Merge pull request #407 from s-hadinger/walrus_index_member

Fix walrus with member or index

src/be_code.c

@@ -721,10 +721,14 @@ int be_code_setvar(bfuncinfo *finfo, bexpdesc *e1, bexpdesc *e2, bbool keep_reg)
         setsupvar(finfo, OP_SETUPV, e1, src);
         break;
     case ETMEMBER: /* store to member R(A).RK(B) <- RK(C) */
-        setsfxvar(finfo, OP_SETMBR, e1, src);
-        break;
     case ETINDEX: /* store to member R(A)[RK(B)] <- RK(C) */
-        setsfxvar(finfo, OP_SETIDX, e1, src);
+        setsfxvar(finfo, (e1->type == ETMEMBER) ? OP_SETMBR : OP_SETIDX, e1, src);
+        if (keep_reg && e2->type == ETREG && e1->v.ss.obj >= be_list_count(finfo->local)) {
+            /* special case of walrus assignemnt when we need to recreate an ETREG */
+            code_move(finfo, e1->v.ss.obj, src);    /* move from ETREG to MEMBER instance*/
+            free_expreg(finfo, e2); /* free source (checks only ETREG) */
+            e2->v.idx = e1->v.ss.obj; /* update to new register */
+        }
         break;
     default:
         return 1;

tests/walrus.be

@@ -33,3 +33,40 @@ assert_attribute_error("var a,b def f() a end")
 
 # while the following does have side effect
 def f() a := b end
+
+# bug when using walrus with member
+def id(x) return x end
+var a = 1
+import global
+def f() return id(global.a := 42) end
+assert(f() == 42)
+# bug: returns <module: global>
+
+def concat(x, y, z) return str(x)+str(y)+str(z) end
+var a = 1
+import global
+def f() return concat(global.a := 1, global.a := 42, global.a := 0) end
+assert(f() == "1420")
+# bug: returns '1<module: global>42'
+
+# same bug when using index
+def id(x) return x end
+l = [10,11]
+import global
+def f() return id(global.l[0] := 42) end
+assert(f() == 42)
+# bug: returns [42, 11]
+
+# bug when using member for self
+class confused_walrus
+    var b
+    def f()
+        var c = 1
+        if self.b := true
+            c = 2
+        end
+        return self
+    end
+end
+var ins = confused_walrus()
+assert(ins.f() == ins)