[llvm] Add OpenACC as a dependency to llvm-config

[leonardchan]

Summary

As of D90848, running ninja check-llvm after a clean cmake configuration will cause these tests to fail:

Failed Tests (2):
  LLVM :: tools/llvm-config/booleans.test
  LLVM :: tools/llvm-config/system-libs.test

from missing lib/libLLVMFrontendOpenACC.a. See https://luci-milo.appspot.com/p/fuchsia/builders/ci/clang-linux-x64/b8863755892480463712?.

This just adds LLVMFrontendOpenACC as a dependency to llvm-config so it we be built when building llvm-config.

[tstellar]

I know this fixes a bug, but I don't think this is quite correct. It's really only the test that depends on the library not the tool. You could add LLVMFrontendOpenACC as a dependency to the check target, but it's pretty uncommon for an LLVM library to not have any tests. I think it would be better to fix this by adding a test case for LLVMFrontendOpenACC.

[mehdi_amini]

I know this fixes a bug, but I don't think this is quite correct.

I agree :)

It's really only the test that depends on the library not the tool.

I am not convinced here: just running bin/llvm-config --shared-mode is broken right now.

I wonder if this library should just not be a component.

[mehdi_amini]

I send out https://reviews.llvm.org/D91470 as another take on this.

[Meinersbur]

Is this obsolete after D91470 has been committed?

[leonardchan]

In D91468#2395487, @Meinersbur wrote:

Is this obsolete after D91470 has been committed?

Yup, closing. Thanks all for the fixes.

llvm/tools/llvm-config/CMakeLists.txt

if(LLVM_ENABLE_MODULES)
   target_compile_options(llvm-config PUBLIC
     "-fmodules-ignore-macro=CMAKE_CFG_INTDIR"
     )
 endif()
 
 # Add the dependency on the generation step.
 add_file_dependencies(${CMAKE_CURRENT_SOURCE_DIR}/llvm-config.cpp ${BUILDVARIABLES_OBJPATH})
 
+add_dependencies(llvm-config LLVMFrontendOpenACC)
+
 if(CMAKE_CROSSCOMPILING AND NOT LLVM_CONFIG_PATH)
   build_native_tool(llvm-config LLVM_CONFIG_PATH)
   set(LLVM_CONFIG_PATH "${LLVM_CONFIG_PATH}" CACHE STRING "")
 
   add_custom_target(NativeLLVMConfig DEPENDS ${LLVM_CONFIG_PATH})
   add_dependencies(llvm-config NativeLLVMConfig)
 endif()