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Diffstat (limited to 'makedepend/ifparser.c')
-rw-r--r-- | makedepend/ifparser.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/makedepend/ifparser.c b/makedepend/ifparser.c new file mode 100644 index 0000000..58c05a0 --- /dev/null +++ b/makedepend/ifparser.c @@ -0,0 +1,553 @@ +/* + * $Xorg: ifparser.c,v 1.3 2000/08/17 19:41:50 cpqbld 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 ':' EXPRESSION + * + * VALUE := '(' EXPRESSION ')' + * | '!' VALUE + * | '-' VALUE + * | '+' VALUE + * | '~' VALUE + * | 'defined' '(' variable ')' + * | 'defined' variable + * | # variable '(' variable-list ')' + * | variable + * | number + * + * BINOP := '*' | '/' | '%' + * | '+' | '-' + * | '<<' | '>>' + * | '<' | '>' | '<=' | '>=' + * | '==' | '!=' + * | '&' | '^' | '|' + * | '&&' | '||' + * + * The normal C order of precedence is supported. + * + * + * External Entry Points: + * + * ParseIfExpression parse a string for #if + */ +/* $XFree86: xc/config/makedepend/ifparser.c,v 3.10tsi Exp $ */ + +#include "ifparser.h" +#include <ctype.h> +#include <stdlib.h> +#include <string.h> +#include <limits.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 (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 (IfParser *g, const char *cp, long *valp) +{ + long base = 10; + SKIPSPACE (cp); + + if (!isdigit(*cp)) + return CALLFUNC(g, handle_error) (g, cp, "number"); + + *valp = 0; + + if (*cp == '0') { + cp++; + if ((*cp == 'x') || (*cp == 'X')) { + base = 16; + cp++; + } else { + base = 8; + } + } + + /* Ignore overflows and assume ASCII, what source is usually written in */ + while (1) { + int increment = -1; + if (base == 8) { + if ((*cp >= '0') && (*cp <= '7')) + increment = *cp++ - '0'; + } else if (base == 16) { + if ((*cp >= '0') && (*cp <= '9')) + increment = *cp++ - '0'; + else if ((*cp >= 'A') && (*cp <= 'F')) + increment = *cp++ - ('A' - 10); + else if ((*cp >= 'a') && (*cp <= 'f')) + increment = *cp++ - ('a' - 10); + } else { /* Decimal */ + if ((*cp >= '0') && (*cp <= '9')) + increment = *cp++ - '0'; + } + if (increment < 0) + break; + *valp = (*valp * base) + increment; + } + + /* Skip trailing qualifiers */ + while (*cp == 'U' || *cp == 'u' || *cp == 'L' || *cp == 'l') cp++; + return cp; +} + +static const char * +parse_character (IfParser *g, const char *cp, long *valp) +{ + char val; + + SKIPSPACE (cp); + if (*cp == '\\') + switch (cp[1]) { + case 'n': val = '\n'; break; + case 't': val = '\t'; break; + case 'v': val = '\v'; break; + case 'b': val = '\b'; break; + case 'r': val = '\r'; break; + case 'f': val = '\f'; break; + case 'a': val = '\a'; break; + case '\\': val = '\\'; break; + case '?': val = '\?'; break; + case '\'': val = '\''; break; + case '\"': val = '\"'; break; + case 'x': val = (char) strtol (cp + 2, NULL, 16); break; + default: val = (char) strtol (cp + 1, NULL, 8); break; + } + else + val = *cp; + while (*cp != '\'') cp++; + *valp = (long) val; + return cp; +} + +static const char * +parse_value (IfParser *g, const char *cp, long *valp) +{ + const char *var, *varend; + + *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_value (g, cp + 1, 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 '\'': + DO (cp = parse_character (g, cp + 1, valp)); + if (*cp != '\'') + return CALLFUNC(g, handle_error) (g, cp, "'"); + return cp + 1; + + case 'd': + if (strncmp (cp, "defined", 7) == 0 && !isalnum(cp[7])) { + int paren = 0; + int len; + + cp += 7; + SKIPSPACE (cp); + if (*cp == '(') { + paren = 1; + cp++; + } + DO (cp = parse_variable (g, cp, &var)); + len = cp - var; + SKIPSPACE (cp); + if (paren && *cp != ')') + return CALLFUNC(g, handle_error) (g, cp, ")"); + *valp = (*(g->funcs.eval_defined)) (g, var, len); + 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)); + varend = cp; + SKIPSPACE(cp); + if (*cp != '(') { + *valp = (*(g->funcs.eval_variable)) (g, var, varend - var); + } else { + do { + long dummy; + DO (cp = ParseIfExpression (g, cp + 1, &dummy)); + SKIPSPACE(cp); + if (*cp == ')') + break; + if (*cp != ',') + return CALLFUNC(g, handle_error) (g, cp, ","); + } while (1); + + *valp = 1; /* XXX */ + cp++; + } + } + + return cp; +} + + + +static const char * +parse_product (IfParser *g, const char *cp, long *valp) +{ + long 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)); + if (rightval) + *valp = (*valp / rightval); + else + *valp = LONG_MAX; + break; + + case '%': + DO (cp = parse_product (g, cp + 1, &rightval)); + *valp = (*valp % rightval); + break; + } + return cp; +} + + +static const char * +parse_sum (IfParser *g, const char *cp, long *valp) +{ + long 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 (IfParser *g, const char *cp, long *valp) +{ + long 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 (IfParser *g, const char *cp, long *valp) +{ + long 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 (IfParser *g, const char *cp, long *valp) +{ + long 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 (IfParser *g, const char *cp, long *valp) +{ + long 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_bxor (IfParser *g, const char *cp, long *valp) +{ + long rightval; + + DO (cp = parse_band (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '^': + DO (cp = parse_bxor (g, cp + 1, &rightval)); + *valp = (*valp ^ rightval); + break; + } + return cp; +} + + +static const char * +parse_bor (IfParser *g, const char *cp, long *valp) +{ + long rightval; + + DO (cp = parse_bxor (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 (IfParser *g, const char *cp, long *valp) +{ + long 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 (IfParser *g, const char *cp, long *valp) +{ + long 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; +} + + +static const char * +parse_cond(IfParser *g, const char *cp, long *valp) +{ + long trueval, falseval; + + DO (cp = parse_lor (g, cp, valp)); + SKIPSPACE (cp); + + switch (*cp) { + case '?': + DO (cp = parse_cond (g, cp + 1, &trueval)); + SKIPSPACE (cp); + if (*cp != ':') + return CALLFUNC(g, handle_error) (g, cp, ":"); + DO (cp = parse_cond (g, cp + 1, &falseval)); + *valp = (*valp ? trueval : falseval); + break; + } + return cp; +} + + +/**************************************************************************** + External Entry Points + ****************************************************************************/ + +const char * +ParseIfExpression (IfParser *g, const char *cp, long *valp) +{ + return parse_cond (g, cp, valp); +} |