[PATCH] D125788: [flang][driver] Rename `flang-new` as `flang`

[Andrzej Warzynski via Phabricator via cfe-commits]

awarzynski added a comment.

In the call yesterday it was proposed that we add a CMake option that will control the name of the driver. I suggest adding `FLANG_USE_LEGACY_NAME`:

- when set to `ON`, the driver binary will be called `flang-new`,
- when set to `OFF`, the driver binary will be called `flang`.

With this approach, everyone will be able to select the preferred driver name. Note that:

- this will affect both the build and installation targets,
- LLVM's testing infrastructure will automatically choose between `flang` and `flang-new` (based on `FLANG_USE_LEGACY_NAME`),
- you won't be required to perform any extra steps (in fact, you will be able to continue with your current workflows).

It was requested that the default value is set to `ON` (i.e. the default name for the driver executable in LLVM Flang will remain `flang-new`).

Later today I will upload a new version of this patch that implements the above. As for changing the default to `flang` (i.e. setting the default for `FLANG_USE_LEGACY_NAME` to `OFF`), the following remains a blocker:

In D125788#3535199 <https://reviews.llvm.org/D125788#3535199>, @sscalpone wrote:

> My proposal is:
>
> If the compiler compiles it, it ought to run.
> If the compiler can't compile it, it ought to clearly say why.
>
> 1. All tests of legal Fortran that compile & link must also execute correctly (which excludes tests that expect to catch a problem at runtime)
> 2. For all tests with unsupported features, the compiler must issues an error message and the message references the source-location of the unsupported feature
>
> My preference is to use the NAG test suite.   It is not freely available.

We did discuss replacing NAG with e.g. SNAP + SPEC, but we run out of time and haven't concluded that part.

As always, please comment if I missed or misread anything!

**Next steps**
I will update this patch by introducing `FLANG_USE_LEGACY_NAME` CMake option - it will control the name of the generated driver executable.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D125788/new/

https://reviews.llvm.org/D125788