-/* $Cambridge: exim/src/src/expand.c,v 1.68 2006/10/31 14:26:34 ph10 Exp $ */
+/* $Cambridge: exim/src/src/expand.c,v 1.69 2006/11/13 11:26:37 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
* Evaluate numeric expression *
*************************************************/
-/* This is a set of mutually recursive functions that evaluate a simple
-arithmetic expression involving only + - * / and parentheses. The only one that
-is called from elsewhere is eval_expr, whose interface is:
+/* This is a set of mutually recursive functions that evaluate an arithmetic
+expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
+these functions that is called from elsewhere is eval_expr, whose interface is:
Arguments:
- sptr pointer to the pointer to the string - gets updated
- decimal TRUE if numbers are to be assumed decimal
- error pointer to where to put an error message - must be NULL on input
- endket TRUE if ')' must terminate - FALSE for external call
+ sptr pointer to the pointer to the string - gets updated
+ decimal TRUE if numbers are to be assumed decimal
+ error pointer to where to put an error message - must be NULL on input
+ endket TRUE if ')' must terminate - FALSE for external call
-
-Returns: on success: the value of the expression, with *error still NULL
- on failure: an undefined value, with *error = a message
+Returns: on success: the value of the expression, with *error still NULL
+ on failure: an undefined value, with *error = a message
*/
-static int eval_sumterm(uschar **, BOOL, uschar **);
+static int eval_op_or(uschar **, BOOL, uschar **);
+
static int
eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
{
uschar *s = *sptr;
-int x = eval_sumterm(&s, decimal, error);
+int x = eval_op_or(&s, decimal, error);
if (*error == NULL)
{
- while (*s == '+' || *s == '-')
+ if (endket)
{
- int op = *s++;
- int y = eval_sumterm(&s, decimal, error);
- if (*error != NULL) break;
- if (op == '+') x += y; else x -= y;
- }
- if (*error == NULL)
- {
- if (endket)
- {
- if (*s != ')')
- *error = US"expecting closing parenthesis";
- else
- while (isspace(*(++s)));
- }
- else if (*s != 0) *error = US"expecting + or -";
+ if (*s != ')')
+ *error = US"expecting closing parenthesis";
+ else
+ while (isspace(*(++s)));
}
+ else if (*s != 0) *error = US"expecting operator";
}
-
*sptr = s;
return x;
}
+
static int
-eval_term(uschar **sptr, BOOL decimal, uschar **error)
+eval_number(uschar **sptr, BOOL decimal, uschar **error)
{
register int c;
int n;
uschar *s = *sptr;
while (isspace(*s)) s++;
c = *s;
-if (isdigit(c) || ((c == '-' || c == '+') && isdigit(s[1])))
+if (isdigit(c))
{
int count;
(void)sscanf(CS s, (decimal? "%d%n" : "%i%n"), &n, &count);
return n;
}
-static int eval_sumterm(uschar **sptr, BOOL decimal, uschar **error)
+
+static int eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
+{
+uschar *s = *sptr;
+int x;
+while (isspace(*s)) s++;
+if (*s == '+' || *s == '-' || *s == '~')
+ {
+ int op = *s++;
+ x = eval_op_unary(&s, decimal, error);
+ if (op == '-') x = -x;
+ else if (op == '~') x = ~x;
+ }
+else
+ {
+ x = eval_number(&s, decimal, error);
+ }
+*sptr = s;
+return x;
+}
+
+
+static int eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
{
uschar *s = *sptr;
-int x = eval_term(&s, decimal, error);
+int x = eval_op_unary(&s, decimal, error);
if (*error == NULL)
{
while (*s == '*' || *s == '/' || *s == '%')
{
int op = *s++;
- int y = eval_term(&s, decimal, error);
+ int y = eval_op_unary(&s, decimal, error);
if (*error != NULL) break;
if (op == '*') x *= y;
else if (op == '/') x /= y;
}
+static int eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
+{
+uschar *s = *sptr;
+int x = eval_op_mult(&s, decimal, error);
+if (*error == NULL)
+ {
+ while (*s == '+' || *s == '-')
+ {
+ int op = *s++;
+ int y = eval_op_mult(&s, decimal, error);
+ if (*error != NULL) break;
+ if (op == '+') x += y; else x -= y;
+ }
+ }
+*sptr = s;
+return x;
+}
+
+
+static int eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
+{
+uschar *s = *sptr;
+int x = eval_op_sum(&s, decimal, error);
+if (*error == NULL)
+ {
+ while ((*s == '<' || *s == '>') && s[1] == s[0])
+ {
+ int y;
+ int op = *s++;
+ s++;
+ y = eval_op_sum(&s, decimal, error);
+ if (*error != NULL) break;
+ if (op == '<') x <<= y; else x >>= y;
+ }
+ }
+*sptr = s;
+return x;
+}
+
+
+static int eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
+{
+uschar *s = *sptr;
+int x = eval_op_shift(&s, decimal, error);
+if (*error == NULL)
+ {
+ while (*s == '&')
+ {
+ int y;
+ s++;
+ y = eval_op_shift(&s, decimal, error);
+ if (*error != NULL) break;
+ x &= y;
+ }
+ }
+*sptr = s;
+return x;
+}
+
+
+static int eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
+{
+uschar *s = *sptr;
+int x = eval_op_and(&s, decimal, error);
+if (*error == NULL)
+ {
+ while (*s == '^')
+ {
+ int y;
+ s++;
+ y = eval_op_and(&s, decimal, error);
+ if (*error != NULL) break;
+ x ^= y;
+ }
+ }
+*sptr = s;
+return x;
+}
+
+
+static int eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
+{
+uschar *s = *sptr;
+int x = eval_op_xor(&s, decimal, error);
+if (*error == NULL)
+ {
+ while (*s == '|')
+ {
+ int y;
+ s++;
+ y = eval_op_xor(&s, decimal, error);
+ if (*error != NULL) break;
+ x |= y;
+ }
+ }
+*sptr = s;
+return x;
+}
+
/*************************************************
git://git.exim.org / exim.git / blobdiff