There was a problem with visibility state from proc that straddles a fiber or is independent.
Therefore, it has been changed to give priority to env objects, if any.
Also, added "separate module" flag to block traversal to a higher level env object.
Note that the "separate module" flag is now set when calling blocks with the `mrb_yield_with_class()` function.
fixed https://github.com/mruby/mruby/issues/6494
Set `env->cxt` to `NULL` when it is detached from the call frame.
In other words, we can determine if `env->cxt` is `NULL` or not.
Also, `mruby-binding` had been setting `env->cxt` unnecessarily, so this has been fixed.
- Don't create multiple envs on one ci.
- Don't share a env to different ci.
- Don't attach a closed env to any ci.
Changes in `envadjust()` can be simplified with those guarantees.
The purpose is to remove the `mid` field from the `mrb_cache_entry` structure.
The resulting RAM requirement for the method cache is reduced from 5 words per entry to 4 words per entry for 32-bit CPUs.
The relevant changes are as follows:
- Removed `MRB_USE_METHOD_T_STRUCT`.
The `mrb_method_t` type is now always defined as a structure.
- Include method IDs in `mrb_method_t`
Change the `flags` member to `uint32_t`.
The bitstring structure should be the same as the keys of the `mt` table in `class.c`.
I believe the impact on API compatibility with previous versions is minimal.
Since `Env` objects are shared by Blocks/Procs in the same context,
making multiple aliases in one context screws up with alias names.
New implementation uses alias bodies (Procs) to refer new names.
As a side effect, `__callee__` stop working correctly for aliases.
To fix this `__callee__` problem, we need to keep alias method names in
`callinfo`, which consumes more memory. We are wondering that is worth
the compatibility.
The `REnv` object is difficult to deal with, and it would be ideal if the user did not have to manipulate it directly.
In some previous situations, it was necessary to call `mrb_env_unshare()`, a non-API function, after `mrb_load_string()` or similar.
With this patch, it is no longer necessary for users to use `mrb_env_unshare()` directly, as it is now handled internally simply by using the `mrb_vm_ci_env_clear()` function.
Also, `mrb_vm_ci_env_set()` is demoted from the `MRB_API` function for the same reason.
ref. commit 1ab3da6f08
Exception raising can now be controlled by the caller.
The main purpose on this patch is:
- Suppress exceptions from `obj_free()` in `src/gc.c` with `mrb_env_unshare()`.
- Consider the possibility that calls to `mrb_malloc()` may cause `e` objects to be subject to GC.
When control is returned to `mrb_env_unshare()`, `struct free_obj::next` in the same offset as `struct REnv::stack` is rewritten.
Unexpected results then occur when the object is reused.
Also, if `mrb_heap_page` containing an `e` object is freed, it may cause `SIGSEGV` at that point.
- Protects the value of the stack on `callinfo` that just exits if GC occurs inside `mrb_env_unshare()`.
```ruby
def m
b = -> { b }
end
p m.call
# => print block object, not nil
```
This patch does not raise a `NoMemoryError` exception in `mrb_env_unshare()` and can detect that error.
Thus, the problem fixed in # 3087 is not resurrected.
Also, it may seem that this patch should suppress exceptions raised by `cipop()` during `mrb_protect_error()` and `mrb_vm_exec()` unwinds.
However, `mrb_callinfo::u.env` by `CINFO_DIRECT` is not seen to be set.
So in that case `mrb_env_unshare()` is assumed to be originally exception-free.
Internal functions can only be called from within the library.
Functions listed in `mruby/internal.h` can be called from:
* core (src/*.c)
* gems (mrbgems/**/*.c)
But not from the application linked with `libmruby`.
The `__id__` method implemented in the C function has `MRB_ARGS_NONE()` specified, but it is also effective in the following cases.
```ruby
p nil.__id__ opts: 1 rescue p :a
p nil.method(:__id__).call 1 rescue p :b
p nil.method(:__id__).call opts: 1 rescue p :c
p nil.method(:__id__).to_proc.call 1 rescue p :d
p nil.method(:__id__).to_proc.call opts: 1 rescue p :e
p nil.method(:__id__).unbind.bind_call nil, 1 rescue p :f
p nil.method(:__id__).unbind.bind_call nil, opts: 1 rescue p :g
p nil.__send__ :__id__, 1 rescue p :h
p nil.__send__ :__id__, opts: 1 rescue p :i
```
After applying this patch, all items will output symbols in the same way as CRuby.
For this purpose, add `MRB_PROC_NOARG` to `struct RProc::flags`.
This enhances self-containment.
- Changed the `mrb_callinfo::pc` field to point to itself.
Previously it indicated the return destination of the previous call level.
`mrb_callinfo::pc` will now hold the address to its own `proc->body.irep->iseq`.
- Removed `mrb_callinfo::err` field.
This is because `mrb_callinfo::pc - 1` is semantically the same as the previous `err`.
- The `pc0` and `pc_save` variables in `mrb_vm_exec()` are no longer needed and have been deleted.
- It removes the argument because `cipush()` doesn't need to save the previous `pc`.
`MRB_METHOD_TABLE_INLINE` was fragile. It requires `-falign-functions=n`.
On platform that uses higher bits of function pointers, you can use new
`MRB_METHOD_T_STRUCT` configuration macro.
So you don't need `-falign-functions=2` anymore. Instead your platform
must not use higher bits of the pointer (true for most platforms).
If not, you have to use `struct mrb_method_t` version.
Yukihiro "Matz" Matsumoto