Deterministic builds delete important module meta data

[delitrem]

Describe the bug
When Erlang is configured with --enable-deterministic-build option, compiler produces BEAMs without options and source subsections in module meta data. This data is required for some dependents, at least Elixir expects it.

To Reproduce
Compile with --enable-deterministic-build option, then run REPL:

$ erl
1> lists:module_info(compile).
[{version,"8.4.3"}]

Expected behavior

1> lists:module_info(compile).
[{version,"8.4.3"},
 {options,[debug_info,
           {i,"/some/path/to/lib/stdlib/src/../include"},
           {i,"/some/path/to/lib/stdlib/src/../../kernel/include"},
           warn_missing_doc_function,warn_missing_doc_callback,
           warn_missing_spec_documented,deterministic]},
 {source,"/some/path/to/lib/stdlib/src/lists.erl"}]

May be it would be suitable to normalize paths somehow, may be by changing '/some/path/to' to something hardcoded, for example: '/deterministic' when compiled with --enable-deterministic-build option.

Affected versions
I have tested it on 27.0 and maint branch.

Additional context
None. Feel free to ask.

[delitrem]

Another solution: to provide some option for preserve compile meta data (at least source).

[delitrem]

Is it be suitable if I just make compiler to preserve source tuple with filename:basename(Source) when deterministic option is switched on (with test suite modification)? It seems to be enough for Elixir's tests to pass.

Proposed output would be:

1> lists:module_info(compile).
[{version,"8.4.3"},
 {options,[]},
 {source,"lists.erl"}]

[delitrem]

I'm very sorry for the long ignorance -- was a kind of busy with other things.

I've made a small fix, as was suggested by @michalmuskala at #8607.

Haven't changed anything in test suite, to my mind the existing tests cover this feature (at least compile_SUITE:deterministic_paths/1).

I can also take yet another one feature (as separate task) which was advised by @michalmuskala, in spite of it is not directly related to deterministic builds. :)

[delitrem]

That solution also breaks Elixir.

Still no ideas, what is better. May be just to revert bootstrap's compile.beam from #8579?

Almost no one needs deterministic out-of-box, but almost everyone many people need workable Elixir.

[delitrem]

Just updated #8607. Branch name is old and not relevant.

What was done there:

• compiler option +preserve_paths for using with +deterministic option for preserving paths such as {source, Source} and {i, Include};
• compiler option +{modify_path,{From,To}} to modify paths such as {source, Source} and {i, Include}.

Those options are also workable from shell:

$ERL_TOP/bin/erlc +deterministic +preserve_paths simple.erl
$ERL_TOP/bin/erlc +deterministic +preserve_paths +'{modify_path,{"/path/to/erlang/otp","/otp"}}' simple.erl

Is it more suitable?

[jhogberg]

Thanks for raising this issue and taking the time to make a PR addressing it. Unfortunately we're in the middle of the vacation period and have limited time to look at things right now, especially changes that require consensus, so we'll revisit this once most of us are back.