Merge branch 'android-unified-headers' into release-3.9

Help/manual/cmake-toolchains.7.rst

@@ -385,6 +385,11 @@ Configure use of an Android NDK with the following variables:
   If not specified, a default for this variable will be chosen
   as specified :ref:`above <Cross Compiling for Android>`.
 
+:variable:`CMAKE_ANDROID_NDK_DEPRECATED_HEADERS`
+  Set to a true value to use the deprecated per-api-level headers
+  instead of the unified headers.  If not specified, the default will
+  be false unless using a NDK that does not provide unified headers.
+
 :variable:`CMAKE_ANDROID_NDK_TOOLCHAIN_VERSION`
   Set to the version of the NDK toolchain to be selected as the compiler.
   If not specified, the default will be the latest available GCC toolchain.

Help/manual/cmake-variables.7.rst

@@ -255,6 +255,7 @@ Variables that Control the Build
    /variable/CMAKE_ANDROID_NATIVE_LIB_DEPENDENCIES
    /variable/CMAKE_ANDROID_NATIVE_LIB_DIRECTORIES
    /variable/CMAKE_ANDROID_NDK
+   /variable/CMAKE_ANDROID_NDK_DEPRECATED_HEADERS
    /variable/CMAKE_ANDROID_NDK_TOOLCHAIN_HOST_TAG
    /variable/CMAKE_ANDROID_NDK_TOOLCHAIN_VERSION
    /variable/CMAKE_ANDROID_PROCESS_MAX

Help/release/3.9.rst

@@ -62,6 +62,11 @@ Commands
 Variables
 ---------
 
+* A :variable:`CMAKE_ANDROID_NDK_DEPRECATED_HEADERS` variable was added
+  for use when :ref:`Cross Compiling for Android with the NDK` to request
+  use of the deprecated headers even when unified headers are available.
+  The default is now to use unified headers if available.
+
 * A :variable:`CMAKE_AUTOMOC_DEPEND_FILTERS` variable was introduced to
   allow :variable:`CMAKE_AUTOMOC` to extract additional dependency file names
   for ``moc`` from the contents of source files.

Help/variable/CMAKE_ANDROID_NDK_DEPRECATED_HEADERS.rst

@@ -0,0 +1,9 @@
+CMAKE_ANDROID_NDK_DEPRECATED_HEADERS
+------------------------------------
+
+When :ref:`Cross Compiling for Android with the NDK`, this variable
+may be set to specify whether to use the deprecated per-api-level
+headers instead of the unified headers.
+
+If not specified, the default will be *false* if using a NDK version
+that provides the unified headers and *true* otherwise.

Modules/Platform/Android-Common.cmake

@@ -161,6 +161,9 @@ macro(__android_compiler_common lang)
   # tied to a specific API version.
   if(CMAKE_ANDROID_NDK)
     list(APPEND CMAKE_${lang}_STANDARD_INCLUDE_DIRECTORIES "${CMAKE_SYSROOT}/usr/include")
+    if(NOT CMAKE_ANDROID_NDK_DEPRECATED_HEADERS)
+      list(APPEND CMAKE_${lang}_STANDARD_INCLUDE_DIRECTORIES "${CMAKE_SYSROOT}/usr/include/${CMAKE_ANDROID_ARCH_HEADER_TRIPLE}")
+    endif()
     list(REMOVE_ITEM CMAKE_${lang}_IMPLICIT_INCLUDE_DIRECTORIES "/usr/include")
   endif()
 endmacro()

Modules/Platform/Android-Determine.cmake

@@ -197,22 +197,30 @@ endif()
 
 # https://developer.android.com/ndk/guides/abis.html
 
-set(_ANDROID_ABI_arm64-v8a_PROC   "aarch64")
-set(_ANDROID_ABI_arm64-v8a_ARCH   "arm64")
-set(_ANDROID_ABI_armeabi-v7a_PROC "armv7-a")
-set(_ANDROID_ABI_armeabi-v7a_ARCH "arm")
-set(_ANDROID_ABI_armeabi-v6_PROC  "armv6")
-set(_ANDROID_ABI_armeabi-v6_ARCH  "arm")
-set(_ANDROID_ABI_armeabi_PROC     "armv5te")
-set(_ANDROID_ABI_armeabi_ARCH     "arm")
-set(_ANDROID_ABI_mips_PROC        "mips")
-set(_ANDROID_ABI_mips_ARCH        "mips")
-set(_ANDROID_ABI_mips64_PROC      "mips64")
-set(_ANDROID_ABI_mips64_ARCH      "mips64")
-set(_ANDROID_ABI_x86_PROC         "i686")
-set(_ANDROID_ABI_x86_ARCH         "x86")
-set(_ANDROID_ABI_x86_64_PROC      "x86_64")
-set(_ANDROID_ABI_x86_64_ARCH      "x86_64")
+set(_ANDROID_ABI_arm64-v8a_PROC     "aarch64")
+set(_ANDROID_ABI_arm64-v8a_ARCH     "arm64")
+set(_ANDROID_ABI_arm64-v8a_HEADER   "aarch64-linux-android")
+set(_ANDROID_ABI_armeabi-v7a_PROC   "armv7-a")
+set(_ANDROID_ABI_armeabi-v7a_ARCH   "arm")
+set(_ANDROID_ABI_armeabi-v7a_HEADER "arm-linux-androideabi")
+set(_ANDROID_ABI_armeabi-v6_PROC    "armv6")
+set(_ANDROID_ABI_armeabi-v6_ARCH    "arm")
+set(_ANDROID_ABI_armeabi-v6_HEADER  "arm-linux-androideabi")
+set(_ANDROID_ABI_armeabi_PROC       "armv5te")
+set(_ANDROID_ABI_armeabi_ARCH       "arm")
+set(_ANDROID_ABI_armeabi_HEADER     "arm-linux-androideabi")
+set(_ANDROID_ABI_mips_PROC          "mips")
+set(_ANDROID_ABI_mips_ARCH          "mips")
+set(_ANDROID_ABI_mips_HEADER        "mipsel-linux-android")
+set(_ANDROID_ABI_mips64_PROC        "mips64")
+set(_ANDROID_ABI_mips64_ARCH        "mips64")
+set(_ANDROID_ABI_mips64_HEADER      "mips64el-linux-android")
+set(_ANDROID_ABI_x86_PROC           "i686")
+set(_ANDROID_ABI_x86_ARCH           "x86")
+set(_ANDROID_ABI_x86_HEADER         "i686-linux-android")
+set(_ANDROID_ABI_x86_64_PROC        "x86_64")
+set(_ANDROID_ABI_x86_64_ARCH        "x86_64")
+set(_ANDROID_ABI_x86_64_HEADER      "x86_64-linux-android")
 
 set(_ANDROID_PROC_aarch64_ARCH_ABI "arm64-v8a")
 set(_ANDROID_PROC_armv7-a_ARCH_ABI "armeabi-v7a")
@@ -264,6 +272,7 @@ if(_ANDROID_SYSROOT_ARCH AND NOT "x${_ANDROID_SYSROOT_ARCH}" STREQUAL "x${CMAKE_
     "does not match architecture '${CMAKE_ANDROID_ARCH}' for the ABI '${CMAKE_ANDROID_ARCH_ABI}'."
     )
 endif()
+set(CMAKE_ANDROID_ARCH_HEADER_TRIPLE "${_ANDROID_ABI_${CMAKE_ANDROID_ARCH_ABI}_HEADER}")
 
 # Select a processor.
 if(NOT CMAKE_SYSTEM_PROCESSOR)
@@ -275,6 +284,16 @@ if(NOT _ANDROID_ABI_${CMAKE_ANDROID_ARCH_ABI}_PROC STREQUAL CMAKE_SYSTEM_PROCESS
   message(FATAL_ERROR "Android: The specified CMAKE_ANDROID_ARCH_ABI='${CMAKE_ANDROID_ARCH_ABI}' and CMAKE_SYSTEM_PROCESSOR='${CMAKE_SYSTEM_PROCESSOR}' is not a valid combination.")
 endif()
 
+if(CMAKE_ANDROID_NDK AND NOT DEFINED CMAKE_ANDROID_NDK_DEPRECATED_HEADERS)
+  if(IS_DIRECTORY "${CMAKE_ANDROID_NDK}/sysroot/usr/include/${CMAKE_ANDROID_ARCH_HEADER_TRIPLE}")
+    # Unified headers exist so we use them by default.
+    set(CMAKE_ANDROID_NDK_DEPRECATED_HEADERS 0)
+  else()
+    # Unified headers do not exist so use the deprecated headers.
+    set(CMAKE_ANDROID_NDK_DEPRECATED_HEADERS 1)
+  endif()
+endif()
+
 # Save the Android-specific information in CMakeSystem.cmake.
 set(CMAKE_SYSTEM_CUSTOM_CODE "
 set(CMAKE_ANDROID_NDK \"${CMAKE_ANDROID_NDK}\")
@@ -283,6 +302,13 @@ set(CMAKE_ANDROID_ARCH \"${CMAKE_ANDROID_ARCH}\")
 set(CMAKE_ANDROID_ARCH_ABI \"${CMAKE_ANDROID_ARCH_ABI}\")
 ")
 
+if(CMAKE_ANDROID_NDK)
+  string(APPEND CMAKE_SYSTEM_CUSTOM_CODE
+    "set(CMAKE_ANDROID_ARCH_HEADER_TRIPLE \"${CMAKE_ANDROID_ARCH_HEADER_TRIPLE}\")\n"
+    "set(CMAKE_ANDROID_NDK_DEPRECATED_HEADERS \"${CMAKE_ANDROID_NDK_DEPRECATED_HEADERS}\")\n"
+    )
+endif()
+
 # Select an ARM variant.
 if(CMAKE_ANDROID_ARCH_ABI MATCHES "^armeabi")
   if(CMAKE_ANDROID_ARM_MODE)

Modules/Platform/Android-Initialize.cmake

@@ -20,6 +20,9 @@ endif()
 if(NOT CMAKE_SYSROOT)
   if(CMAKE_ANDROID_NDK)
     set(CMAKE_SYSROOT "${CMAKE_ANDROID_NDK}/platforms/android-${CMAKE_SYSTEM_VERSION}/arch-${CMAKE_ANDROID_ARCH}")
+    if(NOT CMAKE_ANDROID_NDK_DEPRECATED_HEADERS)
+      set(CMAKE_SYSROOT_COMPILE "${CMAKE_ANDROID_NDK}/sysroot")
+    endif()
   elseif(CMAKE_ANDROID_STANDALONE_TOOLCHAIN)
     set(CMAKE_SYSROOT "${CMAKE_ANDROID_STANDALONE_TOOLCHAIN}/sysroot")
   endif()

Modules/Platform/Android/abi-common.cmake

@@ -3,6 +3,10 @@ string(APPEND _ANDROID_ABI_INIT_CFLAGS
   " -no-canonical-prefixes"
   )
 
+if(CMAKE_ANDROID_NDK AND NOT CMAKE_ANDROID_NDK_DEPRECATED_HEADERS)
+  string(APPEND _ANDROID_ABI_INIT_CFLAGS " -D__ANDROID_API__=${CMAKE_SYSTEM_VERSION}")
+endif()
+
 if(NOT DEFINED CMAKE_POSITION_INDEPENDENT_CODE
     AND NOT CMAKE_SYSTEM_VERSION VERSION_LESS 16)
   set(CMAKE_POSITION_INDEPENDENT_CODE ON)