[tools] build_everything.py should fail immediately for unsupported target

[zgoda]

For not mbed-os capable platforms build process should not be attempted. Now it fails in the middle trying to compile RTOS support:

Failed to build library
./rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c:65:6: error: #error "no target defined"
 #    error "no target defined"
      ^
./rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c:105:6: error: #error "no target defined"
 #    error "no target defined"
      ^
./rtos/rtx/TARGET_CORTEX_M/RTX_Conf_CM.c:269:6: error: #error "no target defined"
 #    error "no target defined"
      ^

Found when testing PR #2285

[ciarmcom]

ARM Internal Ref: IOTMORF-92

[0xc0170]

@zgoda What are you proposing, that a script should fail ,not even trying to compile sources? The build system does not have currently a clue if rtos is supported for a platform or not, that one is in the rtos sources encoded (will be moved to configuration system most probably, the we can check if its supported or not).

cc @bridadan @theotherjimmy

[bridadan]

@zgoda Thanks for bringing up this issue.

I should give a little background on this script and how it relates to the other build scripts in the tools.

Before this script, there was build_release.py. This was (and is) used to create binary releases for developer.mbed.org. It just compiles the HAL (no RTOS) for a list of targets and toolchains and packages it up into a library. When we first started to work on the mbed OS 5 release, I wanted to have a similar script to use in CI, so I created a separate one instead of changing the existing one.

Since then the workflow has changed a bit, and the CI now uses mbed CLI extensively. But I'd like to revisit this so you can run the full build locally that the CI does as well. There are some complications due to the way Jenkins needs the commands to be organized, but nothing that's a show stopper.

Now getting back to @0xc0170's comment, the script should probably follow the same flow that the build_release.py script does, which is build up a list of the supported targets, then build them. The list of supported targets for version 5 and version 2 are different though (due to RTOS support and other things). And the things it builds will be different as well (RTOS, tests, etc). However, I'd really like to merge this into one "release" script that knows how to build 2 and 5, and you just pick which version you want to build.

Really, both scripts should be revisited, and I think build_everything.py needs work since its fairly out of sync with the other tools.

[zgoda]

I don't feel in a position to suggest anything related to mbed os 5 yet, i'm completely new here. It just feels strange to have a tool that fails in the middle of process even if the outcome is known upfront. Shouldn't it fail immediately indicating the operation is not supported for given operands? I think so.

[bridadan]

I think you're right @zgoda, the main issue right now is these scripts don't make it clear what part of the code they are building, so it is not sure if the platform is "supported" or "unsupported". We need to rethink how these scripts fit into the workflow so it is clear what platforms are supported in which configuration.

[sg-]

@bridadan Is this able to be closed?

[bridadan]

@sg- I think it's probably safe to close this issue. I alluded to this above, but the build_everything.py script is pretty out of date and should honestly probably just be removed. If no one has any issue with this I'll submit a PR for it