[ASan tests] Use clang-cl to build tests on Windows

[timurrrr]

Summary

Please note that COMPILER_RT_CAN_EXECUTE_TESTS is still OFF, so this only affects stuff when everything is ready to flip the switch.

[samsonov]

LGTM modulo nits.

CMakeLists.txt

65

_OUT makes no sense to me. You can probably use EXE/OBJ instead.

cmake/Modules/AddCompilerRT.cmake

140

Sanity check: is it ok to not have a space between ${COMPILER_RT_TEST_COMPILER_EXE} and "${output_bin}" ?

[rnk]

Two things:

1. Should we add -o to clang-cl? MSVC ignores it silently, and CMake

always uses it when it does its initial test compile.

2. Should we even use clang-cl when building compiler-rt? Do we have lots

of CFLAGS in compiler-rt? We will either have to expose them as core
clang-cl options, or switch to the regular clang driver. Do you need this
to handle /MT or /MD?

cmake/Modules/AddCompilerRT.cmake

140

There cannot be a space between -Fo and its argument. =/

[timurrrr]

1. Should we add -o to clang-cl?

MSVC ignores it silently, and CMake always uses it when it does its initial test compile.

I don't see any reasons not to do that.

2. Should we even use clang-cl when building compiler-rt? Do we have lots of CFLAGS in compiler-rt?

We will either have to expose them as core clang-cl options, or switch to the regular clang driver.
Do you need this to handle /MT or /MD?

I think we can start using clang-cl as a secondary compiler building c-rt so we have extra test coverage, but stick with CL as a primary compiler until we declare clang-cl production-quality.

CMakeLists.txt

65

Ah, good idea -- I forgot about the "OBJ" possibility :)

cmake/Modules/AddCompilerRT.cmake

140

What Reid says.

[timurrrr]

r208526

CMakeLists.txt

if (NOT COMPILER_RT_STANDALONE_BUILD)
   # Setup the paths where compiler-rt runtimes and headers should be stored.
   set(COMPILER_RT_OUTPUT_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/clang/${CLANG_VERSION})
   set(COMPILER_RT_EXEC_OUTPUT_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
   set(COMPILER_RT_INSTALL_PATH lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION})
   option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests."
          ${LLVM_INCLUDE_TESTS})
  option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered"
         ${LLVM_ENABLE_WERROR})
-  # Use just-built Clang to compile/link tests.
+  # Use just-built Clang to compile/link tests on all platforms, except for
+  # Windows where we need to use clang-cl instead.
+  if(NOT MSVC)
     set(COMPILER_RT_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
+    set(COMPILER_RT_TEST_COMPILER_EXE "-o")
+    set(COMPILER_RT_TEST_COMPILER_OUT "-o")
+  else()
+    set(COMPILER_RT_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang-cl.exe)
+    set(COMPILER_RT_TEST_COMPILER_EXE "-Fe")
+    set(COMPILER_RT_TEST_COMPILER_OUT "-Fo")
+  endif()
 else()
   # Take output dir and install path from the user.
   set(COMPILER_RT_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR} CACHE PATH
     "Path where built compiler-rt libraries should be stored.")
   set(COMPILER_RT_EXEC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/bin CACHE PATH
     "Path where built compiler-rt executables should be stored.")
   set(COMPILER_RT_INSTALL_PATH ${CMAKE_INSTALL_PREFIX} CACHE PATH
     "Path where built compiler-rt libraries should be installed.")

cmake/Modules/AddCompilerRT.cmake

 macro(add_compiler_rt_test test_suite test_name)
   parse_arguments(TEST "OBJECTS;DEPS;LINK_FLAGS" "" ${ARGN})
   set(output_bin "${CMAKE_CURRENT_BINARY_DIR}/${test_name}")
   # Use host compiler in a standalone build, and just-built Clang otherwise.
   if(NOT COMPILER_RT_STANDALONE_BUILD)
     list(APPEND TEST_DEPS clang)
   endif()
   add_custom_target(${test_name}
-    COMMAND ${COMPILER_RT_TEST_COMPILER} ${TEST_OBJECTS} -o "${output_bin}"
+    COMMAND ${COMPILER_RT_TEST_COMPILER} ${TEST_OBJECTS}
+            ${COMPILER_RT_TEST_COMPILER_EXE}"${output_bin}"
             ${TEST_LINK_FLAGS}
     DEPENDS ${TEST_DEPS})
   # Make the test suite depend on the binary.
   add_dependencies(${test_suite} ${test_name})
 endmacro()
 
 macro(add_compiler_rt_resource_file target_name file_name)
   set(src_file "${CMAKE_CURRENT_SOURCE_DIR}/${file_name}")

cmake/Modules/CompilerRTCompile.cmake

else()
     string(REPLACE " " ";" global_flags "${CMAKE_C_FLAGS}")
   endif()
   # Ignore unknown warnings. CMAKE_CXX_FLAGS may contain GCC-specific options
   # which are not supported by Clang.
   list(APPEND global_flags -Wno-unknown-warning-option)
   set(compile_flags ${global_flags} ${SOURCE_CFLAGS})
   add_custom_command(
     OUTPUT ${object_file}
-    COMMAND ${COMPILER_RT_TEST_COMPILER} ${compile_flags} -c -o "${object_file}"
+    COMMAND ${COMPILER_RT_TEST_COMPILER} ${compile_flags} -c
+            ${COMPILER_RT_TEST_COMPILER_OUT}"${object_file}"
             ${source_rpath}
     MAIN_DEPENDENCY ${source}
     DEPENDS ${SOURCE_DEPS})
 endmacro()