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Diffstat (limited to 'unix/vncmkdepend/ifparser.c')
-rw-r--r-- | unix/vncmkdepend/ifparser.c | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/unix/vncmkdepend/ifparser.c b/unix/vncmkdepend/ifparser.c new file mode 100644 index 00000000..60740bcc --- /dev/null +++ b/unix/vncmkdepend/ifparser.c @@ -0,0 +1,445 @@ +/* + * $XConsortium: ifparser.c,v 1.7 94/01/18 21:30:50 rws Exp $ + * + * Copyright 1992 Network Computing Devices, Inc. + * + * Permission to use, copy, modify, and distribute this software and its + * documentation for any purpose and without fee is hereby granted, provided + * that the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation, and that the name of Network Computing Devices may not be + * used in advertising or publicity pertaining to distribution of the software + * without specific, written prior permission. Network Computing Devices makes + * no representations about the suitability of this software for any purpose. + * It is provided ``as is'' without express or implied warranty. + * + * NETWORK COMPUTING DEVICES DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS + * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, + * IN NO EVENT SHALL NETWORK COMPUTING DEVICES BE LIABLE FOR ANY SPECIAL, + * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + * + * Author: Jim Fulton + * Network Computing Devices, Inc. + * + * Simple if statement processor + * + * This module can be used to evaluate string representations of C language + * if constructs. It accepts the following grammar: + * + * EXPRESSION := VALUE + * | VALUE BINOP EXPRESSION + * + * VALUE := '(' EXPRESSION ')' + * | '!' VALUE + * | '-' VALUE + * | 'defined' '(' variable ')' + * | 'defined' variable + * | # variable '(' variable-list ')' + * | variable + * | number + * + * BINOP := '*' | '/' | '%' + * | '+' | '-' + * | '<<' | '>>' + * | '<' | '>' | '<=' | '>=' + * | '==' | '!=' + * | '&' | '|' + * | '&&' | '||' + * + * The normal C order of precidence is supported. + * + * + * External Entry Points: + * + * ParseIfExpression parse a string for #if + */ + +#include "ifparser.h" +#include <ctype.h> + +/**************************************************************************** + Internal Macros and Utilities for Parser + ****************************************************************************/ + +#define DO(val) if (!(val)) return NULL +#define CALLFUNC(ggg,fff) (*((ggg)->funcs.fff)) +#define SKIPSPACE(ccc) while (isspace(*ccc)) ccc++ +#define isvarfirstletter(ccc) (isalpha(ccc) || (ccc) == '_') + + +static const char * +parse_variable (g, cp, varp) + IfParser *g; + const char *cp; + const char **varp; +{ + SKIPSPACE (cp); + + if (!isvarfirstletter (*cp)) + return CALLFUNC(g, handle_error) (g, cp, "variable name"); + + *varp = cp; + /* EMPTY */ + for (cp++; isalnum(*cp) || *cp == '_'; cp++) ; + return cp; +} + + +static const char * +parse_number (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + SKIPSPACE (cp); + + if (!isdigit(*cp)) + return CALLFUNC(g, handle_error) (g, cp, "number"); + + *valp = strtol(cp, &cp, 0); + return cp; +} + + +static const char * +parse_value (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + const char *var; + + *valp = 0; + + SKIPSPACE (cp); + if (!*cp) + return cp; + + switch (*cp) { + case '(': + DO (cp = ParseIfExpression (g, cp + 1, valp)); + SKIPSPACE (cp); + if (*cp != ')') + return CALLFUNC(g, handle_error) (g, cp, ")"); + + return cp + 1; /* skip the right paren */ + + case '!': + DO (cp = parse_value (g, cp + 1, valp)); + *valp = !(*valp); + return cp; + + case '-': + DO (cp = parse_value (g, cp + 1, valp)); + *valp = -(*valp); + return cp; + + case '#': + DO (cp = parse_variable (g, cp + 1, &var)); + SKIPSPACE (cp); + if (*cp != '(') + return CALLFUNC(g, handle_error) (g, cp, "("); + do { + DO (cp = parse_variable (g, cp + 1, &var)); + SKIPSPACE (cp); + } while (*cp && *cp != ')'); + if (*cp != ')') + return CALLFUNC(g, handle_error) (g, cp, ")"); + *valp = 1; /* XXX */ + return cp + 1; + + case 'd': + if (strncmp (cp, "defined", 7) == 0 && !isalnum(cp[7])) { + int paren = 0; + cp += 7; + SKIPSPACE (cp); + if (*cp == '(') { + paren = 1; + cp++; + } + DO (cp = parse_variable (g, cp, &var)); + SKIPSPACE (cp); + if (paren && *cp != ')') + return CALLFUNC(g, handle_error) (g, cp, ")"); + *valp = (*(g->funcs.eval_defined)) (g, var, cp - var); + return cp + paren; /* skip the right paren */ + } + /* fall out */ + } + + if (isdigit(*cp)) { + DO (cp = parse_number (g, cp, valp)); + } else if (!isvarfirstletter(*cp)) + return CALLFUNC(g, handle_error) (g, cp, "variable or number"); + else { + DO (cp = parse_variable (g, cp, &var)); + *valp = (*(g->funcs.eval_variable)) (g, var, cp - var); + } + + return cp; +} + + + +static const char * +parse_product (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_value (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '*': + DO (cp = parse_product (g, cp + 1, &rightval)); + *valp = (*valp * rightval); + break; + + case '/': + DO (cp = parse_product (g, cp + 1, &rightval)); + *valp = (*valp / rightval); + break; + + case '%': + DO (cp = parse_product (g, cp + 1, &rightval)); + *valp = (*valp % rightval); + break; + } + return cp; +} + + +static const char * +parse_sum (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_product (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '+': + DO (cp = parse_sum (g, cp + 1, &rightval)); + *valp = (*valp + rightval); + break; + + case '-': + DO (cp = parse_sum (g, cp + 1, &rightval)); + *valp = (*valp - rightval); + break; + } + return cp; +} + + +static const char * +parse_shift (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_sum (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '<': + if (cp[1] == '<') { + DO (cp = parse_shift (g, cp + 2, &rightval)); + *valp = (*valp << rightval); + } + break; + + case '>': + if (cp[1] == '>') { + DO (cp = parse_shift (g, cp + 2, &rightval)); + *valp = (*valp >> rightval); + } + break; + } + return cp; +} + + +static const char * +parse_inequality (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_shift (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '<': + if (cp[1] == '=') { + DO (cp = parse_inequality (g, cp + 2, &rightval)); + *valp = (*valp <= rightval); + } else { + DO (cp = parse_inequality (g, cp + 1, &rightval)); + *valp = (*valp < rightval); + } + break; + + case '>': + if (cp[1] == '=') { + DO (cp = parse_inequality (g, cp + 2, &rightval)); + *valp = (*valp >= rightval); + } else { + DO (cp = parse_inequality (g, cp + 1, &rightval)); + *valp = (*valp > rightval); + } + break; + } + return cp; +} + + +static const char * +parse_equality (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_inequality (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '=': + if (cp[1] == '=') + cp++; + DO (cp = parse_equality (g, cp + 1, &rightval)); + *valp = (*valp == rightval); + break; + + case '!': + if (cp[1] != '=') + break; + DO (cp = parse_equality (g, cp + 2, &rightval)); + *valp = (*valp != rightval); + break; + } + return cp; +} + + +static const char * +parse_band (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_equality (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '&': + if (cp[1] != '&') { + DO (cp = parse_band (g, cp + 1, &rightval)); + *valp = (*valp & rightval); + } + break; + } + return cp; +} + + +static const char * +parse_bor (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_band (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '|': + if (cp[1] != '|') { + DO (cp = parse_bor (g, cp + 1, &rightval)); + *valp = (*valp | rightval); + } + break; + } + return cp; +} + + +static const char * +parse_land (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_bor (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '&': + if (cp[1] != '&') + return CALLFUNC(g, handle_error) (g, cp, "&&"); + DO (cp = parse_land (g, cp + 2, &rightval)); + *valp = (*valp && rightval); + break; + } + return cp; +} + + +static const char * +parse_lor (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + int rightval; + + DO (cp = parse_land (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '|': + if (cp[1] != '|') + return CALLFUNC(g, handle_error) (g, cp, "||"); + DO (cp = parse_lor (g, cp + 2, &rightval)); + *valp = (*valp || rightval); + break; + } + return cp; +} + + +/**************************************************************************** + External Entry Points + ****************************************************************************/ + +const char * +ParseIfExpression (g, cp, valp) + IfParser *g; + const char *cp; + int *valp; +{ + return parse_lor (g, cp, valp); +} + + |