[libc] Introduce a target named libc-unit-tests to run just the unit tests.

[sivachandra]

Summary

The target "check-libc" now runs all enabled tests which, depending on
the build mode, includes the unit tests, the integration tests and the api
test.

[jhuber6]

Pretty straightforward. Does this get included in ninja check-all or similar right now?

libc/cmake/modules/LLVMLibCTestRules.cmake

expand_flags_for_libc_unittest(
     DEPENDS ${fq_deps_list} IGNORE_MARKER
     FLAGS ${flags} IGNORE_MARKER
     ${ADD_TO_EXPAND_UNPARSED_ARGUMENTS}
   )
 endfunction(add_libc_unittest)
 
 function(add_libc_testsuite suite_name)
   add_custom_target(${suite_name})
-  add_dependencies(check-llvmlibc ${suite_name})
+  add_dependencies(libc-unit-tests ${suite_name})
 endfunction(add_libc_testsuite)
 
 function(add_libc_exhaustive_testsuite suite_name)
   add_custom_target(${suite_name})
   add_dependencies(exhaustive-check-libc ${suite_name})
 endfunction(add_libc_exhaustive_testsuite)
 
 function(add_libc_long_running_testsuite suite_name)

libc/test/CMakeLists.txt

 add_subdirectory(UnitTest)
 
 if(LLVM_LIBC_FULL_BUILD AND NOT
   (LIBC_TARGET_ARCHITECTURE_IS_GPU OR LIBC_TARGET_OS_IS_BAREMETAL))
   add_subdirectory(IntegrationTest)
 endif()
 
 add_header_library(
   errno_setter_matcher
   HDRS
     ErrnoSetterMatcher.h
 )
 
 add_custom_target(check-libc)
-add_custom_target(check-llvmlibc)
-add_dependencies(check-libc check-llvmlibc)
+add_custom_target(libc-unit-tests)
+add_dependencies(check-libc libc-unit-tests)
 
 add_custom_target(exhaustive-check-libc)
 add_custom_target(libc-long-running-tests)
 
 add_subdirectory(src)
 add_subdirectory(utils)
 
 if(NOT LLVM_LIBC_FULL_BUILD)
   return()
 endif()
 
 if(NOT (${LIBC_TARGET_OS} STREQUAL "linux"))
   # Integration tests are currently only available for linux.
   return()
 endif()
 add_subdirectory(integration)

libc/test/integration/CMakeLists.txt

 add_custom_target(libc-integration-tests)
+add_dependencies(check-libc libc-integration-tests)
 
 function(add_libc_integration_test_suite name)
   add_custom_target(${name})
   add_dependencies(libc-integration-tests ${name})
 endfunction()
 
 add_library(
   libc_integration_test_dummy

libc/test/src/CMakeLists.txt

COMMAND $<TARGET_FILE:libc-prototype-testgen> -o ${public_test}
           ${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/api.td
 
   DEPENDS ${LIBC_SOURCE_DIR}/config/${LIBC_TARGET_OS}/api.td ${spec_files}
           libc-prototype-testgen ${TARGET_PUBLIC_HEADERS}
           ${LIBC_TARGET}
 )
 
 add_custom_target(libc-api-test)
+add_dependencies(check-libc libc-api-test)
+
 set(
   allocator_entrypoints 
     libc.src.stdlib.malloc
     libc.src.stdlib.calloc
     libc.src.stdlib.realloc
     libc.src.stdlib.aligned_alloc
     libc.src.stdlib.free
 )