packaging: rename nixexpr -> lixexpr and so on

This breaks downstreams linking to us on purpose to make sure that if
someone is linking to Lix they're doing it on purpose and crucially not
mixing up Nix and Lix versions in compatibility code.

We still need to fix the internal includes to follow the same schema so
we can drop the single-level include system entirely. However, this
requires a little more effort.

This adds pkg-config for libfetchers and config.h.

Migration path:
expr.hh      -> lix/libexpr/expr.hh
nix/config.h -> lix/config.h

To apply this migration automatically, remove all `<nix/>` from
includes, so: `#include <nix/expr.hh>` -> `#include <expr.hh>`. Then,
the correct paths will be resolved from the tangled mess, and the
clang-tidy automated fix will work.

Then run the following for out of tree projects:

```
lix_root=$HOME/lix
(cd $lix_root/clang-tidy && nix develop -c 'meson setup build && ninja -C build')
run-clang-tidy -checks='-*,lix-fixincludes' -load=$lix_root/clang-tidy/build/liblix-clang-tidy.so -p build/ -fix src
```

Related: lix-project/nix-eval-jobs#5
Fixes: lix-project/lix#279
Change-Id: I7498e903afa6850a731ef8ce77a70da6b2b46966

doc/manual/rl-next/rename-lixexpr.md

@@ -0,0 +1,31 @@
+---
+synopsis: Rename all the libraries nixexpr, nixstore, etc to lixexpr, lixstore, etc
+credits: jade
+category: Breaking Changes
+---
+
+The Lix C++ API libraries have had the following changes:
+- Includes moved from `include/nix/` to `include/lix/`
+- `pkg-config` files renamed from `nix-expr` to `lix-expr` and so on.
+- Libraries renamed from `libnixexpr.so` to `liblixexpr.so` and so on.
+
+There are other changes between Nix 2.18 and Lix, since these APIs are not
+stable. However, this change in particular is a deliberate compatibility break
+to force downstreams linking to Lix to specifically handle Lix and avoid Lix
+accidentally getting ensnared in compatibility code for newer CppNix.
+
+Migration path:
+
+- expr.hh      -> lix/libexpr/expr.hh
+- nix/config.h -> lix/config.h
+
+To apply this migration automatically, remove all `<nix/>` from includes, so `#include <nix/expr.hh>` -> `#include <expr.hh>`.
+Then, the correct paths will be resolved from the tangled mess, and the clang-tidy automated fix will work.
+
+Then run the following for out of tree projects:
+
+```console
+lix_root=$HOME/lix
+(cd $lix_root/clang-tidy && nix develop -c 'meson setup build && ninja -C build')
+run-clang-tidy -checks='-*,lix-fixincludes' -load=$lix_root/clang-tidy/build/liblix-clang-tidy.so -p build/ -fix src
+```

doc/manual/src/contributing/hacking.md

@@ -102,14 +102,14 @@ $ meson compile -C build nixexpr
 All targets may be addressed as their output, relative to the build directory, e.g.:
 
 ```bash
-$ meson compile -C build src/libexpr/libnixexpr.so
+$ meson compile -C build src/libexpr/liblixexpr.so
 ```
 
 But Meson does not consider intermediate files like object files targets.
 To build a specific object file, use Ninja directly and specify the output file relative to the build directory:
 
 ```bash
-$ ninja -C build src/libexpr/libnixexpr.so.p/nixexpr.cc.o
+$ ninja -C build src/libexpr/liblixexpr.so.p/nixexpr.cc.o
 ```
 
 To inspect the canonical source of truth on what the state of the buildsystem configuration is, use:

meson.build

@@ -395,7 +395,21 @@ config_h = configure_file(
   output : 'config.h',
 )
 
-install_headers(config_h, subdir : 'nix')
+install_headers(config_h, subdir : 'lix')
+
+# FIXME: not using the pkg-config module because it creates way too many deps
+# while meson migration is in progress, and we want to not include boost here
+configure_file(
+  input : 'src/lix-base.pc.in',
+  output : 'lix-base.pc',
+  install_dir : libdir / 'pkgconfig',
+  configuration : {
+    'prefix' : prefix,
+    'libdir' : libdir,
+    'includedir' : includedir,
+    'PACKAGE_VERSION' : meson.project_version(),
+  },
+)
 
 add_project_arguments(
   # TODO(Qyriad): Yes this is how the autoconf+Make system did it.

meson/cleanup-install.bash

@@ -47,4 +47,4 @@ fi
 
 # Intentionally not using -f.
 # If these files don't exist then our assumptions have been violated and we should fail.
-rm -v "$includedir/nix/parser-tab.cc" "$includedir/nix/lexer-tab.cc"
+rm -v "$includedir/lix/libexpr/parser-tab.cc" "$includedir/lix/libexpr/lexer-tab.cc"

package.nix

@@ -49,7 +49,7 @@
   # internal fork of nix-doc providing :doc in the repl
   lix-doc ? __forDefaults.lix-doc,
 
-  pname ? "nix",
+  pname ? "lix",
   versionSuffix ? "",
   officialRelease ? false,
   # Set to true to build the release notes for the next release.
@@ -333,7 +333,7 @@ stdenv.mkDerivation (finalAttrs: {
       echo "file binary-dist $out/bin/nix" >> $out/nix-support/hydra-build-products
     ''
     + lib.optionalString stdenv.isDarwin ''
-      for lib in libnixutil.dylib libnixexpr.dylib; do
+      for lib in liblixutil.dylib liblixexpr.dylib; do
         install_name_tool \
           -change "${lib.getLib boost}/lib/libboost_context.dylib" \
           "$out/lib/libboost_context.dylib" \

perl/lib/Nix/meson.build

@@ -27,7 +27,7 @@ perl_libstore = shared_module(
   ],
   link_args : [
     # Nix doesn't provide a pkg-config file for libutil.
-    '-lnixutil',
+    '-llixutil',
     soname_args,
   ],
   install : true,

perl/meson.build

@@ -64,6 +64,6 @@ if cxx.get_linker_id() in ['ld.bfd', 'ld.gold']
   add_project_link_arguments('-Wl,--no-copy-dt-needed-entries', language : 'cpp')
 endif
 
-libstore = dependency('nixstore', 'nix-store', required : true)
+libstore = dependency('lixstore', 'lix-store', required : true)
 
 subdir('lib/Nix')

src/libcmd/lix-cmd.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix (libcmd)
+Description: Lix Package Manager (libcmd)
+Version: @PACKAGE_VERSION@
+Requires: lix-base lix-util
+Libs: -L${libdir} -llixcmd
+Cflags: -I${includedir}/lix/libcmd

src/libcmd/meson.build

@@ -39,7 +39,7 @@ libcmd_generated_headers = [
 ]
 
 libcmd = library(
-  'nixcmd',
+  'lixcmd',
   libcmd_generated_headers,
   libcmd_sources,
   dependencies : [
@@ -59,13 +59,13 @@ libcmd = library(
   install_rpath : libdir,
 )
 
-install_headers(libcmd_headers, subdir : 'nix', preserve_path : true)
+install_headers(libcmd_headers, subdir : 'lix/libcmd', preserve_path : true)
 custom_target(
   command : [ 'cp', '@INPUT@', '@OUTPUT@' ],
   input : libcmd_generated_headers,
   output : '@PLAINNAME@',
   install : true,
-  install_dir : includedir / 'nix',
+  install_dir : includedir / 'lix/libcmd',
 )
 
 liblixcmd = declare_dependency(
@@ -76,8 +76,8 @@ liblixcmd = declare_dependency(
 # FIXME: not using the pkg-config module because it creates way too many deps
 # while meson migration is in progress, and we want to not include boost here
 configure_file(
-  input : 'nix-cmd.pc.in',
+  input : 'lix-cmd.pc.in',
-  output : 'nix-cmd.pc',
+  output : 'lix-cmd.pc',
   install_dir : libdir / 'pkgconfig',
   configuration : {
     'prefix' : prefix,

src/libcmd/nix-cmd.pc.in

@@ -1,9 +0,0 @@
-prefix=@prefix@
-libdir=@libdir@
-includedir=@includedir@
-
-Name: Nix
-Description: Nix Package Manager
-Version: @PACKAGE_VERSION@
-Libs: -L${libdir} -lnixcmd
-Cflags: -I${includedir}/nix -std=c++2a

src/libexpr/flake/meson.build

@@ -4,5 +4,5 @@ libexpr_generated_headers += custom_target(
   output : '@PLAINNAME@.gen.hh',
   capture : true,
   install : true,
-  install_dir : includedir / 'nix/flake',
+  install_dir : includedir / 'lix/libexpr/flake',
 )

src/libexpr/lix-expr.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix libexpr
+Description: Lix Package Manager (libexpr)
+Version: @PACKAGE_VERSION@
+Requires: lix-base lix-util lix-fetchers lix-store bdw-gc
+Libs: -L${libdir} -llixexpr
+Cflags: -I${includedir}/lix/libexpr

src/libexpr/meson.build

@@ -15,7 +15,7 @@ parser_tab = custom_target(
   # NOTE(Qyriad): Meson doesn't support installing only part of a custom target, so we add
   # an install script below which removes parser-tab.cc.
   install : true,
-  install_dir : includedir / 'nix',
+  install_dir : includedir / 'lix/libexpr',
 )
 
 lexer_tab = custom_target(
@@ -37,7 +37,7 @@ lexer_tab = custom_target(
   # NOTE(Qyriad): Meson doesn't support installing only part of a custom target, so we add
   # an install script below which removes lexer-tab.cc.
   install : true,
-  install_dir : includedir / 'nix',
+  install_dir : includedir / 'lix/libexpr',
 )
 
 # TODO(Qyriad): When the parser and lexer are rewritten this should be removed.
@@ -59,7 +59,7 @@ foreach header : [ 'imported-drv-to-derivation.nix', 'fetchurl.nix' ]
     output : '@PLAINNAME@.gen.hh',
     capture : true,
     install : true,
-    install_dir : includedir / 'nix',
+    install_dir : includedir / 'lix/libexpr',
   )
 endforeach
 subdir('flake')
@@ -127,7 +127,7 @@ libexpr_headers = files(
 )
 
 libexpr = library(
-  'nixexpr',
+  'lixexpr',
   libexpr_sources,
   parser_tab,
   lexer_tab,
@@ -152,7 +152,7 @@ libexpr = library(
 
 install_headers(
   libexpr_headers,
-  subdir : 'nix',
+  subdir : 'lix/libexpr',
   preserve_path : true,
 )
 
@@ -164,8 +164,8 @@ liblixexpr = declare_dependency(
 # FIXME: not using the pkg-config module because it creates way too many deps
 # while meson migration is in progress, and we want to not include boost here
 configure_file(
-  input : 'nix-expr.pc.in',
+  input : 'lix-expr.pc.in',
-  output : 'nix-expr.pc',
+  output : 'lix-expr.pc',
   install_dir : libdir / 'pkgconfig',
   configuration : {
     'prefix' : prefix,

src/libexpr/nix-expr.pc.in

@@ -1,10 +0,0 @@
-prefix=@prefix@
-libdir=@libdir@
-includedir=@includedir@
-
-Name: Nix
-Description: Nix Package Manager
-Version: @PACKAGE_VERSION@
-Requires: nix-store bdw-gc
-Libs: -L${libdir} -lnixexpr
-Cflags: -I${includedir}/nix -std=c++2a

src/libfetchers/lix-fetchers.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix libfetchers
+Description: Lix Package Manager (libfetchers)
+Version: @PACKAGE_VERSION@
+Requires: lix-base lix-util
+Libs: -L${libdir} -llixfetchers
+Cflags: -I${includedir}/lix/libfetchers

src/libfetchers/meson.build

@@ -23,7 +23,7 @@ libfetchers_headers = files(
 )
 
 libfetchers = library(
-  'nixfetchers',
+  'lixfetchers',
   libfetchers_sources,
   dependencies : [
     liblixstore,
@@ -35,7 +35,21 @@ libfetchers = library(
   install_rpath : libdir,
 )
 
-install_headers(libfetchers_headers, subdir : 'nix', preserve_path : true)
+install_headers(libfetchers_headers, subdir : 'lix/libfetchers', preserve_path : true)
+
+# FIXME: not using the pkg-config module because it creates way too many deps
+# while meson migration is in progress, and we want to not include boost here
+configure_file(
+  input : 'lix-fetchers.pc.in',
+  output : 'lix-fetchers.pc',
+  install_dir : libdir / 'pkgconfig',
+  configuration : {
+    'prefix' : prefix,
+    'libdir' : libdir,
+    'includedir' : includedir,
+    'PACKAGE_VERSION' : meson.project_version(),
+  },
+)
 
 liblixfetchers = declare_dependency(
   include_directories : include_directories('.'),

src/libmain/lix-main.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix libmain
+Description: Lix Package Manager (libmain)
+Version: @PACKAGE_VERSION@
+Requires: lix-base lix-util
+Libs: -L${libdir} -llixmain
+Cflags: -I${includedir}/lix/libmain

src/libmain/meson.build

@@ -14,7 +14,7 @@ libmain_headers = files(
 )
 
 libmain = library(
-  'nixmain',
+  'lixmain',
   libmain_sources,
   dependencies : [
     liblixutil,
@@ -25,7 +25,7 @@ libmain = library(
   install_rpath : libdir,
 )
 
-install_headers(libmain_headers, subdir : 'nix', preserve_path : true)
+install_headers(libmain_headers, subdir : 'lix/libmain', preserve_path : true)
 
 liblixmain = declare_dependency(
   include_directories : include_directories('.'),
@@ -35,8 +35,8 @@ liblixmain = declare_dependency(
 # FIXME: not using the pkg-config module because it creates way too many deps
 # while meson migration is in progress, and we want to not include boost here
 configure_file(
-  input : 'nix-main.pc.in',
+  input : 'lix-main.pc.in',
-  output : 'nix-main.pc',
+  output : 'lix-main.pc',
   install_dir : libdir / 'pkgconfig',
   configuration : {
     'prefix' : prefix,

src/libmain/nix-main.pc.in

@@ -1,9 +0,0 @@
-prefix=@prefix@
-libdir=@libdir@
-includedir=@includedir@
-
-Name: Nix
-Description: Nix Package Manager
-Version: @PACKAGE_VERSION@
-Libs: -L${libdir} -lnixmain
-Cflags: -I${includedir}/nix -std=c++2a

src/libstore/lix-store.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix libstore
+Description: Lix Package Manager (libstore)
+Version: @PACKAGE_VERSION@
+Requires: lix-base lix-util
+Libs: -L${libdir} -llixstore -llixutil
+Cflags: -I${includedir}/lix/libstore

src/libstore/meson.build

@@ -6,7 +6,7 @@ foreach header : [ 'schema.sql', 'ca-specific-schema.sql' ]
     output : '@PLAINNAME@.gen.hh',
     capture : true,
     install : true,
-    install_dir : includedir / 'nix',
+    install_dir : includedir / 'lix/libstore',
   )
 endforeach
 
@@ -201,7 +201,7 @@ foreach name, value : cpp_str_defines
 endforeach
 
 libstore = library(
-  'nixstore',
+  'lixstore',
   libstore_generated_headers,
   libstore_sources,
   dependencies : [
@@ -224,7 +224,7 @@ libstore = library(
   install_rpath : libdir,
 )
 
-install_headers(libstore_headers, subdir : 'nix', preserve_path : true)
+install_headers(libstore_headers, subdir : 'lix/libstore', preserve_path : true)
 
 # Used by libfetchers.
 liblixstore = declare_dependency(
@@ -235,8 +235,8 @@ liblixstore = declare_dependency(
 # FIXME: not using the pkg-config module because it creates way too many deps
 # while meson migration is in progress, and we want to not include boost here
 configure_file(
-  input : 'nix-store.pc.in',
+  input : 'lix-store.pc.in',
-  output : 'nix-store.pc',
+  output : 'lix-store.pc',
   install_dir : libdir / 'pkgconfig',
   configuration : {
     'prefix' : prefix,

src/libstore/nix-store.pc.in

@@ -1,9 +0,0 @@
-prefix=@prefix@
-libdir=@libdir@
-includedir=@includedir@
-
-Name: Nix
-Description: Nix Package Manager
-Version: @PACKAGE_VERSION@
-Libs: -L${libdir} -lnixstore -lnixutil
-Cflags: -I${includedir}/nix -std=c++2a

src/libutil/lix-util.pc.in

@@ -0,0 +1,10 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix libutil
+Description: Lix Package Manager (libutil)
+Version: @PACKAGE_VERSION@
+Requires: lix-base lix-util
+Libs: -L${libdir} -llixutil
+Cflags: -I${includedir}/lix/libutil

src/libutil/meson.build

@@ -100,7 +100,7 @@ libutil_headers = files(
 )
 
 libutil = library(
-  'nixutil',
+  'lixutil',
   libutil_sources,
   dependencies : [
     aws_sdk,
@@ -118,7 +118,21 @@ libutil = library(
   install : true,
 )
 
-install_headers(libutil_headers, subdir : 'nix', preserve_path : true)
+install_headers(libutil_headers, subdir : 'lix/libutil', preserve_path : true)
+
+# FIXME: not using the pkg-config module because it creates way too many deps
+# while meson migration is in progress, and we want to not include boost here
+configure_file(
+  input : 'lix-util.pc.in',
+  output : 'lix-util.pc',
+  install_dir : libdir / 'pkgconfig',
+  configuration : {
+    'prefix' : prefix,
+    'libdir' : libdir,
+    'includedir' : includedir,
+    'PACKAGE_VERSION' : meson.project_version(),
+  },
+)
 
 # Used by libstore and libfetchers.
 liblixutil = declare_dependency(

src/lix-base.pc.in

@@ -0,0 +1,8 @@
+prefix=@prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Lix base
+Description: Lix Package Manager (config.hh fixup)
+Version: @PACKAGE_VERSION@
+Cflags: -I${includedir}/lix

tests/unit/meson.build

@@ -17,7 +17,7 @@ libutil_test_support_sources = files(
   'libutil-support/tests/terminal-code-eater.cc',
 )
 libutil_test_support = library(
-  'nixutil-test-support',
+  'lixutil-test-support',
   libutil_test_support_sources,
   dependencies : [
     liblixutil,
@@ -57,7 +57,7 @@ libutil_tests_sources = files(
 )
 
 libutil_tester = executable(
-  'libnixutil-tests',
+  'liblixutil-tests',
   libutil_tests_sources,
   dependencies : [
     rapidcheck,
@@ -90,7 +90,7 @@ libstore_test_support_sources = files(
 )
 
 libstore_test_support = library(
-  'nixstore-test-support',
+  'lixstore-test-support',
   libstore_test_support_sources,
   dependencies : [
     liblixutil_test_support,
@@ -124,7 +124,7 @@ libstore_tests_sources = files(
 )
 
 libstore_tester = executable(
-  'libnixstore-tests',
+  'liblixstore-tests',
   libstore_tests_sources,
   dependencies : [
     liblixstore_test_support,
@@ -154,7 +154,7 @@ libexpr_test_support_sources = files(
 )
 
 libexpr_test_support = library(
-  'nixexpr-test-support',
+  'lixexpr-test-support',
   libexpr_test_support_sources,
   dependencies : [
     liblixstore_test_support,
@@ -185,7 +185,7 @@ libexpr_tests_sources = files(
 )
 
 libexpr_tester = executable(
-  'libnixexpr-tests',
+  'liblixexpr-tests',
   libexpr_tests_sources,
   dependencies : [
     liblixexpr_test_support,