The reason for this is to fix the following problems
- Even on non-Windows, drive letter recognition was still being handled.
- On Windows, paths starting with a slash were not expanded correctly.
- On Windows, relative paths containing drive letters behaved differently than in CRuby.
Due to reimplementation, the internal methods `File._concat_path`, `File._gethome` and `File._getwd` methods have been removed.
Change to `MRB_USE_IO_PREAD_PWRITE` for consistency with mruby configuration macros.
Similarly, `MRB_WITHOUT_IO_PREAD_PWRITE` is changed to `MRB_NO_IO_PREAD_PWRITE`.
The previous names are available for compatibility but are deprecated.
Since `mruby-io` does not depend on `mruby-env` even for test builds, it is impossible that `ENV` constants are defined.
Therefore, define `MRubyIOTestUtil::ENV_HOME` for alternative use.
It is available by default in environments where `__unix__` is defined.
Other environments are enabled by defining `MRB_WITH_IO_PREAD_PWRITE`
(requires an implementation of `pread()` and `pwrite()` functions).
In any case, you can disable it by defining
`MRB_WITHOUT_IO_PREAD_PWRITE`.
What I intended to fix in #4869 was a patch for an old MinGW.
Recent MinGWs have their own `mkstemp()` function.
I knew this after checking the patch #4903.
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.
Because it always allocate new string. Replace with the followings:
- Use `RSRING_PTR` if string is guaranteed to be null-terminated.
- Use `mrb_string_value_cstr` or `mrb_get_args("z")` if return value isn't
modified.
dearblue