shell/math: code shrink

function                                             old     new   delta
evaluate_string                                     1489    1486      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 12 insertions, 11 deletions

diff --git a/shell/math.c b/shell/math.c
index 4c1b1b762..fee325307 100644
--- a/shell/math.c
+++ b/shell/math.c
@@ -264,10 +264,9 @@ static ALWAYS_INLINE int isalnum_(int c)
 static arith_t
 evaluate_string(arith_state_t *math_state, const char *expr);
 
-static const char*
-arith_lookup_val(arith_state_t *math_state, var_or_num_t *t)
+static arith_t
+arith_lookup_val(arith_state_t *math_state, const char *name)
 {
-        const char *name = t->var_name;
         char c;
         const char *p;
         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);
         *e = c;
         if (p) {
+                arith_t val;
                 size_t len = e - name;
                 remembered_name *cur;
                 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])
                         ) {
                                 /* 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;
 
                 /* 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 */
                 math_state->list_of_recursed_names = remember.next;
 
-                return math_state->errmsg;
+                return val;
         }
         /* treat undefined var as 0 */
-        t->val = 0;
-        return NULL;
+        return 0;
 }
 
 /* "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 "==..." */
                                 ) {
                                         /* Evaluate variable to value */
-                                        errmsg = arith_lookup_val(math_state, numstackptr);
-                                        if (errmsg)
-                                                goto err_with_custom_msg;
+                                        numstackptr->val = arith_lookup_val(math_state, numstackptr->var_name);
+                                        if (math_state->errmsg)
+                                                return numstackptr->val; /* -1 */
                                 }
                         } else {
                                 dbg("[%d] var:IGNORED", (int)(numstackptr - numstack));