[BOLT][CMake] Use correct output paths and passthrough necessary options

[phosek]

Summary

This addresses https://github.com/llvm/llvm-project/issues/62748.

[michaelplatings]

bolt/CMakeLists.txt

88

The documentation for CMAKE_SYSROOT says "This variable may only be set in a toolchain file specified by the CMAKE_TOOLCHAIN_FILE variable."

Maybe pass CMAKE_TOOLCHAIN_FILE through instead?

88

list(APPEND variable_that_may_or_may_not_exist ... is quite fragile. Should someone have -Dextra_args=X on their cmake command line then that will be included here, which I don't think is the intent. I suggest adding set(extra_args "") above the if. This also improves readability because otherwise you have to scan the whole file to figure out that extra_args wasn't previously defined.

98–99

Given that the install step now does nothing, and the install statement below passes -DCMAKE_INSTALL_PREFIX explicitly, could this line be deleted? Alternatively perhaps -DCMAKE_INSTALL_PREFIX could be removed from the install statement.

103

These targets don't appear to be used. I suggest either deleting this line, or if they're needed/useful somehow then adding a comment either here or in the commit message.

[phosek]

bolt/CMakeLists.txt

88

That documentation is inaccurate. CMAKE_SYSROOT can be set outside of the toolchain file, and thus needs to be passed through as is frequently done in LLVM, see for example https://github.com/llvm/llvm-project/blob/7ca1bcbc6043b7ab4635f04746d1b9480960e384/llvm/cmake/modules/LLVMExternalProjectUtils.cmake#L261 or https://github.com/llvm/llvm-project/blob/7ca1bcbc6043b7ab4635f04746d1b9480960e384/compiler-rt/cmake/Modules/AddCompilerRT.cmake#L650.

[michaelplatings]

LGTM

bolt/CMakeLists.txt

88

Deviating from what's documented as permitted could cause a problem with future CMake versions. But evidently this pattern is already established in LLVM, and if it becomes a problem in future then it can be fixed at that time.

[Amir]

Please retitle as "[BOLT][CMake] ..."

[phosek]

bolt/CMakeLists.txt

88

I agree, ideally we would use the same helper function everywhere where we need to invoke CMake as a subbuild so the passthrough is handled uniformly, but that can be done as a future improvement.

bolt/CMakeLists.txt

else()
     message(WARNING "Not including BOLT tests since clang or lld is disabled. \
           Add clang and lld to LLVM_ENABLE_PROJECTS or provide paths to clang \
           and lld binaries in BOLT_CLANG_EXE and BOLT_LLD_EXE.")
   endif()
 endif()
 
 if (BOLT_ENABLE_RUNTIME)
   message(STATUS "Building BOLT runtime libraries for X86")
+  set(extra_args "")
+  if(CMAKE_SYSROOT)
+    list(APPEND extra_args -DCMAKE_SYSROOT=${CMAKE_SYSROOT})
+  endif()
   ExternalProject_Add(bolt_rt
     SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/runtime"
     STAMP_DIR ${CMAKE_CURRENT_BINARY_DIR}/bolt_rt-stamps
     BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/bolt_rt-bins
     CMAKE_ARGS -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
                -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
                -DCMAKE_BUILD_TYPE=Release
                -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
-               -DCMAKE_INSTALL_PREFIX=${LLVM_BINARY_DIR}
                -DLLVM_LIBDIR_SUFFIX=${LLVM_LIBDIR_SUFFIX}
+               -DLLVM_LIBRARY_DIR=${LLVM_LIBRARY_DIR}
+               ${extra_args}
+    INSTALL_COMMAND ""
     BUILD_ALWAYS True
     )
   install(CODE "execute_process\(COMMAND \${CMAKE_COMMAND} -DCMAKE_INSTALL_PREFIX=\${CMAKE_INSTALL_PREFIX} -P ${CMAKE_CURRENT_BINARY_DIR}/bolt_rt-bins/cmake_install.cmake \)"
     COMPONENT bolt)
   add_llvm_install_targets(install-bolt_rt
     DEPENDS bolt_rt bolt
     COMPONENT bolt)
 endif()
 

bolt/runtime/CMakeLists.txt

 check_include_files(elf.h HAVE_ELF_H)
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/config.h.in
                ${CMAKE_CURRENT_BINARY_DIR}/config.h)
 
 add_library(bolt_rt_instr STATIC
   instr.cpp
   ${CMAKE_CURRENT_BINARY_DIR}/config.h
   )
-set_target_properties(bolt_rt_instr PROPERTIES LIBRARY_OUTPUT_DIRECTORY "lib${LLVM_LIBDIR_SUFFIX}")
+set_target_properties(bolt_rt_instr PROPERTIES ARCHIVE_OUTPUT_DIRECTORY "${LLVM_LIBRARY_DIR}")
 add_library(bolt_rt_hugify STATIC
   hugify.cpp
   ${CMAKE_CURRENT_BINARY_DIR}/config.h
   )
-set_target_properties(bolt_rt_hugify PROPERTIES LIBRARY_OUTPUT_DIRECTORY "lib${LLVM_LIBDIR_SUFFIX}")
+set_target_properties(bolt_rt_hugify PROPERTIES ARCHIVE_OUTPUT_DIRECTORY "${LLVM_LIBRARY_DIR}")
 
 set(BOLT_RT_FLAGS
   -ffreestanding
   -fno-exceptions
   -fno-rtti
   -fno-stack-protector
   -mno-sse
   -fPIC)
 
 # Don't let the compiler think it can create calls to standard libs
 target_compile_options(bolt_rt_instr PRIVATE ${BOLT_RT_FLAGS})
 target_include_directories(bolt_rt_instr PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
 target_compile_options(bolt_rt_hugify PRIVATE ${BOLT_RT_FLAGS})
 target_include_directories(bolt_rt_hugify PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
 
 install(TARGETS bolt_rt_instr DESTINATION "lib${LLVM_LIBDIR_SUFFIX}")
 install(TARGETS bolt_rt_hugify DESTINATION "lib${LLVM_LIBDIR_SUFFIX}")
 
 if (CMAKE_CXX_COMPILER_ID MATCHES ".*Clang.*")
   add_library(bolt_rt_instr_osx STATIC
     instr.cpp
     ${CMAKE_CURRENT_BINARY_DIR}/config.h
   )
-  set_target_properties(bolt_rt_instr_osx PROPERTIES LIBRARY_OUTPUT_DIRECTORY "lib${LLVM_LIBDIR_SUFFIX}")
+  set_target_properties(bolt_rt_instr_osx PROPERTIES ARCHIVE_OUTPUT_DIRECTORY "${LLVM_LIBRARY_DIR}")
   target_include_directories(bolt_rt_instr_osx PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
   target_compile_options(bolt_rt_instr_osx PRIVATE
     -target x86_64-apple-darwin19.6.0
     ${BOLT_RT_FLAGS})
   install(TARGETS bolt_rt_instr_osx DESTINATION "lib${LLVM_LIBDIR_SUFFIX}")
 endif()

clang/cmake/caches/Fuchsia-stage2.cmake

 set(LLVM_BUILTIN_TARGETS "${BUILTIN_TARGETS}" CACHE STRING "")
 set(LLVM_RUNTIME_TARGETS "${RUNTIME_TARGETS}" CACHE STRING "")
 
 # Setup toolchain.
 set(LLVM_INSTALL_TOOLCHAIN_ONLY ON CACHE BOOL "")
 set(LLVM_TOOLCHAIN_TOOLS
   dsymutil
   llvm-ar
-  llvm-bolt
   llvm-cov
   llvm-cxxfilt
   llvm-debuginfod-find
   llvm-dlltool
   ${LLVM_DRIVER_TARGET}
   llvm-dwarfdump
   llvm-dwp
   llvm-ifs
set(LLVM_TOOLCHAIN_TOOLS
   llvm-symbolizer
   llvm-undname
   llvm-xray
   sancov
   scan-build-py
   CACHE STRING "")
 
 set(LLVM_Toolchain_DISTRIBUTION_COMPONENTS
+  bolt
   clang
   lld
   clang-apply-replacements
   clang-doc
   clang-format
   clang-resource-headers
   clang-include-fixer
   clang-refactor