Clean up from-import handling.

diff --git a/Python/ast.c b/Python/ast.c
index 25775a4222a040d62c53970f6a4ef13cbe07e60b..54bdacc977fb0e1fc26b5c0bb70b91baa4e83f53 100644 (file)
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -2170,44 +2170,43 @@ ast_for_import_stmt(struct compiling *c, const node *n)
     }
     else if (STR(CHILD(n, 0))[0] == 'f') { /* from */
         int n_children;
-        const char *from_modules;
        int lineno = LINENO(n);
        alias_ty mod = alias_for_import_name(c, CHILD(n, 1));
        if (!mod)
             return NULL;
 
-        /* XXX this needs to be cleaned up */
-
-        from_modules = STR(CHILD(n, 3));
-        if (!from_modules) {
-            n = CHILD(n, 3);                  /* from ... import x, y, z */
-            if (NCH(n) % 2 == 0) {
-                /* it ends with a comma, not valid but the parser allows it */
+        switch (TYPE(CHILD(n, 3))) {
+        case STAR:
+            /* from ... import * */
+           n = CHILD(n, 3);
+           n_children = 1;
+           break;
+       case LPAR:
+           /* from ... import (x, y, z) */
+           n = CHILD(n, 4);
+           n_children = NCH(n);
+           break;
+       case import_as_names:
+           /* from ... import x, y, z */
+           n = CHILD(n, 3);
+           n_children = NCH(n);
+            if (n_children % 2 == 0) {
                 ast_error(n, "trailing comma not allowed without"
                              " surrounding parentheses");
                 return NULL;
             }
-        }
-        else if (from_modules[0] == '*') {
-            n = CHILD(n, 3); /* from ... import * */
-        }
-        else if (from_modules[0] == '(')
-            n = CHILD(n, 4);                  /* from ... import (x, y, z) */
-        else {
-           /* XXX: don't we need to call ast_error(n, "..."); */
-            return NULL;
+           break;
+       default:
+           ast_error(n, "Unexpected node-type in from-import");
+           return NULL;
        }
 
-        n_children = NCH(n);
-        if (from_modules && from_modules[0] == '*')
-            n_children = 1;
-
        aliases = asdl_seq_new((n_children + 1) / 2, c->c_arena);
        if (!aliases)
             return NULL;
 
         /* handle "from ... import *" special b/c there's no children */
-        if (from_modules && from_modules[0] == '*') {
+        if (TYPE(n) == STAR) {
             alias_ty import_alias = alias_for_import_name(c, n);
             if (!import_alias)
                 return NULL;