[HLSL][clang-format] Add Language Mode for HLSL

[V-FEXrt]

clang-format supports many different languages and as part of that support it can switch between different languages to add/remove formatting rules. Right now clang-format can fairly reasonably format HLSL running under C++ mode however annotation syntax could use better support.

Adding an HLSL mode is the first step in supporting HLSL specific formatting rules.

Automatically determining HLSL as the source language is a downstream task that may or may not actually be possible. Plenty of HLSL programs will not have obvious differences from C++ so autodetection may have to be limited to huristics or file extension. This is still an open design question.

AC:

• A test in the flavor of this one verifies language mode is HLSL

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: Ashley Coleman (V-FEXrt)

clang-format supports many different languages and as part of that support it can switch between different languages to add/remove formatting rules. Right now clang-format can fairly reasonably format HLSL running under C++ mode however annotation syntax could use better support.

Adding an HLSL mode is the first step in supporting HLSL specific formatting rules.

Automatically determining HLSL as the source language is a downstream task that may or may not actually be possible. Plenty of HLSL programs will not have obvious differences from C++ so autodetection may have to be limited to huristics or file extension. This is still an open design question.

AC:

• A test in the flavor of this one verifies language mode is HLSL