Meson build for libexpr and libflake

src/libflake/meson.build

@@ -0,0 +1,120 @@
+project('nix-flake', 'cpp',
+  version : files('.version'),
+  default_options : [
+    'cpp_std=c++2a',
+    # TODO(Qyriad): increase the warning level
+    'warning_level=1',
+    'debug=true',
+    'optimization=2',
+    'errorlogs=true', # Please print logs for tests that fail
+  ],
+  meson_version : '>= 1.1',
+  license : 'LGPL-2.1-or-later',
+)
+
+cxx = meson.get_compiler('cpp')
+
+# See note in ../nix-util/meson.build
+deps_private = [ ]
+
+# See note in ../nix-util/meson.build
+deps_public = [ ]
+
+# See note in ../nix-util/meson.build
+deps_public_subproject = [ ]
+
+# See note in ../nix-util/meson.build
+deps_other = [ ]
+
+foreach nix_dep : [
+  dependency('nix-util'),
+  dependency('nix-store'),
+  dependency('nix-fetchers'),
+  dependency('nix-expr'),
+]
+  if nix_dep.type_name() == 'internal'
+    deps_public_subproject += nix_dep
+    # subproject sadly no good for pkg-config module
+    deps_other += nix_dep
+  else
+    deps_public += nix_dep
+  endif
+endforeach
+
+nlohmann_json = dependency('nlohmann_json', version : '>= 3.9')
+deps_public += nlohmann_json
+
+libgit2 = dependency('libgit2')
+deps_public += libgit2
+
+add_project_arguments(
+  # TODO(Qyriad): Yes this is how the autoconf+Make system did it.
+  # It would be nice for our headers to be idempotent instead.
+  '-include', 'config-util.h',
+  '-include', 'config-store.h',
+  # '-include', 'config-fetchers.h',
+  '-include', 'config-expr.h',
+  '-Wno-deprecated-declarations',
+  '-Wimplicit-fallthrough',
+  '-Werror=switch',
+  '-Werror=switch-enum',
+  '-Wdeprecated-copy',
+  '-Wignored-qualifiers',
+  # Enable assertions in libstdc++ by default. Harmless on libc++. Benchmarked
+  # at ~1% overhead in `nix search`.
+  #
+  # FIXME: remove when we get meson 1.4.0 which will default this to on for us:
+  # https://mesonbuild.com/Release-notes-for-1-4-0.html#ndebug-setting-now-controls-c-stdlib-assertions
+  '-D_GLIBCXX_ASSERTIONS=1',
+  language : 'cpp',
+)
+
+sources = files(
+  'flake-settings.cc',
+  'flake/config.cc',
+  'flake/flake.cc',
+  'flake/flakeref.cc',
+  'flake/url-name.cc',
+  'flake/lockfile.cc',
+)
+
+headers = files(
+  'flake-settings.hh',
+  'flake/flake.hh',
+  'flake/flakeref.hh',
+  'flake/lockfile.hh',
+  'flake/url-name.hh',
+)
+
+this_library = library(
+  'nixflake',
+  sources,
+  dependencies : deps_public + deps_private + deps_other,
+  install : true,
+)
+
+install_headers(headers, subdir : 'nix', preserve_path : true)
+
+requires = []
+foreach dep : deps_public_subproject
+  requires += dep.name()
+endforeach
+requires += deps_public
+
+import('pkgconfig').generate(
+  this_library,
+  filebase : meson.project_name(),
+  name : 'Nix',
+  description : 'Nix Package Manager',
+  subdirs : ['nix'],
+  extra_cflags : ['-std=c++2a'],
+  requires : requires,
+  requires_private : deps_private,
+)
+
+meson.override_dependency(meson.project_name(), declare_dependency(
+  include_directories : include_directories('.'),
+  link_with : this_library,
+  compile_args : ['-std=c++2a'],
+  dependencies : deps_public_subproject + deps_public,
+))