Erlang's typespecs define only cover_compiled and preloaded
as valid atoms and uses an empty list for generated code.
So we should follow Erlang's rules until we can officially
relax them.
Tables named after modules are very likely to be used
the application itself, which can lead to conflicts in
scenarios such as code reloading.
Closes#6361
Module attributes that are imported from other
contexts are not warned. This keeps the same
semantics regarding variables and function definition
ordering which are not warned when they come from
other contexts.
In previous versions, when trying to compile a file and the file
depended on a module that was not yet compiled or was unavailable,
the parallel compiler would wait until the missing dependency shows
up. In case it did not, the compiler would "release" the file being
compiled, disabling any further missing dependency resolution.
This lead to issues in code like the following:
Code.ensure_compiled(SomeModuleThatWontBeAvailable)
%SomeStructFromMyProject{}
Because `SomeModuleThatWontBeAvailable` would never be available,
the file above would block until released. When released, the
parallel compiler would disable further lookups for that file,
meaning we would no longer wait for missing dependencies when we
attempt to load the struct.
In the majorify of cases, the struct would already be available,
which meant compilation would work. But if the file that defined
the struct was also blocked by the compiler (and consequently
released), compilation would be non-deterministic.
This patch solves the issue by removing the "release" behaviour
from the compiler. If a dependency is not available, we will
notify the file of such and move on, with the parallel compiler
still enabled. In order to guarantee this works without
introducing deadlocks, the parallel compiler now also knows which
module is being defined by a given file, building a graph and
solving dependencies from the leaves. In case it is a cyclic
graph, we will raise that a deadlock was found.
Closes#4294Closes#4055
José Valim
José Valim
Michał Muskała
Sam Davies
Aleksei Magusev
Andrea Leopardi
eksperimental
Alexei Sholik
jisaacstone
Eric Entin