Merge pull request #174460 from hercules-ci/module-docs-Nix-driven-location-links

make-options-doc: Support Nix-provided declaration links

doc/doc-support/default.nix

@@ -1,5 +1,8 @@
 { pkgs ? (import ../.. {}), nixpkgs ? { }}:
 let
+  inherit (pkgs) lib;
+  inherit (lib) hasPrefix removePrefix;
+
   locationsXml = import ./lib-function-locations.nix { inherit pkgs nixpkgs; };
   functionDocs = import ./lib-function-docs.nix { inherit locationsXml pkgs; };
   version = pkgs.lib.version;
@@ -29,6 +32,18 @@ let
   optionsDoc = pkgs.nixosOptionsDoc {
     inherit (pkgs.lib.evalModules { modules = [ ../../pkgs/top-level/config.nix ]; }) options;
     documentType = "none";
+    transformOptions = opt:
+      opt // {
+        declarations =
+          map
+            (decl:
+              if hasPrefix (toString ../..) (toString decl)
+              then
+                let subpath = removePrefix "/" (removePrefix (toString ../..) (toString decl));
+                in { url = "https://github.com/NixOS/nixpkgs/blob/master/${subpath}"; name = subpath; }
+              else decl)
+            opt.declarations;
+        };
   };
 
 in pkgs.runCommand "doc-support" {}

nixos/lib/make-options-doc/options-to-docbook.xsl

@@ -213,6 +213,23 @@
 
   <xsl:template match="attr[@name = 'declarations' or @name = 'definitions']">
     <simplelist>
+      <!--
+        Example:
+          opt.declarations = [ { name = "foo/bar.nix"; url = "https://github.com/....."; } ];
+      -->
+      <xsl:for-each select="list/attrs[attr[@name = 'name']]">
+        <member><filename>
+          <xsl:if test="attr[@name = 'url']">
+            <xsl:attribute name="xlink:href"><xsl:value-of select="attr[@name = 'url']/string/@value"/></xsl:attribute>
+          </xsl:if>
+          <xsl:value-of select="attr[@name = 'name']/string/@value"/>
+        </filename></member>
+      </xsl:for-each>
+
+      <!--
+        When the declarations/definitions are raw strings,
+        fall back to hardcoded location logic, specific to Nixpkgs.
+      -->
       <xsl:for-each select="list/string">
         <member><filename>
           <!-- Hyperlink the filename either to the NixOS Subversion