[profile] Install headers for custom runtime maintainers

[vsk]

Summary

Some users maintain custom runtimes which provide support for
-fprofile-instr-generate instrumentation in non-standard environments
(e.g the kernel).

It may not be obvious which functions need to be implemented or what
their signatures are. Silent breakage is possible if the runtime's
internal interface changes.

This patch installs a few headers from the profiling runtime to serve as
a reference:

$ ninja install-compiler-rt-headers -v
...
-- Installing: /usr/local/lib/clang/10.0.0/include/profile/InstrProfiling.h
-- Installing: /usr/local/lib/clang/10.0.0/include/profile/InstrProfilingInternal.h
-- Installing: /usr/local/lib/clang/10.0.0/include/profile/InstrProfData.inc

rdar://44375648

[vsk]

Ping.

[beanz]

LGTM.

[delcypher]

@vsk I'm not entirely convinced this is correct but this might be because I don't understand how these header files are meant to be consumed.

Your implementation of add_compiler_rt_header() calls add_compiler_rt_resource_file() which installs into the Clang resource directory (<install_root>/share/). This is not the same path that other sanitizer interface headers get installed (see include/CMakeLists.txt in the compiler-rt source tree) which is <install_root>/include.

This means that clients of won't be able consume these header files in the same way that they consume other sanitizer header files. Perhaps this is intentional because these header files might be internal headers (I don't know. I've not really looked at the profile portion of compiler-rt before).
If that is your intention I really think you need to rename add_compiler_rt_header to something that expresses the intent more explicitly. The name add_compiler_rt_header could easily lead someone to believe it will get installed to <install_root>/include which doesn't appear to be the case.

[vsk]

@delcypher apologies for the massive delay, and thanks for pointing out that issue. This just came up again internally -- PTAL :)?

[vsk]

• Drop an extraneous lldb change.

[delcypher]

@vsk other than the minor nit LGTM.

compiler-rt/include/CMakeLists.txt

33 ↗

(On Diff #221651)

@vsk Minor nit. Any particular reason why those header files live under lib instead on under include/ in the source tree?

[vsk]

compiler-rt/include/CMakeLists.txt

33 ↗

(On Diff #221651)

Not that I'm aware of -- this could be a nice chance to clean things up.

Unfortunately I'm having a bear of a time figuring out why the rest of the sanitizers don't seem to pass -I ${COMPILER_RT_SOURCE_DIR}/include, but still manage to find the right headers. The profile runtime isn't built with this -I -- I suppose I could just add it in the profile runtime's CMakeLists.txt (and that works), but feel like I'm missing something. Any chance you've stumbled into this before?

[vsk]

compiler-rt/include/CMakeLists.txt

33 ↗

(On Diff #221651)

Oh, actually, it looks like the sanitizer implementations don't include their public interface headers on purpose. In light of that, it actually seems more consistent to keep the profile headers in lib.

[vsk]

Friendly ping

compiler-rt/cmake/Modules/AddCompilerRT.cmake

macro(add_compiler_rt_resource_file target_name file_name component)
   install(FILES ${file_name}
     DESTINATION ${COMPILER_RT_INSTALL_PATH}/share
     COMPONENT ${component})
   add_dependencies(${component} ${target_name})
 
   set_target_properties(${target_name} PROPERTIES FOLDER "Compiler-RT Misc")
 endmacro()
 
+function(add_compiler_rt_header file_name component)
+  add_compiler_rt_resource_file(${file_name} ${file_name} ${component})
+endfunction()
+
 macro(add_compiler_rt_script name)
   set(dst ${COMPILER_RT_EXEC_OUTPUT_DIR}/${name})
   set(src ${CMAKE_CURRENT_SOURCE_DIR}/${name})
   add_custom_command(OUTPUT ${dst}
     DEPENDS ${src}
     COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
     COMMENT "Copying ${name}...")
   add_custom_target(${name} DEPENDS ${dst})

compiler-rt/lib/profile/CMakeLists.txt

else()
   add_compiler_rt_runtime(clang_rt.profile
     STATIC
     ARCHS ${PROFILE_SUPPORTED_ARCH}
     CFLAGS ${EXTRA_FLAGS}
     SOURCES ${PROFILE_SOURCES}
     ADDITIONAL_HEADERS ${PROFILE_HEADERS}
     PARENT_TARGET profile)
 endif()
+
+add_compiler_rt_header(InstrProfiling.h profile)
+add_compiler_rt_header(InstrProfilingInternal.h profile)
+add_compiler_rt_header(InstrProfData.inc profile)