Import rules instead of hard-coding

8 files changed, 91 insertions, 16 deletions

diff --git a/README.md b/README.md
index cfb1773..0e6d1f9 100644
--- a/README.md
+++ b/README.md
@@ -112,13 +112,10 @@ There are two files pinning dependencies
    be updated using [update-nix-dependencies.sh](./update-nix-dependencies.sh)
    which simply calls `niv update` in our `nix-shell`.
  - The dependencies on other other justbuild projects are
-   pinned in [etc/repos.json](etc/repos.json). As, at the
-   moment, there is only one external justbuild dependency,
-   the [rules-cc](https://github.com/just-buildsystem/rules-cc),
-   this is updated by hand. For larger
-   projects [just-import-git](https://github.com/just-buildsystem/justbuild/blob/master/share/man/just-import-git.1.md)
-   would be used to generate this file out of a description of the
-   local repositories and the dependencies to import.
+   pinned in [etc/repos.json](etc/repos.json). They can be updated using
+   [update-just-dependencies.sh](./update-just-dependencies.sh) which
+   calls [etc/generate-repos.sh](./etc/generate-repos.sh) in our `nix-shell`,
+   which also brings in tools required for this step.
 
 ### Logical repositories
 
diff --git a/etc/generate-repos.sh b/etc/generate-repos.sh
new file mode 100755
index 0000000..f7b4cf8
--- /dev/null
+++ b/etc/generate-repos.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+
+readonly ROOT=$(readlink -f $(dirname $0)/..)
+
+: ${RULES_CC_REPO:=https://github.com/just-buildsystem/rules-cc}
+: ${RULES_CC_BRANCH:=master}
+
+just-import-git -C ${ROOT}/etc/repos.template.json \
+                --as rules -b ${RULES_CC_BRANCH} ${RULES_CC_REPO} rules \
+    | hdump > ${ROOT}/etc/repos.json
diff --git a/etc/repos.json b/etc/repos.json
index d1537db..5ab3477 100644
--- a/etc/repos.json
+++ b/etc/repos.json
@@ -8,15 +8,6 @@
     , "bindings": {"rules": "rules/nix-test", "src": ""}
     }
   , "defaults": {"repository": {"type": "file", "path": "etc/defaults"}}
-  , "rules":
-    { "repository":
-      { "type": "git"
-      , "branch": "master"
-      , "commit": "0d436f26134d3fcaa695e4e6e87249d7fa381e44"
-      , "repository": "https://github.com/just-buildsystem/rules-cc.git"
-      , "subdir": "rules"
-      }
-    }
   , "rules/nix":
     {"repository": "rules", "target_root": "defaults", "rule_root": "rules"}
   , "rules/nix-test":
@@ -26,5 +17,14 @@
     , "target_file_name": "test.TARGETS"
     , "bindings": {"base": "rules/nix"}
     }
+  , "rules":
+    { "repository":
+      { "type": "git"
+      , "repository": "https://github.com/just-buildsystem/rules-cc"
+      , "branch": "master"
+      , "commit": "0e9d13a761c878a647fde5a543946a02bf2c693d"
+      , "subdir": "rules"
+      }
+    }
   }
 }
diff --git a/etc/repos.template.json b/etc/repos.template.json
new file mode 100644
index 0000000..bb4d04c
--- /dev/null
+++ b/etc/repos.template.json
@@ -0,0 +1,21 @@
+{ "repositories":
+  { "":
+    { "repository": {"type": "file", "path": "src"}
+    , "bindings": {"rules": "rules/nix"}
+    }
+  , "test":
+    { "repository": {"type": "file", "path": "test"}
+    , "bindings": {"rules": "rules/nix-test", "src": ""}
+    }
+  , "defaults": {"repository": {"type": "file", "path": "etc/defaults"}}
+  , "rules/nix":
+    {"repository": "rules", "target_root": "defaults", "rule_root": "rules"}
+  , "rules/nix-test":
+    { "repository": "rules"
+    , "target_root": "defaults"
+    , "rule_root": "rules"
+    , "target_file_name": "test.TARGETS"
+    , "bindings": {"base": "rules/nix"}
+    }
+  }
+}
diff --git a/nix-import-tools/default.nix b/nix-import-tools/default.nix
new file mode 100644
index 0000000..e8f8026
--- /dev/null
+++ b/nix-import-tools/default.nix
@@ -0,0 +1,2 @@
+{ nixpkgs ? import <nixpkgs> {} }:
+nixpkgs.callPackage ./import-tools.nix {}
diff --git a/nix-import-tools/import-tools.nix b/nix-import-tools/import-tools.nix
new file mode 100644
index 0000000..cfb7a91
--- /dev/null
+++ b/nix-import-tools/import-tools.nix
@@ -0,0 +1,41 @@
+{ stdenv
+, fetchFromGitHub
+, python3
+}:
+
+stdenv.mkDerivation rec {
+  name = "just-import-tools";
+  version = "2024-06-25";
+
+  buildInputs = [ (python3.withPackages (ps: [])) ];
+
+  srcjust = fetchFromGitHub {
+    owner = "just-buildsystem";
+    repo = "justbuild";
+    rev = "v1.3.1";
+    sha256 = "sha256-kv7HpDEYZml5uk06s8Cxt5rEpxaJBz9s+or6Od1q4Io=";
+  };
+
+  srcrustrules = fetchFromGitHub {
+    owner = "just-buildsystem";
+    repo = "rules-rust";
+    rev = "bf3e05a614f1de5a9a8a0f8e40f1dd9e1f6609da";
+    sha256 = "sha256-8y10ZmZpeTGtbkIeneaVISyMbVKfIi3gHqyvztnKn0M=";
+  };
+
+
+  unpackPhase = ''
+    cp $srcjust/bin/just-import-git.py .
+    cp $srcrustrules/bin/hdump.py .
+  '';
+
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp just-import-git.py $out/bin/just-import-git
+    cp hdump.py $out/bin/hdump
+    chmod 555 $out/bin/just-import-git $out/bin/hdump
+  '';
+
+}
diff --git a/shell.nix b/shell.nix
index b89488b..2a1b356 100644
--- a/shell.nix
+++ b/shell.nix
@@ -7,6 +7,7 @@ let
   pkgs = import nixpkgs {};
 
   nix-dependencies = import ./nix-dependencies { nixpkgs = pkgs; } ;
+  update-deps = import ./nix-import-tools { nixpkgs = pkgs; } ;
 
 in pkgs.mkShell rec {
 
@@ -14,6 +15,7 @@ in pkgs.mkShell rec {
 
   buildInputs = with pkgs; [
      niv
+     update-deps
   ];
 
   shellHook = ''
diff --git a/update-just-dependencies.sh b/update-just-dependencies.sh
new file mode 100755
index 0000000..e9469d3
--- /dev/null
+++ b/update-just-dependencies.sh
@@ -0,0 +1 @@
+nix-shell --run "./etc/generate-repos.sh"