__builtin_inline!

Add an experimental `__builtin_inline!(c_expression)` special intrinsic
which run a C code snippet.
In `c_expression`, you can access the following variables:
  * ec (rb_execution_context_t *)
  * self (const VALUE)
  * local variables (const VALUE)
Not that you can read these variables, but you can not write them.
You need to return from this expression and return value will be a
result of __builtin_inline!().

Examples:
  `def foo(x) __builtin_inline!('return rb_p(x);'); end` calls `p(x)`.
  `def double(x) __builtin_inline!('return INT2NUM(NUM2INT(x) * 2);')`
  returns x*2.

1 files changed, 13 insertions, 0 deletions

diff --git a/builtin.h b/builtin.h
index ee99e21dcc..236dfd961c 100644
--- a/builtin.h
+++ b/builtin.h
@@ -43,6 +43,19 @@ static inline void rb_builtin_function_check_arity13(VALUE (*f)(rb_execution_con
 static inline void rb_builtin_function_check_arity14(VALUE (*f)(rb_execution_context_t *ec, VALUE self, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE)){}
 static inline void rb_builtin_function_check_arity15(VALUE (*f)(rb_execution_context_t *ec, VALUE self, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE, VALUE)){}
 
+VALUE rb_vm_lvar_exposed(rb_execution_context_t *ec, int index);
+
+// inline
+inline VALUE
+rb_vm_lvar(rb_execution_context_t *ec, int index)
+{
+#if VM_CORE_H_EC_DEFINED
+    return ec->cfp->ep[index];
+#else
+    return rb_vm_lvar_exposed(ec, index);
+#endif
+}
+
 // dump/load
 
 struct builtin_binary {