fcndef == YES || ppdefine == YES || rules == YES) {
				token = FCNCALL;
				goto fcn;
				/* NOTREACHED */
			}
			if (template == NO) {
				templateparens = parens;
				template = YES;
			}
			goto ident;
			/* NOTREACHED */
		}
{identifier}/([*]|{wsnl})+[a-zA-Z0-9_]	{	/* typedef name use */
			goto ident;
			/* NOTREACHED */
		}
{identifier}	{
			char	*s;

			if (global == YES && ppdefine == NO && yytext[0] != '#' &&
			    external == NO && initializer == NO && 
			    arraydimension == NO && structfield == NO &&
			    template == NO && fcndef == NO) {
				if (esudef == YES) {	/* if enum/struct/union */
					token = MEMBERDEF;
				}
				else {
					token = GLOBALDEF;
				}
			}
			else {
		ident:		token = IDENT;
			}
		fcn:
			/* if a long line */
			if (yyleng > STMTMAX) {
				int	c;
				
				/* skip to the end of the line */
				warning("line too long");
				while ((c = skipcomment_input()) != LEXEOF) { 
					if (c == '\n') {
						unput(c);
						break;
					}
				}
			}
			/* truncate a long symbol */
			if (yyleng - first > PATLEN) {
				warning("symbol too long");
				yyleng = first + PATLEN;
				yytext[yyleng] = '\0';
			}
			/* if a keyword */
			yymore();
			if ((s = lookup(yytext + first)) != NULL) {
				first = yyleng;
				
				/* if the start of a typedef */
				if (s == typedeftext) {
					typedefbraces = braces;
					oldtype = YES;
				}
				/* if an enum/struct/union */
				/* (needed for "typedef struct tag name;" so
				   tag isn't marked as the typedef name) */
				else if (s == enumtext || s == structtext || s == uniontext) {
				}
				/* if an external definition */
				else if (s == externtext) {
					externalbraces = braces;
					external = YES;
				}
				/* keyword doesn't start a function template */
				else if (templateparens == parens && template == YES) {
					templateparens = -1;
					template = NO;
				}
				else {	/* next identifier after typedef was a keyword */
					oldtype = NO;
				}
			}
			else {	/* identifier */
				last = yyleng;
				
				/* if a class/enum/struct/union tag definition */
				if (tagdef && strnotequal(yytext + first, "class")) {
					token = tagdef;
					tagdef = '\0';
					if (braces == 0) {
						esudef = YES;
					}
				}
				/* if a typedef name */
				else if (braces == typedefbraces && oldtype == NO &&
				    arraydimension == NO) {
					token = TYPEDEF;
				}
				else {
					oldtype = NO;
				}
				return(token);
				/* NOTREACHED */
			}
		}
\[		{	/* array dimension (don't worry or about subscripts) */
			arraydimension = YES;
			goto more;
			/* NOTREACHED */
		}
\]		{
			arraydimension = NO;
			goto more;
			/* NOTREACHED */
		}
\\\n		{	/* preprocessor statement is continued on next line */
			goto eol;
			/* NOTREACHED */
		}
\n		{	/* end of the line */
			if (ppdefine == YES) {	/* end of a #define */
				ppdefine = NO;
				yyless(yyleng - 1);	/* rescan \n */
				last = first;
				yymore();
				return(DEFINEEND);
			}
			/* skip the first 8 columns of a breakpoint listing line */
			/* and skip the file path in the page header */
			if (bplisting == YES) {
				int	c, i;

				switch (skipcomment_input()) {	/* tab and EOF just fall through */
				case ' ':	/* breakpoint number line */
				case '[':
					for (i = 1; i < 8 && skipcomment_input() != LEXEOF; ++i)
						;
					break;
				case '.':	/* header line */
				case '/':
					/* skip to the end of the line */
					while ((c = skipcomment_input()) != LEXEOF) {
						if (c == '\n') {
							unput(c);
							break;
						}
					}
					break;
				case '\n':	/* empty line */
					unput('\n');
					break;
				}
			}
		eol:
			++myylineno;
			first = 0;
			last = 0;
			if (symbols > 0) {
				return(NEWLINE);
			}
			lineno = myylineno;
		}
\'		{	/* character constant */
			if (sdl == NO) {
				multicharconstant('\'');
			}
			goto more;
			/* NOTREACHED */
		}
\"		{	/* string constant */
			multicharconstant('"');
			goto more;
			/* NOTREACHED */
		}
^{ws}+		{	/* don't save leading white space */
		}
\#{ws}*include{ws}*["<][^"> \t\n]+	{ /* #include file */
			char	*s;
			
			s = strpbrk(yytext, "\"<");
			incfile(s + 1, s);
			/* HBB: avoid pointer mismatch if yytext is
			 * unsigned, or a pointer */
			first = s - (char *)&(yytext[0]);
			last = yyleng;
			if (compress == YES) {
				yytext[0] = '\2';	/* compress the keyword */
			}
			yymore();
			return(INCLUDE);
			/* NOTREACHED */
		}
\#{ws}*{identifier}	|	/* preprocessor keyword */
{number}	|	/* number */
.		{	/* punctuation and operators */
		more:	first = yyleng;
			yymore();
		}
%%

void
initscanner(char *srcfile)
{
	char	*s;
	
	if (maxifbraces == NULL) {
		maxifbraces = mymalloc(miflevel * sizeof(int));
		preifbraces = mymalloc(miflevel * sizeof(int));
	}
	first = 0;		/* buffer index for first char of symbol */
	last = 0;		/* buffer index for last char of symbol */
	lineno = 1;		/* symbol line number */
	myylineno = 1;		/* input line number */
	arraydimension = NO;	/* inside array dimension declaration */
	bplisting = NO;		/* breakpoint listing */
	braces = 0;		/* unmatched left brace count */
	classdef = NO;		/* c++ class definition */
	elseelif = NO;		/* #else or #elif found */
	esudef = NO;		/* enum/struct/union global definition */
	external = NO;		/* external definition */
	externalbraces = -1;	/* external definition outer brace count */
	fcndef = NO;		/* function definition */
	global = YES;		/* file global scope (outside functions) */
	iflevel = 0;		/* #if nesting level */
	initializer = NO;	/* data initializer */
	initializerbraces = -1;	/* data initializer outer brace count */
	lex = NO;		/* lex file */
	parens = 0;		/* unmatched left parenthesis count */
	ppdefine = NO;		/* preprocessor define statement */
	pseudoelif = NO;	/* pseudo-#elif */
	oldtype = NO;		/* next identifier is an old type */
	rules = NO;		/* lex/yacc rules */
	sdl = NO;		/* sdl file */
	structfield = NO;	/* structure field declaration */
	tagdef = '\0';		/* class/enum/struct/union tag definition */
	template = NO;		/* function template */
	templateparens = -1;	/* function template outer parentheses count */
	typedefbraces = -1;	/* initial typedef braces count */

	BEGIN 0;

	/* if this is not a C file */
	if ((s = strrchr(srcfile, '.')) != NULL) {
		switch (*++s) {	/* this switch saves time on C files */
		case 'b':
			if (strcmp(s, "bp") == 0) {	/* breakpoint listing */
				bplisting = YES;
			}
			break;
		case 'l':
			if (strcmp(s, "l") == 0) {	/* lex */
				lex = YES;
				global = NO;
			}
			break;
		case 's':
			if (strcmp(s, "sd") == 0) {	/* sdl */
				sdl = YES;
				BEGIN SDL;
			}
			break;
		case 'y':
			if (strcmp(s, "y") == 0) {	/* yacc */
				global = NO;
			}
			break;
		}
	}
}

int
skipcomment_input(void)
{
	int	c;

	if ((c = getc (yyin)) == '/') {
		return comment ();
	}
	else {
		return c;
	}
	
}

int
comment_input(void)
{
	int c;

	c = getc (yyin);

	return (c == EOF) ? LEXEOF : c;
}

int
comment(void)
{
	int	c, lastc;

	do {
		if ((c = getc(yyin)) == '*') {	/* C comment */
			lastc = '\0';
			while ((c = getc(yyin)) != EOF &&
			    (c != '/' || lastc != '*')) { /* fewer '/'s */
				if (c == '\n') {
					++myylineno;
				}
				lastc = c;
			}
			/* return a blank for Reiser cpp token concatenation */
			if ((c = getc(yyin)) == '_' || isalnum(c)) {
				(void) ungetc(c, yyin);
				c = ' ';
				break;
			}
		}
		else if (c == '/') {		/* C++ comment */
			while ((c = getc(yyin)) != EOF && c != '\n') {
				;
			}
			break;
		}
		else {	/* not a comment */
			(void) ungetc(c, yyin);
			c = '/';
			break;
			/* NOTREACHED */
		}
		
	/* there may be an immediately following comment */
	} while (c == '/');
	return(c);
}

void
multicharconstant(char terminator)
{
	char	c;

	/* scan until the terminator is found */
	while ((c = yytext[yyleng++] = comment_input()) != terminator) {
		switch (c) {
		case '\\':	/* escape character */
			if ((yytext[yyleng++] = comment_input()) == '\n') {
				++myylineno;
			}
			break;
		case '\t':	/* tab character */
		
			/* if not a lex program, continue */
			if (lex == NO) {
				break;
			}
			/* fall through */
			
		case '\n':	/* illegal character */
			
			/* assume the terminator is missing, so put
			   this character back */
			unput(c);
			yytext[--yyleng] = '\0';
			/* fall through */
			
		case LEXEOF:	/* end of file */
			return;
			
		default:
			/* change a control character to a blank */
			if (!isprint((unsigned char)c)) {
				yytext[yyleng - 1] = ' ';
			}
		}
		/* if this token will overflow the line buffer */
		/* note: '\\' may cause yyleng to be > STMTMAX */
		if (yyleng >= STMTMAX) {
			
			/* truncate the token */
			while ((c = comment_input()) != LEXEOF) {
				if (c == terminator) {
					unput(c);
					break;
				}
				else if (c == '\n') {
					++myylineno;
				}
			}
		}
	}
	yytext[yyleng] = '\0';
}