[flang][test] Share all driver test dirs between `f18` and `flang-new`

[awarzynski]

Summary

Originally, when we added the new driver, we created dedicated test
directories for flang-new. This way we separated the tests for the
throwaway and the new driver.

As we are increasing test coverage and starting to share tests between
the two drivers, it makes sense to share all directories and instead
rely on:

! REQUIRES: new-flang-driver

to mark tests as exclusively for the new driver.

[tskeith]

It looks like there are other tests in Flang-Driver that can be run on f18 as well. That doesn't have to happen in this change if you prefer not to.

flang/test/Frontend/prescanner-diag.f90

5

I think you need to keep the %f18 command so that the test is run on f18 when the new driver is enabled. Unfortunately that means when it is disabled the same test is run on f18 three times, but none of these should take much time.

[awarzynski]

In D97207#2579523, @tskeith wrote:

It looks like there are other tests in Flang-Driver that can be run on f18 as well. That doesn't have to happen in this change if you prefer not to.

Thank you for reviewing Tim!

Yes, I'll port other tests separately. This patch is mostly about enabling https://reviews.llvm.org/D97197.

flang/test/Frontend/prescanner-diag.f90

5

Do we _want_ to test f18 when the new driver is enabled?

I'm fine to keep %f18 here, but so far we've been using %flang and %flang_fc1 for tests that are shared between the drivers. We've already ported quite a few tests this way (e.g. preprocessor tests) and diverging from that approach might be confusing for us later.

[tskeith]

flang/test/Frontend/prescanner-diag.f90

5

OK, that makes sense. I guess devs working on the new driver have to do a build with the new driver disabled anyway to be sure the tests still pass with f18. I was thinking that could be avoided, but maybe not.

flang/test/Frontend/prescanner-diag.f90

 ! Test that the driver correctly reports diagnostics from the prescanner. The contents of the include file are irrelevant here.
 
 ! Test with -E (i.e. PrintPreprocessedAction, stops after prescanning)
-! RUN: %f18 -E -I %S/Inputs/ %s 2>&1 | FileCheck %s
-! RUN: %flang-new -E -I %S/Inputs/ %s 2>&1 | FileCheck %s
-! RUN: %flang-new -fc1 -E -I %S/Inputs/ %s 2>&1 | FileCheck %s
+! RUN: %flang -E -I %S/Inputs/ %s 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -E -I %S/Inputs/ %s 2>&1 | FileCheck %s
 
 ! Test with -fsyntax-only (i.e. ParseSyntaxOnlyAction, stops after semantic checks)
-! RUN: %f18 -fsyntax-only -I %S/Inputs/ %s 2>&1 | FileCheck %s
-! RUN: %flang-new -fsyntax-only -I %S/Inputs/ %s 2>&1 | FileCheck %s
-! RUN: %flang-new -fc1 -fsyntax-only -I %S/Inputs/ %s 2>&1 | FileCheck %s
+! RUN: %flang -fsyntax-only -I %S/Inputs/ %s 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -fsyntax-only -I %S/Inputs/ %s 2>&1 | FileCheck %s
 
-! CHECK: prescanner-diag.f90:14:20: #include: extra stuff ignored after file name
+! CHECK: prescanner-diag.f90:12:20: #include: extra stuff ignored after file name
 #include <empty.h> comment
-! CHECK: prescanner-diag.f90:16:20: #include: extra stuff ignored after file name
+! CHECK: prescanner-diag.f90:14:20: #include: extra stuff ignored after file name
 #include "empty.h" comment
 end

flang/test/lit.cfg.py

 llvm_config.use_default_substitutions()
 
 # excludes: A list of directories to exclude from the testsuite. The 'Inputs'
 # subdirectories contain auxiliary inputs for various tests in their parent
 # directories.
 config.excludes = ['Inputs', 'CMakeLists.txt', 'README.txt', 'LICENSE.txt']
 
 # If the new Flang driver is enabled, add the corresponding feature to
-# config. Otherwise, exclude the corresponding test directory.
+# config.
 if config.include_flang_new_driver_test:
   config.available_features.add('new-flang-driver')
-else:
-  config.excludes.append('Flang-Driver')
-  config.excludes.append('Frontend')
 
 # test_source_root: The root path where tests are located.
 config.test_source_root = os.path.dirname(__file__)
 
 # test_exec_root: The root path where tests should be run.
 config.test_exec_root = os.path.join(config.flang_obj_root, 'test')
 
 # Tweak the PATH to include the tools dir.