drop-in type check for rb_define_global_function

We can check the function pointer passed to rb_define_global_function
like we do so in rb_define_method.  It turns out that almost anybody
is misunderstanding the API.

1 files changed, 14 insertions, 2 deletions

diff --git a/proc.c b/proc.c
index 1b8aa3953b..7a5ccd3508 100644
--- a/proc.c
+++ b/proc.c
@@ -836,6 +836,12 @@ rb_block_proc(void)
     return proc_new(rb_cProc, FALSE);
 }
 
+static VALUE
+f_proc(VALUE _)
+{
+    return rb_block_proc();
+}
+
 /*
  * call-seq:
  *   lambda { |...| block }  -> a_proc
@@ -850,6 +856,12 @@ rb_block_lambda(void)
     return proc_new(rb_cProc, TRUE);
 }
 
+static VALUE
+f_lambda(VALUE _)
+{
+    return rb_block_lambda();
+}
+
 /*  Document-method: Proc#===
  *
  *  call-seq:
@@ -3623,8 +3635,8 @@ Init_Proc(void)
     rb_vm_register_special_exception(ruby_error_sysstack, rb_eSysStackError, "stack level too deep");
 
     /* utility functions */
-    rb_define_global_function("proc", rb_block_proc, 0);
-    rb_define_global_function("lambda", rb_block_lambda, 0);
+    rb_define_global_function("proc", f_proc, 0);
+    rb_define_global_function("lambda", f_lambda, 0);
 
     /* Method */
     rb_cMethod = rb_define_class("Method", rb_cObject);