Previously the following code did not produce the expected results:
```ruby
bx = binding
block = bx.eval("a = 1; proc { a }")
bx.eval("a = 2")
p block.call # Expect 2 but return 1 due to a bug
```
The previous implementation of `Binding#eval` evaluated the code and then merged the top layer variables.
This patch will parse and expand the variable space before making a call to `eval`.
This means that the call to `Binding#eval` will do the parsing twice.
In addition, the following changes will be made:
- Make `mrb_parser_foreach_top_variable()`, `mrb_binding_extract_proc()` and `mrb_binding_extract_env()` functions private global functions.
- Remove the `posthook` argument from `mrb_exec_irep()`.
The `posthook` argument was introduced to implement the `binding` method.
This patch is unnecessary because it uses a different implementation method.
ref #5362fixed#5491
- ` mrb_block_given_p()` -- The name comes from CRuby's `rb_block_given_p ()`
At the same time, it applies to `f_instance_eval()` and `f_class_eval()` of `mruby-eval`.
Change the old `mrb_exec_irep()` as-is to static `mrb_exec_irep_vm()`.
Extract the VM entry part from the old `exec_irep()` in `mruby-eval/src/eval.c` and make it the core of the new `mrb_exec_irep()`.
- Added to `mruby-binding-core`
- `Binding#local_variable_defined?`
- `Binding#local_variable_get`
- `Binding#local_variable_set`
- `Binding#local_variables`
- `Binding#receiver`
- `Binding#source_location`
- `Binding#inspect`
- Added to `mruby-proc-binding`
- `Proc#binding`
The reason for separating `Proc#binding` is that core-mrbgems has a method that returns a closure object to minimize possible problems with being able to manipulate internal variables.
By separating it as different mrbgem, each user can judge this problem and incorporate it arbitrarily.
Instead of including `mruby/presym.h` everywhere, we provided the
fallback `mruby/presym.inc` under `include/mruby` directory, and specify
`-I<build-dir>/include` before `-I<top-dir>/include` in `presym.rake`.
So even when someone drops `-I<build-dir>/include` in compiler options,
it just compiles without failure.
This enhances self-containment.
Previously `mrb_context::stack` had the current call level stack, but now it owns it.
The `mrb_context::stack` field, which is no longer needed, will be removed.
The comment says that if `mrb_parse_nstring()` returns `NULL`, it is only out of memory.
I'm worried about compatibility if I set the exception class to `NoMemoryError`, so it's still `RuntimeError`.
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.
We assume meta-programming is less used in embedded environments.
We have moved following methods:
* Kernel module
global_variables, local_variables, singleton_class,
instance_variables, instance_variables_defined?, instance_variable_get,
instance_variable_set, methods, private_methods, public_methods,
protected_methods, singleton_methods, define_singleton_methods
* Module class
class_variables, class_variables_defined?, class_variable_get,
class_variable_set, remove_class_variable, included_modules,
instance_methods, remove_method, method_removed, constants
* Module class methods
constants, nesting
Note:
Following meta-programming methods are kept in the core:
* Module class
alias_method, undef_method, ancestors, const_defined?, const_get,
const_set, remove_const, method_defined?, define_method
* Toplevel object
define_method
`mruby-metaprog` gem is linked by default (specified in default.gembox).
When it is removed, it will save 40KB (stripped:8KB) on x86-64
environment last time I measured.
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`.
Yukihiro "Matz" Matsumoto