check and show a warning for incorrect yield.

* compile.c (check_yield_place): this function check the yield location.
  * show a warning if yield in `class` syntax. [Feature #15575]

  * do strict check for toplevel `yield`. Without this patch,
    `1.times{ yield }` in toplevel is valid-syntax (raise LocalJumpError
    at runtime) although toplevel simple `yield` is not valid syntax.
    This patch make them syntax error.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66999 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 19 insertions, 4 deletions

diff --git a/compile.c b/compile.c
index 5fe4febac5..4f76ee297b 100644
--- a/compile.c
+++ b/compile.c
@@ -5922,6 +5922,21 @@ qcall_branch_end(rb_iseq_t *iseq, LINK_ANCHOR *const ret, LABEL *else_label, VAL
 }
 
 static int
+check_yield_place(const rb_iseq_t *iseq)
+{
+    switch (iseq->body->local_iseq->body->type) {
+      case ISEQ_TYPE_TOP:
+      case ISEQ_TYPE_MAIN:
+        return FALSE;
+      case ISEQ_TYPE_CLASS:
+        rb_warn("`yield' in class syntax will not be supported from Ruby 3.0. [Feature #15575]");
+        return TRUE;
+      default:
+        return TRUE;
+    }
+}
+
+static int
 iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, int popped)
 {
     const int line = (int)nd_line(node);
@@ -6827,11 +6842,11 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *node, in
 	struct rb_call_info_kw_arg *keywords = NULL;
 
 	INIT_ANCHOR(args);
-	if (body->type == ISEQ_TYPE_TOP ||
-	    body->type == ISEQ_TYPE_MAIN) {
+
+        if (check_yield_place(iseq) == FALSE) {
 	    COMPILE_ERROR(ERROR_ARGS "Invalid yield");
-	    goto ng;
-	}
+            goto ng;
+        }
 
 	if (node->nd_head) {
 	    argc = setup_args(iseq, args, node->nd_head, &flag, &keywords);