The catch handler table is combined with iseq block.
This is to prevent the structure from growing by adding a field for the
catch handler table to the `mrb_irep` structure.
"iseq block" and "catch handler table":
[number of catch handler table (2 bytes)]
[number of byte code (4 bytes)]
[iseq (any bytes)]
[catch handlers (multiple of 7 bytes)]
catch handler:
[catch type (1 byte)]
[begin offset (2 bytes)]
[end offset (2 bytes)]
[target offset (2 bytes)]
catch type: enum mrb_catch_type (0 = rescue, 1 = ensure)
begin offset: Includes the specified instruction address
end offset: Does not include the specified instruction address
target offset: replaces pc with the specified instruction address
This table is not expanded by `read_irep_record_1()`.
The necessary elements are expanded one by one when used.
Type `mrbc -S -B<init> -o<outfile> <rbfiles...>` to generate the C
source code that holds compiled `mrb_irep`.
Appending the following code to the bottom of the generated code,
`mruby` executes the compiled code:
```C
int
main()
{
mrb_state *mrb = mrb_open();
struct RProc *p = mrb_proc_new(mrb, &init_irep);
mrb_vm_run(mrb, p, mrb_top_self(mrb), 0);
mrb_close(mrb);
return 0;
}
```
Eventually static compile should use this representation, instead
of `uint8_t` array that holds `mrb` data, so that we can skip
interpreting `mrb` data.
Changes:
- `pool format is completely replaced
- supported types: `STR`, `INT32`, `INT64`, `FLOAT`
- `FLOAT` may be replaced by binary representation in the future
- insert `NUL` after string literals in `mrb` files
- `irep->pool` no longer store values in `mrb_value`
- instead it stores in `mrb_pool_value`
- less allocation
- `mrb_irep` can be stored in ROM
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`.
Instead of `irep -> proc` chain, we use `irep -> irep` chain to
avoid GC bugs like #3804. We added `target_class` reference to
`mrb_irep` struct. That means one more word consumption per `irep`.
Issue #1137.
In the present implementation, when calling mrb_load_string continuously, irep is not released.
Therefore, a 16-bit index was overflowing.
dearblue