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shell/math: code shrink

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function                                             old     new   delta
evaluate_string                                     1489    1486      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2023-06-18 18:31:55 +02:00
parent c72c5552ed
commit 2d06c83b87
1 changed files with 12 additions and 11 deletions
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23
shell/math.c
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@ -264,10 +264,9 @@ static ALWAYS_INLINE int isalnum_(int c)
static arith_t static arith_t
evaluate_string(arith_state_t *math_state, const char *expr); evaluate_string(arith_state_t *math_state, const char *expr);
static const char* static arith_t
arith_lookup_val(arith_state_t *math_state, var_or_num_t *t) arith_lookup_val(arith_state_t *math_state, const char *name)
{ {
const char *name = t->var_name;
char c; char c;
const char *p; const char *p;
char *e = (char*)endofname(name); char *e = (char*)endofname(name);
@ -277,6 +276,7 @@ arith_lookup_val(arith_state_t *math_state, var_or_num_t *t)
p = math_state->lookupvar(name); p = math_state->lookupvar(name);
*e = c; *e = c;
if (p) { if (p) {
arith_t val;
size_t len = e - name; size_t len = e - name;
remembered_name *cur; remembered_name *cur;
remembered_name remember; remembered_name remember;
@ -289,7 +289,8 @@ arith_lookup_val(arith_state_t *math_state, var_or_num_t *t)
&& !isalnum_(cur->var_name[len]) && !isalnum_(cur->var_name[len])
) { ) {
/* yes */ /* yes */
return "expression recursion loop detected"; math_state->errmsg = "expression recursion loop detected";
return -1;
} }
} }
@ -299,16 +300,16 @@ arith_lookup_val(arith_state_t *math_state, var_or_num_t *t)
math_state->list_of_recursed_names = &remember; math_state->list_of_recursed_names = &remember;
/* recursively evaluate p as expression */ /* recursively evaluate p as expression */
t->val = evaluate_string(math_state, p); /* this sets math_state->errmsg on error */
val = evaluate_string(math_state, p);
/* pop current var name */ /* pop current var name */
math_state->list_of_recursed_names = remember.next; math_state->list_of_recursed_names = remember.next;
return math_state->errmsg; return val;
} }
/* treat undefined var as 0 */ /* treat undefined var as 0 */
t->val = 0; return 0;
return NULL;
} }
/* "Applying" a token means performing it on the top elements on the integer /* "Applying" a token means performing it on the top elements on the integer
@ -684,9 +685,9 @@ evaluate_string(arith_state_t *math_state, const char *expr)
|| expr[1] == '=' /* or "==..." */ || expr[1] == '=' /* or "==..." */
) { ) {
/* Evaluate variable to value */ /* Evaluate variable to value */
errmsg = arith_lookup_val(math_state, numstackptr); numstackptr->val = arith_lookup_val(math_state, numstackptr->var_name);
if (errmsg) if (math_state->errmsg)
goto err_with_custom_msg; return numstackptr->val; /* -1 */
} }
} else { } else {
dbg("[%d] var:IGNORED", (int)(numstackptr - numstack)); dbg("[%d] var:IGNORED", (int)(numstackptr - numstack));