[all-commits] [llvm/llvm-project] 6c93e1: [flang][driver] Add support for `-mmlir`

[Andrzej Warzyński via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6c93e1d329e6c6ef828ec63c66f4cb39ee9cb9ce
      https://github.com/llvm/llvm-project/commit/6c93e1d329e6c6ef828ec63c66f4cb39ee9cb9ce
  Author: Andrzej Warzynski <andrzej.warzynski at arm.com>
  Date:   2022-04-14 (Thu, 14 Apr 2022)

  Changed paths:
    M clang/include/clang/Driver/Options.td
    M clang/lib/Driver/ToolChains/Flang.cpp
    M flang/include/flang/Frontend/FrontendOptions.h
    M flang/lib/Frontend/CompilerInvocation.cpp
    M flang/lib/Frontend/FrontendActions.cpp
    M flang/lib/FrontendTool/CMakeLists.txt
    M flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
    M flang/test/Driver/driver-help-hidden.f90
    M flang/test/Driver/driver-help.f90
    A flang/test/Driver/mllvm_vs_mmlir.f90

  Log Message:
  -----------
  [flang][driver] Add support for `-mmlir`

The semantics of `-mmlir` are identical to `-mllvm`. The only notable
difference is that `-mmlir` options should be forwarded to MLIR rather
than LLVM.

Note that MLIR llvm::cl options are lazily constructed on demand (see
the definition of options in PassManagerOptions.cpp). This means that:
  * MLIR global options are only visible when explicitly initialised and
    displayed only when using `-mmlir --help`,
  * Flang and LLVM global options are always visible and displayed when
    using either `-mllvm -help` or `-mmlir --help`.

In other words, `-mmlir --help` is a superset of `-mllvm --help`. This is not
ideal, but we'd need to refactor all option definitions in Flang and
LLVM to improve this. I suggesting leaving this for later.

Differential Revision: https://reviews.llvm.org/D123297