Merge changes Ifcb0d310,I664366b8,Ibe7cf546 into main

* changes:
  gitignore: delete 90% of it
  build-time: remove 20% more by PCH'ing C++ stdlib
  shellHook: make it actually run

.gitignore

@@ -1,128 +1,5 @@
-Makefile.config
-perl/Makefile.config
-
-# /
-/aclocal.m4
-/autom4te.cache
-/precompiled-headers.h.gch
-/config.*
-/configure
-/stamp-h1
-/svn-revision
-/libtool
-/config
-
-# /doc/manual/
-/doc/manual/*.1
-/doc/manual/*.5
-/doc/manual/*.8
-/doc/manual/generated/*
-/doc/manual/nix.json
-/doc/manual/conf-file.json
-/doc/manual/language.json
-/doc/manual/xp-features.json
-/doc/manual/src/command-ref/experimental-features-shortlist.md
-/doc/manual/src/contributing/experimental-feature-descriptions.md
-/doc/manual/src/release-notes/rl-next-generated.md
-
-# /scripts/
-/scripts/nix-profile.sh
-/scripts/nix-profile-daemon.sh
-/scripts/nix-profile.fish
-/scripts/nix-profile-daemon.fish
-
-# /src/libexpr/
-/src/libexpr/lexer-tab.cc
-/src/libexpr/lexer-tab.hh
-/src/libexpr/parser-tab.cc
-/src/libexpr/parser-tab.hh
-/src/libexpr/parser-tab.output
-/src/libexpr/nix.tbl
-/src/libexpr/tests
-/tests/unit/libexpr/libnixexpr-tests
-
-# /src/libstore/
-*.gen.*
-/src/libstore/tests
-/tests/unit/libstore/libnixstore-tests
-
-# /src/libutil/
-/src/libutil/tests
-/tests/unit/libutil/libnixutil-tests
-
-/src/nix/nix
-
-/src/nix/doc
-
-# /src/nix-env/
-/src/nix-env/nix-env
-
-# /src/nix-instantiate/
-/src/nix-instantiate/nix-instantiate
-
-# /src/nix-store/
-/src/nix-store/nix-store
-
-/src/nix-prefetch-url/nix-prefetch-url
-
-/src/nix-collect-garbage/nix-collect-garbage
-
-# /src/nix-channel/
-/src/nix-channel/nix-channel
-
-# /src/nix-build/
-/src/nix-build/nix-build
-
-/src/nix-copy-closure/nix-copy-closure
-
-/src/error-demo/error-demo
-
-/src/build-remote/build-remote
-
-# /tests/functional/
-/tests/functional/test-tmp
-/tests/functional/common/vars-and-functions.sh
-/tests/functional/result*
-/tests/functional/restricted-innocent
-/tests/functional/shell
-/tests/functional/shell.drv
-/tests/functional/config.nix
-/tests/functional/ca/config.nix
-/tests/functional/dyn-drv/config.nix
-/tests/functional/repl-result-out
-/tests/functional/debugger-test-out
-/tests/functional/test-libstoreconsumer/test-libstoreconsumer
-
-# /tests/functional/lang/
-/tests/functional/lang/*.out
-/tests/functional/lang/*.out.xml
-/tests/functional/lang/*.err
-/tests/functional/lang/*.ast
-
-/perl/lib/Nix/Config.pm
-/perl/lib/Nix/Store.cc
-
-/misc/systemd/nix-daemon.service
-/misc/systemd/nix-daemon.socket
-/misc/systemd/nix-daemon.conf
-/misc/upstart/nix-daemon.conf
-
-/src/resolve-system-dependencies/resolve-system-dependencies
-
 outputs/
 
-*.a
-*.o
-*.o.tmp
-*.so
-*.dylib
-*.dll
-*.exe
-*.dep
-*~
-*.pc
-*.plist
-
 # GNU Global
 GPATH
 GRTAGS
@@ -132,17 +9,11 @@ GTAGS
 # ccls
 /.ccls-cache
 
-# auto-generated compilation database
-compile_commands.json
-
-nix-rust/target
-
 result
 result-*
 
 .vscode/
 .direnv/
-.envrc.local
 
 # clangd and possibly more
 .cache/

misc/pre-commit.nix

@@ -87,11 +87,12 @@ pre-commit-run {
         "file"
         "header"
       ];
+      excludes = [
+        ''^src/pch/.*$''
         # generated files; these will never actually be seen by this
         # check, and are left here as documentation
-      excludes = [
+        ''(parser|lexer)-tab\.hh$''
-        "(parser|lexer)-tab\\.hh$"
+        ''\.gen\.hh$''
-        "\\.gen\\.hh$"
       ];
       entry = lib.getExe pkgs.check-headers;
     };

package.nix

@@ -169,7 +169,6 @@ stdenv.mkDerivation (finalAttrs: {
           ./boehmgc-coroutine-sp-fallback.diff
           ./doc
           ./misc
-          ./precompiled-headers.h
           ./src
           ./COPYING
         ]
@@ -449,7 +448,10 @@ stdenv.mkDerivation (finalAttrs: {
           shellHook = ''
             # don't re-run the hook in (other) nested nix-shells
             function lixShellHook() {
-              if [[ $name != lix-shell-env ]]; then
+              # n.b. how the heck does this become -env-env? well, `nix develop` does it:
+              # https://git.lix.systems/lix-project/lix/src/commit/7575db522e9008685c4009423398f6900a16bcce/src/nix/develop.cc#L240-L241
+              # this is, of course, absurd.
+              if [[ $name != lix-shell-env && $name != lix-shell-env-env ]]; then
                 return;
               fi
 

src/libcmd/meson.build

@@ -54,6 +54,7 @@ libcmd = library(
     nlohmann_json,
     lix_doc
   ],
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   install : true,
   # FIXME(Qyriad): is this right?
   install_rpath : libdir,

src/libexpr/meson.build

@@ -145,6 +145,7 @@ libexpr = library(
   include_directories : [
     '../libmain',
   ],
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   install : true,
   # FIXME(Qyriad): is this right?
   install_rpath : libdir,

src/libfetchers/meson.build

@@ -30,6 +30,7 @@ libfetchers = library(
     liblixutil,
     nlohmann_json,
   ],
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   install : true,
   # FIXME(Qyriad): is this right?
   install_rpath : libdir,

src/libmain/meson.build

@@ -20,6 +20,7 @@ libmain = library(
     liblixutil,
     liblixstore,
   ],
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   install : true,
   # FIXME(Qyriad): is this right?
   install_rpath : libdir,

src/libstore/meson.build

@@ -220,6 +220,7 @@ libstore = library(
     nlohmann_json,
   ],
   cpp_args : cpp_args,
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   install : true,
   # FIXME(Qyriad): is this right?
   install_rpath : libdir,

src/libutil/meson.build

@@ -129,6 +129,7 @@ libutil = library(
     openssl,
     nlohmann_json,
   ],
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   implicit_include_directories : true,
   install : true,
 )

src/nix/meson.build

@@ -89,6 +89,7 @@ nix = executable(
     boehm,
     nlohmann_json,
   ],
+  cpp_pch : ['../pch/precompiled-headers.hh'],
   install : true,
   # FIXME(Qyriad): is this right?
   install_rpath : libdir,

tests/unit/meson.build

@@ -68,6 +68,7 @@ libutil_tester = executable(
     liblixutil_test_support,
     nlohmann_json,
   ],
+  cpp_pch : ['../../src/pch/precompiled-headers.hh'],
 )
 
 test(
@@ -102,6 +103,7 @@ libstore_test_support = library(
   include_directories : include_directories(
     'libstore-support',
   ),
+  cpp_pch : ['../../src/pch/precompiled-headers.hh'],
 )
 liblixstore_test_support = declare_dependency(
   include_directories : include_directories('libstore-support'),
@@ -135,6 +137,7 @@ libstore_tester = executable(
     gtest,
     nlohmann_json,
   ],
+  cpp_pch : ['../../src/pch/precompiled-headers.hh'],
 )
 
 test(
@@ -166,6 +169,7 @@ libexpr_test_support = library(
   include_directories : include_directories(
     'libexpr-support',
   ),
+  cpp_pch : ['../../src/pch/precompiled-headers.hh'],
 )
 liblixexpr_test_support = declare_dependency(
   include_directories : include_directories('libexpr-support'),
@@ -199,6 +203,7 @@ libexpr_tester = executable(
     gtest,
     nlohmann_json,
   ],
+  cpp_pch : ['../../src/pch/precompiled-headers.hh'],
 )
 
 test(
@@ -225,6 +230,7 @@ libcmd_tester = executable(
     gtest,
     boost,
   ],
+  cpp_pch : ['../../src/pch/precompiled-headers.hh'],
 )
 
 test(