[libc] Run libc tests unconditionally, even if there are no source changes.

[sivachandra]

Summary

Before this change, the test binaries were executed only if the deps
changed. This change makes the test binaries run unconditionally. This
is more in line with the rest of LLVM. Future patches will print test
statistics etc., much like the rest of LLVM.

[sivachandra]

This is one of the steps towards addressing the proposal made here: https://discourse.llvm.org/t/rfc-running-libc-tests-unconditionally/68207. Future changes will address other aspects of the proposal.

[gchatelet]

libc/cmake/modules/LLVMLibCTestRules.cmake

132–136

How about removing the NOT and swapping the two blocks? The condition is already a double negation.

Actually, how about renaming the CMake variable into LIBC_UNITTEST_RUN_POSTBUILD?

[sivachandra]

Address comment.

libc/cmake/modules/LLVMLibCTestRules.cmake

132–136

I have reversed the conditional but kept the name as is as it a optional argument to the function. So, it is OFF by default.

libc/cmake/modules/LLVMLibCTestRules.cmake

if(SHOW_INTERMEDIATE_OBJECTS)
     message(STATUS "Adding unit test ${fq_target_name}")
     if(${SHOW_INTERMEDIATE_OBJECTS} STREQUAL "DEPS")
       foreach(dep IN LISTS ADD_OBJECT_DEPENDS)
         message(STATUS "  ${fq_target_name} depends on ${dep}")
       endforeach()
     endif()
   endif()
 
+  if(LIBC_UNITTEST_NO_RUN_POSTBUILD)
+    set(fq_build_target_name ${fq_target_name})
+  else()
+    set(fq_build_target_name ${fq_target_name}.__build__)
+  endif()
+
   add_executable(
-    ${fq_target_name}
+    ${fq_build_target_name}
     EXCLUDE_FROM_ALL
     ${LIBC_UNITTEST_SRCS}
     ${LIBC_UNITTEST_HDRS}
   )
   target_include_directories(
-    ${fq_target_name}
+    ${fq_build_target_name}
     PRIVATE
       ${LIBC_SOURCE_DIR}
       ${LIBC_BUILD_DIR}
       ${LIBC_BUILD_DIR}/include
   )
   target_compile_options(
-    ${fq_target_name}
+    ${fq_build_target_name}
     PRIVATE ${LIBC_COMPILE_OPTIONS_DEFAULT}
   )
   if(LIBC_UNITTEST_COMPILE_OPTIONS)
     target_compile_options(
-      ${fq_target_name}
+      ${fq_build_target_name}
       PRIVATE ${LIBC_UNITTEST_COMPILE_OPTIONS}
     )
   endif()
   if(NOT LIBC_UNITTEST_CXX_STANDARD)
     set(LIBC_UNITTEST_CXX_STANDARD ${CMAKE_CXX_STANDARD})
   endif()
   set_target_properties(
-    ${fq_target_name}
+    ${fq_build_target_name}
     PROPERTIES
       CXX_STANDARD ${LIBC_UNITTEST_CXX_STANDARD}
   )
 
   # Test object files will depend on LINK_LIBRARIES passed down from `add_fp_unittest`
   set(link_libraries ${link_object_files} ${LIBC_UNITTEST_LINK_LIBRARIES})
 
-  set_target_properties(${fq_target_name}
+  set_target_properties(${fq_build_target_name}
     PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 
   add_dependencies(
-    ${fq_target_name}
+    ${fq_build_target_name}
     ${fq_deps_list}
   )
 
   # LibcUnitTest and libc_test_utils should not depend on anything in LINK_LIBRARIES.
   if(NO_LIBC_UNITTEST_TEST_MAIN)
     list(APPEND link_libraries LibcUnitTest libc_test_utils)
   else()
     list(APPEND link_libraries LibcUnitTest LibcUnitTestMain libc_test_utils)
   endif()
 
-  target_link_libraries(${fq_target_name} PRIVATE ${link_libraries})
+  target_link_libraries(${fq_build_target_name} PRIVATE ${link_libraries})
 
   if(NOT LIBC_UNITTEST_NO_RUN_POSTBUILD)
-    add_custom_command(
-      TARGET ${fq_target_name}
-      POST_BUILD
-      COMMAND $<TARGET_FILE:${fq_target_name}>
+    add_custom_target(
+      ${fq_target_name}
+      COMMAND $<TARGET_FILE:${fq_build_target_name}>
+      COMMENT "Running unit test ${fq_target_name}"
     )
   endif()
 
   if(LIBC_UNITTEST_SUITE)
     add_dependencies(
       ${LIBC_UNITTEST_SUITE}
       ${fq_target_name}
     )
add_library(
     $<TARGET_OBJECTS:libc.src.string.memcmp>
     $<TARGET_OBJECTS:libc.src.string.memcpy>
     $<TARGET_OBJECTS:libc.src.string.memmove>
     $<TARGET_OBJECTS:libc.src.string.memset>
   )
   set_target_properties(${fq_libc_target_name} PROPERTIES ARCHIVE_OUTPUT_NAME c)
   set_target_properties(${fq_libc_target_name} PROPERTIES ARCHIVE_OUTPUT_DIRECTORY ${sysroot_lib})
 
+  set(fq_build_target_name ${fq_target_name}.__build__)
   add_executable(
-    ${fq_target_name}
+    ${fq_build_target_name}
     EXCLUDE_FROM_ALL
     ${INTEGRATION_TEST_SRCS}
     ${INTEGRATION_TEST_HDRS}
   )
-  set_target_properties(${fq_target_name}
+  set_target_properties(${fq_build_target_name}
       PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
   target_include_directories(
-    ${fq_target_name}
+    ${fq_build_target_name}
     PRIVATE
       ${LIBC_SOURCE_DIR}
       ${LIBC_BUILD_DIR}
       ${LIBC_BUILD_DIR}/include
   )
-  target_compile_options(${fq_target_name} PRIVATE -ffreestanding ${INTEGRATION_TEST_COMPILE_OPTIONS})
+  target_compile_options(${fq_build_target_name} PRIVATE -ffreestanding ${INTEGRATION_TEST_COMPILE_OPTIONS})
   # We set a number of link options to prevent picking up system libc binaries.
   # Also, we restrict the integration tests to fully static executables. The
   # rtlib is set to compiler-rt to make the compiler drivers pick up the compiler
   # runtime binaries using full paths. Otherwise, files like crtbegin.o are passed
   # as is (and not as paths like /usr/lib/.../crtbegin.o).
-  target_link_options(${fq_target_name} PRIVATE --sysroot=${sysroot} -static -stdlib=libc++ --rtlib=compiler-rt)
-  add_dependencies(${fq_target_name}
+  target_link_options(${fq_build_target_name} PRIVATE --sysroot=${sysroot} -static -stdlib=libc++ --rtlib=compiler-rt)
+  add_dependencies(${fq_build_target_name}
                    ${fq_target_name}.__copy_startup__
                    ${fq_libc_target_name}
                    libc.test.IntegrationTest.test
                    ${INTEGRATION_TEST_DEPENDS})
 
-  add_custom_command(
-    TARGET ${fq_target_name}
-    POST_BUILD
-    COMMAND ${INTEGRATION_TEST_ENV} $<TARGET_FILE:${fq_target_name}> ${INTEGRATION_TEST_ARGS}
+  add_custom_target(
+    ${fq_target_name}
+    COMMAND ${INTEGRATION_TEST_ENV} $<TARGET_FILE:${fq_build_target_name}> ${INTEGRATION_TEST_ARGS}
+    COMMENT "Running integration test ${fq_target_name}"
   )
 
   add_dependencies(${INTEGRATION_TEST_SUITE} ${fq_target_name})
 endfunction(add_integration_test)