Add a script to CI to check dynamic symbols in Android binary #8351

[cengizIO]

Tries to fix #8351.

This is meaningful only with the PR to servo/saltfs

Cross PR: servo/saltfs#249

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This change is

[cengizIO]

I'm not sure about the path of arm-linux-androideabi-objdump tool

[cengizIO]

According to buildbot/master/master.cfg#L219, libservo.so is built in debug mode, with default mach target path.

[Ms2ger]

I would much rather see this written in python.

[cengizIO]

@Ms2ger actually I just tried to follow the pattern in etc/ci directory.

But if you think python is more maintainable, I can convert it.

[aneeshusa]

To make this more robust, we should be agnostic as to the order of the symbols, i.e. for bash adding a call to sort in the pipeline after the awk command, or in Python, using sets instead of lists.

[cengizIO]

@Ms2ger @aneeshusa I've converted it to a python script which is sort order agnostic and much more readable.

[cengizIO]

@larsbergstrom This doesn't have an assignee at the moment.

[aneeshusa]

Sets are built-in since Python 2.6 and you don't need to import them; the sets module isn't even available in Python 3. See https://docs.python.org/2/library/stdtypes.html#set and https://docs.python.org/3/library/stdtypes.html#set.

[aneeshusa]

Also, I think a frozenset would be appropriate for the allowed_symbols variable.

[aneeshusa]

I believe we need to do actual_symbols.difference(allowed_symbols), which can written with syntax sugar as actual_symbols - allowed_symbols. This will take the actual symbols and remove the symbols we know are OK, leaving the symbols that are not OK.

[larsbergstrom]

@aneeshusa Thanks for handling the python parts of the review! I would also add that there is some output from our tidy tool:

Checking files for tidiness...

./etc/ci/check_dynamic_symbols.py:1: E265 block comment should start with '# '

./etc/ci/check_dynamic_symbols.py:3: E401 multiple imports on one line

./etc/ci/check_dynamic_symbols.py:11: E126 continuation line over-indented for hanging indent

./etc/ci/check_dynamic_symbols.py:14: E123 closing bracket does not match indentation of opening bracket's line

./etc/ci/check_dynamic_symbols.py:18: E711 comparison to None should be 'if cond is not None:'

./etc/ci/check_dynamic_symbols.py:1: incorrect license

@cengizIO I apologize for not shepherding this review! I didn't notice that it was not assigned and will make sure that sort of thing doesn't slip through the cracks again. Thanks also for your patience in rewriting what was originally supposed to be a cheesy shell script into a much more robust python script.

[cengizIO]

@aneeshusa and @larsbergstrom thanks for the feedback!

Please check latest revision.

This is probably my 3rd python script ever.

And I didn't know about ./mach test-tidy until you mentioned. It's cool 😎

[larsbergstrom]

@bors-servo r+

[bors-servo]

📌 Commit 135429f has been approved by larsbergstrom

[bors-servo]

⌛ Testing commit 135429f with merge 1db70db...

[bors-servo]

☀️ Test successful - android, gonk, linux-dev, linux-rel, mac-dev-unit, mac-rel-css, mac-rel-wpt, status-appveyor