treewide: use optionalString instead of 'then ""'

33 files changed, 59 insertions, 68 deletions

diff --git a/pkgs/applications/editors/texmacs/darwin.nix b/pkgs/applications/editors/texmacs/darwin.nix
index ff090dd3259a5..8c74d8c5c8f24 100644
--- a/pkgs/applications/editors/texmacs/darwin.nix
+++ b/pkgs/applications/editors/texmacs/darwin.nix
@@ -47,10 +47,10 @@ stdenv.mkDerivation {
 
   postInstall = "wrapProgram $out/Applications/TeXmacs-${version}/Contents/MacOS/TeXmacs --suffix PATH : " +
     "${ghostscript}/bin:" +
-    (if aspell == null then "" else "${aspell}/bin:") +
-    (if tex == null then "" else "${tex}/bin:") +
-    (if netpbm == null then "" else "${lib.getBin netpbm}/bin:") +
-    (if imagemagick == null then "" else "${imagemagick}/bin:");
+    (lib.optionalString (aspell != null) "${aspell}/bin:") +
+    (lib.optionalString (tex != null) "${tex}/bin:") +
+    (lib.optionalString (netpbm != null) "${lib.getBin netpbm}/bin:") +
+    (lib.optionalString (imagemagick != null) "${imagemagick}/bin:");
 
   enableParallelBuilding = true;
 
diff --git a/pkgs/applications/editors/vscode/vscodium.nix b/pkgs/applications/editors/vscode/vscodium.nix
index 3e66c7e6abd04..b434279621d1c 100644
--- a/pkgs/applications/editors/vscode/vscodium.nix
+++ b/pkgs/applications/editors/vscode/vscodium.nix
@@ -22,7 +22,7 @@ let
     armv7l-linux = "0m1v24gg2dy79hgrz37gysgrazg8vkr1gkp52j6m6y76vi0l8249";
   }.${system} or throwSystem;
 
-  sourceRoot = if stdenv.isDarwin then "" else ".";
+  sourceRoot = lib.optionalString (!stdenv.isDarwin) ".";
 in
   callPackage ./generic.nix rec {
     inherit sourceRoot commandLineArgs useVSCodeRipgrep;
diff --git a/pkgs/applications/networking/browsers/chromium/default.nix b/pkgs/applications/networking/browsers/chromium/default.nix
index 77f4def41f33a..a5e6855e9637d 100644
--- a/pkgs/applications/networking/browsers/chromium/default.nix
+++ b/pkgs/applications/networking/browsers/chromium/default.nix
@@ -134,9 +134,7 @@ let
     };
   };
 
-  suffix = if (channel == "stable" || channel == "ungoogled-chromium")
-    then ""
-    else "-" + channel;
+  suffix = lib.optionalString (channel != "stable" && channel != "ungoogled-chromium") ("-" + channel);
 
   sandboxExecutableName = chromium.browser.passthru.sandboxExecutableName;
 
diff --git a/pkgs/applications/networking/browsers/microsoft-edge/browser.nix b/pkgs/applications/networking/browsers/microsoft-edge/browser.nix
index 2af28bb8dd068..7f72a42ffe0d0 100644
--- a/pkgs/applications/networking/browsers/microsoft-edge/browser.nix
+++ b/pkgs/applications/networking/browsers/microsoft-edge/browser.nix
@@ -46,13 +46,9 @@ let
              then baseName
              else baseName + "-" + channel;
 
-  iconSuffix = if channel == "stable"
-               then ""
-               else "_${channel}";
+  iconSuffix = lib.optionalString (channel != "stable") "_${channel}";
 
-  desktopSuffix = if channel == "stable"
-                  then ""
-                  else "-${channel}";
+  desktopSuffix = lib.optionalString (channel != "stable") "-${channel}";
 in
 
 stdenv.mkDerivation rec {
diff --git a/pkgs/applications/office/libreoffice/default.nix b/pkgs/applications/office/libreoffice/default.nix
index 25e8f18998e2e..518167cb33d12 100644
--- a/pkgs/applications/office/libreoffice/default.nix
+++ b/pkgs/applications/office/libreoffice/default.nix
@@ -395,7 +395,7 @@ in
   dontWrapQtApps = true;
 
   configureFlags = [
-    (if withHelp then "" else "--without-help")
+    (lib.optionalString (!withHelp) "--without-help")
     "--with-boost=${getDev boost}"
     "--with-boost-libdir=${getLib boost}/lib"
     "--with-beanshell-jar=${bsh}"
diff --git a/pkgs/applications/science/logic/hol_light/default.nix b/pkgs/applications/science/logic/hol_light/default.nix
index 4c105a40e20db..9f379252fd529 100644
--- a/pkgs/applications/science/logic/hol_light/default.nix
+++ b/pkgs/applications/science/logic/hol_light/default.nix
@@ -2,8 +2,7 @@
 
 let
   load_num =
-    if num == null then "" else
-    ''
+    lib.optionalString (num != null) ''
       -I ${num}/lib/ocaml/${ocaml.version}/site-lib/num \
       -I ${num}/lib/ocaml/${ocaml.version}/site-lib/top-num \
       -I ${num}/lib/ocaml/${ocaml.version}/site-lib/stublibs \
diff --git a/pkgs/applications/science/math/sage/sage-tests.nix b/pkgs/applications/science/math/sage/sage-tests.nix
index 4910f5e8bf1d2..1a415ae65e96a 100644
--- a/pkgs/applications/science/math/sage/sage-tests.nix
+++ b/pkgs/applications/science/math/sage/sage-tests.nix
@@ -19,7 +19,7 @@ let
   runAllTests = files == null;
   testArgs = if runAllTests then "--all" else testFileList;
   patienceSpecifier = lib.optionalString longTests "--long";
-  timeSpecifier = if timeLimit == null then "" else "--short ${toString timeLimit}";
+  timeSpecifier = lib.optionalString (timeLimit != null) "--short ${toString timeLimit}";
   relpathToArg = relpath: lib.escapeShellArg "${src}/${relpath}"; # paths need to be absolute
   testFileList = lib.concatStringsSep " " (map relpathToArg files);
 in
diff --git a/pkgs/applications/version-management/sapling/default.nix b/pkgs/applications/version-management/sapling/default.nix
index 0d14d512c5f29..796d76cc6ef82 100644
--- a/pkgs/applications/version-management/sapling/default.nix
+++ b/pkgs/applications/version-management/sapling/default.nix
@@ -38,7 +38,7 @@ let
   #
   # See https://github.com/NixOS/nixpkgs/pull/198311#issuecomment-1326894295
   myCargoSetupHook = rustPlatform.cargoSetupHook.overrideAttrs (old: {
-    cargoConfig = if stdenv.isDarwin then "" else old.cargoConfig;
+    cargoConfig = lib.optionalString (!stdenv.isDarwin) old.cargoConfig;
   });
 
   src = fetchFromGitHub {
diff --git a/pkgs/applications/window-managers/sway/wrapper.nix b/pkgs/applications/window-managers/sway/wrapper.nix
index 42384fa06ae20..e786e1463816e 100644
--- a/pkgs/applications/window-managers/sway/wrapper.nix
+++ b/pkgs/applications/window-managers/sway/wrapper.nix
@@ -28,7 +28,7 @@ let
        export DBUS_SESSION_BUS_ADDRESS
        exec ${sway}/bin/sway "$@"
      else
-       exec ${if !dbusSupport then "" else "${dbus}/bin/dbus-run-session"} ${sway}/bin/sway "$@"
+       exec ${lib.optionalString dbusSupport "${dbus}/bin/dbus-run-session"} ${sway}/bin/sway "$@"
      fi
    '';
 in symlinkJoin {
diff --git a/pkgs/build-support/bintools-wrapper/default.nix b/pkgs/build-support/bintools-wrapper/default.nix
index acc433496b0e8..cc6f0ff897ed6 100644
--- a/pkgs/build-support/bintools-wrapper/default.nix
+++ b/pkgs/build-support/bintools-wrapper/default.nix
@@ -59,12 +59,12 @@ let
   bintoolsVersion = lib.getVersion bintools;
   bintoolsName = lib.removePrefix targetPrefix (lib.getName bintools);
 
-  libc_bin = if libc == null then "" else getBin libc;
-  libc_dev = if libc == null then "" else getDev libc;
-  libc_lib = if libc == null then "" else getLib libc;
-  bintools_bin = if nativeTools then "" else getBin bintools;
+  libc_bin = lib.optionalString (libc != null) (getBin libc);
+  libc_dev = lib.optionalString (libc != null) (getDev libc);
+  libc_lib = lib.optionalString (libc != null) (getLib libc);
+  bintools_bin = lib.optionalString (!nativeTools) (getBin bintools);
   # The wrapper scripts use 'cat' and 'grep', so we may need coreutils.
-  coreutils_bin = if nativeTools then "" else getBin coreutils;
+  coreutils_bin = lib.optionalString (!nativeTools) (getBin coreutils);
 
   # See description in cc-wrapper.
   suffixSalt = replaceStrings ["-" "."] ["_" "_"] targetPlatform.config;
@@ -103,7 +103,7 @@ in
 stdenv.mkDerivation {
   pname = targetPrefix
     + (if name != "" then name else "${bintoolsName}-wrapper");
-  version = if bintools == null then "" else bintoolsVersion;
+  version = lib.optionalString (bintools != null) bintoolsVersion;
 
   preferLocalBuild = true;
 
@@ -265,7 +265,7 @@ stdenv.mkDerivation {
     # install the wrapper, you get tools like objdump (same for any
     # binaries of libc).
     + optionalString (!nativeTools) ''
-      printWords ${bintools_bin} ${if libc == null then "" else libc_bin} > $out/nix-support/propagated-user-env-packages
+      printWords ${bintools_bin} ${lib.optionalString (libc != null) libc_bin} > $out/nix-support/propagated-user-env-packages
     ''
 
     ##
@@ -381,7 +381,7 @@ stdenv.mkDerivation {
     # for substitution in utils.bash
     expandResponseParams = "${expand-response-params}/bin/expand-response-params";
     shell = getBin shell + shell.shellPath or "";
-    gnugrep_bin = if nativeTools then "" else gnugrep;
+    gnugrep_bin = lib.optionalString (!nativeTools) gnugrep;
     wrapperName = "BINTOOLS_WRAPPER";
     inherit dynamicLinker targetPrefix suffixSalt coreutils_bin;
     inherit bintools_bin libc_bin libc_dev libc_lib;
diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index ffde44c538e3a..a843e64402025 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -75,14 +75,14 @@ let
   ccVersion = lib.getVersion cc;
   ccName = lib.removePrefix targetPrefix (lib.getName cc);
 
-  libc_bin = if libc == null then "" else getBin libc;
-  libc_dev = if libc == null then "" else getDev libc;
-  libc_lib = if libc == null then "" else getLib libc;
+  libc_bin = optionalString (libc != null) (getBin libc);
+  libc_dev = optionalString (libc != null) (getDev libc);
+  libc_lib = optionalString (libc != null) (getLib libc);
   cc_solib = getLib cc
     + optionalString (targetPlatform != hostPlatform) "/${targetPlatform.config}";
 
   # The wrapper scripts use 'cat' and 'grep', so we may need coreutils.
-  coreutils_bin = if nativeTools then "" else getBin coreutils;
+  coreutils_bin = optionalString (!nativeTools) (getBin coreutils);
 
   # The "suffix salt" is a arbitrary string added in the end of env vars
   # defined by cc-wrapper's hooks so that multiple cc-wrappers can be used
@@ -164,7 +164,7 @@ assert nativePrefix == bintools.nativePrefix;
 stdenv.mkDerivation {
   pname = targetPrefix
     + (if name != "" then name else "${ccName}-wrapper");
-  version = if cc == null then "" else ccVersion;
+  version = optionalString (cc != null) ccVersion;
 
   preferLocalBuild = true;
 
@@ -600,10 +600,10 @@ stdenv.mkDerivation {
     # for substitution in utils.bash
     expandResponseParams = "${expand-response-params}/bin/expand-response-params";
     shell = getBin shell + shell.shellPath or "";
-    gnugrep_bin = if nativeTools then "" else gnugrep;
+    gnugrep_bin = optionalString (!nativeTools) gnugrep;
     # stdenv.cc.cc should not be null and we have nothing better for now.
     # if the native impure bootstrap is gotten rid of this can become `inherit cc;` again.
-    cc = if nativeTools then "" else cc;
+    cc = optionalString (!nativeTools) cc;
     wrapperName = "CC_WRAPPER";
     inherit suffixSalt coreutils_bin bintools;
     inherit libc_bin libc_dev libc_lib;
diff --git a/pkgs/build-support/docker/default.nix b/pkgs/build-support/docker/default.nix
index 5f48fb9f7bdbe..b74d7885d54ae 100644
--- a/pkgs/build-support/docker/default.nix
+++ b/pkgs/build-support/docker/default.nix
@@ -594,7 +594,7 @@ rec {
           nativeBuildInputs = [ jshon pigz jq moreutils ];
           # Image name must be lowercase
           imageName = lib.toLower name;
-          imageTag = if tag == null then "" else tag;
+          imageTag = lib.optionalString (tag != null) tag;
           inherit fromImage baseJson;
           layerClosure = writeReferencesToFile layer;
           passthru.buildArgs = args;
diff --git a/pkgs/build-support/fetchgithub/default.nix b/pkgs/build-support/fetchgithub/default.nix
index faa338b672f0c..a2498700b545d 100644
--- a/pkgs/build-support/fetchgithub/default.nix
+++ b/pkgs/build-support/fetchgithub/default.nix
@@ -24,7 +24,7 @@ let
     position = "${position.file}:${toString position.line}";
   };
   passthruAttrs = removeAttrs args [ "owner" "repo" "rev" "fetchSubmodules" "forceFetchGit" "private" "githubBase" "varPrefix" ];
-  varBase = "NIX${if varPrefix == null then "" else "_${varPrefix}"}_GITHUB_PRIVATE_";
+  varBase = "NIX${lib.optionalString (varPrefix != null) "_${varPrefix}"}_GITHUB_PRIVATE_";
   useFetchGit = fetchSubmodules || (leaveDotGit == true) || deepClone || forceFetchGit || (sparseCheckout != []);
   # We prefer fetchzip in cases we don't need submodules as the hash
   # is more stable in that case.
diff --git a/pkgs/build-support/kernel/make-initrd-ng.nix b/pkgs/build-support/kernel/make-initrd-ng.nix
index f3cf3d59f92b0..2418838176ef3 100644
--- a/pkgs/build-support/kernel/make-initrd-ng.nix
+++ b/pkgs/build-support/kernel/make-initrd-ng.nix
@@ -72,7 +72,7 @@ in
   ${if makeUInitrd then "uInitrdCompression" else null} = uInitrdCompression;
 
   passAsFile = ["contents"];
-  contents = lib.concatMapStringsSep "\n" ({ object, symlink, ... }: "${object}\n${if symlink == null then "" else symlink}") contents + "\n";
+  contents = lib.concatMapStringsSep "\n" ({ object, symlink, ... }: "${object}\n${lib.optionalString (symlink != null) symlink}") contents + "\n";
 
   nativeBuildInputs = [makeInitrdNGTool cpio] ++ lib.optional makeUInitrd ubootTools ++ lib.optional strip binutils;
 
diff --git a/pkgs/build-support/nix-gitignore/default.nix b/pkgs/build-support/nix-gitignore/default.nix
index d55465302e44e..5fc1f2cf7f8cc 100644
--- a/pkgs/build-support/nix-gitignore/default.nix
+++ b/pkgs/build-support/nix-gitignore/default.nix
@@ -66,7 +66,7 @@ in rec {
       handleSlashPrefix = l:
         let
           split = (match "^(/?)(.*)" l);
-          findSlash = l: if (match ".+/.+" l) != null then "" else l;
+          findSlash = l: lib.optionalString ((match ".+/.+" l) == null) l;
           hasSlash = mapAroundCharclass findSlash l != l;
         in
           (if (elemAt split 0) == "/" || hasSlash
diff --git a/pkgs/build-support/rust/build-rust-crate/configure-crate.nix b/pkgs/build-support/rust/build-rust-crate/configure-crate.nix
index 5168eb6ab7592..60310f178747e 100644
--- a/pkgs/build-support/rust/build-rust-crate/configure-crate.nix
+++ b/pkgs/build-support/rust/build-rust-crate/configure-crate.nix
@@ -21,7 +21,7 @@
 , verbose
 , workspace_member }:
 let version_ = lib.splitString "-" crateVersion;
-    versionPre = if lib.tail version_ == [] then "" else lib.elemAt version_ 1;
+    versionPre = lib.optionalString (lib.tail version_ != []) (lib.elemAt version_ 1);
     version = lib.splitVersion (lib.head version_);
     rustcOpts = lib.foldl' (opts: opt: opts + " " + opt)
         (if release then "-C opt-level=3" else "-C debuginfo=2")
diff --git a/pkgs/build-support/vm/default.nix b/pkgs/build-support/vm/default.nix
index 403bc9b1d2dab..e05848217d2bb 100644
--- a/pkgs/build-support/vm/default.nix
+++ b/pkgs/build-support/vm/default.nix
@@ -468,7 +468,7 @@ rec {
 
         echo "installing RPMs..."
         PATH=/usr/bin:/bin:/usr/sbin:/sbin $chroot /mnt \
-          rpm -iv --nosignature ${if runScripts then "" else "--noscripts"} $rpms
+          rpm -iv --nosignature ${lib.optionalString (!runScripts) "--noscripts"} $rpms
 
         echo "running post-install script..."
         eval "$postInstall"
diff --git a/pkgs/data/sgml+xml/stylesheets/xslt/docbook-xsl/default.nix b/pkgs/data/sgml+xml/stylesheets/xslt/docbook-xsl/default.nix
index 2f9d22e57d89e..66ebf105ffd0a 100644
--- a/pkgs/data/sgml+xml/stylesheets/xslt/docbook-xsl/default.nix
+++ b/pkgs/data/sgml+xml/stylesheets/xslt/docbook-xsl/default.nix
@@ -3,7 +3,7 @@
 let
 
   common = { pname, sha256, suffix ? "" }: let
-    legacySuffix = if suffix == "-nons" then "" else "-ns";
+    legacySuffix = lib.optionalString (suffix != "-nons") "-ns";
     self = stdenv.mkDerivation rec {
       inherit pname;
       version = "1.79.2";
diff --git a/pkgs/development/compilers/purescript/purescript/default.nix b/pkgs/development/compilers/purescript/purescript/default.nix
index d7c8394a57b17..fd3d1a810a5c3 100644
--- a/pkgs/development/compilers/purescript/purescript/default.nix
+++ b/pkgs/development/compilers/purescript/purescript/default.nix
@@ -7,10 +7,7 @@ let
   dynamic-linker = stdenv.cc.bintools.dynamicLinker;
 
   patchelf = libPath :
-    if stdenv.isDarwin
-      then ""
-      else
-        ''
+    lib.optionalString (!stdenv.isDarwin) ''
           chmod u+w $PURS
           patchelf --interpreter ${dynamic-linker} --set-rpath ${libPath} $PURS
           chmod u-w $PURS
diff --git a/pkgs/development/interpreters/acl2/libipasirglucose4/default.nix b/pkgs/development/interpreters/acl2/libipasirglucose4/default.nix
index dc8308267f40e..c31e0dbe67f73 100644
--- a/pkgs/development/interpreters/acl2/libipasirglucose4/default.nix
+++ b/pkgs/development/interpreters/acl2/libipasirglucose4/default.nix
@@ -24,7 +24,7 @@ stdenv.mkDerivation rec {
 
   postBuild = ''
     $CXX -shared -o ${libname} \
-        ${if stdenv.cc.isClang then "" else "-Wl,-soname,${libname}"} \
+        ${lib.optionalString (!stdenv.cc.isClang) "-Wl,-soname,${libname}"} \
         ipasirglucoseglue.o libipasirglucose4.a
   '';
 
diff --git a/pkgs/development/interpreters/python/mk-python-derivation.nix b/pkgs/development/interpreters/python/mk-python-derivation.nix
index 17b5667e8ee9c..79e45b8dc395b 100644
--- a/pkgs/development/interpreters/python/mk-python-derivation.nix
+++ b/pkgs/development/interpreters/python/mk-python-derivation.nix
@@ -118,7 +118,7 @@ let
 
     optionalLocation = let
         pos = builtins.unsafeGetAttrPos (if attrs ? "pname" then "pname" else "name") attrs;
-      in if pos == null then "" else " at ${pos.file}:${toString pos.line}:${toString pos.column}";
+      in lib.optionalString (pos != null) " at ${pos.file}:${toString pos.line}:${toString pos.column}";
 
     leftPadName = name: against: let
         len = lib.max (lib.stringLength name) (lib.stringLength against);
diff --git a/pkgs/development/interpreters/python/wrapper.nix b/pkgs/development/interpreters/python/wrapper.nix
index b36662335abe2..f5f9b03e0fd3c 100644
--- a/pkgs/development/interpreters/python/wrapper.nix
+++ b/pkgs/development/interpreters/python/wrapper.nix
@@ -42,7 +42,7 @@ let
             if [ -f "$prg" ]; then
               rm -f "$out/bin/$prg"
               if [ -x "$prg" ]; then
-                makeWrapper "$path/bin/$prg" "$out/bin/$prg" --set NIX_PYTHONPREFIX "$out" --set NIX_PYTHONEXECUTABLE ${pythonExecutable} --set NIX_PYTHONPATH ${pythonPath} ${if permitUserSite then "" else ''--set PYTHONNOUSERSITE "true"''} ${lib.concatStringsSep " " makeWrapperArgs}
+                makeWrapper "$path/bin/$prg" "$out/bin/$prg" --set NIX_PYTHONPREFIX "$out" --set NIX_PYTHONEXECUTABLE ${pythonExecutable} --set NIX_PYTHONPATH ${pythonPath} ${lib.optionalString (!permitUserSite) ''--set PYTHONNOUSERSITE "true"''} ${lib.concatStringsSep " " makeWrapperArgs}
               fi
             fi
           done
diff --git a/pkgs/development/libraries/ffmpeg/generic.nix b/pkgs/development/libraries/ffmpeg/generic.nix
index 12e59c939afee..4c31b82f31038 100644
--- a/pkgs/development/libraries/ffmpeg/generic.nix
+++ b/pkgs/development/libraries/ffmpeg/generic.nix
@@ -330,7 +330,7 @@ assert buildPostproc -> buildAvutil;
 assert buildSwscale -> buildAvutil;
 
 stdenv.mkDerivation (finalAttrs: {
-  pname = "ffmpeg" + (if ffmpegVariant == "small" then "" else "-${ffmpegVariant}");
+  pname = "ffmpeg" + (optionalString (ffmpegVariant != "small") "-${ffmpegVariant}");
   inherit version;
 
   src = fetchgit {
diff --git a/pkgs/development/libraries/opencv/tests.nix b/pkgs/development/libraries/opencv/tests.nix
index 03a89db0882fa..d1966b1a4aa82 100644
--- a/pkgs/development/libraries/opencv/tests.nix
+++ b/pkgs/development/libraries/opencv/tests.nix
@@ -39,7 +39,7 @@ let
     "stitching"
     "video"
   ] ++ lib.optionals (!stdenv.isAarch64 && enableGStreamer) [ "gapi" ];
-  testRunner = if stdenv.isDarwin then "" else "${lib.getExe xvfb-run} -a ";
+  testRunner = lib.optionalString (!stdenv.isDarwin) "${lib.getExe xvfb-run} -a ";
   testsPreparation = ''
     touch $out
     # several tests want a write access, so we have to copy files
diff --git a/pkgs/development/libraries/qt-4.x/4.8/default.nix b/pkgs/development/libraries/qt-4.x/4.8/default.nix
index 68a300ac250dd..a8257a36d39d1 100644
--- a/pkgs/development/libraries/qt-4.x/4.8/default.nix
+++ b/pkgs/development/libraries/qt-4.x/4.8/default.nix
@@ -173,9 +173,9 @@ stdenv.mkDerivation rec {
     "-make" "libs" "-make" "tools" "-make" "translations"
     "-no-phonon" "-no-webkit" "-no-multimedia" "-audio-backend"
   ]) ++ [
-    "-${if demos then "" else "no"}make" "demos"
-    "-${if examples then "" else "no"}make" "examples"
-    "-${if docs then "" else "no"}make" "docs"
+    "-${lib.optionalString (!demos) "no"}make" "demos"
+    "-${lib.optionalString (!examples) "no"}make" "examples"
+    "-${lib.optionalString (!docs) "no"}make" "docs"
   ] ++ lib.optional developerBuild "-developer-build"
     ++ lib.optionals stdenv.hostPlatform.isDarwin [ platformFlag "unsupported/macx-clang-libc++" ]
     ++ lib.optionals stdenv.hostPlatform.isWindows [ platformFlag "win32-g++-4.6" ];
diff --git a/pkgs/development/mobile/titaniumenv/build-app.nix b/pkgs/development/mobile/titaniumenv/build-app.nix
index fa2eeae00b559..42b70c64abe9b 100644
--- a/pkgs/development/mobile/titaniumenv/build-app.nix
+++ b/pkgs/development/mobile/titaniumenv/build-app.nix
@@ -158,8 +158,7 @@ stdenv.mkDerivation ({
 
   installPhase = ''
     ${if target == "android" then ''
-      ${if release then ""
-      else ''
+      ${lib.optionalString (!release) ''
         cp "$(ls build/android/bin/*.apk | grep -v '\-unsigned.apk')" $out
       ''}
 
diff --git a/pkgs/development/python-modules/azure-common/default.nix b/pkgs/development/python-modules/azure-common/default.nix
index 504748f033ff4..47d0039e5e4bb 100644
--- a/pkgs/development/python-modules/azure-common/default.nix
+++ b/pkgs/development/python-modules/azure-common/default.nix
@@ -23,7 +23,7 @@ buildPythonPackage rec {
     azure-nspkg
   ] ++ lib.optionals (!isPy3k) [ setuptools ]; # need for namespace lookup
 
-  postInstall = if isPy3k then "" else ''
+  postInstall = lib.optionalString (!isPy3k) ''
     echo "__import__('pkg_resources').declare_namespace(__name__)" >> "$out/lib/${python.libPrefix}"/site-packages/azure/__init__.py
   '';
 
diff --git a/pkgs/development/python-modules/azure-mgmt-common/default.nix b/pkgs/development/python-modules/azure-mgmt-common/default.nix
index 28043046d8aa6..dfd7ac2a3f058 100644
--- a/pkgs/development/python-modules/azure-mgmt-common/default.nix
+++ b/pkgs/development/python-modules/azure-mgmt-common/default.nix
@@ -26,7 +26,7 @@ buildPythonPackage rec {
     msrestazure
   ];
 
-  postInstall = if isPy3k then "" else ''
+  postInstall = pkgs.lib.optionalString (!isPy3k) ''
     echo "__import__('pkg_resources').declare_namespace(__name__)" >> "$out/lib/${python.libPrefix}"/site-packages/azure/mgmt/__init__.py
     echo "__import__('pkg_resources').declare_namespace(__name__)" >> "$out/lib/${python.libPrefix}"/site-packages/azure/__init__.py
   '';
diff --git a/pkgs/development/python-modules/tensorflow/bin.nix b/pkgs/development/python-modules/tensorflow/bin.nix
index a988a39c388b2..5bb668965048e 100644
--- a/pkgs/development/python-modules/tensorflow/bin.nix
+++ b/pkgs/development/python-modules/tensorflow/bin.nix
@@ -53,7 +53,7 @@ in buildPythonPackage {
   disabled = pythonAtLeast "3.11";
 
   src = let
-    pyVerNoDot = lib.strings.stringAsChars (x: if x == "." then "" else x) python.pythonVersion;
+    pyVerNoDot = lib.strings.stringAsChars (x: lib.optionalString (x != ".") x) python.pythonVersion;
     platform = if stdenv.isDarwin then "mac" else "linux";
     unit = if cudaSupport then "gpu" else "cpu";
     key = "${platform}_py_${pyVerNoDot}_${unit}";
diff --git a/pkgs/development/ruby-modules/bundled-common/default.nix b/pkgs/development/ruby-modules/bundled-common/default.nix
index aa903a5637c08..01d27b91561e7 100644
--- a/pkgs/development/ruby-modules/bundled-common/default.nix
+++ b/pkgs/development/ruby-modules/bundled-common/default.nix
@@ -70,11 +70,12 @@ let
       assert gemFiles.gemdir != null; "cp -a ${gemFiles.gemdir}/* $out/") #*/
   );
 
-  maybeCopyAll = pkgname: if pkgname == null then "" else
-  let
-    mainGem = gems.${pkgname} or (throw "bundlerEnv: gem ${pkgname} not found");
-  in
-    copyIfBundledByPath mainGem;
+  maybeCopyAll = pkgname: lib.optionalString (pkgname != null) (
+    let
+      mainGem = gems.${pkgname} or (throw "bundlerEnv: gem ${pkgname} not found");
+    in
+      copyIfBundledByPath mainGem
+  );
 
   # We have to normalize the Gemfile.lock, otherwise bundler tries to be
   # helpful by doing so at run time, causing executables to immediately bail
diff --git a/pkgs/development/ruby-modules/gem/default.nix b/pkgs/development/ruby-modules/gem/default.nix
index 7105663413a2b..d57eeb2ea0550 100644
--- a/pkgs/development/ruby-modules/gem/default.nix
+++ b/pkgs/development/ruby-modules/gem/default.nix
@@ -224,7 +224,7 @@ stdenv.mkDerivation ((builtins.removeAttrs attrs ["source"]) // {
     pushd $out/${ruby.gemPath}
     find doc/ -iname created.rid -delete -print
     find gems/*/ext/ extensions/ \( -iname Makefile -o -iname mkmf.log -o -iname gem_make.out \) -delete -print
-    ${if keepGemCache then "" else "rm -fvr cache"}
+    ${lib.optionalString (!keepGemCache) "rm -fvr cache"}
     popd
 
     # write out metadata and binstubs
diff --git a/pkgs/development/tools/misc/distcc/default.nix b/pkgs/development/tools/misc/distcc/default.nix
index b7270f79c4315..312f693285801 100644
--- a/pkgs/development/tools/misc/distcc/default.nix
+++ b/pkgs/development/tools/misc/distcc/default.nix
@@ -26,7 +26,7 @@ let
       configureFlagsArray=( CFLAGS="-O2 -fno-strict-aliasing"
                             CXXFLAGS="-O2 -fno-strict-aliasing"
           --mandir=$out/share/man
-                            ${if sysconfDir == "" then "" else "--sysconfdir=${sysconfDir}"}
+                            ${lib.optionalString (sysconfDir != "") "--sysconfdir=${sysconfDir}"}
                             ${lib.optionalString static "LDFLAGS=-static"}
                             ${lib.withFeature (static == true || popt == null) "included-popt"}
                             ${lib.withFeature (avahi != null) "avahi"}
diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index d7ea4ac2c4988..1f9039136f4c6 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -397,10 +397,11 @@ stdenv.mkDerivation ({
   meta = {
     description =
       "The Linux kernel" +
-      (if kernelPatches == [] then "" else
+      (lib.optionalString (kernelPatches != []) (
         " (with patches: "
         + lib.concatStringsSep ", " (map (x: x.name) kernelPatches)
-        + ")");
+        + ")"
+      ));
     license = lib.licenses.gpl2Only;
     homepage = "https://www.kernel.org/";
     maintainers = lib.teams.linux-kernel.members ++ [