[flang-commits] [flang] [llvm] [flang] Implement 'F_C_STRING' library function (Fortran 2023) (PR #174474)

[Caroline Newcombe via flang-commits]

cenewcombe wrote:

> I'll run some internal testing and can help submit this PR once it's approved.
> 
> @cenewcombe , did you run llvm-test-suite with this change? There may be some gfortran tests that may need tweaking after this feature is implemented.

@eugeneepshteyn thanks! Let me know if there are any concerns with your testing. Otherwise, this should be ready to merge now. I do have one llvm-test-suite failure on this branch, but it does not seem related (fails if I build the branch before or after my commits).

```
-- Testing: 6926 tests, 224 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80
FAIL: test-suite :: Fortran/gfortran/regression/goacc/gfortran-regression-compile-regression__goacc__cache-1_f95.test (5768 of 6926)
******************** TEST 'test-suite :: Fortran/gfortran/regression/goacc/gfortran-regression-compile-regression__goacc__cache-1_f95.test' FAILED ********************

/lus/cflus04/canewcombe/flang/test-build-dir/tools/timeit-target --timeout 7200 --limit-core 0 --limit-cpu 7200 --limit-file-size 209715200 --limit-rss-size 838860800 --redirect-input /dev/null --summary /lus/cflus04/canewcombe/flang/test-build-dir/Fortran/gfortran/regression/goacc/Output/gfortran-regression-compile-regression__goacc__cache-1_f95.test.time /lus/cflus04/canewcombe/flang/test-build-dir/Fortran/gfortran/regression/goacc/../..//dummy
/usr/bin/diff /lus/cflus04/canewcombe/flang/test-build-dir/Fortran/gfortran/regression/goacc/../..//gfortran-compile-empty.reference.out /lus/cflus04/canewcombe/flang/test-build-dir/Fortran/gfortran/regression/goacc/gfortran-regression-compile-regression__goacc__cache-1_f95.out
0a1,2
> error: loc("/lus/cflus04/canewcombe/flang/llvm-test-suite/Fortran/gfortran/regression/goacc/cache-1.f95":11:11): /lus/cflus04/canewcombe/flang/llvm-project/flang/lib/Lower/OpenACC.cpp:4845: not yet implemented: OpenACC cache directive
> LLVM ERROR: aborting
\ No newline at end of file

+ /usr/bin/diff /lus/cflus04/canewcombe/flang/test-build-dir/Fortran/gfortran/regression/goacc/../..//gfortran-compile-empty.reference.out /lus/cflus04/canewcombe/flang/test-build-dir/Fortran/gfortran/regression/goacc/gfortran-regression-compile-regression__goacc__cache-1_f95.out

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
********************
Failed Tests (1):
  test-suite :: Fortran/gfortran/regression/goacc/gfortran-regression-compile-regression__goacc__cache-1_f95.test


Testing Time: 415.47s

Total Discovered Tests: 6926
  Passed: 6925 (99.99%)
  Failed:    1 (0.01%)
FAILED: CMakeFiles/check /lus/cflus04/canewcombe/flang/test-build-dir/CMakeFiles/check
```

https://github.com/llvm/llvm-project/pull/174474