[LIBCLC] Modify libclc-remangler cmds for cross-compile support #16182
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Because libclc-remangler commands executed in cmake use `libclc::libclc-remangler`, builds where `CMAKE_CROSSCOMPILING=ON` do not work correctly since cmake assumes the target is not executable on the host machine. This change modifies the custom commands to use the cache variable `LIBCLC_REMANGLER_PATH` instead, where this variable is set in a similar way as llvm tools such as `llvm-config` by calling `compile_native_tool`. Signed-off-by: Jack Myers <[email protected]>
| if(CMAKE_CROSSCOMPILING) | ||
| if(LLVM_NATIVE_TOOL_DIR AND NOT LIBCLC_REMANGLER_PATH) | ||
| if(EXISTS "${LLVM_NATIVE_TOOL_DIR}/libclc-remangler${LLVM_HOST_EXECUTABLE_SUFFIX}") | ||
| set(LLVM_CONFIG_PATH "${LLVM_NATIVE_TOOL_DIR}/libclc-remangler${LLVM_HOST_EXECUTABLE_SUFFIX}") |
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Should this be setting LIBCLC_REMANGLER_PATH?
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Yes it should've but I have decided to not do all the cross compiling logic manually, instead using setup_host_tool.
libclc/cmake/modules/AddLibclc.cmake
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| @@ -456,7 +456,7 @@ function(add_libclc_builtin_set) | |||
| "${LIBCLC_LIBRARY_OUTPUT_INTDIR}/remangled-${long_width}-${signedness}_char.${obj_suffix_mangled}" ) | |||
| add_custom_command( OUTPUT "${builtins_remangle_path}" | |||
| COMMAND ${CMAKE_COMMAND} -E make_directory ${LIBCLC_LIBRARY_OUTPUT_INTDIR} | |||
| COMMAND libclc::libclc-remangler | |||
| COMMAND ${LIBCLC_REMANGLER_PATH} | |||
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Perhaps the variable should be named libclc-remangler_exe like the other tools: clang_exe, llvm-link_exe?
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Same thing as my previous comment above, but yes:
Yes it should've but I have decided to not do all the cross compiling logic manually, instead using
setup_host_tool.
| add_dependencies(libclc-remangler NativeLibCLCRemangler) | ||
| endif() | ||
| else() | ||
| set(LIBCLC_REMANGLER_PATH "${CMAKE_CURRENT_BINARY_DIR}/bin/libclc-remangler" CACHE STRING "") |
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I'm not sure relying on the path like this is the best idea. Perhaps we can get the path to the binary using the libclc-remangler target itself? Does $<TARGET_PROPERTY:libclc-remangler,TARGET_FILE> work?
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Referencing again 😅:
Same thing as my previous comment above, but yes:
Yes it should've but I have decided to not do all the cross compiling logic manually, instead using
setup_host_tool.
| else() | ||
| set(LIBCLC_REMANGLER_PATH "${CMAKE_CURRENT_BINARY_DIR}/bin/libclc-remangler" CACHE STRING "") | ||
| endif() | ||
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| # If we've not already imported a libclc-remangler tool from an external build, | ||
| # set it up now. | ||
| if(NOT TARGET libclc::libclc-remangler) |
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This comment makes me realise this PR breaks the ability to import libclc-remangler from another build, using LIBCLC_CUSTOM_LLVM_TOOLS_BINARY_DIR. We should keep that.
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Yeah, this is actually a bit confusing to me. I found PR #13743 that introduced this, but as far as I can tell, this breaks the LIBCLC_CUSTOM_LLVM_TOOLS_BINARY_DIR functionality since the target is never imported through anything like find_package.
I'm realizing now that this might be because I was testing everything with CMAKE_CROSSCOMPILING enabled which may have messed with the target import.
Regardless, the libclc::libclc-remangler pattern seems to be unique among the rest of LLVM where other tools used during the build that are also built as a part of LLVM use things like compile_native_tool or setup_host_tool + LLVM_NATIVE_TOOL_DIR which is assigned automatically if needed.
My latest commit uses libclc-remangler_target which is populated by setup_host_tool. But I think LIBCLC_CUSTOM_LLVM_TOOLS_BINARY_DIR might still be broken.
I see why LIBCLC_CUSTOM_LLVM_TOOLS_BINARY_DIR is used since it can be built as a standalone. I'm wondering if in the case that it has not been set, then it should be set to LLVM_NATIVE_TOOL_DIR if it has been set. Thoughts?
Because libclc-remangler commands executed in cmake use `libclc::libclc-remangler`, builds where `CMAKE_CROSSCOMPILING=ON` do not work correctly since cmake assumes the target is not executable on the host machine. This change modifies the custom commands to use the cache variable `LIBCLC_REMANGLER_PATH` instead, where this variable is set in a similar way as llvm tools such as `llvm-config` by calling `compile_native_tool`. Signed-off-by: Jack Myers <[email protected]>
Because libclc-remangler commands executed in cmake use `libclc::libclc-remangler`, builds where `CMAKE_CROSSCOMPILING=ON` do not work correctly since cmake assumes the target is not executable on the host machine. This change modifies the custom commands to use the cache variable `LIBCLC_REMANGLER_PATH` instead, where this variable is set in a similar way as llvm tools such as `llvm-config` by calling `compile_native_tool`. Signed-off-by: Jack Myers <[email protected]>
Because libclc-remangler commands executed in cmake use
libclc::libclc-remangler, builds whereCMAKE_CROSSCOMPILING=ONdo not work correctly since cmake assumes the target is not executable on the host machine.This change modifies the custom commands to use the cache variable
LIBCLC_REMANGLER_PATHinstead, where this variable is set in a similar way as llvm tools such asllvm-configby callingcompile_native_tool.