pkg-config-wrapper: Init

This fixes longstanding build issues

pkgs/build-support/pkg-config-wrapper/add-flags.sh

···
+# See cc-wrapper for comments.
+var_templates_list=(
+    PKG_CONFIG_PATH
+)
+
+accumulateRoles
+
+for var in "${var_templates_list[@]}"; do
+    mangleVarList "$var" ${role_suffixes[@]+"${role_suffixes[@]}"}
+done
+
+export NIX_PKG_CONFIG_WRAPPER_FLAGS_SET_@suffixSalt@=1

pkgs/build-support/pkg-config-wrapper/default.nix

···
+# The wrapper script ensures variables like PKG_CONFIG_PATH and
+# PKG_CONFIG_PATH_FOR_BUILD work properly.
+
+{ stdenvNoCC
+, buildPackages
+, pkg-config
+, propagateDoc ? pkg-config != null && pkg-config ? man
+, extraPackages ? [], extraBuildCommands ? ""
+}:
+
+with stdenvNoCC.lib;
+
+let
+  stdenv = stdenvNoCC;
+  inherit (stdenv) hostPlatform targetPlatform;
+
+  # Prefix for binaries. Customarily ends with a dash separator.
+  #
+  # TODO(@Ericson2314) Make unconditional, or optional but always true by
+  # default.
+  targetPrefix = stdenv.lib.optionalString (targetPlatform != hostPlatform)
+                                        (targetPlatform.config + "-");
+
+  # See description in cc-wrapper.
+  suffixSalt = replaceStrings ["-" "."] ["_" "_"] targetPlatform.config;
+
+in
+
+stdenv.mkDerivation {
+  pname = targetPrefix + pkg-config.pname + "-wrapper";
+  inherit (pkg-config) version;
+
+  preferLocalBuild = true;
+
+  shell = getBin stdenvNoCC.shell + stdenvNoCC.shell.shellPath or "";
+
+  inherit targetPrefix suffixSalt;
+
+  outputs = [ "out" ] ++ optionals propagateDoc [ "man" ];
+
+  passthru = {
+    inherit pkg-config;
+  };
+
+  dontBuild = true;
+  dontConfigure = true;
+
+  unpackPhase = ''
+    src=$PWD
+  '';
+
+  installPhase =
+    ''
+      mkdir -p $out/bin $out/nix-support
+
+      wrap() {
+        local dst="$1"
+        local wrapper="$2"
+        export prog="$3"
+        substituteAll "$wrapper" "$out/bin/$dst"
+        chmod +x "$out/bin/$dst"
+      }
+
+      echo $pkg-config > $out/nix-support/orig-pkg-config
+
+      wrap ${targetPrefix}pkg-config ${./pkg-config-wrapper.sh} "${getBin pkg-config}/bin/pkg-config"
+    '';
+
+  strictDeps = true;
+
+  wrapperName = "PKG_CONFIG_WRAPPER";
+
+  setupHooks = [
+    ../setup-hooks/role.bash
+    ./setup-hook.sh
+  ];
+
+  postFixup =
+    ''
+
+      ##
+      ## User env support
+      ##
+
+      # Propagate the underling unwrapped pkg-config so that if you
+      # install the wrapper, you get anything else it might provide.
+      printWords ${pkg-config} > $out/nix-support/propagated-user-env-packages
+    ''
+
+    + optionalString propagateDoc ''
+      ##
+      ## Man page and info support
+      ##
+
+      ln -s ${pkg-config.man} $man
+    ''
+
+    + ''
+      substituteAll ${./add-flags.sh} $out/nix-support/add-flags.sh
+      substituteAll ${../wrapper-common/utils.bash} $out/nix-support/utils.bash
+
+      ##
+      ## Extra custom steps
+      ##
+    ''
+
+    + extraBuildCommands;
+
+  meta =
+    let pkg-config_ = if pkg-config != null then pkg-config else {}; in
+    (if pkg-config_ ? meta then removeAttrs pkg-config.meta ["priority"] else {}) //
+    { description =
+        stdenv.lib.attrByPath ["meta" "description"] "pkg-config" pkg-config_
+        + " (wrapper script)";
+      priority = 10;
+  };
+}

pkgs/build-support/pkg-config-wrapper/pkg-config-wrapper.sh

···
+#! @shell@
+set -eu -o pipefail +o posix
+shopt -s nullglob
+
+if (( "${NIX_DEBUG:-0}" >= 7 )); then
+    set -x
+fi
+
+source @out@/nix-support/utils.bash
+
+if [ -z "${NIX_PKG_CONFIG_WRAPPER_FLAGS_SET_@suffixSalt@:-}" ]; then
+    source @out@/nix-support/add-flags.sh
+fi
+
+if (( ${#role_suffixes[@]} > 0 )); then
+	# replace env var with nix-modified one
+    PKG_CONFIG_PATH=$PKG_CONFIG_PATH_@suffixSalt@ exec @prog@ "$@"
+else
+	# pkg-config isn't a bonafied dependency so ignore setup hook entirely
+	exec @prog@ "$@"
+fi

pkgs/build-support/pkg-config-wrapper/setup-hook.sh

···
+# pkg-config Wrapper hygiene
+#
+# See comments in cc-wrapper's setup hook. This works exactly the same way.
+
+# Skip setup hook if we're neither a build-time dep, nor, temporarily, doing a
+# native compile.
+#
+# TODO(@Ericson2314): No native exception
+[[ -z ${strictDeps-} ]] || (( "$hostOffset" < 0 )) || return 0
+
+pkgConfigWrapper_addPkgConfigPath () {
+    # See ../setup-hooks/role.bash
+    local role_post
+    getHostRoleEnvHook
+
+    addToSearchPath "PKG_CONFIG_PATH${role_post}" "$1/lib/pkgconfig"
+    addToSearchPath "PKG_CONFIG_PATH${role_post}" "$1/share/pkgconfig"
+}
+
+# See ../setup-hooks/role.bash
+getTargetRole
+getTargetRoleWrapper
+
+addEnvHooks "$targetOffset" pkgConfigWrapper_addPkgConfigPath
+
+export PKG_CONFIG${role_post}=@targetPrefix@pkg-config
+
+# No local scope in sourced file
+unset -v role_post

pkgs/development/python-modules/pkgconfig/default.nix

···
   pname = "pkgconfig";
   version = "1.5.1";
 
-  setupHook = pkgconfig.setupHook;
+  setupHooks = pkgconfig.setupHooks;
 
   src = fetchPypi {
     inherit pname version;

pkgs/development/tools/misc/pkg-config/default.nix

···
   pname = "pkg-config";
   version = "0.29.2";
 
-  setupHook = ./setup-hook.sh;
-
   src = fetchurl {
     url = "https://pkgconfig.freedesktop.org/releases/${pname}-${version}.tar.gz";
     sha256 = "14fmwzki1rlz8bs2p810lk6jqdxsk966d8drgsjmi54cd00rrikg";

pkgs/development/tools/misc/pkg-config/setup-hook.sh

···
-addPkgConfigPath () {
-    addToSearchPath PKG_CONFIG_PATH $1/lib/pkgconfig
-    addToSearchPath PKG_CONFIG_PATH $1/share/pkgconfig
-}
-
-addEnvHooks "$targetOffset" addPkgConfigPath

pkgs/test/cross/default.nix

···
       pkgFun = pkgs: pkgs.hello;
     };
 
+    pkg-config = {platformFun, crossPkgs, emulator}: crossPkgs.runCommand
+      "test-pkg-config-${crossPkgs.hostPlatform.config}"
+    {
+      depsBuildBuild = [ crossPkgs.pkgsBuildBuild.pkg-config ];
+      nativeBuildInputs = [ crossPkgs.pkgsBuildHost.pkg-config crossPkgs.buildPackages.zlib ];
+      depsBuildTarget = [ crossPkgs.pkgsBuildTarget.pkg-config ];
+      buildInputs = [ crossPkgs.zlib ];
+      NIX_DEBUG = 7;
+    } ''
+       mkdir $out
+       ${crossPkgs.pkgsBuildBuild.pkg-config.targetPrefix}pkg-config --cflags zlib > "$out/for-build"
+       ${crossPkgs.pkgsBuildHost.pkg-config.targetPrefix}pkg-config --cflags zlib > "$out/for-host"
+       ! diff "$out/for-build" "$out/for-host"
+    '';
   };
 
 in {

pkgs/top-level/all-packages.nix

···
       # break dependency cycles
       fetchurl = stdenv.fetchurlBoot;
       zlib = buildPackages.zlib.override { fetchurl = stdenv.fetchurlBoot; };
-      pkgconfig = buildPackages.pkgconfig.override { fetchurl = stdenv.fetchurlBoot; };
+      pkgconfig = buildPackages.pkgconfig.override (old: {
+        pkg-config = old.pkg-config.override {
+          fetchurl = stdenv.fetchurlBoot;
+        };
+      });
       perl = buildPackages.perl.override { fetchurl = stdenv.fetchurlBoot; };
       openssl = buildPackages.openssl.override {
         fetchurl = stdenv.fetchurlBoot;
···
 
   pkgconf = callPackage ../development/tools/misc/pkgconf {};
 
-  pkg-config = callPackage ../development/tools/misc/pkg-config { };
+  pkg-config-unwrapped = callPackage ../development/tools/misc/pkg-config { };
+  pkg-config = callPackage ../build-support/pkg-config-wrapper {
+    pkg-config = pkg-config-unwrapped;
+  };
   pkgconfig = pkg-config; # added 2018-02-02
 
-  pkg-configUpstream = lowPrio (pkg-config.override { vanilla = true; });
+  pkg-configUpstream = lowPrio (pkg-config.override (old: {
+    pkg-config = old.pkg-config.override {
+      vanilla = true;
+    };
+  }));
   pkgconfigUpstream = pkg-configUpstream; # added 2018-02-02
 
   inherit (nodePackages) postcss-cli;