package: enable _LIBCPP_REMOVE_TRANSITIVE_INCLUDES for all libc++ builds.

Which makes libc++ since version 16 not use transitive includes for
backwards compatibility, both for faster build times and to detect if
some code is missing a transitive include (which could blow up for the
user even w/o this macro defined, as compiling with -std=c++23 also
removes quite a lot such includes).

This affects Android, macOS/iOS and Emscripten. On the CI right now all
VMs use older libc++, which means it does nothing, but it's done there
anyway to future-proof. Locally on Arch it affects the Android and
Emscripten builds already, as well as an explicit clang + libc++ build.

package/archlinux/PKGBUILD-android-arm64

@@ -35,6 +35,10 @@ build() {
     # CLICOLOR_FORCE=1: https://github.com/ninja-build/ninja/issues/2196
     cmake .. \
         -DCMAKE_BUILD_TYPE=Release \
+        `# Make libc++ remove transitive includes, both for faster build` \
+        `# times and to detect if we're missing a transitive include. Works` \
+        `# with libc++ 16+, which is used by NDK r26+.` \
+        -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
         -DCMAKE_COLOR_DIAGNOSTICS=ON \
         -DMAGNUM_WITH_VK=ON \
         -DMAGNUM_WITH_ANYAUDIOIMPORTER=OFF \

package/archlinux/PKGBUILD-clang-libc++

@@ -25,7 +25,10 @@ build() {
             -DCMAKE_CROSS_CONFIGS=all \
             -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="-O2 -g -DNDEBUG -fno-omit-frame-pointer" \
             -DCMAKE_CXX_COMPILER=clang++ \
-            -DCMAKE_CXX_FLAGS="-stdlib=libc++" \
+            `# Make libc++ remove transitive includes, both for faster build` \
+            `# times and to detect if we're missing a transitive include.` \
+            `# Works with libc++ 16+, which is used by NDK r26+.` \
+            -DCMAKE_CXX_FLAGS="-stdlib=libc++ -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
             -DCMAKE_EXE_LINKER_FLAGS=-lc++abi \
             -G "Ninja Multi-Config"
     fi

package/archlinux/PKGBUILD-emscripten-wasm

@@ -51,6 +51,10 @@ build() {
     cmake .. \
         -DCMAKE_BUILD_TYPE=Release \
         -DCMAKE_INSTALL_PREFIX=/usr/lib/emscripten/system \
+        `# Make libc++ remove transitive includes, both for faster build` \
+        `# times and to detect if we're missing a transitive include. Works` \
+        `# with libc++ 16+.` \
+        -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
         -DCMAKE_COLOR_DIAGNOSTICS=ON \
         -DMAGNUM_DEPLOY_PREFIX=/srv/http/emscripten \
         -DMAGNUM_WITH_AUDIO=ON \

package/archlinux/PKGBUILD-emscripten-wasm-webgl2

@@ -51,6 +51,10 @@ build() {
     cmake .. \
         -DCMAKE_BUILD_TYPE=Release \
         -DCMAKE_INSTALL_PREFIX=/usr/lib/emscripten/system \
+        `# Make libc++ remove transitive includes, both for faster build` \
+        `# times and to detect if we're missing a transitive include. Works` \
+        `# with libc++ 16+.` \
+        -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
         -DCMAKE_COLOR_DIAGNOSTICS=ON \
         -DMAGNUM_DEPLOY_PREFIX=/srv/http/emscripten-webgl2 \
         -DMAGNUM_TARGET_GLES2=OFF \

package/ci/android-x86-gles.sh

@@ -54,6 +54,13 @@ cmake .. \
     -DCMAKE_INSTALL_PREFIX=$HOME/deps \
     -DCMAKE_PREFIX_PATH=$HOME/deps \
     -DCMAKE_BUILD_TYPE=Release \
+    `# Make libc++ remove transitive includes, both for faster build times` \
+    `# and to detect if we're missing a transitive include. Works with` \
+    `# libc++ 16+, which is used by NDK r26+ (i.e., will get used next time` \
+    `# the android image is bumped). Not doing this for the Corrade build,` \
+    `# as that'd only add extra friction with no possibility of fixing from` \
+    `# here.` \
+    -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
     -DCORRADE_RC_EXECUTABLE=$HOME/deps-native/bin/corrade-rc \
     -DMAGNUM_TARGET_GLES2=$TARGET_GLES2 \
     -DMAGNUM_WITH_AUDIO=OFF \

package/ci/android-x86-vulkan.sh

@@ -55,6 +55,13 @@ cmake .. \
     -DCMAKE_ANDROID_STL_TYPE=c++_static \
     -DCMAKE_FIND_ROOT_PATH="/opt/android/sdk/ndk/21.4.7075529/toolchains/llvm/prebuilt/linux-x86_64/sysroot;$HOME/deps" \
     -DCMAKE_FIND_LIBRARY_CUSTOM_LIB_SUFFIX=/i686-linux-android/29 \
+    `# Make libc++ remove transitive includes, both for faster build times` \
+    `# and to detect if we're missing a transitive include. Works with` \
+    `# libc++ 16+, which is used by NDK r26+ (i.e., will get used next time` \
+    `# the android image is bumped). Not doing this for the Corrade build,` \
+    `# as that'd only add extra friction with no possibility of fixing from` \
+    `# here.` \
+    -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
     -DCMAKE_INSTALL_PREFIX=$HOME/deps \
     -DCMAKE_PREFIX_PATH=$HOME/deps \
     -DCMAKE_BUILD_TYPE=Release \

package/ci/circleci.yml

@@ -671,7 +671,11 @@ jobs:
   macos-gl:
     executor: xcode-14_3
     environment:
-      CMAKE_CXX_FLAGS: --coverage
+      # Make libc++ remove transitive includes, both for faster build times and
+      # to detect if we're missing a transitive include. Works with libc++ 16+,
+      # which is used by Xcode 15 (i.e., will get used on the next CircleCI
+      # executor update).
+      CMAKE_CXX_FLAGS: --coverage -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES
       CONFIGURATION: Debug
       EXTRA_OPTS: >
         -DMAGNUM_WITH_WINDOWLESSCGLAPPLICATION=ON
@@ -690,7 +694,11 @@ jobs:
   macos-gles3:
     executor: xcode-14_3
     environment:
-      CMAKE_CXX_FLAGS: --coverage
+      # Make libc++ remove transitive includes, both for faster build times and
+      # to detect if we're missing a transitive include. Works with libc++ 16+,
+      # which is used by Xcode 15 (i.e., will get used on the next CircleCI
+      # executor update).
+      CMAKE_CXX_FLAGS: --coverage -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES
       CONFIGURATION: Debug
       EXTRA_OPTS: >
         -DMAGNUM_WITH_WINDOWLESSEGLAPPLICATION=ON
@@ -712,7 +720,11 @@ jobs:
   macos-vulkan:
     executor: xcode-14_3
     environment:
-      CMAKE_CXX_FLAGS: --coverage
+      # Make libc++ remove transitive includes, both for faster build times and
+      # to detect if we're missing a transitive include. Works with libc++ 16+,
+      # which is used by Xcode 15 (i.e., will get used on the next CircleCI
+      # executor update).
+      CMAKE_CXX_FLAGS: --coverage -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES
     steps:
     - install-base-macos:
         extra: sdl2 glfw wget
@@ -746,7 +758,11 @@ jobs:
       # For some reason on the 15.1 image OpenAL hangs on startup. Skip those
       # tests.
       EXTRA_EXCLUDED_TESTS: "|ALTest"
-      CMAKE_CXX_FLAGS: --coverage
+      # Make libc++ remove transitive includes, both for faster build times and
+      # to detect if we're missing a transitive include. Works with libc++ 16+,
+      # which is used by Xcode 15 (i.e., will get used on the next CircleCI
+      # executor update).
+      CMAKE_CXX_FLAGS: --coverage -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES
       CONFIGURATION: Debug
     steps:
     # macos-gl tests with dynamic MoltenVK

package/ci/emscripten.sh

@@ -32,6 +32,13 @@ cmake .. \
     -DCMAKE_BUILD_TYPE=Debug \
     -DCMAKE_INSTALL_PREFIX=$HOME/deps \
     -DCMAKE_FIND_ROOT_PATH=$HOME/deps \
+    `# Make libc++ remove transitive includes, both for faster build times` \
+    `# and to detect if we're missing a transitive include. Works with` \
+    `# libc++ 16+, which is used by Emscripten 3.1.18+ (i.e., will get used` \
+    `# next time emsdk is bumped). Not doing this for the Corrade build, as` \
+    `# that'd only add extra friction with no possibility of fixing from` \
+    `# here.` \
+    -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
     -DMAGNUM_WITH_AUDIO=ON \
     -DMAGNUM_WITH_VK=OFF \
     -DMAGNUM_WITH_EMSCRIPTENAPPLICATION=ON \

package/ci/ios-simulator-gles.sh

@@ -56,6 +56,13 @@ cmake .. \
     -DCMAKE_PREFIX_PATH="$HOME/deps" \
     -DCORRADE_RC_EXECUTABLE=$HOME/deps-native/bin/corrade-rc \
     -DCMAKE_INSTALL_PREFIX=$HOME/deps \
+    `# Make libc++ remove transitive includes, both for faster build times` \
+    `# and to detect if we're missing a transitive include. Works with` \
+    `# libc++ 16+, which is used by Xcode 15 (i.e., will get used on the` \
+    `# next CircleCI executor update). Not doing this for the Corrade build` \
+    `# as that'd only add extra friction with no possibility of fixing from` \
+    `# here.` \
+    -DCMAKE_CXX_FLAGS="-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES" \
     -DMAGNUM_TARGET_GLES2=$TARGET_GLES2 \
     -DMAGNUM_WITH_AUDIO=ON \
     -DMAGNUM_WITH_VK=OFF \