## 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)
* Closes#1965
* Implements the `unroll` pragma to control the unrolling depth on a
per-function basis.
* Implements parsing of the `inline` pragma.
---------
Co-authored-by: janmasrovira <janmasrovira@gmail.com>
If an import statement to a missing module occurs when parsing in a
project with no dependencies the error message has the following form:
```
The module Foo does not exist.
It should be in /Users/paul/heliax/juvix-2023/tests/negative/NoDependencies/Foo.juvix
or in one of the dependencies:
```
This PR changes this error message to the `or in one of the
dependencies:` line is omitted from the error message when there are no
dependencies in the project.
This commit also adds a negative parse error test for missing module.
Previously we were:
* discarding the types table
* discarding the name ids state
after processing an expression in the REPL.
For example evaluating:
```
let even : _; odd : _; odd zero := false; odd (suc n) := not (even n); even zero := true; even (suc n) := not (odd n) in even 10
```
would loop in the REPL.
We noticed that the `n` in `suc n` was being given type `Type` instead
of `Nat`. This was because the name id given to n was incorrect, the
REPL started using name ids from 0 again.
We fixed this issue by storing information, including the types table
and name ids state in the Artifacts data structure that is returned when
we run the pipeline for the first time. This information is then used
when we call functions to compile / type check REPL expressions.
---------
Co-authored-by: Paul Cadman <git@paulcadman.dev>
- Fixes#1723
- It refactors parsing/scoping so that the scoper does not need to read
files or parse any module. Instead, the parser takes care of parsing all
the imported modules transitively.
