1 files changed, 69 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/build-support/make-pkgconfigitem/default.nix b/nixpkgs/pkgs/build-support/make-pkgconfigitem/default.nix
new file mode 100644
index 000000000000..d3bcabbb940f
--- /dev/null
+++ b/nixpkgs/pkgs/build-support/make-pkgconfigitem/default.nix
@@ -0,0 +1,69 @@
+{ lib, writeTextFile, buildPackages }:
+
+# See https://people.freedesktop.org/~dbn/pkg-config-guide.html#concepts
+{ name # The name of the pc file
+  # keywords
+  # provide a default description for convenience. it's not important but still required by pkg-config.
+, description ? "A pkg-config file for ${name}"
+, url ? ""
+, version ? ""
+, requires ? [ ]
+, requiresPrivate ? [ ]
+, conflicts ? [ ]
+, cflags ? [ ]
+, libs ? [ ]
+, libsPrivate ? [ ]
+, variables ? { }
+}:
+
+let
+  # only 'out' has to be changed, otherwise it would be replaced by the out of the writeTextFile
+  placeholderToSubstVar = builtins.replaceStrings [ "${placeholder "out"}" ] [ "@out@" ];
+
+  replacePlaceholderAndListToString = x:
+    if builtins.isList x
+    then placeholderToSubstVar (builtins.concatStringsSep " " x)
+    else placeholderToSubstVar x;
+
+  keywordsSection =
+    let
+      mustBeAList = attr: attrName: lib.throwIfNot (lib.isList attr) "'${attrName}' must be a list" attr;
+    in
+    {
+      "Name" = name;
+      "Description" = description;
+      "URL" = url;
+      "Version" = version;
+      "Requires" = mustBeAList requires "requires";
+      "Requires.private" = mustBeAList requiresPrivate "requiresPrivate";
+      "Conflicts" = mustBeAList conflicts "conflicts";
+      "Cflags" = mustBeAList cflags "cflags";
+      "Libs" = mustBeAList libs "libs";
+      "Libs.private" = mustBeAList libsPrivate "libsPrivate";
+    };
+
+  renderVariable = name: value:
+    lib.optionalString (value != "" && value != [ ]) "${name}=${replacePlaceholderAndListToString value}";
+  renderKeyword = name: value:
+    lib.optionalString (value != "" && value != [ ]) "${name}: ${replacePlaceholderAndListToString value}";
+
+  renderSomething = renderFunc: attrs:
+    lib.pipe attrs [
+      (lib.mapAttrsToList renderFunc)
+      (builtins.filter (v: v != ""))
+      (builtins.concatStringsSep "\n")
+      (section: ''${section}
+      '')
+    ];
+
+  variablesSectionRendered = renderSomething renderVariable variables;
+  keywordsSectionRendered = renderSomething renderKeyword keywordsSection;
+
+  content = [ variablesSectionRendered keywordsSectionRendered ];
+in
+writeTextFile {
+  name = "${name}.pc";
+  destination = "/lib/pkgconfig/${name}.pc";
+  text = builtins.concatStringsSep "\n" content;
+  checkPhase = ''${buildPackages.pkg-config}/bin/${buildPackages.pkg-config.targetPrefix}pkg-config --validate "$target"'';
+}