Fix 'netsocket: several dynamic allocation results not checked' (#14210)

[chrisswinchatt-arm]

Summary of changes

(Copied from #14223)

This changes adds std::nowthrow and the checks for allocation failure to all places in the netsocket portion that lacked it. This change addresses #14210.

Impact of changes

add_event_listener in NetworkInterface now returns an error if the method fails. Previous attempts to add the event listener would attempt to use an unchecked standard dynamically allocated ns_list_* item.

In other cases, the dynamically allocated items will now be checked, and if unsuccessful, will return after cleaning up any outstanding issues.

TCPSocket::accept will now check that its own internally allocated new TCPSocket call will succeed, and if not, will clean up the stack resources. This should help when memory is low but an incoming connection requests a connection when the TCPSocket is listening.

Migration actions required

As new calls are now handled, code that did not check against this failure may now check for failure and handle it at the application layer.

add_event_listener now returns nsapi_error_t instead of void. The two return values possible are NSAPI_ERROR_OK and NSAPI_ERROR_NO_MEMORY in the case of memory allocation failure.

Documentation

NetworkInterface.h now has changes to the add_event_listener method. This method will now return nsapi_error_t instead of void. The docstring for the interface has been updated.

Pull request type

[] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[x] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

Test results

[] No Tests required for this change (E.g docs only update)
[X] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

Reviewers

[mergify]

This PR cannot be merged due to conflicts. Please rebase to resolve them.

[ciarmcom]

@chrisswinchatt-arm, thank you for your changes.
@ARMmbed/mbed-os-connectivity @ARMmbed/mbed-os-maintainers please review.

[paul-szczepanek-arm]

Pull request type can be set to [x] Patch update. The behaviour does not change unless new configuration option is set so it is not a breaking change.

Pull request has been modified.

[pan-]

I must have missed that one but why targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F401xE/TOOLCHAIN_GCC_ARM/stm32f401xe.ld is deleted ?

[chrisswinchatt-arm]

@pan-
I'm not sure how that happened. I've restored the file.

[JojoS62]

I must have missed that one but why targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F401xE/TOOLCHAIN_GCC_ARM/stm32f401xe.ld is deleted ?

#14601
I've seen also that windows git got confused after this fix, the deleted file is shown as changed in the master branch.

[0xc0170]

@JojoS62 How can I reproduce , can you report as new issue. We should look at it if there is an issue with the file

[ciarmcom]

This pull request has automatically been marked as stale because it has had no recent activity. @ARMmbed/mbed-os-maintainers, please start CI to get the PR merged.

[adbridge]

@chrisswinchatt-arm can you take a look at #14661 and the issue that spawned it #14601 ? I'm wondering if you had an out of date mbed-os which caused the problems. It might be safer to rebase your changes needed for this PR on top of the latest mbed-os just to make sure ?

[adbridge]

Pull request type can be set to [x] Patch update. The behaviour does not change unless new configuration option is set so it is not a breaking change.

This is still affecting the API so while not Major it should be Feature. I will update it.

Pull request has been modified.

[0xc0170]

Please rebase instead of merging (the git history should be linear here without merge commits)

[mergify]

This PR cannot be merged due to conflicts. Please rebase to resolve them.

[chrisswinchatt-arm]

Re-forked and moved to #14740.