Mbed-os: some exporters clobber .mbedignore file

[bmcdonnell-ionx]

Description

• Type: Bug (arguably)
• Related issue: https://github.com/ARMmbed/mbed-cli/issues/378#issuecomment-362000601
• Priority: Minor

Some exporters (e2studio, gnuarmeclipse, and mcuxpresso, I think) overwrite the .mbedignore file, leaving no apparent way to generate an IDE project that has user-defined files excluded from the build.

Here's why I think it's just those three:

/path/to/myproj/mbed-os/tools/export
$ grep -R --binary-files=without-match mbedignore . | grep \.py
./e2studio/__init__.py:        self.gen_file('gnuarmeclipse/mbedignore.tmpl', jinja_ctx, '.mbedignore')
./gnuarmeclipse/__init__.py:        self.gen_file('gnuarmeclipse/mbedignore.tmpl', jinja_ctx, '.mbedignore')
./mcuxpresso/__init__.py:        self.gen_file('mcuxpresso/mbedignore.tmpl', jinja_ctx, '.mbedignore')

---

Bug

mbed-cli version:
1.3.0

mbed-os sha:
96d9a00d0 (tag: mbed_lib_rev158, tag: mbed-os-5.7.3) Merge pull request #5841 from ARMmbed/release-candidate

Expected behavior
Adding files to .mbedignore causes them to be excluded from the build in any offline IDE for projects created by mbed export.

Actual behavior
Some exporters overwrite the .mbedignore file, so anything added to it by the user is overwritten, thus not ignored.

Steps to reproduce

mbed new demoproj
cd demoproj
touch ignore-me-please.cpp

echo ignore-me-please.cpp > .mbedignore
echo .mbedignore before export:
cat .mbedignore
# try with -i {e2studio, gnuarmeclipse, mcuxpresso}
mbed export -m LPC4088 -i mcuxpresso
echo .mbedignore after export:
cat .mbedignore

[bmcdonnell-ionx]

Suggested behavior: if an exporter wants to ignore some files, it could parse .mbedignore, and append whatever it needs to add to it.

[loverdeg]

@janjongboom @screamerbg I believe this is one of the issues we were having with "mbed-cli" before I emailed you.

[theotherjimmy]

@bmcdonnell-ionx I think I'll have the exporters do just that. I have a few other bugs queued for the exporters to look into, so I may not get to this bug this week.

[loverdeg]

@theotherjimmy
We export gnuarmeclipse projects to get the benefits of the CDT indexer but still build with mbed-cli.

Any time we make a change to the project configuration we re-export the project; so this issue is very inconvenient.

[theotherjimmy]

Ah, I'll look into this today. I think It should be simple to workaround.