Is it intended that C++ headers are in e.g. /usr/include/cucumber/cucumber/messages/ ?

[musicinmybrain]

👓 What did you see?

In a fresh checkout:

$ cd cpp/
$ cmake -S. -Bbuild
$ cmake --build build
$ DESTDIR=foo cmake --install build
$ find foo/ -name all.hpp
foo/usr/local/include/cucumber/cucumber/messages/all.hpp

✅ What did you expect to see?

I’m surprised that headers aren’t installed in e.g. /usr/include/cucumber/messages/ rather than /usr/include/cucumber/cucumber/messages/. Is this intentional?

📦 Which tool/library version are you using?

Current main, 9114562.

🔬 How could we reproduce it?

See What did you see?, above.

📚 Any additional context?

The additional cucumber/ seems to be handled in cucumber_messages-targets.cmake, which has

set_target_properties(cucumber::messages PROPERTIES
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include/cucumber"
  […]
)

but the cucumber/cucumber still seems like it might have been an accident.

[mpkorstanje]

@chybz @jenisys I think you could comment on this?

[musicinmybrain]

If it’s not intentional, it seems like

--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -140,5 +140,5 @@ install(
 
 install(
     DIRECTORY "${PROJECT_SOURCE_DIR}/include/messages/"
-    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/cucumber
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
 )

would fix it.

[chybz]

It is intentional indeed and related to namespacing and while what you suggest might seem a solution, I think it oversimplifies (while it seems I overcomplicated it). Let me explain:

If we take only include (let's ignore DESTDIR/PREFIX), all C++ headers under Cucumber's umbrella will be rooted at include/cucumber.
Next, each project may choose its C++ namespace, and for messages, I naturally chose cucumber::messages and made a direct mapping of that namespace to directories cucumber/messages, hence the resulting:

${DESTDIR}/${xxPREFIX}/include/
    cucumber/              <-- Cucumber related projects
        cucumber/messages  <-- Cucumber Messages library
        cucumber/gherkin   <-- Cucumber Gherkin compiler library
        whatever           <-- fictional Whatever library
        foo/bar/baz        <-- ...

That's the reason why you see foo/usr/local/include/cucumber/cucumber/messages/all.hpp which, I recon, seems "unusual", but is here to avoid clutter.

If you don't have any issues using this library, I'd like to keep the current structure.

[musicinmybrain]

Thank you very much for the explanation, which makes perfect sense.

Given that the structure is intentional, there is no problem with it at all.