[clang-doc][cmake] Copy assets to build directory

[ilovepi]

While we copy the asset files, like index.js, into the correct location in the install step, tests do not have access to those resources in the build directory.

This patch copies the contents of the clang-doc/assets directory into the build folder, so that they can be used in testing.

Pull Request: #95185

[llvmbot]

@llvm/pr-subscribers-clang-tools-extra

Author: Paul Kirth (ilovepi)

Changes

While we copy the asset files, like index.js, into the correct location in the install step, tests do not have access to those resources in the build directory.

This patch copies the contents of the clang-doc/assets directory into the build folder, so that they can be used in testing.

Pull Request: #95185

---

Full diff: https://github.com/llvm/llvm-project/pull/95187.diff

1 Files Affected:

• (modified) clang-tools-extra/clang-doc/tool/CMakeLists.txt (+8)

diff --git a/clang-tools-extra/clang-doc/tool/CMakeLists.txt b/clang-tools-extra/clang-doc/tool/CMakeLists.txt
index fb8317b272932..c2425747562b9 100644
--- a/clang-tools-extra/clang-doc/tool/CMakeLists.txt
+++ b/clang-tools-extra/clang-doc/tool/CMakeLists.txt
@@ -25,3 +25,11 @@ install(FILES ../assets/clang-doc-default-stylesheet.css
 install(FILES ../assets/index.js
   DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
   COMPONENT clang-doc)
+
+add_custom_target(copy-clang-doc-assets
+  COMMAND ${CMAKE_COMMAND} -E copy_directory_if_different "${CMAKE_CURRENT_SOURCE_DIR}/../assets" "${CMAKE_BINARY_DIR}/share/clang"
+  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/../assets"
+  COMMENT "Copying Clang-Doc Assets"
+  )
+set_target_properties(copy-clang-doc-assets PROPERTIES FOLDER "Clang-Doc/Assets")
+add_dependencies(clang-doc copy-clang-doc-assets)

[ilovepi]

@petrhosek I'm pretty sure there's a better way to spell this, but I think we need something similar to properly test clang-doc w/o an install step.

cc: @PeterChou1

[PeterChou1]

@petrhosek I'm pretty sure there's a better way to spell this, but I think we need something similar to properly test clang-doc w/o an install step.

cc: @PeterChou1

It looks like copy_directory_if_different is not available on windows

[petrhosek]

We prefer having a rule per file since most systems don't have a reliable way to tell if the directory content has changed. The approach we usually use to to have one add_custom_command per file with a single add_custom_target that depends on all output files, see for example

llvm-project/libcxx/include/CMakeLists.txt

Lines 1024 to 1043 in 092dbfa

	foreach(f ${files})
	set(src "${CMAKE_CURRENT_SOURCE_DIR}/${f}")
	set(dst "${LIBCXX_GENERATED_INCLUDE_DIR}/${f}")
	add_custom_command(OUTPUT ${dst}
	DEPENDS ${src}
	COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
	COMMENT "Copying CXX header ${f}")
	list(APPEND _all_includes "${dst}")
	endforeach()
	# Generate the IWYU mapping. This depends on all header files but it's also considered as an
	# "include" for dependency tracking.
	add_custom_command(OUTPUT "${LIBCXX_GENERATED_INCLUDE_DIR}/libcxx.imp"
	COMMAND "${Python3_EXECUTABLE}" "${LIBCXX_SOURCE_DIR}/utils/generate_iwyu_mapping.py" "-o" "${LIBCXX_GENERATED_INCLUDE_DIR}/libcxx.imp"
	DEPENDS ${_all_includes}
	COMMENT "Generate the mapping file for include-what-you-use"
	)
	list(APPEND _all_includes "${LIBCXX_GENERATED_INCLUDE_DIR}/libcxx.imp")
	add_custom_target(generate-cxx-headers ALL DEPENDS ${_all_includes})

or https://github.com/llvm/llvm-project/blob/092dbfaad257885692fa64559e9eb43a5c466798/clang/lib/Headers/CMakeLists.txt

[ilovepi]

OK, I’ll take a pass at adapting one of those for use here. If I think I can generalize it, I’ll make another PR to add it as a utility in the llvm cmake module.

[ilovepi]

I think this is addressed now. I more or less cribed directly from the clang header example. Initially I tried to have the function be a bit more generic and put it in llvm/cmake/modules/CopyLLVMFiles.cmake, but my normal methods of including don't seem to work in clang-doc. Likely I'm just holding that part wrong, but I don't see anything in clang-tools-extra using include(AddLLVM) or some other module.

Happy to refactor if you have some other suggestions.

[ilovepi]

@petrhosek I'm pretty sure there's a better way to spell this, but I think we need something similar to properly test clang-doc w/o an install step.
cc: @PeterChou1

It looks like copy_directory_if_different is not available on windows

Ugh. I forgot to check the minimum cmake version. This was introduced in 3.26, which IIRC is higher than LLVM’S minimum. https://cmake.org/cmake/help/latest/manual/cmake.1.html#cmdoption-cmake-E-arg-copy_directory_if_different