Fix allocation-error-handlings for scope_new().

src/codegen.c

@@ -85,6 +85,7 @@ static void gen_assignment(codegen_scope *s, node *node, int sp, int val);
 static void gen_vmassignment(codegen_scope *s, node *tree, int rhs, int val);
 
 static void codegen(codegen_scope *s, node *tree, int val);
+static void raise_error(codegen_scope *s, const char *msg);
 
 static void
 codegen_error(codegen_scope *s, const char *message)
@@ -552,6 +553,10 @@ for_body(codegen_scope *s, node *tree)
   codegen(s, tree->cdr->car, VAL);
   /* generate loop-block */
   s = scope_new(s->mrb, s, NULL);
+  if (s == NULL) {
+    raise_error(s, "unexpected scope");
+  }
+
   push();                       /* push for a block parameter */
 
   lp = loop_push(s, LOOP_FOR);
@@ -589,6 +594,10 @@ lambda_body(codegen_scope *s, node *tree, int blk)
   mrb_code c;
   codegen_scope *parent = s;
   s = scope_new(s->mrb, s, tree->car);
+  if (s == NULL) {
+    raise_error(s, "unexpected scope");
+  }
+
   s->mscope = !blk;
 
   if (blk) {
@@ -674,6 +683,9 @@ static int
 scope_body(codegen_scope *s, node *tree, int val)
 {
   codegen_scope *scope = scope_new(s->mrb, s, tree->car);
+  if (scope == NULL) {
+    raise_error(s, "unexpected scope");
+  }
 
   codegen(scope, tree->cdr, VAL);
   if (!s->iseq) {