To be also able to build mruby without presym in the future. However,
`MRB_QSYM` has been removed and changed as follows:
### Example
| Type | Symbol | Previous Style | New Style |
|---------------------------|--------|------------------|----------------|
| Operator | & | MRB_QSYM(and) | MRB_OPSYM(and) |
| Class Variable | @@foo | MRB_QSYM(00_foo) | MRB_CVSYM(foo) |
| Instance Variable | @foo | MRB_QSYM(0_foo) | MRB_IVSYM(foo) |
| Method with Bang | foo! | MRB_QSYM(foo_b) | MRB_SYM_B(foo) |
| Method with Question mark | foo? | MRB_QSYM(foo_p) | MRB_SYM_Q(foo) |
| Mmethod with Equal | foo= | MRB_QSYM(foo_e) | MRB_SYM_E(foo) |
This change makes it possible to define, for example, `MRB_IVSYM(foo)` as
`mrb_intern_lit(mrb, "@" "foo")`, which is useful if we support building
without presym in the future.
New instructions:
* OP_LOADL16
* OP_LOADSYM16
* OP_STRING16
Size of pools, symbols are `int16_t` but offset representation in the
bytecode was 8 bits. Size of child `irep` array is `int16_t`, too but
this change does not address it.
- Integrate `Fixnum` and `Integer`
- Remove `Integral`
- `int / int -> int`
- Replace `mrb_fixnum()` to `mrb_int()`
- Replace `mrb_fixnum_value()` to `mrb_int_value()`.
- Use `mrb_integer_p()` instead of `mrb_fixnum_p()`
- `MRB_WITHOUT_FLOAT` => `MRB_NO_FLOAT`
- `MRB_USE_FLOAT` => `MRB_USE_FLOAT32`
The former is to use `USE_XXX` naming convention. The latter is to make
sure `float` is 32bit float and not floating point number in general.
When a global jump occurs, look at the catch handler table to determine where to jump.
In that case, `pc` already shows the following instruction, but since the table shows `begin_offset ... end_offset`, the comparison is done with `begin_offset < pc && pc <= end_offset`.
If there is a corresponding handler, move `pc` to `handler.target_offset` and continue running the VM.
When a global jump across `ensure` is made by `return`, `break`, `next`, `redo` and `retry`, the extended `RBreak` object saves and restores the C-level execution position.
This extended `RBreak` can have tag information, which makes it a pseudo coroutine (the "tag" mimics CRuby).
The implementation of pseudo coroutines by `RBreak` is summarized by `CHECKPOINT_RESTORE ... CHECKPOINT_MAIN ... CHECKPOINT_END` and `throw_tagged_break` / `unwind_ensure` macros.
The restart of processing is branched by `RBREAK_TAG_FOREACH(DISPATCH_CHECKPOINTS)`.
- Not only `rescue` blocks but also `ensure` blocks are now sandwiched between `OP_EXCEPT` and `OP_RAISEIF`.
- Remove the function `ecall()`.
It is no longer necessary to re-enter the VM to perform an "ensure block".
This will resolves#1888.
- Added instruction `OP_JUW` (Jump while UnWind).
It jumps unconditionally like `OP_JMP`, but searches the catch handler table and executes the ensure block.
Since it searches the catch handler table, it is much heavier than `OP_JMP`.
- `OP_EXCEPT` checks if `mrb->exc` is `NULL`, `MRB_TT_EXCEPTION` or
`MRB_TT_BREAK`.
If `mrb->exc` is `NULL`, it will be replaced with `nil`.
- If `OP_RAISE` is `nil`, it does nothing and the immediately
following instruction is executed (like `OP_NOP`).
Also, in case of `RBreak` object, it moves to the processing for
`break`.
With this change, the instruction name is changed from
`OP_RAISE` to `OP_RAISEIF`.
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.
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
- 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`
```
It was making a negative integer if the highest-order bit of a 16-bit
integer was 1.
no patched:
```ruby
p 0x7fff # => 32767
p 0x8000 # => -32768
p 0xffff # => -1
p 0x10000 # => 65536
```
Which loads 16bit integer to the register. The instruction number should
be reorder on massive instruction refactoring. The instruction is added
for `mruby/c` which had performance issue with `OP_EXT`. With this
instruction, `mruby/c` VM can just raise errors on `OP_EXT` extension
instructions.
The basic idea of this change is from @dearblue.
Note: the arguments of `mrb_str_pool()` have changed, but the function
is provided for internal use (No `MRB_API`). So basically you don't have
to worry about the change.
Besides that fix bugs that mistakenly calls `raise_error` that emits
code to raise runtime error instead of `codegen_error` that terminates
code generation immediately.
But this changes requires `OP_ARYCAT` and `OP_ARYPUSH` to accept `nil`
as their first operand. Alternative VMs (e.g. `mruby/c`) that understand
mruby bytecode need to be updated.
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.
The addresses for packed inline symbols reference `mrb->symbuf` that
could be overridden by the later call of `mrb_sym2name_len`. Since
file names in call stack information are kept as symbols, keeping the
address in the C structures could cause problems like #4342.
This changes small incompatible changes in function prototypes:
* `mrb_parser_get_filename`: return value changed to `mrb_sym`.
* `mrb_debug_get_filename`: add `mrb_state*` as a first argument.
* `mrb_debug_get_line`: ditto.
I believe above functions are almost internal, and no third-party
mrbgem use them.
Yukihiro "Matz" Matsumoto