R6.6 is the Xorg base-lineXORG-MAINXORG-STABLE

1 files changed, 492 insertions, 0 deletions

diff --git a/ifparser.c b/ifparser.c
new file mode 100644
index 0000000..c91c236
--- /dev/null
+++ b/ifparser.c
@@ -0,0 +1,492 @@
+/*
+ * $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  ')'
+ * 			 |	'!'  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;
+    long *valp;
+{
+    SKIPSPACE (cp);
+
+    if (!isdigit(*cp))
+	return CALLFUNC(g, handle_error) (g, cp, "number");
+
+    *valp = strtol(cp, &cp, 0);
+    /* skip trailing qualifiers */
+    while (*cp == 'U' || *cp == 'u' || *cp == 'L' || *cp == 'l') cp++;
+#if 0
+    *valp = atoi (cp);
+    /* EMPTY */
+    for (cp++; isdigit(*cp); cp++) ;
+#endif
+    return cp;
+}
+
+static const char *
+parse_character (g, cp, valp)
+    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 (g, cp, valp)
+    IfParser *g;
+    const char *cp;
+    long *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 '\'':
+	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));
+	*valp = (*(g->funcs.eval_variable)) (g, var, cp - var);
+    }
+    
+    return cp;
+}
+
+
+
+static const char *
+parse_product (g, cp, valp)
+    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));
+	*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;
+    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 (g, cp, valp)
+    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 (g, cp, valp)
+    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 (g, cp, valp)
+    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 (g, cp, valp)
+    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_bor (g, cp, valp)
+    IfParser *g;
+    const char *cp;
+    long *valp;
+{
+    long 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;
+    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 (g, cp, valp)
+    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;
+}
+
+
+/****************************************************************************
+			     External Entry Points
+ ****************************************************************************/
+
+const char *
+ParseIfExpression (g, cp, valp)
+    IfParser *g;
+    const char *cp;
+    long *valp;
+{
+    return parse_lor (g, cp, valp);
+}
+
+