q_parse.cpp

quakeIII源码这个不用我多说吧

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// q_parse.c -- support for parsing text files

#include "q_shared.h"

/*
============================================================================

PARSING

============================================================================
*/

// multiple character punctuation tokens
static const char *punctuation[] = {
	"+=", "-=",  "*=",  "/=", "&=", "|=", "++", "--",
		"&&", "||",  "<=",  ">=", "==", "!=",
	NULL
};

typedef struct {
	char	token[MAX_TOKEN_CHARS];
	int		lines;
	qboolean	ungetToken;
	char	parseFile[MAX_QPATH];
} parseInfo_t;

#define	MAX_PARSE_INFO	16
static parseInfo_t	parseInfo[MAX_PARSE_INFO];
static int			parseInfoNum;
static parseInfo_t	*pi = &parseInfo[0];

/*
===================
Com_BeginParseSession
===================
*/
void Com_BeginParseSession( const char *filename ) {
	if ( parseInfoNum == MAX_PARSE_INFO - 1 ) {
		Com_Error( ERR_FATAL, "Com_BeginParseSession: session overflow" );
	}
	parseInfoNum++;
	pi = &parseInfo[parseInfoNum];

	pi->lines = 1;
	Q_strncpyz( pi->parseFile, filename, sizeof( pi->parseFile ) );
}

/*
===================
Com_EndParseSession
===================
*/
void Com_EndParseSession( void ) {
	if ( parseInfoNum == 0 ) {
		Com_Error( ERR_FATAL, "Com_EndParseSession: session underflow" );
	}
	parseInfoNum--;
	pi = &parseInfo[parseInfoNum];
}

/*
===================
Com_GetCurrentParseLine
===================
*/
int Com_GetCurrentParseLine( void ) {
	return pi->lines;
}

/*
===================
Com_ScriptError

Prints the script name and line number in the message
===================
*/
void Com_ScriptError( const char *msg, ... ) {
	va_list		argptr;
	char		string[32000];

	va_start( argptr, msg );
	vsprintf( string, msg,argptr );
	va_end( argptr );

	Com_Error( ERR_DROP, "File %s, line %i: %s", pi->parseFile, pi->lines, string );
}

void Com_ScriptWarning( const char *msg, ... ) {
	va_list		argptr;
	char		string[32000];

	va_start( argptr, msg );
	vsprintf( string, msg,argptr );
	va_end( argptr );

	Com_Printf( "File %s, line %i: %s", pi->parseFile, pi->lines, string );
}


/*
===================
Com_UngetToken

Calling this will make the next Com_Parse return
the current token instead of advancing the pointer
===================
*/
void Com_UngetToken( void ) {
	if ( pi->ungetToken ) {
		Com_ScriptError( "UngetToken called twice" );
	}
	pi->ungetToken = qtrue;
}


static const char *SkipWhitespace( const char (*data), qboolean *hasNewLines ) {
	int c;

	while( (c = *data) <= ' ') {
		if( !c ) {
			return NULL;
		}
		if( c == '\n' ) {
			pi->lines++;
			*hasNewLines = qtrue;
		}
		data++;
	}

	return data;
}

/*
==============
Com_ParseExt

Parse a token out of a string
Will never return NULL, just empty strings.
An empty string will only be returned at end of file.

If "allowLineBreaks" is qtrue then an empty
string will be returned if the next token is
a newline.
==============
*/
static char *Com_ParseExt( const char *(*data_p), qboolean allowLineBreaks ) {
	int c = 0, len;
	qboolean hasNewLines = qfalse;
	const char *data;
	const char **punc;

	if ( !data_p ) {
		Com_Error( ERR_FATAL, "Com_ParseExt: NULL data_p" );
	}

	data = *data_p;
	len = 0;
	pi->token[0] = 0;

	// make sure incoming data is valid
	if ( !data ) {
		*data_p = NULL;
		return pi->token;
	}

	// skip any leading whitespace
	while ( 1 ) {
		// skip whitespace
		data = SkipWhitespace( data, &hasNewLines );
		if ( !data ) {
			*data_p = NULL;
			return pi->token;
		}
		if ( hasNewLines && !allowLineBreaks ) {
			*data_p = data;
			return pi->token;
		}

		c = *data;

		// skip double slash comments
		if ( c == '/' && data[1] == '/' ) {
			while (*data && *data != '\n') {
				data++;
			}
			continue;
		}

		// skip /* */ comments
		if ( c=='/' && data[1] == '*' ) {
			while ( *data && ( *data != '*' || data[1] != '/' ) ) {
				if( *data == '\n' ) {
					pi->lines++;
				}
				data++;
			}
			if ( *data ) {
				data += 2;
			}
			continue;
		}

		// a real token to parse
		break;
	}

	// handle quoted strings
	if ( c == '\"' ) {
		data++;
		while( 1 ) {
			c = *data++;
			if ( ( c=='\\' ) && ( *data == '\"' ) ) {
				// allow quoted strings to use \" to indicate the " character
				data++;
			} else if ( c=='\"' || !c ) {
				pi->token[len] = 0;
				*data_p = ( char * ) data;
				return pi->token;
			} else if( *data == '\n' ) {
				pi->lines++;
			}
			if ( len < MAX_TOKEN_CHARS - 1 ) {
				pi->token[len] = c;
				len++;
			}
		}
	}

	// check for a number
	// is this parsing of negative numbers going to cause expression problems
	if ( ( c >= '0' && c <= '9' ) || ( c == '-' && data[ 1 ] >= '0' && data[ 1 ] <= '9' ) || 
		( c == '.' && data[ 1 ] >= '0' && data[ 1 ] <= '9' ) ) {
		do  {

			if (len < MAX_TOKEN_CHARS - 1) {
				pi->token[len] = c;
				len++;
			}
			data++;

			c = *data;
		} while ( ( c >= '0' && c <= '9' ) || c == '.' );

		// parse the exponent
		if ( c == 'e' || c == 'E' ) {
			if (len < MAX_TOKEN_CHARS - 1) {
				pi->token[len] = c;
				len++;
			}
			data++;
			c = *data;

			if ( c == '-' || c == '+' ) {
				if (len < MAX_TOKEN_CHARS - 1) {
					pi->token[len] = c;
					len++;
				}
				data++;
				c = *data;
			}

			do  {
				if (len < MAX_TOKEN_CHARS - 1) {
					pi->token[len] = c;
					len++;
				}
				data++;

				c = *data;
			} while ( c >= '0' && c <= '9' );
		}

		if (len == MAX_TOKEN_CHARS) {
			len = 0;
		}
		pi->token[len] = 0;

		*data_p = ( char * ) data;
		return pi->token;
   	}

	// check for a regular word
	// we still allow forward and back slashes in name tokens for pathnames
	// and also colons for drive letters
	if ( ( c >= 'a' && c <= 'z' ) || ( c >= 'A' && c <= 'Z' ) || c == '_' || c == '/' || c == '\\' ) {
		do  {
			if (len < MAX_TOKEN_CHARS - 1) {
				pi->token[len] = c;
				len++;
			}
			data++;

			c = *data;
		} while ( ( c >= 'a' && c <= 'z' ) || ( c >= 'A' && c <= 'Z' ) || c == '_' 
			|| ( c >= '0' && c <= '9' ) || c == '/' || c == '\\' || c == ':' || c == '.' );

		if (len == MAX_TOKEN_CHARS) {
			len = 0;
		}
		pi->token[len] = 0;

		*data_p = ( char * ) data;
		return pi->token;
	}

	// check for multi-character punctuation token
	for ( punc = punctuation ; *punc ; punc++ ) {
		int		l;
		int		j;

		l = strlen( *punc );
		for ( j = 0 ; j < l ; j++ ) {
			if ( data[j] != (*punc)[j] ) {
				break;
			}
		}
		if ( j == l ) {
			// a valid multi-character punctuation
			memcpy( pi->token, *punc, l );
			pi->token[l] = 0;
			data += l;
			*data_p = (char *)data;
			return pi->token;
		}
	}

	// single character punctuation
	pi->token[0] = *data;
	pi->token[1] = 0;
	data++;
	*data_p = (char *)data;

	return pi->token;
}

/*
===================
Com_Parse
===================
*/
const char *Com_Parse( const char *(*data_p) ) {
	if ( pi->ungetToken ) {
		pi->ungetToken = qfalse;
		return pi->token;
	}
	return Com_ParseExt( data_p, qtrue );
}

/*
===================
Com_ParseOnLine
===================
*/
const char *Com_ParseOnLine( const char *(*data_p) ) {
	if ( pi->ungetToken ) {
		pi->ungetToken = qfalse;
		return pi->token;
	}
	return Com_ParseExt( data_p, qfalse );
}



/*
==================
Com_MatchToken
==================
*/
void Com_MatchToken( const char *(*buf_p), const char *match, qboolean warning ) {
	const char	*token;

	token = Com_Parse( buf_p );
	if ( strcmp( token, match ) ) {
		if (warning) {
			Com_ScriptWarning( "MatchToken: %s != %s", token, match );
		} else {
			Com_ScriptError( "MatchToken: %s != %s", token, match );
		}
	}
}


/*
=================
Com_SkipBracedSection

The next token should be an open brace.
Skips until a matching close brace is found.
Internal brace depths are properly skipped.
=================
*/
void Com_SkipBracedSection( const char *(*program) ) {
	const char			*token;
	int				depth;

	depth = 0;
	do {
		token = Com_Parse( program );
		if( token[1] == 0 ) {
			if( token[0] == '{' ) {
				depth++;
			}
			else if( token[0] == '}' ) {
				depth--;
			}
		}
	} while( depth && *program );
}

/*
=================
Com_SkipRestOfLine
=================
*/
void Com_SkipRestOfLine ( const char *(*data) ) {
	const char	*p;
	int		c;

	p = *data;
	while ( (c = *p++) != 0 ) {
		if ( c == '\n' ) {
			pi->lines++;
			break;
		}
	}

	*data = p;
}

/*
====================
Com_ParseRestOfLine
====================
*/
const char *Com_ParseRestOfLine( const char *(*data_p) ) {
	static char	line[MAX_TOKEN_CHARS];
	const char *token;

	line[0] = 0;
	while( 1 ) {
		token = Com_ParseOnLine( data_p );
		if ( !token[0] ) {
			break;
		}
		if ( line[0] ) {
			Q_strcat( line, sizeof(line), " " );
		}
		Q_strcat( line, sizeof(line), token );
	}

	return line;
}


float Com_ParseFloat( const char *(*buf_p) ) {
	const char		*token;

	token = Com_Parse( buf_p );
	if ( !token[0] ) {
		return 0;
	}
	return atof( token );
}

int Com_ParseInt( const char *(*buf_p) ) {
	const char		*token;

	token = Com_Parse( buf_p );
	if ( !token[0] ) {
		return 0;
	}
	return atof( token );
}



void Com_Parse1DMatrix( const char *(*buf_p), int x, float *m ) {
	const char	*token;
	int		i;

	Com_MatchToken( buf_p, "(" );

	for (i = 0 ; i < x ; i++) {
		token = Com_Parse(buf_p);
		m[i] = atof(token);
	}

	Com_MatchToken( buf_p, ")" );
}

void Com_Parse2DMatrix( const char *(*buf_p), int y, int x, float *m ) {
	int		i;

	Com_MatchToken( buf_p, "(" );

	for (i = 0 ; i < y ; i++) {
		Com_Parse1DMatrix (buf_p, x, m + i * x);
	}

	Com_MatchToken( buf_p, ")" );
}

void Com_Parse3DMatrix( const char *(*buf_p), int z, int y, int x, float *m ) {
	int		i;

	Com_MatchToken( buf_p, "(" );

	for (i = 0 ; i < z ; i++) {
		Com_Parse2DMatrix (buf_p, y, x, m + i * x*y);
	}

	Com_MatchToken( buf_p, ")" );
}