[MLIR][IRDL][CMake] Switch to using setup_host_tool to fix cross compilation

[Zentrik]

Using build_native_tool directly doesn't seem to be standard, instead other tools seem to call setup_host_tool (e.g. milr-linalg-ods-gen and add_tablegen seems to have a copy of setup_host_tool internally).

When cross compiling llvm in two stages, the first building all native tools and then the second using those built tools to cross compile, this prevents the second stage from trying to rebuild mlir-irdl-to-cpp, which fails.

[Zentrik]

@Moxinilian do you mind reviewing this

[Moxinilian]

Excellent! This looks much better indeed, thanks. I wish this was documented somewhere, I swear I did my best with the original implementation 😆

[llvmbot]

@llvm/pr-subscribers-mlir-core

@llvm/pr-subscribers-mlir

Author: None (Zentrik)

Changes

Using build_native_tool directly doesn't seem to be standard, instead other tools seem to call setup_host_tool (e.g. milr-linalg-ods-gen and add_tablegen seems to have a copy of setup_host_tool internally).

When cross compiling llvm in two stages, the first building all native tools and then the second using those built tools to cross compile, this prevents the second stage from trying to rebuild mlir-irdl-to-cpp, which fails.

---

Full diff: https://github.com/llvm/llvm-project/pull/156606.diff

1 Files Affected:

• (modified) mlir/tools/mlir-irdl-to-cpp/CMakeLists.txt (+1-20)

diff --git a/mlir/tools/mlir-irdl-to-cpp/CMakeLists.txt b/mlir/tools/mlir-irdl-to-cpp/CMakeLists.txt
index 3a0f77d856b44..27a7e22db7d7b 100644
--- a/mlir/tools/mlir-irdl-to-cpp/CMakeLists.txt
+++ b/mlir/tools/mlir-irdl-to-cpp/CMakeLists.txt
@@ -6,23 +6,4 @@ mlir_target_link_libraries(mlir-irdl-to-cpp
   MLIRTargetIRDLToCpp
   )
 
-# Set up a native build when cross-compiling.
-if(LLVM_USE_HOST_TOOLS)
-  build_native_tool(
-    mlir-irdl-to-cpp
-    MLIR_IRDL_TO_CPP_EXE
-
-    # Native tool must depend on target tool so that the native tool gets
-    # properly rebuilt when the target tool changes.
-    DEPENDS mlir-irdl-to-cpp
-  )
-  add_custom_target(mlir-irdl-to-cpp-host DEPENDS ${MLIR_IRDL_TO_CPP_EXE})
-  set(MLIR_IRDL_TO_CPP_TARGET mlir-irdl-to-cpp-host)
-else()
-  set(MLIR_IRDL_TO_CPP_EXE $<TARGET_FILE:mlir-irdl-to-cpp>)
-  set(MLIR_IRDL_TO_CPP_TARGET mlir-irdl-to-cpp)
-endif()
-
-# Save the executable path and target name to the cache to expose it globally.
-set(MLIR_IRDL_TO_CPP_EXE "${MLIR_IRDL_TO_CPP_EXE}" CACHE INTERNAL "")
-set(MLIR_IRDL_TO_CPP_TARGET "${MLIR_IRDL_TO_CPP_TARGET}" CACHE INTERNAL "")
+setup_host_tool(mlir-irdl-to-cpp MLIR_IRDL_TO_CPP MLIR_IRDL_TO_CPP_EXE MLIR_IRDL_TO_CPP_TARGET)