shell/math: return string error indicator, not integer
function old new delta
expand_and_evaluate_arith 87 106 +19
expand_one_var 1563 1570 +7
arith 12 18 +6
evaluate_string 678 680 +2
arith_apply 1269 1271 +2
builtin_umask 133 132 -1
ash_arith 118 75 -43
expand_vars_to_list 1094 1038 -56
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/3 up/down: 36/-100) Total: -64 bytes
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/shell/math.c b/shell/math.c
index 8397157..871c06c 100644
--- a/shell/math.c
+++ b/shell/math.c
@@ -26,26 +26,26 @@
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/* Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com>
-
- Permission is hereby granted, free of charge, to any person obtaining
- a copy of this software and associated documentation files (the
- "Software"), to deal in the Software without restriction, including
- without limitation the rights to use, copy, modify, merge, publish,
- distribute, sublicense, and/or sell copies of the Software, and to
- permit persons to whom the Software is furnished to do so, subject to
- the following conditions:
-
- The above copyright notice and this permission notice shall be
- included in all copies or substantial portions of the Software.
-
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
- IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
- CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
- TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
- SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*/
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
/* This is my infix parser/evaluator. It is optimized for size, intended
* as a replacement for yacc-based parsers. However, it may well be faster
@@ -60,9 +60,6 @@
* this is based (this code differs in that it applies operators immediately
* to the stack instead of adding them to a queue to end up with an
* expression).
- *
- * To use the routine, call it with an expression string and error return
- * pointer
*/
/*
@@ -250,7 +247,7 @@
static arith_t FAST_FUNC
evaluate_string(arith_state_t *math_state, const char *expr);
-static int
+static const char*
arith_lookup_val(arith_state_t *math_state, v_n_t *t)
{
if (t->var) {
@@ -264,8 +261,8 @@
*/
for (cur = math_state->list_of_recursed_names; cur; cur = cur->next) {
if (strcmp(cur->var, t->var) == 0) {
- /* Yes. Expression recursion loop detected */
- return -5;
+ /* Yes */
+ return "expression recursion loop detected";
}
}
@@ -281,7 +278,7 @@
/* pop current var name */
math_state->list_of_recursed_names = cur;
- return math_state->errcode;
+ return math_state->errmsg;
}
/* treat undefined var as 0 */
t->val = 0;
@@ -292,14 +289,14 @@
/* "Applying" a token means performing it on the top elements on the integer
* stack. For an unary operator it will only change the top element, but a
* binary operator will pop two arguments and push the result */
-static NOINLINE int
+static NOINLINE const char*
arith_apply(arith_state_t *math_state, operator op, v_n_t *numstack, v_n_t **numstackptr)
{
#define NUMPTR (*numstackptr)
v_n_t *numptr_m1;
arith_t numptr_val, rez;
- int err;
+ const char *err;
/* There is no operator that can work without arguments */
if (NUMPTR == numstack)
@@ -399,13 +396,13 @@
} else if (op == TOK_EXPONENT) {
arith_t c;
if (numptr_val < 0)
- return -3; /* exponent less than 0 */
+ return "exponent less than 0";
c = 1;
while (--numptr_val >= 0)
c *= rez;
rez = c;
- } else if (numptr_val==0) /* zero divisor check */
- return -2;
+ } else if (numptr_val == 0)
+ return "divide by zero";
else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
rez /= numptr_val;
else if (op == TOK_REM || op == TOK_REM_ASSIGN)
@@ -430,9 +427,9 @@
numptr_m1->val = rez;
/* erase var name, it is just a number now */
numptr_m1->var = NULL;
- return 0;
+ return NULL;
err:
- return -1;
+ return "arithmetic syntax error";
#undef NUMPTR
}
@@ -498,7 +495,7 @@
evaluate_string(arith_state_t *math_state, const char *expr)
{
operator lasttok;
- int errcode;
+ const char *errmsg;
const char *start_expr = expr = skip_whitespace(expr);
unsigned expr_len = strlen(expr) + 2;
/* Stack of integers */
@@ -512,7 +509,7 @@
operator *stackptr = stack;
*stackptr++ = lasttok = TOK_LPAREN; /* start off with a left paren */
- errcode = 0;
+ errmsg = NULL;
while (1) {
const char *p;
@@ -548,7 +545,7 @@
}
if (numstack->var) {
/* expression is $((var)) only, lookup now */
- errcode = arith_lookup_val(math_state, numstack);
+ errmsg = arith_lookup_val(math_state, numstack);
}
goto ret;
}
@@ -663,8 +660,8 @@
break;
}
}
- errcode = arith_apply(math_state, prev_op, numstack, &numstackptr);
- if (errcode)
+ errmsg = arith_apply(math_state, prev_op, numstack, &numstackptr);
+ if (errmsg)
goto ret;
}
if (op == TOK_RPAREN) {
@@ -678,15 +675,17 @@
} /* while (1) */
err:
- numstack->val = errcode = -1;
+ numstack->val = -1;
+ errmsg = "arithmetic syntax error";
ret:
- math_state->errcode = errcode;
+ math_state->errmsg = errmsg;
return numstack->val;
}
arith_t FAST_FUNC
arith(arith_state_t *math_state, const char *expr)
{
+ math_state->errmsg = NULL;
math_state->list_of_recursed_names = NULL;
return evaluate_string(math_state, expr);
}