Install API header file via install(target)

[ThomsonTan]

In today's SIG meeting, @eyakimov-bbg had a question that why the API header files are installed via install(DIRECTORY) instead of using the existing install(TARGET) as below. There is CMake target property PUBLIC_HEADER which is honored by install(TARGET), but that does flat the directory structure of the header file. It seems install(DIRECTORY) is necessary to preserve the directory structure of our API header files.

opentelemetry-cpp/api/CMakeLists.txt

Line 16 in d8467a7

install(

Reference:
StackOverflow

@owent @maxgolov @eyakimov-bbg @lalitb

[eyjohn]

Thanks for raising this one Thomas, This answers my initial question,