tree e3df93d58e7acc563edc54fd222a6282f0f206e6
parent 70fe6ad535365de20c3a960dcfe97bd5cf68abb5
author Tom Eccles <tom.eccles@arm.com> 1713259526 +0100
committer GitHub <noreply@github.com> 1713259526 +0100
gpgsig -----BEGIN PGP SIGNATURE-----
 
 wsFcBAABCAAQBQJmHkQGCRC1aQ7uu5UhlAAAcfkQADrGLioKRYDbkV+l326aDBbX
 LRLgAnI4W+xAVwQrpNnddAKbiTYvO3WQHlkq0g2l7ucLZ2ThW0Pggz3is2hvpXoy
 vTm8K3zjqYdTPc0FYNF1Pnu0a7AC5Cm5rQsrLG/J7ZFmzdiBibDWbKnY8XEf3M/S
 RT/vGEGqJrU0/PitQ5oGh/sUsrmcXicIcZgiZdTzFWYv/fO0Qf3hpRzupcMMZEev
 7oznsFrws/KPRfHy5ijOVc9F/Fn6GMqnyiCYeTx4CmTLgxHDNACzhqV7zQGcsOvj
 mOg4GfupomcUHmDKR6TnE0cwukgufEIjGhGt0OPoCC9T00NCKRScBef+ycOXyVVF
 9Ak0i8W7k2ImPfHcgZiEOdOJP0LMYu4+DP5NDwjsUG7apPhN2a1E2OzLbY17rRpd
 45yUdJoQ+F5j9QYscSdE+phkBlYOTPOU/VlXd6VdXgo2xZc9V8lPpZjGV3HNzCQJ
 uKDqfV2+fK+O9MbrvNQH1jPlPY6TIrx/u5Oq+fto63IwW8JHnl6mkMq57BBYqRO9
 XhdgO9P7sCgkmjmH45GdVEWAlk2KlV56JTU6j07zHjBBpF1sabQu+wmnsfRhGe5m
 fcmAq+pbuFSVF0g0DhKrP/O25Zyn5/WK8q3bazyO6wB4phPMSxaNqVZZNvUrVq75
 WKyZsXsWkoHu84AlAJKa
 =352z
 -----END PGP SIGNATURE-----
 

[flang][runtime] Add ACCESS library procedure (#88517)

Re-land https://github.com/llvm/llvm-project/pull/88395

Two build-bots were broken by the old version:
 - https://lab.llvm.org/buildbot/#/builders/285/builds/245
 - https://lab.llvm.org/buildbot/#/builders/21/builds/96988

The problem in both cases was that the compiler did not support
`std::filesystem` (which I use in the unit test).

I have removed the dependency upon std::filesystem because there isn't
an easy way to add the right linker options so that this is supported
correctly in all build environments [1]

[1] https://gitlab.kitware.com/cmake/cmake/-/issues/17834

---

This is a GNU extension:
https://gcc.gnu.org/onlinedocs/gfortran/ACCESS.html

Used in SALMON:
https://salmon-tddft.jp/download.html

Unfortunately the intrinsic takes a file path to operate on so there
isn't an easy way to make the test robust. The unit test expects to be
able to create, set read write and execute permissions, and delete files
called
std::filesystem::temp_directory_path() / <test_name>.<pid>

The test will fail if a file already exists with that name.

I have not implemented the intrinsic on Windows because this is wrapping
a POSIX system call and Windows doesn't support all of the permission
bits tested by the intrinsic. I don't have a Windows machine easily
available to check if Gfortran implements this intrinsic on Windows.