RFR: 8338851: Hoist os::Posix::realpath() to os::realpath() and implement on Windows [v20]

[Simon Tooke]

On Wed, 16 Oct 2024 00:02:13 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Simon Tooke has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   clean up test code
>
> test/hotspot/gtest/runtime/test_os.cpp line 413:
> 
>> 411: 
>> 412: TEST_VM(os, realpath) {
>> 413:   /* POSIX requires that the file exists, Windows doesn't */
> 
> I'm not sure what this comment means. I can't fully discern from
> 
> https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/fullpath-wfullpath?view=msvc-170
> 
> what Windows does if the path does not exist.

I can only report by example - on my local machine, Windows doesn't appear to care if the file exists or not, but according to the docs you point to, Windows **does** care if the drive letter is valid.
Adding an invalid drive letter test is beyond the current scope of this test.
I have expanded this comment to be more explanatory:

`// POSIX requires that the file exists; `
`// Windows tests for a valid drive letter but may or may not test if the file exists.`

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PR Review Comment: https://git.openjdk.org/jdk/pull/20683#discussion_r1803033957