Copy the program library to the place where PX4Firmware CMake build will look
for and trigger the firmware build. There isn't really a real output defined
for px4_copy_lib because Waf would complain about multiple tasks having same
output when building multiple programs.
After the firmware build, copy it to the correct place (from program group and
name perspective) and add git hashes.
Since the place where the library is placed is shared by different target
programs, we need to synchronize the firmware build, that's why the use of
_firmware_semaphorish_tasks. That variable is set as a list because of the
upcoming upload task.
Recursively collect objects from dependency libraries and create a single
library. That way we just need to pass down one single library to PX4Firmware
build system.
In the upcoming build for PX4 boards, we will pass down the program a single
static library to PX4 Firmware's cmake build system. This patch is partially
providing a way to do that: the configuration for PX4 will define the
AP_PROGRAM_AS_STLIB environment variable.
The function ap_program() was the only one that was using it, so let's just
inline it. Besides, the name was misleading, since the (only) feature added was
for programs instead of general task generators.
Two things are fixed with this patch:
1. We sort dictionaries' keys if they aren't OrderedDict instances. Since
dict objects don't guarantee order, environment variables may have contents
in wrong order, causing unnecessary rebuilds.
2. We only use prepend_value() if there's already a value set for the key
and that value is list. Before this change, boards couldn't set
non-iterable values.
That will make platform specific naming be ignored. We use a string instead, to
let Waf tweak the target name correctly for us. The '#' prefix is to tell Waf
that the path is relative to bld.bldnode (instead of bld.path, which is the
default).
We need to remove CMakeCache.txt, otherwise cached variables would remain the
old value when they are removed from cmake_vars parameter.
We use `os.remove()` instead of `Node.delete()` because the latter removes the
node instance from its parent's children list. That makes the node be ignored
when storing persistent information after the build, thus the node signature
wouldn't be saved with that approach, which would make waf always think that
the task should be executed.
The default implementation takes into account the task's output and input
nodes. That isn't very well applicable for cmake tasks, so we define proper
uid() methods.
That allows options being declared where they're really used. Additionally, we
load ardupilotwaf after the other tools so that we can create our groups after
all non-ardupilot option groups are created. That makes our groups appear as
the last ones in the help message, which makes it easier to locate them.
The gtest header uses lots of undefined macros, showing lots of warnings
if we enable -Wundef. Ideally we could use a #pragma to ignore the
warning only from the correct header, but this currently doesn't work
with g++ - see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53431
So for now we disable the warning completely when compiling gtest or any
test that uses its header.
Thanks Gustavo Sousa
