[libc-commits] [libc] 4a87241 - [libc] Fix dependencies for generating the GPU binary file

[Joseph Huber via libc-commits]

Author: Joseph Huber
Date: 2023-02-20T09:37:19-06:00
New Revision: 4a872412d868ff468a30a99060293e11a43ffab9

URL: https://github.com/llvm/llvm-project/commit/4a872412d868ff468a30a99060293e11a43ffab9
DIFF: https://github.com/llvm/llvm-project/commit/4a872412d868ff468a30a99060293e11a43ffab9.diff

LOG: [libc] Fix dependencies for generating the GPU binary file

This patch adjusts the way dependencies are handled in the packaed
version of the GPU libc runtime. Previously the files were not getting
updated properly in the install when they changed.

Depends on D144214

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D144280

Added: 
    

Modified: 
    libc/cmake/modules/LLVMLibCObjectRules.cmake

Removed: 
    


################################################################################
diff  --git a/libc/cmake/modules/LLVMLibCObjectRules.cmake b/libc/cmake/modules/LLVMLibCObjectRules.cmake
index bdd600df4de1..6947d623bb2c 100644
--- a/libc/cmake/modules/LLVMLibCObjectRules.cmake
+++ b/libc/cmake/modules/LLVMLibCObjectRules.cmake
@@ -132,9 +132,9 @@ function(_build_gpu_objects fq_target_name internal_target_name)
   add_custom_command(OUTPUT ${packaged_output_name}
                      COMMAND ${LIBC_CLANG_OFFLOAD_PACKAGER}
                              ${packager_images} -o ${packaged_output_name}
-                     DEPENDS ${gpu_target_names}
+                     DEPENDS ${gpu_target_names} ${ADD_GPU_OBJ_SRCS} ${ADD_GPU_OBJ_HDRS}
                      COMMENT "Packaging LLVM offloading binary")
-  add_custom_target(${packaged_target_name} DEPENDS ${packaged_output_name})
+  add_custom_target(${packaged_target_name} DEPENDS ${packaged_output_name} ${gpu_target_name})
 
   # We create an empty 'stub' file for the host to contain the embedded device
   # code. This will be packaged into 'libcgpu.a'.
@@ -142,20 +142,28 @@ function(_build_gpu_objects fq_target_name internal_target_name)
   #       into a single bitcode file and use that. For now we simply build for
   #       every single one and let the offloading linker handle it.
   get_filename_component(stub_filename ${ADD_GPU_OBJ_SRCS} NAME)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/stubs)
-  file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/stubs/${stub_filename} "// Empty file.\n")
+  add_custom_command(
+    OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/stubs/${stub_filename}"
+    COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/stubs/
+    COMMAND ${CMAKE_COMMAND} -E touch ${CMAKE_CURRENT_BINARY_DIR}/stubs/${stub_filename}
+    DEPENDS ${gpu_target_names} ${ADD_GPU_OBJ_SRCS} ${ADD_GPU_OBJ_HDRS}
+  )
+  set(stub_target_name ${fq_target_name}.__stub__)
+  add_custom_target(${stub_target_name} DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/stubs/${stub_filename})
+
   add_library(
     ${fq_target_name}
     # We want an object library as the objects will eventually get packaged into
     # an archive (like libcgpu.a).
     EXCLUDE_FROM_ALL
     OBJECT
-    "${CMAKE_CURRENT_BINARY_DIR}/stubs/${stub_filename}"
+    ${CMAKE_CURRENT_BINARY_DIR}/stubs/${stub_filename}
   )
   target_compile_options(${fq_target_name} BEFORE PRIVATE ${common_compile_options}
                          -nostdlib -Xclang -fembed-offload-object=${packaged_output_name})
   target_include_directories(${fq_target_name} PRIVATE ${include_dirs})
-  add_dependencies(${fq_target_name} ${full_deps_list} ${packaged_target_name})
+  add_dependencies(${fq_target_name} 
+                   ${full_deps_list} ${packaged_target_name} ${stub_target_name})
 
   # We only build the internal target for a single supported architecture.
   set(include_dirs ${LIBC_BUILD_DIR}/include ${LIBC_SOURCE_DIR} ${LIBC_BUILD_DIR})
@@ -561,7 +569,6 @@ function(create_entrypoint_object fq_target_name)
     )
   endif()
 
-
   if(LLVM_LIBC_ENABLE_LINTING AND TARGET ${internal_target_name})
     if(NOT LLVM_LIBC_CLANG_TIDY)
       message(FATAL_ERROR "Something is wrong!  LLVM_LIBC_ENABLE_LINTING is "