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/* |
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* $Xorg: ifparser.c,v 1.3 2000/08/17 19:41:50 cpqbld Exp $ |
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* |
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* Copyright 1992 Network Computing Devices, Inc. |
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* |
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* Permission to use, copy, modify, and distribute this software and its |
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* documentation for any purpose and without fee is hereby granted, provided |
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* that the above copyright notice appear in all copies and that both that |
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* copyright notice and this permission notice appear in supporting |
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* documentation, and that the name of Network Computing Devices may not be |
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* used in advertising or publicity pertaining to distribution of the software |
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* without specific, written prior permission. Network Computing Devices makes |
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* no representations about the suitability of this software for any purpose. |
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* It is provided ``as is'' without express or implied warranty. |
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* |
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* NETWORK COMPUTING DEVICES DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS |
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* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, |
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* IN NO EVENT SHALL NETWORK COMPUTING DEVICES BE LIABLE FOR ANY SPECIAL, |
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* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM |
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE |
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* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR |
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* PERFORMANCE OF THIS SOFTWARE. |
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* |
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* Author: Jim Fulton |
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* Network Computing Devices, Inc. |
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* |
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* Simple if statement processor |
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* |
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* This module can be used to evaluate string representations of C language |
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* if constructs. It accepts the following grammar: |
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* |
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* EXPRESSION := VALUE |
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* | VALUE BINOP EXPRESSION |
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* | VALUE '?' EXPRESSION ':' EXPRESSION |
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* |
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* VALUE := '(' EXPRESSION ')' |
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* | '!' VALUE |
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* | '-' VALUE |
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* | '+' VALUE |
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* | '~' VALUE |
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* | 'defined' '(' variable ')' |
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* | 'defined' variable |
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* | # variable '(' variable-list ')' |
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* | variable |
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* | number |
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* |
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* BINOP := '*' | '/' | '%' |
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* | '+' | '-' |
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* | '<<' | '>>' |
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* | '<' | '>' | '<=' | '>=' |
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* | '==' | '!=' |
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* | '&' | '^' | '|' |
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* | '&&' | '||' |
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* |
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* The normal C order of precedence is supported. |
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* |
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* |
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* External Entry Points: |
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* |
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* ParseIfExpression parse a string for #if |
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*/ |
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/* $XFree86: xc/config/makedepend/ifparser.c,v 3.11 2002/09/23 01:48:08 tsi Exp $ */ |
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|
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#include "ifparser.h" |
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#include <ctype.h> |
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#include <stdlib.h> |
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#include <string.h> |
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|
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/**************************************************************************** |
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Internal Macros and Utilities for Parser |
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****************************************************************************/ |
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|
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#define DO(val) if (!(val)) return NULL |
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#define CALLFUNC(ggg,fff) (*((ggg)->funcs.fff)) |
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#define SKIPSPACE(ccc) while (isspace(*ccc)) ccc++ |
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#define isvarfirstletter(ccc) (isalpha(ccc) || (ccc) == '_') |
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|
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|
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static const char * |
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parse_variable (IfParser *g, const char *cp, const char **varp) |
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{ |
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SKIPSPACE (cp); |
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|
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if (!isvarfirstletter (*cp)) |
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return CALLFUNC(g, handle_error) (g, cp, "variable name"); |
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|
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*varp = cp; |
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/* EMPTY */ |
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for (cp++; isalnum(*cp) || *cp == '_'; cp++) ; |
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return cp; |
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} |
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|
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|
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static const char * |
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parse_number (IfParser *g, const char *cp, long *valp) |
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{ |
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long base = 10; |
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SKIPSPACE (cp); |
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|
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if (!isdigit(*cp)) |
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return CALLFUNC(g, handle_error) (g, cp, "number"); |
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|
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*valp = 0; |
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|
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if (*cp == '0') { |
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cp++; |
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if ((*cp == 'x') || (*cp == 'X')) { |
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base = 16; |
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cp++; |
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} else { |
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base = 8; |
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} |
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} |
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|
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/* Ignore overflows and assume ASCII, what source is usually written in */ |
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while (1) { |
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int increment = -1; |
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if (base == 8) { |
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if ((*cp >= '0') && (*cp <= '7')) |
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increment = *cp++ - '0'; |
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} else if (base == 16) { |
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if ((*cp >= '0') && (*cp <= '9')) |
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increment = *cp++ - '0'; |
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else if ((*cp >= 'A') && (*cp <= 'F')) |
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increment = *cp++ - ('A' - 10); |
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else if ((*cp >= 'a') && (*cp <= 'f')) |
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increment = *cp++ - ('a' - 10); |
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} else { /* Decimal */ |
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if ((*cp >= '0') && (*cp <= '9')) |
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increment = *cp++ - '0'; |
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} |
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if (increment < 0) |
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break; |
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*valp = (*valp * base) + increment; |
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} |
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|
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/* Skip trailing qualifiers */ |
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while (*cp == 'U' || *cp == 'u' || *cp == 'L' || *cp == 'l') cp++; |
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return cp; |
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} |
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|
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static const char * |
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parse_character (IfParser *g, const char *cp, long *valp) |
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{ |
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char val; |
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|
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SKIPSPACE (cp); |
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if (*cp == '\\') |
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switch (cp[1]) { |
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case 'n': val = '\n'; break; |
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case 't': val = '\t'; break; |
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case 'v': val = '\v'; break; |
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case 'b': val = '\b'; break; |
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case 'r': val = '\r'; break; |
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case 'f': val = '\f'; break; |
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case 'a': val = '\a'; break; |
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case '\\': val = '\\'; break; |
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case '?': val = '\?'; break; |
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case '\'': val = '\''; break; |
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case '\"': val = '\"'; break; |
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case 'x': val = (char) strtol (cp + 2, NULL, 16); break; |
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default: val = (char) strtol (cp + 1, NULL, 8); break; |
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} |
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else |
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val = *cp; |
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while (*cp != '\'') cp++; |
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*valp = (long) val; |
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return cp; |
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} |
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|
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static const char * |
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parse_value (IfParser *g, const char *cp, long *valp) |
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{ |
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const char *var, *varend; |
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|
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*valp = 0; |
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|
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SKIPSPACE (cp); |
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if (!*cp) |
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return cp; |
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|
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switch (*cp) { |
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case '(': |
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DO (cp = ParseIfExpression (g, cp + 1, valp)); |
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SKIPSPACE (cp); |
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if (*cp != ')') |
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return CALLFUNC(g, handle_error) (g, cp, ")"); |
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|
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return cp + 1; /* skip the right paren */ |
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|
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case '!': |
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DO (cp = parse_value (g, cp + 1, valp)); |
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*valp = !(*valp); |
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return cp; |
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|
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case '-': |
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DO (cp = parse_value (g, cp + 1, valp)); |
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*valp = -(*valp); |
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return cp; |
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|
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case '+': |
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DO (cp = parse_value (g, cp + 1, valp)); |
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return cp; |
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|
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case '~': |
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DO (cp = parse_value (g, cp + 1, valp)); |
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*valp = ~(*valp); |
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return cp; |
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|
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case '#': |
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DO (cp = parse_variable (g, cp + 1, &var)); |
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SKIPSPACE (cp); |
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if (*cp != '(') |
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return CALLFUNC(g, handle_error) (g, cp, "("); |
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do { |
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DO (cp = parse_variable (g, cp + 1, &var)); |
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SKIPSPACE (cp); |
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} while (*cp && *cp != ')'); |
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if (*cp != ')') |
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return CALLFUNC(g, handle_error) (g, cp, ")"); |
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*valp = 1; /* XXX */ |
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return cp + 1; |
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|
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case '\'': |
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DO (cp = parse_character (g, cp + 1, valp)); |
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if (*cp != '\'') |
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return CALLFUNC(g, handle_error) (g, cp, "'"); |
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return cp + 1; |
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|
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case 'd': |
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if (strncmp (cp, "defined", 7) == 0 && !isalnum(cp[7])) { |
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int paren = 0; |
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int len; |
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|
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cp += 7; |
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SKIPSPACE (cp); |
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if (*cp == '(') { |
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paren = 1; |
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cp++; |
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} |
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DO (cp = parse_variable (g, cp, &var)); |
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len = cp - var; |
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SKIPSPACE (cp); |
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if (paren && *cp != ')') |
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return CALLFUNC(g, handle_error) (g, cp, ")"); |
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*valp = (*(g->funcs.eval_defined)) (g, var, len); |
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return cp + paren; /* skip the right paren */ |
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} |
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/* fall out */ |
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} |
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|
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if (isdigit(*cp)) { |
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DO (cp = parse_number (g, cp, valp)); |
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} else if (!isvarfirstletter(*cp)) |
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return CALLFUNC(g, handle_error) (g, cp, "variable or number"); |
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else { |
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DO (cp = parse_variable (g, cp, &var)); |
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varend = cp; |
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SKIPSPACE(cp); |
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if (*cp != '(') { |
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*valp = (*(g->funcs.eval_variable)) (g, var, varend - var); |
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} else { |
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do { |
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long dummy; |
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DO (cp = ParseIfExpression (g, cp + 1, &dummy)); |
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SKIPSPACE(cp); |
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if (*cp == ')') |
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break; |
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if (*cp != ',') |
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return CALLFUNC(g, handle_error) (g, cp, ","); |
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} while (1); |
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|
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*valp = 1; /* XXX */ |
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cp++; |
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} |
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} |
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|
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return cp; |
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} |
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|
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|
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|
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static const char * |
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parse_product (IfParser *g, const char *cp, long *valp) |
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{ |
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long rightval; |
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|
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DO (cp = parse_value (g, cp, valp)); |
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SKIPSPACE (cp); |
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|
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switch (*cp) { |
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case '*': |
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DO (cp = parse_product (g, cp + 1, &rightval)); |
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*valp = (*valp * rightval); |
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break; |
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|
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case '/': |
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DO (cp = parse_product (g, cp + 1, &rightval)); |
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if (rightval == 0) |
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return CALLFUNC(g, handle_error) (g, cp, "0"); |
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*valp = (*valp / rightval); |
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break; |
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|
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case '%': |
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DO (cp = parse_product (g, cp + 1, &rightval)); |
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*valp = (*valp % rightval); |
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break; |
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} |
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return cp; |
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} |
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|
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|
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static const char * |
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parse_sum (IfParser *g, const char *cp, long *valp) |
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{ |
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long rightval; |
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|
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DO (cp = parse_product (g, cp, valp)); |
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SKIPSPACE (cp); |
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|
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switch (*cp) { |
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case '+': |
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DO (cp = parse_sum (g, cp + 1, &rightval)); |
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*valp = (*valp + rightval); |
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break; |
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|
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case '-': |
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DO (cp = parse_sum (g, cp + 1, &rightval)); |
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*valp = (*valp - rightval); |
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break; |
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} |
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return cp; |
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} |
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|
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|
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static const char * |
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parse_shift (IfParser *g, const char *cp, long *valp) |
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{ |
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long rightval; |
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|
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DO (cp = parse_sum (g, cp, valp)); |
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SKIPSPACE (cp); |
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|
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switch (*cp) { |
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case '<': |
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if (cp[1] == '<') { |
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DO (cp = parse_shift (g, cp + 2, &rightval)); |
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*valp = (*valp << rightval); |
| 349 |
} |
| 350 |
break; |
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|
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case '>': |
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if (cp[1] == '>') { |
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DO (cp = parse_shift (g, cp + 2, &rightval)); |
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*valp = (*valp >> rightval); |
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} |
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break; |
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} |
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return cp; |
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} |
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|
| 362 |
|
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static const char * |
| 364 |
parse_inequality (IfParser *g, const char *cp, long *valp) |
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{ |
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long rightval; |
| 367 |
|
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DO (cp = parse_shift (g, cp, valp)); |
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SKIPSPACE (cp); |
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|
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switch (*cp) { |
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case '<': |
| 373 |
if (cp[1] == '=') { |
| 374 |
DO (cp = parse_inequality (g, cp + 2, &rightval)); |
| 375 |
*valp = (*valp <= rightval); |
| 376 |
} else { |
| 377 |
DO (cp = parse_inequality (g, cp + 1, &rightval)); |
| 378 |
*valp = (*valp < rightval); |
| 379 |
} |
| 380 |
break; |
| 381 |
|
| 382 |
case '>': |
| 383 |
if (cp[1] == '=') { |
| 384 |
DO (cp = parse_inequality (g, cp + 2, &rightval)); |
| 385 |
*valp = (*valp >= rightval); |
| 386 |
} else { |
| 387 |
DO (cp = parse_inequality (g, cp + 1, &rightval)); |
| 388 |
*valp = (*valp > rightval); |
| 389 |
} |
| 390 |
break; |
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} |
| 392 |
return cp; |
| 393 |
} |
| 394 |
|
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|
| 396 |
static const char * |
| 397 |
parse_equality (IfParser *g, const char *cp, long *valp) |
| 398 |
{ |
| 399 |
long rightval; |
| 400 |
|
| 401 |
DO (cp = parse_inequality (g, cp, valp)); |
| 402 |
SKIPSPACE (cp); |
| 403 |
|
| 404 |
switch (*cp) { |
| 405 |
case '=': |
| 406 |
if (cp[1] == '=') |
| 407 |
cp++; |
| 408 |
DO (cp = parse_equality (g, cp + 1, &rightval)); |
| 409 |
*valp = (*valp == rightval); |
| 410 |
break; |
| 411 |
|
| 412 |
case '!': |
| 413 |
if (cp[1] != '=') |
| 414 |
break; |
| 415 |
DO (cp = parse_equality (g, cp + 2, &rightval)); |
| 416 |
*valp = (*valp != rightval); |
| 417 |
break; |
| 418 |
} |
| 419 |
return cp; |
| 420 |
} |
| 421 |
|
| 422 |
|
| 423 |
static const char * |
| 424 |
parse_band (IfParser *g, const char *cp, long *valp) |
| 425 |
{ |
| 426 |
long rightval; |
| 427 |
|
| 428 |
DO (cp = parse_equality (g, cp, valp)); |
| 429 |
SKIPSPACE (cp); |
| 430 |
|
| 431 |
switch (*cp) { |
| 432 |
case '&': |
| 433 |
if (cp[1] != '&') { |
| 434 |
DO (cp = parse_band (g, cp + 1, &rightval)); |
| 435 |
*valp = (*valp & rightval); |
| 436 |
} |
| 437 |
break; |
| 438 |
} |
| 439 |
return cp; |
| 440 |
} |
| 441 |
|
| 442 |
|
| 443 |
static const char * |
| 444 |
parse_bxor (IfParser *g, const char *cp, long *valp) |
| 445 |
{ |
| 446 |
long rightval; |
| 447 |
|
| 448 |
DO (cp = parse_band (g, cp, valp)); |
| 449 |
SKIPSPACE (cp); |
| 450 |
|
| 451 |
switch (*cp) { |
| 452 |
case '^': |
| 453 |
DO (cp = parse_bxor (g, cp + 1, &rightval)); |
| 454 |
*valp = (*valp ^ rightval); |
| 455 |
break; |
| 456 |
} |
| 457 |
return cp; |
| 458 |
} |
| 459 |
|
| 460 |
|
| 461 |
static const char * |
| 462 |
parse_bor (IfParser *g, const char *cp, long *valp) |
| 463 |
{ |
| 464 |
long rightval; |
| 465 |
|
| 466 |
DO (cp = parse_bxor (g, cp, valp)); |
| 467 |
SKIPSPACE (cp); |
| 468 |
|
| 469 |
switch (*cp) { |
| 470 |
case '|': |
| 471 |
if (cp[1] != '|') { |
| 472 |
DO (cp = parse_bor (g, cp + 1, &rightval)); |
| 473 |
*valp = (*valp | rightval); |
| 474 |
} |
| 475 |
break; |
| 476 |
} |
| 477 |
return cp; |
| 478 |
} |
| 479 |
|
| 480 |
|
| 481 |
static const char * |
| 482 |
parse_land (IfParser *g, const char *cp, long *valp) |
| 483 |
{ |
| 484 |
long rightval; |
| 485 |
|
| 486 |
DO (cp = parse_bor (g, cp, valp)); |
| 487 |
SKIPSPACE (cp); |
| 488 |
|
| 489 |
switch (*cp) { |
| 490 |
case '&': |
| 491 |
if (cp[1] != '&') |
| 492 |
return CALLFUNC(g, handle_error) (g, cp, "&&"); |
| 493 |
DO (cp = parse_land (g, cp + 2, &rightval)); |
| 494 |
*valp = (*valp && rightval); |
| 495 |
break; |
| 496 |
} |
| 497 |
return cp; |
| 498 |
} |
| 499 |
|
| 500 |
|
| 501 |
static const char * |
| 502 |
parse_lor (IfParser *g, const char *cp, long *valp) |
| 503 |
{ |
| 504 |
long rightval; |
| 505 |
|
| 506 |
DO (cp = parse_land (g, cp, valp)); |
| 507 |
SKIPSPACE (cp); |
| 508 |
|
| 509 |
switch (*cp) { |
| 510 |
case '|': |
| 511 |
if (cp[1] != '|') |
| 512 |
return CALLFUNC(g, handle_error) (g, cp, "||"); |
| 513 |
DO (cp = parse_lor (g, cp + 2, &rightval)); |
| 514 |
*valp = (*valp || rightval); |
| 515 |
break; |
| 516 |
} |
| 517 |
return cp; |
| 518 |
} |
| 519 |
|
| 520 |
|
| 521 |
static const char * |
| 522 |
parse_cond(IfParser *g, const char *cp, long *valp) |
| 523 |
{ |
| 524 |
long trueval, falseval; |
| 525 |
|
| 526 |
DO (cp = parse_lor (g, cp, valp)); |
| 527 |
SKIPSPACE (cp); |
| 528 |
|
| 529 |
switch (*cp) { |
| 530 |
case '?': |
| 531 |
DO (cp = parse_cond (g, cp + 1, &trueval)); |
| 532 |
SKIPSPACE (cp); |
| 533 |
if (*cp != ':') |
| 534 |
return CALLFUNC(g, handle_error) (g, cp, ":"); |
| 535 |
DO (cp = parse_cond (g, cp + 1, &falseval)); |
| 536 |
*valp = (*valp ? trueval : falseval); |
| 537 |
break; |
| 538 |
} |
| 539 |
return cp; |
| 540 |
} |
| 541 |
|
| 542 |
|
| 543 |
/**************************************************************************** |
| 544 |
External Entry Points |
| 545 |
****************************************************************************/ |
| 546 |
|
| 547 |
const char * |
| 548 |
ParseIfExpression (IfParser *g, const char *cp, long *valp) |
| 549 |
{ |
| 550 |
return parse_cond (g, cp, valp); |
| 551 |
} |
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