Only Linux / FastRTPS with linter tests since the change shouldn't have any runtime impact (if it compiles successfully):

Since I screwed up the arguments the linter tests didn't run. Since I need to make several more rounds of PRs for all the rosidl_generator_c/cpp API review follow ups I will go ahead and merge this (and fix linter warnings if they appear).

I accidentally squash merged the PR. Since the intention was to keep the two commits separate (to maintain history) I force pushed to master to keep them separate.

I just updated my workspace with vcs pull and run into the following errors:

--- stderr: rosidl_runtime_c
/Users/karsten/workspace/ros2/ros2_master/src/ros2/rosidl/rosidl_runtime_c/src/service_type_support.c:15:10: fatal error: 'rosidl_generator_c/service_type_support_struct.h' file not found
#include "rosidl_generator_c/service_type_support_struct.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/karsten/workspace/ros2/ros2_master/src/ros2/rosidl/rosidl_runtime_c/src/message_bounds.c:15:10: fatal error: 'rosidl_generator_c/message_bounds_struct.h' file not found
#include "rosidl_generator_c/message_bounds_struct.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/karsten/workspace/ros2/ros2_master/src/ros2/rosidl/rosidl_runtime_c/src/message_type_support.c:15:10: fatal error: 'rosidl_generator_c/message_type_support_struct.h' file not found
/Users/karsten/workspace/ros2/ros2_master/src/ros2/rosidl/rosidl_runtime_c/src/u16string_functions.c:15:10: fatal error: 'rosidl_generator_c/u16string_functions.h' file not found
#include "rosidl_generator_c/message_type_support_struct.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include "rosidl_generator_c/u16string_functions.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/karsten/workspace/ros2/ros2_master/src/ros2/rosidl/rosidl_runtime_c/src/string_functions.c:15:10: fatal error: 'rosidl_generator_c/string_functions.h' file not found
#include "rosidl_generator_c/string_functions.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

am I missing something here? I tried compiling with --packages-up-to rosbag2 --cmake-clean-cache

You might want to check that you have the latest master of this repo as well as all the referenced PRs. If you use a branch on any of them you will likely need to rebase it.

The build is currently failing on a fresh checkout of master from this PR - https://ci.ros2.org/view/All/job/ci_linux/10100/console

Edit 1 for context: Built up to rosidl_generator_c - it seems to require some headers from rosidl_runtime_c but the dependency direction is in reverse

Edit 2: but i don't fully understand why this change would cause the breakage, it doesn't seem to have touched rosidl_generator_c / rosidl_runtime_c

I don't fully grasp the dependencies here:

rosidl_generator_c is depending on rosidl_runtime_c: https://github.com/ros2/rosidl/blob/master/rosidl_generator_c/CMakeLists.txt#L16
But then, rosidl_runtime_c is using headers from rosidl_generator_c: https://github.com/ros2/rosidl/blob/master/rosidl_runtime_c/src/service_type_support.c#L15

I accidentally squash merged the PR. Since the intention was to keep the two commits separate (to maintain history) I force pushed to master to keep them separate.

This was the actual problem - I was already working on the follow up patch to move the rosidl_generator_c headers and some changes from that slipped in the force push.

I have fixed the problem with the two recently referenced commits which only touch rosidl_generator_cpp as intended. See (which is a rebuild of the minimal build @emersonknapp started above).

Sorry for the hassle (it didn't help that I went for a bike ride after force push...).

I don't fully grasp the dependencies here:
rosidl_generator_c is depending on rosidl_runtime_c: https://github.com/ros2/rosidl/blob/master/rosidl_generator_c/CMakeLists.txt#L16
But then, rosidl_runtime_c is using headers from rosidl_generator_c: https://github.com/ros2/rosidl/blob/master/rosidl_runtime_c/src/service_type_support.c#L15

The headers have been moved in #442 but the directory / namespace has not been updated. This PR does exactly that - update the namespace to match the package name - for the C++ generator / runtime. A similar PR for C will need to follow. All part of the API review in #446 / #447.