cquery is a highly-scalable, low-latency language server for C/C++. It is tested and designed for large code bases like Chromium. cquery provides accurate and fast semantic analysis without interrupting workflow.
cquery implements almost the entire language server protocol and provides some extra features to boot:
- code completion (with both signature help and snippets)
- references
- type hierarchy (parent type, derived types, expandable tree view)
- calls to functions, calls to base and derived functions, call tree
- symbol rename
- goto definition, goto base method
- document and global symbol search
- hover tooltips showing symbol type
- diagnostics
- code actions (clang FixIts)
- darken/fade code disabled by preprocessor
- #include auto-complete, undefined type include insertion, include quick-jump (goto definition, document links)
- auto-implement functions without a definition
There are three steps to get cquery up and running. Eventually, cquery will be published in the vscode extension marketplace which will reduce these three steps to only project setup.
Building cquery is simple. The external dependencies are few:
- relatively modern c++11 compiler (ie, clang 3.4 or greater)
- python
- git
$ clang --version # if missing, sudo apt-get install clang
$ git clone https://github.com/jacobdufault/cquery --recursive
$ cd cquery
$ ./waf configure --prefix ~/.local/stow/cquery # --prefix is optional, it specifies install directory
$ ./waf build # -g -O3, built build/release/bin/cquery
$ ./waf install # optional, copies the executable to $PREFIX/bin/cquery
For a debug build:
$ ./waf configure --variant=debug
$ ./waf build --variant=debug # -g -O0, built build/debug/bin/cquery
cquery includes a vscode extension; it is part of the repository. Launch vscode
and install the vscode-extension.tsix
extension. To do this:
- Hit
F1
; execute the commandInstall from VSIX
. - Select
vscode-extension.vsix
in the file chooser.
IMPORTANT: Please reinstall the extension when you sync the code base - it is still being developed.
If you run into issues, you can view debug output by running the
(F1
) View: Toggle Output
command and opening the cquery
output section.
See wiki for how to generate compile_commands.json
with CMake, Build EAR, Ninja, ...
If the compile_commands.json
is not in the top-level workspace directory,
then the cquery.misc.compilationDatabaseDirectory
setting can be used to
specify its location.
If for whatever reason you cannot generate a compile_commands.json
file, you
can add the flags to the cquery.index.extraClangArguments
configuration
option.
If for whatever reason you cannot generate a compile_commands.json
file, you
can add the flags to a file called .cquery
located in the top-level
workspace directory.
Each argument in that file is separated by a newline. Lines starting with #
are skipped. Here's an example:
# Language
-xc++
-std=c++11
# Includes
-I/work/cquery/third_party
If you wish to modify the vscode extension, you will need to build it locally. Luckily, it is pretty easy - the only dependency is npm.
# Build extension
$ cd vscode-client
$ npm install
$ code .
When VSCode is running, you can hit F5
to build and launch the extension
locally.
cquery is able to respond to queries quickly because it caches a huge amount of information. When a request comes in, cquery just looks it up in the cache without running many computations. As a result, there's a large memory overhead. For example, a full index of Chrome will take about 10gb of memory. If you exclude v8, webkit, and third_party, it goes down to about 6.5gb.
For Emacs/Vim/other editors integration and some additional tips, see wiki.
Chromium is a very large codebase, so cquery benefits from a bit of tuning. Optionally add these to your settings:
// Set slightly lower than your CPU core count to keep other tools responsive.
"cquery.misc.indexerCount": 50,
// Remove uncommonly used directories with large numbers of files.
"cquery.index.blacklist": [
".*/src/base/third_party/.*",
".*/src/native_client/.*",
".*/src/native_client_sdk/.*",
".*/src/third_party/.*",
".*/src/v8/.*",
".*/src/webkit/.*"
]
MIT