The "a"/"*" specifier of the `mrb_get_args()` function will now return `const mrb_value *`.
This is because it is difficult for the caller to check if it is an array object and write-barrier if necessary.
And it requires calling `mrb_ary_modify()` on the unmodified array object, which is also difficult (this is similar to #5087).
- The `s` specifier is a string pointer obtained without performing `mrb_str_modify()`, so it cannot be changed.
- The `z` specifier cannot be changed because it is a string pointer obtained by `RSTRING_CSTR()` which returns `const char *`.
- It can now deal with operands in the range of `OP_EXT*`.
- It can now call the same method as the variable name without arguments.
```ruby
def a
"Safe!"
end
a = "Auto!"
eval "a()" # call method `a`
```
The binary sizes (gems are only `mruby-bin-mruby`) are reduced slightly in
my environment than before the introduction of new specifiers/modifiers
(5116789a) with this change.
------------+-------------------+-------------------+--------
BINARY | BEFORE (5116789a) | AFTER (This PR) | RATIO
------------+-------------------+-------------------+--------
mruby | 593416 bytes | 593208 bytes | -0.04%
libmruby.a | 769048 bytes | 767264 bytes | -0.23%
------------+-------------------+-------------------+--------
BTW, I accidentally changed `tasks/toolchains/visualcpp.rake` at #4613,
so I put it back.
Instead of `irep` links, we added a `upper` link to `struct RProc`.
To make a space for the `upper` link, we moved `target_class` reference.
If a `Proc` does not have `env`, `target_class` is saved in an `union`
shared with `env` (if a `Proc` has env, you can tell it by `MRB_PROC_ENV_P()).
Otherwise `target_class` is referenced from `env->c`. We removed links
in `env` as well.
This change removes 2 members from `mrb_irep` struct, thus saving 2
words per method/proc/block. This also fixes potential memory leaks
due to the circular references caused by a link from `mrb_irep`.
mrbgems/mruby-eval/src/eval.c: In function ‘create_proc_from_string’:
mrbgems/mruby-eval/src/eval.c:152:10: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
file = "(eval)";
^
dearblue