## Overview
This PR makes the compiler pipeline thread-safe so that the test suite
can be run in parallel.
This is achieved by:
* Removing use of `{get, set, with}CurrentDir` functions.
* Adding locking around shared file resources like the the
global-project and internal build directory.
NB: **Locking is disabled for the main compiler target**, as it is
single threaded they are not required.
## Run test suite in parallel
To run the test suite in parallel you must add `--ta '+RTS -N -RTS'` to
your stack test arguments. For example:
```
stack test --fast --ta '+RTS -N -RTS'
```
The `-N` instructs the Haskell runtime to choose the number of threads
to use based on how many processors there are on your machine. You can
use `-Nn` to see the number of threads to `n`.
These flags are already [set in the
Makefile](e6dca22cfd/Makefile (L26))
when you or CI uses `stack test`.
## Locking
The Haskell package
[filelock](https://hackage.haskell.org/package/filelock) is used for
locking. File locks are used instead of MVars because Juvix code does
not control when new threads are created, they are created by the test
suite. This means that MVars created by Juvix code will have no effect,
because they are created independently on each test-suite thread.
Additionally the resources we're locking live on the filesystem and so
can be conveniently tagged by path.
### FileLock
The filelock library is wrapped in a FileLock effect:
e6dca22cfd/src/Juvix/Data/Effect/FileLock/Base.hs (L6-L8)
There is an [IO
interpreter](e6dca22cfd/src/Juvix/Data/Effect/FileLock/IO.hs (L8))
that uses filelock and an [no-op
interpreter](e6dca22cfd/src/Juvix/Data/Effect/FileLock/Permissive.hs (L7))
that just runs actions unconditionally.
### TaggedLock
To make the file locks simpler to use a TaggedLock effect is introduced:
e6dca22cfd/src/Juvix/Data/Effect/TaggedLock/Base.hs (L5-L11)
And convenience function:
e6dca22cfd/src/Juvix/Data/Effect/TaggedLock.hs (L28)
This allows an action to be locked, tagged by a directory that may or
may not exist. For example in the following code, an action is performed
on a directory `root` that may delete the directory before repopulating
the files. So the lockfile cannot be stored in the `root` itself.
e6dca22cfd/src/Juvix/Extra/Files.hs (L55-L60)
## Pipeline
As noted above, we only use locking in the test suite. The main app
target pipeline is single threaded and so locking is unnecessary. So the
interpretation of locks is parameterised so that locking can be disabled
e6dca22cfd/src/Juvix/Compiler/Pipeline/Run.hs (L64)
* Adds end-to-end tests for compiling Juvix to Geb
* Fixes bugs in the Core-to-Geb translation (`<=` and `let`)
* Fixes a bug in the Geb evaluator (equality on integers)
This PR adds testing for the core-to-geb translation.
It works as follows:
1. Parse the Juvix Core file.
2. Prepare the Juvix Core node for translation to Geb.
3. Translate the Juvix Core node to Geb.
5. Perform type checking on the translated Geb node to ensure that the
types
from the core node make sense in the Geb context and avoid any Geb
runtime
errors.
6. Evaluate the Juvix Core node to see if it produces the expected
result.
7. Translate the result of the evaluated Juvix Core node to Geb for
comparison
with the expected output later.
8. Compare the result of the evaluation of the Geb term produced in step
3
with the result of the evaluation of the Geb term produced in step 6 to
ensure consistency.
9. If step 8 succeeds, then compare the output of step 6 (the evaluation
of the core
node) with the expected output (given in Geb format) to ensure that
the program is functioning as intended.
This PR goes after:
- https://github.com/anoma/juvix/pull/1863
and
https://github.com/anoma/juvix/pull/1832
