The WORKSPACE file is deprecated; support is already off by default, and
it'll be removed in the next major bazel release. Our main dependency is
tree-sitter, and I'm trying to address that here.
We're currently using https://github.com/elliottt/rules_tree_sitter, but
that hasn't been updated in a couple years, meaning it lacks
MODULE.bazel support. In the registry, there's
https://registry.bazel.build/modules/tree-sitter-bazel, but this is only
the *parser* libraries of tree-sitter, not the *generator*. I'm using it
for that much, at least.
For the *generator*, which transforms grammar.js to parser.c/h, I'm just
requiring a non-hermetic invocation (i.e., people who want to work on it
will need to install tree-sitter; see the README.md updates). I tried
running it manually, but parser.c is about 600 KB; pre-commit rejects
files that large and I don't think an exception makes sense to override
for this (it'd probably also grow substantially if the grammar were
updated to cover more syntax). In order to make the non-hermetic call
not break "bazel build //..." for most developers, I'm marking most
targets in the package as manual.
Note, I did look long and hard at using `aspect_rules_js`/`rules_nodejs`
to invoke npm. This took a lot of time, and I have a commit that's
mostly working, except I hit a point where it uses `declare_symlink`
which we disallow for compatibility reasons (commit "Lots of work for
figuring out rule_js uses declare_symlink" on the PR). As a consequence,
I think we can't use the primary supported ways to have hermetic npm
calls.
Also, `treesitter` -> `tree_sitter` because it's generally called
`tree-sitter`, two words. We even had a `treesitter/src/tree_sitter`
directory so it's a bit inconsistent.
As far as bugs here, the parser library breaks bazel queries, e.g. the
error:
```
ERROR: Evaluation of query "somepath(//..., @llvm-project//third-party/unittest:gtest)" failed: preloading transitive closure failed: no such package '@@[unknown repo 'platforms' requested from @@tree-sitter-bazel+]//': The repository '@@[unknown repo 'platforms' requested from @@tree-sitter-bazel+]' could not be resolved: No repository visible as '@platforms' from repository '@@tree-sitter-bazel+'
```
I'm just excluding tree_sitter from queries where I can to work around
the error.
Removes the separate language server binary; I'm not sure we need to
provide it. Instead, `carbon language-server` is added as a subcommand.
Moves //language_server to //toolchain/language_server. Splits into a
trivial language_server.h, and a substantive server.h. I wasn't sure
about a better name, but wanted the split similar to check/check.h,
lex/lex.h, etc. At the same time, the class is probably going to be a
little big so not a good fit to through into just a cpp file.
This fixes some style issues with the language server class, but
generally I'm trying to not address things here in order to keep it
simpler.
Following a short discussion on Discord about where to locate developer tools, I suggest we collect developer utils inside a `/utils` directory at the repository root.
The idea behind this directory is taken from LLVM's utils directories in the various LLVM subprojects which host tooling such as Vim and VSCode extensions, utility scripts, and other useful bits for developers developing or using LLVM.
This patch moves the highlightjs code into said utils directory.
Let me know if there's anything else that's missing 😄
cc @jonmeow
Jon Ross-Perkins
maan2003
Mats Larsen