feat: propagating hooks and context

lib/src/dag/default.nix

@@ -47,10 +47,12 @@ lib: {
         in
         if sorted ? result then
           {
-            result = builtins.map (value: {
+            result = builtins.map
+              (value: {
                 name = value.name;
                 value = value.value;
-            }) sorted.result;
+              })
+              sorted.result;
           }
         else
           sorted;
@@ -64,7 +66,8 @@ lib: {
       defaults =
         graph: defaults:
         let
-          result = builtins.mapAttrs (
+          result = builtins.mapAttrs
+            (
               name: entry:
                 if defaults ? ${name} then
                   if builtins.isString entry then
@@ -81,7 +84,8 @@ lib: {
                     }
                 else
                   entry
-          ) graph;
+            )
+            graph;
         in
         defaults // result;
     };

lib/src/lists/default.nix

@@ -23,10 +23,12 @@ lib: {
               parts = lib.strings.split "(0|[1-9][0-9]*)" string;
             in
             builtins.map serialize parts;
-          prepared = builtins.map (value: [
+          prepared = builtins.map
+            (value: [
               (vectorize value)
               value
-          ]) list;
+            ])
+            list;
           isLess = a: b: (lib.lists.compare lib.numbers.compare (builtins.head a) (builtins.head b)) < 0;
         in
         builtins.map (x: builtins.elemAt x 1) (builtins.sort isLess prepared);
@@ -189,10 +191,12 @@ lib: {
         list
       else
         builtins.tail (
-          builtins.concatMap (part: [
+          builtins.concatMap
+            (part: [
               separator
               part
-          ]) list
+            ])
+            list
         );
 
     ## Create a list of integers from a starting number to an ending
@@ -224,5 +228,14 @@ lib: {
         filter = result: value: if builtins.elem value result then result else result ++ [ value ];
       in
       builtins.foldl' filter [ ] list;
+
+    ## Flatten a list of lists into a single list.
+    ##
+    ## @type List (List a) -> List a
+    flatten = value:
+      if builtins.isList value then
+        builtins.concatMap lib.lists.flatten value
+      else
+        [ value ];
   };
 }

tidepool/flake.lock

@@ -8,10 +8,10 @@
       },
       "locked": {
         "dir": "foundation",
-        "dirtyRev": "2be3111b2c0911f40b47fe0a1fb22b5f5188cf59-dirty",
+        "dirtyRev": "42e69f7d43c0fb108ac70fde118c4a8ff6a777b0-dirty",
-        "dirtyShortRev": "2be3111-dirty",
+        "dirtyShortRev": "42e69f7-dirty",
-        "lastModified": 1719251485,
+        "lastModified": 1720466389,
-        "narHash": "sha256-9G1TPBdlQNXCZf6A66bCT9m2vhodkSF+rDtqOVuFteY=",
+        "narHash": "sha256-Zrmbcb+42r6eZV05QbcG2znHXrOh0sbdRaEZYxV0C7A=",
         "type": "git",
         "url": "file:../?dir=foundation"
       },
@@ -24,10 +24,10 @@
     "lib": {
       "locked": {
         "dir": "lib",
-        "dirtyRev": "2be3111b2c0911f40b47fe0a1fb22b5f5188cf59-dirty",
+        "dirtyRev": "42e69f7d43c0fb108ac70fde118c4a8ff6a777b0-dirty",
-        "dirtyShortRev": "2be3111-dirty",
+        "dirtyShortRev": "42e69f7-dirty",
-        "lastModified": 1719251485,
+        "lastModified": 1720466389,
-        "narHash": "sha256-9G1TPBdlQNXCZf6A66bCT9m2vhodkSF+rDtqOVuFteY=",
+        "narHash": "sha256-Zrmbcb+42r6eZV05QbcG2znHXrOh0sbdRaEZYxV0C7A=",
         "type": "git",
         "url": "file:../?dir=lib"
       },

tidepool/src/builders/basic.nix

@@ -1,10 +1,8 @@
-{ lib, config }:
+{ config }:
 let
   cfg = config.builders.basic;
 
-  lib' = config.lib;
+  inherit (config) lib foundation;
-
-  inherit (config) foundation;
 in
 {
   config.builders = {
@@ -14,7 +12,36 @@ in
       build =
         package:
         let
-          phases = lib.dag.apply.defaults package.phases {
+          system = package.platform.build.double;
+
+          dependencies = lib.packages.dependencies.collect package;
+
+          context = lib.packages.context.create dependencies { };
+
+          hooks = lib.packages.hooks.create dependencies context;
+
+          cflags = builtins.concatStringsSep " " (context.build.host.cflags or [ ]);
+
+          phasesWithHooks =
+            let
+              all = lib.lists.flatten [
+                hooks.build.only
+                hooks.build.build
+                hooks.build.host
+                hooks.build.target
+                hooks.host.only
+                hooks.host.host
+                hooks.host.target
+                hooks.target.only
+                hooks.target.target
+              ];
+            in
+            builtins.foldl'
+              (final: defaults: lib.dag.apply.defaults final defaults)
+              package.phases
+              all;
+
+          phases = lib.dag.apply.defaults phasesWithHooks {
             unpack = lib.dag.entry.before [ "patch" ] "";
 
             patch = lib.dag.entry.between [ "unpack" ] [ "configure" ] "";
@@ -25,13 +52,12 @@ in
 
             install = lib.dag.entry.after [ "build" ] "";
           };
+
           sorted = lib.dag.sort.topological phases;
 
-          script = lib.strings.concatMapSep "\n" (
+          script = lib.strings.concatMapSep "\n"
-            entry: if builtins.isFunction entry.value then entry.value package else entry.value
+            (entry: entry.value)
-          ) sorted.result;
+            sorted.result;
-
-          system = package.platform.build.double;
 
           built = builtins.derivation (
             package.env
@@ -46,7 +72,7 @@ in
               PATH =
                 let
                   bins = lib.paths.bin (
-                    (lib'.packages.dependencies.getPackages package.deps.build.host)
+                    (lib.packages.dependencies.get dependencies.build.host)
                     ++ [
                       foundation.stage2-bash
                       foundation.stage2-coreutils
@@ -85,7 +111,8 @@ in
           inherit (package) meta;
           extras = {
             inherit package;
-          };
+            phases = builtins.listToAttrs sorted.result;
+          } // package.extras;
         };
     };
   };

tidepool/src/export.nix

@@ -14,6 +14,7 @@ in
 
       packages = {
         aux-a = config.packages.aux.a;
+        aux-b = config.packages.aux.b;
 
         # foundation-gcc-x86_64 =
         # (config.packages.foundation.gcc.versions."13.2.0".extend (args: {

tidepool/src/lib/packages.nix

@@ -6,18 +6,178 @@ in
   config = {
     lib.packages = {
       dependencies = {
-        getPackages =
+        get =
           dependencies:
           let
-            available = builtins.filter (dependency: !(builtins.isNull dependency)) (
+            exists = value: ! (builtins.isNull value);
-              builtins.attrValues dependencies
+            available = builtins.filter exists dependencies;
-            );
           in
           builtins.map (dependency: dependency.package) available;
 
         build =
           build': host': target':
           builtins.mapAttrs (name: dep: lib'.packages.build dep build' host' target');
+
+        collect = package:
+          let
+            isPropagated = name: package: package.propagate or false;
+            getPropagatedDependencies = target: builtins.attrValues (lib.attrs.filter isPropagated target);
+
+            process = dependencies:
+              let
+                getDeps = name: dependency:
+                  let
+                    deps =
+                      {
+                        build = {
+                          only = getPropagatedDependencies dependency.deps.build.only ++ process dependency.deps.build.only;
+                          build = getPropagatedDependencies dependency.deps.build.build ++ process dependency.deps.build.build;
+                          host = getPropagatedDependencies dependency.deps.build.host ++ process dependency.deps.build.host;
+                          target = getPropagatedDependencies dependency.deps.build.target ++ process dependency.deps.build.target;
+                        };
+                        host = {
+                          only = getPropagatedDependencies dependency.deps.host.only ++ process dependency.deps.host.only;
+                          host = getPropagatedDependencies dependency.deps.host.host ++ process dependency.deps.host.host;
+                          target = getPropagatedDependencies dependency.deps.host.target ++ process dependency.deps.host.target;
+                        };
+                        target = {
+                          only = getPropagatedDependencies dependency.deps.target.only ++ process dependency.deps.target.only;
+                          target = getPropagatedDependencies dependency.deps.target.target ++ process dependency.deps.target.target;
+                        };
+                      };
+                  in
+                  lib.lists.flatten
+                    [
+                      deps.build.only
+                      deps.build.build
+                      deps.build.host
+                      deps.build.target
+                      deps.host.only
+                      deps.host.host
+                      deps.host.target
+                      deps.target.only
+                      deps.target.target
+                    ];
+
+                propagated = lib.attrs.mapToList getDeps dependencies;
+              in
+              lib.lists.flatten propagated;
+          in
+          {
+            build = {
+              only = builtins.attrValues package.deps.build.only ++ process package.deps.build.only;
+              build = builtins.attrValues package.deps.build.build ++ process package.deps.build.build;
+              host = builtins.attrValues package.deps.build.host ++ process package.deps.build.host;
+              target = builtins.attrValues package.deps.build.target ++ process package.deps.build.target;
+            };
+            host = {
+              only = builtins.attrValues package.deps.host.only ++ process package.deps.host.only;
+              host = builtins.attrValues package.deps.host.host ++ process package.deps.host.host;
+              target = builtins.attrValues package.deps.host.target ++ process package.deps.host.target;
+            };
+            target = {
+              only = builtins.attrValues package.deps.target.only ++ process package.deps.target.only;
+              target = builtins.attrValues package.deps.target.target ++ process package.deps.target.target;
+            };
+          };
+      };
+
+      context = {
+        create = collected: ctx:
+          let
+            process = path:
+              let
+                dependencies = lib.attrs.selectOrThrow path collected;
+                contexts = builtins.map (dependency: dependency.context or { }) dependencies;
+                base = ctx // {
+                  target = builtins.concatStringsSep "." path;
+                };
+                result = lib.modules.run {
+                  modules = builtins.map
+                    (context: { config }: {
+                      config = context;
+                    })
+                    contexts
+                  ++ [
+                    {
+                      freeform = lib.types.any;
+
+                      options = config.packages.context.options // {
+                        target = lib.options.create {
+                          description = "The dependency target that is being generated.";
+                          type = lib.types.enum [
+                            "build.only"
+                            "build.build"
+                            "build.host"
+                            "build.target"
+                            "host.only"
+                            "host.host"
+                            "host.target"
+                            "target.only"
+                            "target.target"
+                          ];
+                        };
+                      };
+
+                      config = base;
+                    }
+                  ];
+                };
+              in
+              result.config;
+          in
+          {
+            build = {
+              only = process [ "build" "only" ];
+              build = process [ "build" "build" ];
+              host = process [ "build" "host" ];
+              target = process [ "build" "target" ];
+            };
+            host = {
+              only = process [ "host" "only" ];
+              host = process [ "host" "host" ];
+              target = process [ "host" "target" ];
+            };
+            target = {
+              only = process [ "target" "only" ];
+              target = process [ "target" "target" ];
+            };
+          };
+      };
+
+      hooks = {
+        create = collected: ctx:
+          let
+            process = path:
+              let
+                dependencies = lib.attrs.selectOrThrow path collected;
+                hooks = builtins.map
+                  (dependency:
+                    let
+                      getHooks = dependency.hooks or (lib.fp.const { });
+                    in
+                    getHooks ctx)
+                  dependencies;
+              in
+              hooks;
+          in
+          {
+            build = {
+              only = process [ "build" "only" ];
+              build = process [ "build" "build" ];
+              host = process [ "build" "host" ];
+              target = process [ "build" "target" ];
+            };
+            host = {
+              only = process [ "host" "only" ];
+              host = process [ "host" "host" ];
+              target = process [ "host" "target" ];
+            };
+            target = {
+              only = process [ "target" "only" ];
+              target = process [ "target" "target" ];
+            };
+          };
       };
 
       getLatest =

tidepool/src/lib/types.nix

@@ -280,6 +280,12 @@ in
                   };
                 };
 
+                extras = lib.options.create {
+                  description = "Extra information for the package.";
+                  type = lib.types.attrs.of lib.types.any;
+                  default.value = { };
+                };
+
                 platform = {
                   build = lib.options.create {
                     description = "The build platform for the package.";
@@ -327,12 +333,6 @@ in
                   type = lib'.types.builder;
                 };
 
-                phases = lib.options.create {
-                  description = "The phases for the package.";
-                  type = lib.types.dag.of lib.types.string;
-                  default.value = { };
-                };
-
                 env = lib.options.create {
                   description = "The environment for the package.";
                   type = lib.types.attrs.of lib.types.string;
@@ -345,6 +345,30 @@ in
                   default.value = config.builder.build config;
                 };
 
+                phases = lib.options.create {
+                  description = "The phases for the package.";
+                  type = lib.types.dag.of lib.types.string;
+                  default.value = { };
+                };
+
+                context = lib.options.create {
+                  description = "The context information that the package provides.";
+                  type = lib.types.attrs.of lib.types.raw;
+                  default.value = { };
+                };
+
+                hooks = lib.options.create {
+                  description = "The hooks that the package provides.";
+                  type = lib.types.function (lib.types.dag.of lib.types.string);
+                  default.value = ctx: { };
+                };
+
+                propagate = lib.options.create {
+                  description = "Whether the package should propagate its hooks and context.";
+                  type = lib.types.bool;
+                  default.value = false;
+                };
+
                 deps = lib.options.create {
                   description = "The dependencies for the package.";
                   type = deps build host target;

tidepool/src/packages/aux/b.nix

@@ -26,6 +26,16 @@ in
 
             builder = builders.basic;
 
+            context = {
+              cflags = [ "-I $AUX_B/include" ];
+            };
+
+            hooks = ctx: {
+              "aux:b:env" = lib.dag.entry.after
+                [ "unpack" ]
+                ''export AUX_B=${config.package}'';
+            };
+
             phases = {
               install = ''
                 echo "b" > $out

tidepool/src/packages/default.nix

@@ -19,14 +19,24 @@ in
       type = lib.types.submodule {
         freeform = lib.types.packages;
 
-        options.cross = lib.attrs.generate doubles (
+        options = {
+          cross = lib.attrs.generate doubles (
             system:
             lib.options.create {
               description = "The cross-compiled package set for the ${system} target.";
               type = lib.types.packages;
-            default = { };
+              default.value = { };
             }
           );
+
+          # NOTE: We may offer a way to set default context values. For this reason we have
+          # nested `options` under `context` rather than using a plain option directly under `packages`.
+          context.options = lib.options.create {
+            description = "The available options for package contexts.";
+            default.value = { };
+            type = lib.types.attrs.of lib.types.option;
+          };
+        };
       };
     };
 
@@ -42,9 +52,11 @@ in
     };
   };
 
-  config.packages.cross = lib.attrs.generate doubles (
+  config = {
+    packages.cross = lib.attrs.generate doubles (
       system:
-    builtins.mapAttrs (
+      builtins.mapAttrs
+        (
           namespace:
           builtins.mapAttrs (
             name: alias:
@@ -62,38 +74,6 @@ in
                       }
                     ];
                   };
-          # if package != {}
-          # then
-          #   (package.extend (
-          #     {config}: {
-          #       config = {
-          #         platform = {
-          #           host = lib.modules.overrides.force system;
-          #           target = lib.modules.overrides.default system;
-          #         };
-
-          #         deps = {
-          #           build = {
-          #             only = setHost package.deps.build.only;
-          #             build = setHost package.deps.build.build;
-          #             host = setHost package.deps.build.host;
-          #             target = setHost package.deps.build.target;
-          #           };
-          #           host = {
-          #             only = setHost package.deps.host.only;
-          #             host = setHost package.deps.host.host;
-          #             target = setHost package.deps.host.target;
-          #           };
-          #           target = {
-          #             only = setHost package.deps.target.only;
-          #             target = setHost package.deps.target.target;
-          #           };
-          #         };
-          #       };
-          #     }
-          #   ))
-          #   .config
-          # else package;
 
                 updated = alias // {
                   versions = builtins.mapAttrs (version: package: setHost package) alias.versions;
@@ -101,6 +81,8 @@ in
               in
               updated
           )
-    ) packages
+        )
+        packages
     );
+  };
 }