Tunnels `Manger` object into the `ScanningAllProjectModules` so it can
be used to perform necessary command-line modifications (which also adds
`--resources` path previously added there explicitly). This allows using
the experimental C++ modules support with gcc.
This was discussed in the issue with @ChuanqiXu9 and @kadircet
Closes#112635
Prior to this, the "old != new" check would always evaluate to true because it was comparing a pre-mangling new command to a post-mangling old command.
Alternatives to https://reviews.llvm.org/D153114.
Try to address https://github.com/clangd/clangd/issues/1293.
See the links for design ideas and the consensus so far. We want to have
some initial support in clang18.
This is the initial support for C++20 Modules in clangd.
As suggested by sammccall in https://reviews.llvm.org/D153114,
we should minimize the scope of the initial patch to make it easier
to review and understand so that every one are in the same page:
> Don't attempt any cross-file or cross-version coordination: i.e. don't
> try to reuse BMIs between different files, don't try to reuse BMIs
> between (preamble) reparses of the same file, don't try to persist the
> module graph. Instead, when building a preamble, synchronously scan
> for the module graph, build the required PCMs on the single preamble
> thread with filenames private to that preamble, and then proceed to
> build the preamble.
This patch reflects the above opinions.
# Testing in real-world project
I tested this with a modularized library:
https://github.com/alibaba/async_simple/tree/CXX20Modules. This library
has 3 modules (async_simple, std and asio) and 65 module units. (Note
that a module consists of multiple module units). Both `std` module and
`asio` module have 100k+ lines of code (maybe more, I didn't count). And
async_simple itself has 8k lines of code. This is the scale of the
project.
The result shows that it works pretty well, ..., well, except I need to
wait roughly 10s after opening/editing any file. And this falls in our
expectations. We know it is hard to make it perfect in the first move.
# What this patch does in detail
- Introduced an option `--experimental-modules-support` for the support
for C++20 Modules. So that no matter how bad this is, it wouldn't affect
current users. Following off the page, we'll assume the option is
enabled.
- Introduced two classes `ModuleFilesInfo` and
`ModuleDependencyScanner`. Now `ModuleDependencyScanner` is only used by
`ModuleFilesInfo`.
- The class `ModuleFilesInfo` records the built module files for
specific single source file. The module files can only be built by the
static member function `ModuleFilesInfo::buildModuleFilesInfoFor(PathRef
File, ...)`.
- The class `PreambleData` adds a new member variable with type
`ModuleFilesInfo`. This refers to the needed module files for the
current file. It means the module files info is part of the preamble,
which is suggested in the first patch too.
- In `isPreambleCompatible()`, we add a call to
`ModuleFilesInfo::CanReuse()` to check if the built module files are
still up to date.
- When we build the AST for a source file, we will load the built module
files from ModuleFilesInfo.
# What we need to do next
Let's split the TODOs into clang part and clangd part to make things
more clear.
The TODOs in the clangd part include:
1. Enable reusing module files across source files. The may require us
to bring a ModulesManager like thing which need to handle `scheduling`,
`the possibility of BMI version conflicts` and `various events that can
invalidate the module graph`.
2. Get a more efficient method to get the `<module-name> ->
<module-unit-source>` map. Currently we always scan the whole project
during `ModuleFilesInfo::buildModuleFilesInfoFor(PathRef File, ...)`.
This is clearly inefficient even if the scanning process is pretty fast.
I think the potential solutions include:
- Make a global scanner to monitor the state of every source file like I
did in the first patch. The pain point is that we need to take care of
the data races.
- Ask the build systems to provide the map just like we ask them to
provide the compilation database.
3. Persist the module files. So that we can reuse module files across
clangd invocations or even across clangd instances.
TODOs in the clang part include:
1. Clang should offer an option/mode to skip writing/reading the bodies
of the functions. Or even if we can requrie the parser to skip parsing
the function bodies.
And it looks like we can say the support for C++20 Modules is initially
workable after we made (1) and (2) (or even without (2)).
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This gives CommandMangler access to other fields of
tooling::CompileCommand as well, e.g. Directory.
Differential Revision: https://reviews.llvm.org/D133756
This is on the critical path (it blocks getting the compile command for
the first file).
It's not trivially fast: it involves processing all filenames in the CDB
and doing some IO to look for shadowing CDBs.
And we may make this slower soon - making CDB configurable implies evaluating
the config for each listed to see which ones really are owned by the
broadcasted CDB.
Differential Revision: https://reviews.llvm.org/D94606
When querying the CDB, we stat the underlying file to check it hasn't changed.
We don't do this every time, but only if we didn't check within 5 seconds.
This behavior only exists for compile_commands.json and compile_flags.txt.
The CDB plugin system doesn't expose enough information to handle others.
Slight behavior change: we now only look for `build/compile_commands.json`
rather than trying every CDB strategy under `build` subdirectories.
Differential Revision: https://reviews.llvm.org/D92663
This is a step towards making compile_commands.json reloadable.
The idea is:
- in addition to rare CDB loads we're soon going to have somewhat-rare CDB
reloads and fairly-common stat() of files to validate the CDB
- so stop doing all our work under a big global lock, instead using it to
acquire per-directory structures with their own locks
- each directory can be refreshed from disk every N seconds, like filecache
- avoid locking these at all in the most common case: directory has no CDB
Differential Revision: https://reviews.llvm.org/D92381
Summary:
Clangd is returning current working directory for overriden commands.
This can cause inconsistencies between:
- header and the main files, as OverlayCDB only contains entries for the main
files it direct any queries for the headers to the base, creating a
discrepancy between the two.
- different clangd instances, as the results will be different depending on the
timing of execution of the query and override of the command. hence clangd
might see two different project infos for the same file between different
invocations.
- editors and the way user has invoked it, as current working directory of
clangd will depend on those, hence even when there's no underlying base CWD
might change depending on the editor, or the directory user has started the
editor in.
This patch gets rid of that discrepency by always directing queries to base or
returning llvm::None in absence of it.
For a sample bug see https://reviews.llvm.org/D83099#2154185.
Reviewers: sammccall
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, usaxena95, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D83934
Summary:
This was originally committed in 88bccded8fa169481fa367debf5ec615640635a1,
and reverted in 93f77617abba512d2861e2fc50ce385883f587b6.
This version is now much more testable: the "detect toolchain properties" part
is still not tested but also not active in tests.
All the command manipulation based on the detected properties is
directly tested, and also not active in other tests.
Fixes https://github.com/clangd/clangd/issues/211
Fixes https://github.com/clangd/clangd/issues/178
Reviewers: kbobyrev, ilya-biryukov
Subscribers: mgorny, ormris, cfe-commits, usaxena95, kadircet, arphaman, jkorous, MaskRay
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71029
Summary:
This isn't a general fix to all paths where we assume case-sensitivity, it's
a minimally-invasive fix targeting the llvm 9 branch.
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D65320
llvm-svn: 367112
This was reverted in rL365678, the failure was due to YAML parsing of
compile_commands.json.
Converting backslashes to forward slashes to fix the issue in unittest.
llvm-svn: 365748
Summary:
...template argument.
Remove the forward declaration and include the appropriate header instead.
Remove CompileCommand too, which is also in the header.
llvm-svn: 365713
Summary:
Some custom toolchains come with their own header files and compiler
drivers. Those compiler drivers implicitly know about include search path for
those headers. This patch aims to extract that information from drivers and add
it to the command line when invoking clang frontend.
Reviewers: sammccall
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62804
llvm-svn: 364389
Summary:
Some projects make use of clang plugins when building, but clangd is
not aware of those plugins therefore can't work with the same compile command
arguments.
There were multiple places clangd performed commandline manipulations,
this one also moves them all into OverlayCDB.
Reviewers: ilya-biryukov
Subscribers: klimek, sammccall, ioeric, MaskRay, jkorous, arphaman, cfe-commits
Differential Revision: https://reviews.llvm.org/D56841
llvm-svn: 351788
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
Instead of receiving compilation commands, auto-index is triggered by just
filenames to reindex, and gets commands from the global comp DB internally.
This has advantages:
- more of the work can be done asynchronously (fetching compilation commands
upfront can be slow for large CDBs)
- we get access to the CDB which can be used to retrieve interpolated commands
for headers (useful in some cases where the original TU goes away)
- fits nicely with the filename-only change observation from r347297
The interface to GlobalCompilationDatabase gets extended: when retrieving a
compile command, the GCDB can optionally report the project the file belongs to.
This naturally fits together with getCompileCommand: it's hard to implement one
without the other. But because most callers don't care, I've ended up with an
awkward optional-out-param-in-virtual method pattern - maybe there's a better
one.
This is the main missing integration point between ClangdServer and
BackgroundIndex, after this we should be able to add an auto-index flag.
Reviewers: ioeric, kadircet
Subscribers: MaskRay, jkorous, arphaman, cfe-commits, ilya-biryukov
Differential Revision: https://reviews.llvm.org/D54865
llvm-svn: 347538
Summary:
Currently, changes *within* CDBs are not tracked (CDB has no facility to do so).
However, discovery of new CDBs are tracked (all files are marked as modified).
Also, files whose compilation commands are explicitly set are marked modified.
The intent is to use this for auto-index. Newly discovered files will be indexed
with low priority.
Reviewers: ilya-biryukov
Subscribers: ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D54475
llvm-svn: 347297
Summary:
The new implementation is a GlobalCompilationDatabase that overlays a base.
Normally this is the directory-based CDB.
To preserve the behavior of compile_args_from=LSP, the base may be null.
The OverlayCDB is always present, and so the extensions to populate it
are always supported.
It also allows overriding the flags of the fallback command. This is
just unit-tested for now, but the plan is to expose this as an extension
on the initialize message. This addresses use cases like
https://github.com/thomasjo/atom-ide-cpp/issues/16
Reviewers: ilya-biryukov
Subscribers: ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D53687
llvm-svn: 345970
Summary:
This was added in D34947 to support YCM, but YCM actually provides *all* args,
and this was never actually used.
Meanwhile, we grew another extension that allows specifying all args.
I did find one user of this extension: https://github.com/thomasjo/atom-ide-cpp.
I'll reach out, there are multiple good alternatives:
- compile_commands.txt can serve the same purpose as .clang_complete there
- we can add an extension to support setting the fallback command
Reviewers: ilya-biryukov
Subscribers: ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D53641
llvm-svn: 345969
Summary:
It doesn't make much sense: setting them is not coupled to opening the file,
it's an asynchronous notification.
I don't think this is a breaking change - this behavior is hard to observe!
Reviewers: ilya-biryukov
Subscribers: ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D53642
llvm-svn: 345231
Summary:
The CDB implementations used in open-source code are fast, and our private
slow CDB will soon do the relevant caching itself.
Simplifying the GlobalCDB layer in clangd is important to get auto-index
implemented at the right layer.
Reviewers: ioeric, ilya-biryukov
Subscribers: MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D53439
llvm-svn: 345024
compilationDatabaseChanges in the 'workspace/didChangeConfiguration' request
This commit allows clangd to use an in-memory compilation database that's
controlled from the LSP client (-compile_args_from=lsp). It extends the
'workspace/didChangeConfiguration' request to allow the client to pass in a
compilation database subset that needs to be updated in the workspace.
Differential Revision: https://reviews.llvm.org/D49758
llvm-svn: 338597
Summary:
Caching is now handled by ClangdLSPServer and hidden behind the
GlobalCompilationDatabase interface. This simplifies ClangdServer.
This change also removes the SkipCache flag from addDocument,
which is now obsolete.
No behavioral changes are intended, the clangd binary still caches the
compile commands on the first read.
Reviewers: sammccall
Reviewed By: sammccall
Subscribers: mgorny, ioeric, MaskRay, jkorous, cfe-commits
Differential Revision: https://reviews.llvm.org/D48068
llvm-svn: 334585
Summary: This makes C++/objC not totally broken, without hurting C files too much.
Reviewers: ilya-biryukov
Subscribers: klimek, jkorous-apple, ioeric, cfe-commits
Differential Revision: https://reviews.llvm.org/D45442
llvm-svn: 330418
Summary:
Implementation of DidChangeConfiguration notification handling in
clangd. This currently only supports changing one setting: the path of
the compilation database to be used for the current project. In other
words, it is no longer necessary to restart clangd with a different
command line argument in order to change the compilation database.
Reviewers: malaperle, krasimir, bkramer, ilya-biryukov
Subscribers: jkorous-apple, ioeric, simark, klimek, ilya-biryukov, arphaman, rwols, cfe-commits
Differential Revision: https://reviews.llvm.org/D39571
Signed-off-by: Simon Marchi <simon.marchi@ericsson.com>
Signed-off-by: William Enright <william.enright@polymtl.ca>
llvm-svn: 325784
Summary:
- GlobalCompilationDatabase now returns a single command (that's all we use)
- fallback flags are now part of the GlobalCompilationDatabase.
There's a default implementation that they can optionally customize.
- this allows us to avoid invoking the fallback logic on two separate codepaths
- race on extra flags fixed by locking the mutex
- made GCD const-correct (DBGCD does have mutating methods)
Reviewers: hokein
Subscribers: klimek, cfe-commits, ilya-biryukov
Differential Revision: https://reviews.llvm.org/D40733
llvm-svn: 319647
Summary: Adds compileCommands command line argument to specify an absolute path directly to the requested compile_commands.json for flags.
Reviewed By: ilya-biryukov
Differential Revision: https://reviews.llvm.org/D37150
llvm-svn: 314678
