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Nix, the purely functional package manager
20431 commits 177 branches 218 tags 162 MiB
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Sergei Zimmerman 9bc6c30d97
meson: Further optimize compile times with PCH template instantiations 
This is a follow-up to 6ec50ba736, which
also almost halves the compile times on clang for subprojects that use PCH.

`-fpch-instantiate-templates` is a clang-only option to force the instantiation
of templates once in the PCH itself, not all of the translation units that
it gets included to. This really cuts down on the overhead from nlohmann::json
and std::format code:

 48244 ms: nlohmann::basic_json<>::parse<const char *> (76 times, avg 634 ms)
 36193 ms: nlohmann::basic_json<>::basic_json (310 times, avg 116 ms)
 28307 ms: nlohmann::detail::parser<nlohmann::basic_json<>, nlohmann::detail::i... (76 times, avg 372 ms)
 20334 ms: nlohmann::detail::parser<nlohmann::basic_json<>, nlohmann::detail::i... (76 times, avg 267 ms)
 17387 ms: nlohmann::basic_json<>::json_value::json_value (389 times, avg 44 ms)
 16822 ms: std::vformat_to<std::__format::_Sink_iter<char>> (76 times, avg 221 ms)
 16771 ms: std::__format::__do_vformat_to<std::__format::_Sink_iter<char>, char... (76 times, avg 220 ms)
 12160 ms: std::vformat_to<std::__format::_Sink_iter<wchar_t>> (76 times, avg 160 ms)
 12127 ms: std::__format::__do_vformat_to<std::__format::_Sink_iter<wchar_t>, w... (76 times, avg 159 ms)
 10397 ms: nlohmann::detail::json_sax_dom_callback_parser<nlohmann::basic_json<... (76 times, avg 136 ms)
  9118 ms: nlohmann::basic_json<>::data::data (76 times, avg 119 ms)

Initially done by Jade Lovelace <lix@jade.fyi> in https://gerrit.lix.systems/c/lix/+/1842.
We are doing basically the same, but unconditionally. It would be
a huge pain to add a pch option for all subprojects to just support the
usecase of using clangd in a gcc devshell.

In total, this basically halves the frontend times for nix-util and nix-store
to the point that the most expensive part of the build is linking.

(nix-store before):

```
**** Time summary:
Compilation (77 times):
  Parsing (frontend):          243.4 s
  Codegen & opts (backend):    140.3 s
```

(nix-store after):

```
**** Time summary:
Compilation (77 times):
  Parsing (frontend):          120.2 s
  Codegen & opts (backend):    141.2 s
```
2025-07-22 02:39:06 +03:00
.github ci: Add build profiling job 2025-07-20 18:26:26 +03:00
ci/gha/profile-build ci: Add build profiling job 2025-07-20 18:26:26 +03:00
contrib function-trace: always show the trace 2019-09-18 23:23:21 +02:00
doc/manual Require rsync in nix-manual meson.build 2025-07-17 22:59:37 +02:00
maintainers Drop a ton of files that should just get formatted 2025-07-18 12:46:51 -04:00
misc libstore: Don't default build-dir to temp-dir, store setting 2025-06-22 16:49:44 +02:00
nix-meson-build-support meson: Further optimize compile times with PCH template instantiations 2025-07-22 02:39:06 +03:00
packaging doc: Add brief comments to the components 2025-07-19 16:27:55 +03:00
scripts installers, tests: remove --preserve=mode from cp invocations 2025-07-07 15:34:18 -06:00
src nix-cli: Speed up builds by using precompiled headers 2025-07-20 22:02:01 +03:00
tests Apply clang-format universally. 2025-07-18 12:47:27 -04:00
.clang-format Update clang-format with fixing namespace coments, and separate definition blocks 2025-07-18 12:46:51 -04:00
.clang-tidy Add .clang-tidy 2024-02-01 01:01:39 +01:00
.dir-locals.el .dir-locals.el: Set c-block-comment-prefix 2020-07-10 11:21:06 +02:00
.editorconfig No global eval settings in libnixexpr 2024-06-24 12:15:16 -04:00
.git-blame-ignore-revs Update .git-blame-ignore-revs to ignore the mass reformatting 2025-07-18 12:47:27 -04:00
.gitignore Overriding gtest with gmock 2025-05-31 07:41:27 -07:00
.mergify.yml Update .mergify.yml 2025-07-08 16:18:53 +02:00
.shellcheckrc housekeeping: shellcheck for tests/functional/ca/build-cache.sh 2024-06-12 17:41:16 -04:00
.version Bump version 2025-07-08 16:14:50 +02:00
CITATION.cff chore: PhD thesis as reference in CITATION.cff 2024-05-18 20:05:22 +02:00
CONTRIBUTING.md Rename doc/manual{src -> source} 2024-10-14 11:21:24 -04:00
COPYING * Change this to LGPL to keep the government happy. 2006-04-25 16:41:06 +00:00
default.nix Format .nix files 2025-01-24 17:04:02 +01:00
docker.nix docker: set default parameters values 2025-07-13 22:49:12 +02:00
flake.lock flake.lock: Update 2025-05-15 11:31:34 +02:00
flake.nix overlays.default: Only set nix 2025-07-19 16:27:55 +03:00
HACKING.md Rename doc/manual{src -> source} 2024-10-14 11:21:24 -04:00
meson.build Restore multiline formatting of lists in meson files 2025-06-20 23:12:36 +03:00
meson.format flake: Add meson formatter 2025-06-11 22:08:03 +00:00
meson.options flake: Add meson formatter 2025-06-11 22:08:03 +00:00
README.md fix(docs): update Matrix channel links 2025-05-04 12:17:48 +02:00
shell.nix Remove url literals 2022-01-24 13:28:21 +01:00

README.md

Nix

Open Collective supporters CI

Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. Please refer to the Nix manual for more details.

Installation and first steps

Visit nix.dev for installation instructions and beginner tutorials.

Full reference documentation can be found in the Nix manual.

Building and developing

Follow instructions in the Nix reference manual to set up a development environment and build Nix from source.

Contributing

Check the contributing guide if you want to get involved with developing Nix.

Additional resources

Nix was created by Eelco Dolstra and developed as the subject of his PhD thesis The Purely Functional Software Deployment Model, published 2006. Today, a world-wide developer community contributes to Nix and the ecosystem that has grown around it.

License

Nix is released under the LGPL v2.1.