[all-commits] [llvm/llvm-project] 7d246c: [flang][driver] Add support for `-fsyntax-only`

[Andrzej Warzyński via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7d246cb19db9fce65946fb4bac6e570787dbe78a
      https://github.com/llvm/llvm-project/commit/7d246cb19db9fce65946fb4bac6e570787dbe78a
  Author: Andrzej Warzynski <andrzej.warzynski at arm.com>
  Date:   2020-12-18 (Fri, 18 Dec 2020)

  Changed paths:
    M clang/include/clang/Driver/Options.td
    M flang/include/flang/Frontend/CompilerInstance.h
    M flang/include/flang/Frontend/FrontendActions.h
    M flang/include/flang/Frontend/FrontendOptions.h
    M flang/lib/Frontend/CMakeLists.txt
    M flang/lib/Frontend/CompilerInstance.cpp
    M flang/lib/Frontend/CompilerInvocation.cpp
    M flang/lib/Frontend/FrontendActions.cpp
    M flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
    A flang/test/Flang-Driver/syntax-only.f90
    M flang/unittests/Frontend/PrintPreprocessedTest.cpp

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

The behaviour triggered with this flag is consistent with `-fparse-only`
in `flang` (i.e. the throwaway driver). This new spelling is consistent
with Clang and gfortran, and was proposed and agreed on for the new
driver in [1].

This patch also adds some minimal logic to communicate whether the
semantic checks have failed or not. When semantic checks fail, a
frontend driver error is generated. The return code from the frontend
driver is then determined by checking the driver diagnostics - the
presence of driver errors means that the compilation has failed. This
logic is consistent with `clang -cc1`.

[1] http://lists.llvm.org/pipermail/flang-dev/2020-November/000588.html

Differential Revision: https://reviews.llvm.org/D92854