nix: port over packaging patches from nix repo (#562702)

pkgs/tools/package-management/nix/modular/packaging/components.nix

@@ -174,6 +174,17 @@ let
     outputs = prevAttrs.outputs or [ "out" ] ++ [ "dev" ];
   };
 
+  fixupStaticLayer = finalAttrs: prevAttrs: {
+    postFixup =
+      prevAttrs.postFixup or ""
+      + lib.optionalString (stdenv.hostPlatform.isStatic) ''
+        # HACK: Otherwise the result will have the entire buildInputs closure
+        # injected by the pkgsStatic stdenv
+        # <https://github.com/NixOS/nixpkgs/issues/83667>
+        rm -f $out/nix-support/propagated-build-inputs
+      '';
+  };
+
   # Work around weird `--as-needed` linker behavior with BSD, see
   # https://github.com/mesonbuild/meson/issues/3593
   bsdNoLinkAsNeeded =
@@ -323,6 +334,7 @@ in
     scope.sourceLayer
     setVersionLayer
     mesonLayer
+    fixupStaticLayer
     scope.mesonComponentOverrides
   ];
   mkMesonExecutable = mkPackageBuilder [
@@ -332,6 +344,7 @@ in
     setVersionLayer
     mesonLayer
     mesonBuildLayer
+    fixupStaticLayer
     scope.mesonComponentOverrides
   ];
   mkMesonLibrary = mkPackageBuilder [
@@ -342,9 +355,17 @@ in
     setVersionLayer
     mesonBuildLayer
     mesonLibraryLayer
+    fixupStaticLayer
     scope.mesonComponentOverrides
   ];
 
+  /**
+    Whether to embed the public C API into nix-cli so plugins can resolve those symbols from the executable.
+  */
+  withPluginCAPI =
+    (lib.versionAtLeast (lib.versions.majorMinor version) "2.35")
+    && !(stdenv.hostPlatform.isWindows || stdenv.hostPlatform.isStatic);
+
   nix-util = callPackage ../src/libutil/package.nix { };
   nix-util-c = callPackage ../src/libutil-c/package.nix { };
   nix-util-test-support = callPackage ../src/libutil-test-support/package.nix { };

pkgs/tools/package-management/nix/modular/src/libexpr-c/package.nix

@@ -8,6 +8,7 @@
   # Configuration Options
 
   version,
+  withPluginCAPI,
 }:
 
 mkMesonLibrary (finalAttrs: {
@@ -21,8 +22,9 @@ mkMesonLibrary (finalAttrs: {
     nix-expr
   ];
 
-  mesonFlags = [
-  ];
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" withPluginCAPI
+  );
 
   meta = {
     platforms = lib.platforms.unix ++ lib.platforms.windows;

pkgs/tools/package-management/nix/modular/src/libfetchers-c/package.nix

@@ -10,6 +10,7 @@
   # Configuration Options
 
   version,
+  withPluginCAPI,
 }:
 
 mkMesonLibrary (finalAttrs: {
@@ -25,7 +26,9 @@ mkMesonLibrary (finalAttrs: {
     nix-fetchers
   ];
 
-  mesonFlags = [ ];
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" withPluginCAPI
+  );
 
   meta = {
     platforms = lib.platforms.unix ++ lib.platforms.windows;

pkgs/tools/package-management/nix/modular/src/libflake-c/package.nix

@@ -10,6 +10,7 @@
   # Configuration Options
 
   version,
+  withPluginCAPI,
 }:
 
 mkMesonLibrary (finalAttrs: {
@@ -29,8 +30,9 @@ mkMesonLibrary (finalAttrs: {
     nix-flake
   ];
 
-  mesonFlags = [
-  ];
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" withPluginCAPI
+  );
 
   meta = {
     platforms = lib.platforms.unix ++ lib.platforms.windows;

pkgs/tools/package-management/nix/modular/src/libmain-c/package.nix

@@ -10,6 +10,7 @@
   # Configuration Options
 
   version,
+  withPluginCAPI,
 }:
 
 mkMesonLibrary (finalAttrs: {
@@ -25,8 +26,9 @@ mkMesonLibrary (finalAttrs: {
     nix-main
   ];
 
-  mesonFlags = [
-  ];
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" withPluginCAPI
+  );
 
   meta = {
     platforms = lib.platforms.unix ++ lib.platforms.windows;

pkgs/tools/package-management/nix/modular/src/libstore-c/package.nix

@@ -8,6 +8,7 @@
   # Configuration Options
 
   version,
+  withPluginCAPI,
 }:
 
 mkMesonLibrary (finalAttrs: {
@@ -21,8 +22,9 @@ mkMesonLibrary (finalAttrs: {
     nix-store
   ];
 
-  mesonFlags = [
-  ];
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" withPluginCAPI
+  );
 
   meta = {
     platforms = lib.platforms.unix ++ lib.platforms.windows;

pkgs/tools/package-management/nix/modular/src/libutil-c/package.nix

@@ -7,6 +7,7 @@
   # Configuration Options
 
   version,
+  withPluginCAPI,
 }:
 
 mkMesonLibrary (finalAttrs: {
@@ -19,8 +20,9 @@ mkMesonLibrary (finalAttrs: {
     nix-util
   ];
 
-  mesonFlags = [
-  ];
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" withPluginCAPI
+  );
 
   meta = {
     platforms = lib.platforms.unix ++ lib.platforms.windows;

pkgs/tools/package-management/nix/modular/src/nix/package.nix

@@ -8,6 +8,13 @@
   nix-main,
   nix-cmd,
 
+  nix-expr-c,
+  nix-fetchers-c,
+  nix-flake-c,
+  nix-main-c,
+  nix-store-c,
+  nix-util-c,
+
   mimalloc,
 
   # Configuration Options
@@ -18,6 +25,10 @@
   # Significantly improves evaluation performance on allocation-heavy
   # workloads (~10-15% on large evaluations).
   withMimalloc ? !stdenv.hostPlatform.isWindows,
+
+  # Whether to embed the public C API into the `nix` executable so plugins can
+  # resolve those symbols without linking Nix libraries directly.
+  withPluginCApi ? !stdenv.hostPlatform.isWindows && !stdenv.hostPlatform.isStatic,
 }:
 
 mkMesonExecutable (finalAttrs: {
@@ -32,11 +43,27 @@ mkMesonExecutable (finalAttrs: {
     nix-main
     nix-cmd
   ]
+  ++ lib.optionals ((lib.versionAtLeast (lib.versions.majorMinor version) "2.35") && withPluginCApi) [
+    nix-expr-c
+    nix-fetchers-c
+    nix-flake-c
+    nix-main-c
+    nix-store-c
+    nix-util-c
+  ]
   ++ lib.optional ((lib.versionAtLeast version "2.35pre") && withMimalloc) mimalloc;
 
-  mesonFlags = lib.optionals (lib.versionAtLeast version "2.35pre") [
-    (lib.mesonEnable "mimalloc" withMimalloc)
-  ];
+  mesonFlags =
+    lib.optionals (lib.versionAtLeast version "2.35pre") [
+      (lib.mesonEnable "mimalloc" withMimalloc)
+    ]
+    ++ lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+      lib.mesonBool "plugin-c-api" withPluginCApi
+    );
+
+  passthru = {
+    exportsPluginCApi = withPluginCApi;
+  };
 
   meta = {
     mainProgram = "nix";

pkgs/tools/package-management/nix/modular/tests/functional/package.nix

@@ -77,6 +77,10 @@ mkMesonDerivation (finalAttrs: {
     "--print-errorlogs"
   ];
 
+  mesonFlags = lib.optional (lib.versionAtLeast (lib.versions.majorMinor version) "2.35") (
+    lib.mesonBool "plugin-c-api" nix-cli.exportsPluginCApi
+  );
+
   doCheck = true;
 
   installPhase = ''