Here's the doc comment from the commit:
For one example of why this is handy, consider the case of building musl libc.
We keep a lock open for each of the object files in the form of a file descriptor
until they are finally put into an archive file. This is to allow a zig-cache
garbage collector to run concurrently to zig processes, and to allow multiple
zig processes to run concurrently with each other, without clobbering each other.
This code is disabled until #6361 is implemented (getrlimit/setrlimit
are not yet added to the standard library).
* caching system: use 16 bytes siphash final(), there was a bug in the
std lib that wasn't catching undefined values for 18 bytes. fixed in
master branch.
* fix caching system unit test logic to not cause error.TextBusy on windows
* port the logic from stage1 for building glibc shared objects
* add is_native_os to the base cache hash
* fix incorrectly freeing crt_files key (which is always a reference to
global static constant data)
* fix 2 use-after-free in loading glibc metadata
* fix memory leak in buildCRTFile (errdefer instead of defer on arena)
This reverts commit 40cb712d13.
Thanks to Ava & Luna of Lavatech, we don't need to resort to this, they
have graciously given zig a SourceHut instance to use that gives us 8GB
RAM.
Before merging, do this for every item in the file:
* solve the issue, or
* convert the task to a github issue and update the comment
to link to the issue (and remove "TODO" text from the comment).
Then delete the file.
Related: #363
Drew won't give us enough RAM for stage1 to build stage2. We'll still
have freebsd builds available on releases but we're going to lose
freebsd CI testing for master branch builds until we fully switch over
to stage2 (and have lower memory usage).
Let me know if anyone wants to run a SourceHut instance and give zig
access to run on slightly more powerful machines. We need about 8 GiB
RAM to run the CI test suite for now.
After we're fully self hosted I expect to re-enable this.
The API is pretty specific to the implementationt details of the
self-hosted compiler. I don't want to have to independently support
and maintain this as part of the standard library, and be obligated
to not make breaking changes to it with changes to the implementation of
stage2.
This is not strictly necessary but it increases the likelihood of cache
hits because foo.c and bar.c now will have different cache directories
and can be updated independently without clobbering each other's cache
data.
Andrew Kelley
Samrat Man Singh
LemonBoy
Vexu