SDL: cmake: install Android.mk files for ndk-build

SDL Commits
1 
From 3617691fe0cb3b29ffcdeb5567d85126de91ba15 Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Thu, 16 Jun 2022 03:37:05 +0200
Subject: [PATCH] cmake: install Android.mk files for ndk-build

This allows including SDL2 with ndk-build using
NDK_MODULE_PATH + import-module

An install tree looks like:

-- share |-- aclocal | – sdl2.m4
|-- licenses
| -- SDL2 | – LICENSE.txt
-- ndk-modules |-- SDL2 | – Android.mk
|-- SDL2-static
| -- Android.mk |-- SDL2main | – Android.mk
-- SDL2test – Android.mk


The generated `/share/ndk-modules/SDL2/Android.mk` contains:

LOCAL_PATH := $(call my-dir)
_IMPORT_PREFIX := $(LOCAL_PATH)/…/…/…

include $(CLEAR_VARS)
LOCAL_MODULE := SDL2
LOCAL_SRC_FILES := $(_IMPORT_PREFIX)/lib/libSDL2.so
LOCAL_CPP_FEATURES := rtti exceptions
LOCAL_EXPORT_C_INCLUDES := ${_IMPORT_PREFIX}/include
${_IMPORT_PREFIX}/include/SDL2
include $(PREBUILT_SHARED_LIBRARY)`

---
 CMakeLists.txt | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4a8b20a6a64..1194ecc1cbc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3160,6 +3160,10 @@ if(NOT SDL2_DISABLE_INSTALL)
       NAMESPACE SDL2::
       DESTINATION ${PKG_PREFIX}
     )
+    if(ANDROID AND NOT CMAKE_VERSION VERSION_LESS 3.7)
+      install(EXPORT_ANDROID_MK SDL2Targets
+        DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/ndk-modules/SDL2")
+    endif()
   endif()
 
   if(NOT WINDOWS_STORE AND NOT SDL2_DISABLE_SDL2MAIN)
@@ -3168,6 +3172,10 @@ if(NOT SDL2_DISABLE_INSTALL)
       NAMESPACE SDL2::
       DESTINATION ${PKG_PREFIX}
     )
+    if(ANDROID AND NOT CMAKE_VERSION VERSION_LESS 3.7)
+      install(EXPORT_ANDROID_MK SDL2mainTargets
+        DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/ndk-modules/SDL2main")
+    endif()
   endif()
 
   if(SDL_STATIC)
@@ -3176,6 +3184,10 @@ if(NOT SDL2_DISABLE_INSTALL)
       NAMESPACE SDL2::
       DESTINATION ${PKG_PREFIX}
     )
+    if(ANDROID AND NOT CMAKE_VERSION VERSION_LESS 3.7)
+      install(EXPORT_ANDROID_MK SDL2staticTargets
+        DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/ndk-modules/SDL2-static")
+    endif()
   endif()
 
   if(SDL_TEST)
@@ -3184,6 +3196,10 @@ if(NOT SDL2_DISABLE_INSTALL)
       NAMESPACE SDL2::
       DESTINATION ${PKG_PREFIX}
     )
+    if(ANDROID AND NOT CMAKE_VERSION VERSION_LESS 3.7)
+      install(EXPORT_ANDROID_MK SDL2testTargets
+        DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/ndk-modules/SDL2test")
+    endif()
   endif()
 
   install(