DISABLE_STDIO/ENABLE_DEBUG macros to rename; close #3014

changes:
 * rename DISABLE_STDIO -> MRB_DISABLE_STDIO
 * rename ENABLE_DEBUG -> MRB_ENABLE_DEBUG_HOOK
 * no more opposite macro definitions (e.g. ENABLE_STDIO, DISABLE_DEBUG).
 * rewrite above macro references throughout the code.
 * update documents

1 files changed, 5 insertions, 16 deletions

diff --git a/src/print.c b/src/print.c
index 077fa4f06..111145a34 100644
--- a/src/print.c
+++ b/src/print.c
@@ -8,7 +8,7 @@
 #include "mruby/string.h"
 #include "mruby/variable.h"
 
-#ifdef ENABLE_STDIO
+#ifndef MRB_DISABLE_STDIO
 static void
 printstr(mrb_value obj, FILE *stream)
 {
@@ -24,35 +24,24 @@ printstr(mrb_value obj, FILE *stream)
 MRB_API void
 mrb_p(mrb_state *mrb, mrb_value obj)
 {
-  mrb_value val = mrb_inspect(mrb, obj);
-
-  printstr(val, stdout);
+  printstr(mrb_inspect(mrb, obj), stdout);
 }
 
 MRB_API void
 mrb_print_error(mrb_state *mrb)
 {
-  mrb_value s;
-
   mrb_print_backtrace(mrb);
-  s = mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0);
-  printstr(s, stderr);
+  printstr(mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0), stderr);
 }
 
 MRB_API void
 mrb_show_version(mrb_state *mrb)
 {
-  mrb_value msg;
-
-  msg = mrb_const_get(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_DESCRIPTION"));
-  printstr(msg, stdout);
+  printstr(mrb_const_get(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_DESCRIPTION")), stdout);
 }
 
 MRB_API void
 mrb_show_copyright(mrb_state *mrb)
 {
-  mrb_value msg;
-
-  msg = mrb_const_get(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_COPYRIGHT"));
-  printstr(msg, stdout);
+  printstr(mrb_const_get(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_COPYRIGHT")), stdout);
 }