[flang][cmake] Add a custom target for the "flang" wrapper script.

[ygribov]

I realize that the wrapper may be removed in few months so let me know if this is irrelevant.

[awarzynski]

Hi @ygribov, thank you for this patch!

I think that it would make sense to update the summary of this change to e.g. [flang][cmake] Add a custom target for the "flang" wrapper script. This would more accurately reflect what this patch implements. Instead, the current description focuses on the side effects, i.e. that the script will be re-copied into the build dir whenever {ninja|make} flang-wrapper is run. Unless I misunderstood?

Thanks!

flang/tools/f18/CMakeLists.txt

52

I think that it's a bit confusing if the name of the target and the generated tool are different.

[ygribov]

Resolve review comments.

[awarzynski]

LGTM, thank you!

flang/tools/f18/CMakeLists.txt

foreach(filename ${MODULES})
   list(APPEND MODULE_FILES ${base}.mod ${base}.f18.mod)
   install(FILES ${base}.mod ${base}.f18.mod DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/flang")
 endforeach()
 
 add_custom_target(module_files ALL DEPENDS ${MODULE_FILES})
 
 # This flang shell script will only work in a POSIX shell.
 if (NOT WIN32)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/flang
-    DESTINATION ${CMAKE_BINARY_DIR}/bin
-    FILE_PERMISSIONS OWNER_EXECUTE OWNER_READ OWNER_WRITE)
+  add_custom_command(
+    OUTPUT ${CMAKE_BINARY_DIR}/bin/flang
+    DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/flang
+    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/flang ${CMAKE_BINARY_DIR}/bin)
+  add_custom_target(flang ALL DEPENDS ${CMAKE_BINARY_DIR}/bin/flang)
   install(PROGRAMS ${CMAKE_BINARY_DIR}/bin/flang DESTINATION "${CMAKE_INSTALL_BINDIR}")
 endif()