RFR: 8338851: Hoist os::Posix::realpath() to os::realpath() and implement on Windows [v2]

[Thomas Stuefe]

On Wed, 4 Sep 2024 20:10:54 GMT, Simon Tooke <stooke at openjdk.org> wrote:

>> This PR changes the status of realpath() from a Posix-specific API to a globally available API, i.e. adding it to the "Hotspot Porting API".  Code would refer to os::realpath() instead of os::Posix::realpath().
>> 
>> This requires the addition of a stub routine in os_posix.cpp and a Windows implementation of realpath(), using Windows _fullpath().
>> 
>> This PR depends on #20597 in that it removes the need for one #ifdef in that PR.  Because of that, this PR will be modified when and if #20597 is integrated.
>> 
>> Please note that guidelines for doing this appear in src/hotspot/share/runtime/os.hpp
>
> Simon Tooke has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - simplify windwos realpath() implementation
>  - get rid of os::posix::realpath() and os::win32::realpath()

Looks good, thanks for the work. One question inline.

src/hotspot/os/windows/os_windows.cpp line 5327:

> 5325: 
> 5326:   char* result = nullptr;
> 5327:   ALLOW_C_FUNCTION(::_fullpath, result = ::_fullpath(outbuf, filename, outbuflen);)

Would this work for non-Latin-1 utf-8?

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Marked as reviewed by stuefe (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20683#pullrequestreview-2282041961
PR Review Comment: https://git.openjdk.org/jdk/pull/20683#discussion_r1744925864