support builtin features with Ruby and C.

Support loading builtin features written in Ruby, which implement
with C builtin functions.
[Feature #16254]

Several features:

(1) Load .rb file at boottime with native binary.

Now, prelude.rb is loaded at boottime. However, this file is contained
into the interpreter as a text format and we need to compile it.
This patch contains a feature to load from binary format.

(2) __builtin_func() in Ruby call func() written in C.

In Ruby file, we can write `__builtin_func()` like method call.
However this is not a method call, but special syntax to call
a function `func()` written in C. C functions should be defined
in a file (same compile unit) which load this .rb file.

Functions (`func` in above example) should be defined with
  (a) 1st parameter: rb_execution_context_t *ec
  (b) rest parameters (0 to 15).
  (c) VALUE return type.
This is very similar requirements for functions used by
rb_define_method(), however `rb_execution_context_t *ec`
is new requirement.

(3) automatic C code generation from .rb files.

tool/mk_builtin_loader.rb creates a C code to load .rb files
needed by miniruby and ruby command. This script is run by
BASERUBY, so *.rb should be written in BASERUBY compatbile
syntax. This script load a .rb file and find all of __builtin_
prefix method calls, and generate a part of C code to export
functions.

tool/mk_builtin_binary.rb creates a C code which contains
binary compiled Ruby files needed by ruby command.

1 files changed, 11 insertions, 0 deletions

diff --git a/iseq.c b/iseq.c
index 0ca697ceb8..3cfb7602d0 100644
--- a/iseq.c
+++ b/iseq.c
@@ -12,6 +12,7 @@
 #include "internal.h"
 #include "ruby/util.h"
 #include "eval_intern.h"
+#include "builtin.h"
 
 #ifdef HAVE_DLADDR
 # include <dlfcn.h>
@@ -559,6 +560,8 @@ prepare_iseq_build(rb_iseq_t *iseq,
 
     ISEQ_COMPILE_DATA(iseq)->ivar_cache_table = NULL;
 
+    ISEQ_COMPILE_DATA(iseq)->builtin_function_table = GET_VM()->builtin_function_table;
+
     if (option->coverage_enabled) {
 	VALUE coverages = rb_get_coverages();
 	if (RTEST(coverages)) {
@@ -1968,6 +1971,14 @@ rb_insn_operand_intern(const rb_iseq_t *iseq,
 	}
 	break;
 
+      case TS_BUILTIN:
+        {
+            const struct rb_builtin_function *bf = (const struct rb_builtin_function *)op;
+            ret = rb_sprintf("<builtin!%s/%d>",
+                             bf->name, bf->argc);
+        }
+        break;
+
       default:
 	rb_bug("unknown operand type: %c", type);
     }