Add support for HXCPP_ANDROID_PLATFORM define (#1201)

* Add support for the HXCPP_ANDROID_PLATFORM define

This also deprecates the PLATFORM_NUMBER define.

Also removes notes about frameworks setting minSdkVersion as this was
outdated and confusing.

* Use ndk metadata for default android platform

Instead of hardcoding default values per ndk version, it is better to
read the ndk metadata to figure out the minimum version supported by the
ndk.

Author: tobil4sk

docs/build_xml/Defines.md

@@ -67,7 +67,7 @@ Defines affecting target architecture.
 | *HXCPP_LINUX_ARM64*     | Run on a linux ARM64 device |
 | *winrt*                 | Compile for windowsRt/windows UWP |
 | *android*               | Compile for android |
-| *PLATFORM*              | Specify the android platform for NDK compilation |
+| *HXCPP_ANDROID_PLATFORM* | Specify the android platform for NDK compilation |
 | *ANDROID_NDK_ROOT*      | Specify the location of the android NDK toolchain |
 | *ANDROID_NDK_DIR*       | Specify the search location for finding the android NDK toolchain |
 | *HXCPP_X86*             | Compile android for x86 architecture |

toolchain/android-toolchain-clang.xml

@@ -1,36 +1,29 @@
 <xml>
-    
+
 <!-- Set architecture -->
 <section if="HXCPP_X86">
   <set name="ARCH" value="-x86" />
-  <set name="PLATFORM_NUMBER" value="21" unless="PLATFORM_NUMBER" />
   <set name="ABITRIPLE" value="i686-linux-android" />
 </section>
 
 <section if="HXCPP_X86_64">
   <set name="ARCH" value="-x86_64" />
-  <set name="PLATFORM_NUMBER" value="21" unless="PLATFORM_NUMBER" />
   <set name="ABITRIPLE" value="x86_64-linux-android" />
 </section>
 
 <section if="HXCPP_ARMV7">
   <set name="ARCH" value="-v7" />
-  <set name="PLATFORM_NUMBER" value="21" unless="PLATFORM_NUMBER" />
   <set name="ABITRIPLE" value="armv7a-linux-androideabi" />
   <set name="EXEPREFIX" value="arm-linux-androideabi" />
 </section>
 
 <section if="HXCPP_ARM64">
   <set name="ARCH" value="-64"/>
-  <set name="PLATFORM_NUMBER" value="21" unless="PLATFORM_NUMBER" />
   <set name="ABITRIPLE" value="aarch64-linux-android" />
 </section>
 
 <error value="Please set one of the architectures, eg HXCPP_ARM64, HXCPP_X86, ..." unless="ABITRIPLE" />
 
-<set name="PLATFORM" value="android-${PLATFORM_NUMBER}" />
-<set name="ANDROID_PLATFORM_DEFINE" value="HXCPP_ANDROID_PLATFORM=${PLATFORM_NUMBER}" />
-     
 <path name="${ANDROID_NDK_ROOT}/toolchains/llvm/prebuilt/${ANDROID_HOST}/bin" />
 
 <section unless="NDKV22+">
@@ -47,7 +40,7 @@
 <compiler id="android-gcc" exe="clang++">
 
   <exe name="clang++" />
-  <flag value="--target=${ABITRIPLE}${PLATFORM_NUMBER}" />
+  <flag value="--target=${ABITRIPLE}${HXCPP_ANDROID_PLATFORM}" />
 
   <!-- File Related -->
   <include name="toolchain/common-defines.xml" />
@@ -64,8 +57,8 @@
   <flag value="-DHXCPP_CLANG"/>
   <flag value="-DHX_ANDROID"/>
   <flag value="-DHXCPP_LOAD_DEBUG" if="HXCPP_LOAD_DEBUG"/>
-  <flag value="-D${ANDROID_PLATFORM_DEFINE}"/>
-  
+  <flag value="-DHXCPP_ANDROID_PLATFORM=${HXCPP_ANDROID_PLATFORM}" />
+
   <!-- Options -->
   <cppflag value="-std=c++17" if="HXCPP_CPP17" />
   <flag value="-flto" if="HXCPP_OPTIMIZE_LINK" unless="debug"/>
@@ -90,7 +83,7 @@
 
   <exe name="clang++" />
   <flag value ="-shared" />
-  <flag value="--target=${ABITRIPLE}${PLATFORM_NUMBER}" />
+  <flag value="--target=${ABITRIPLE}${HXCPP_ANDROID_PLATFORM}" />
 
   <!-- Build time error, not run time -->
   <flag value="-Wl,--no-undefined" unless="HXCPP_ALLOW_UNDEFINED" />

toolchain/android-toolchain-gcc.xml

@@ -129,7 +129,7 @@
   <flag value="-finline-limit=10000"/>
   <flag value="-DANDROID=ANDROID"/>
   <flag value="-DHX_ANDROID"/>
-  <flag value="-D${ANDROID_PLATFORM_DEFINE}"/>
+  <flag value="-DHXCPP_ANDROID_PLATFORM=${HXCPP_ANDROID_PLATFORM}"/>
   <!-- todo <flag value="-Werror"/> -->
   <flag value="-Wa,--noexecstack"/>
   <flag value="-O2" unless="debug || HXCPP_OPTIMIZE_FOR_SIZE || HXCPP_OPTIMIZE_FOR_FAST"/>

tools/hxcpp/Setup.hx

@@ -516,14 +516,36 @@ class Setup
       }
       catch(e:Dynamic) { }
 
-      if(defines.exists('NDKV20+')) {
-         Log.v([
-            "x86 Platform: 16",
-            "arm Platform: 16",
-            "x86_64 Platform: 21",
-            "arm_64 Platform: 21",
-            "Frameworks should set the minSdkVersion for each APK to these values."
-         ].join('\n'));
+      if (defines.exists('HXCPP_ANDROID_PLATFORM')) {
+         Log.info("", "\x1b[33;1mUsing Android NDK platform: " + defines.get("HXCPP_ANDROID_PLATFORM") + "\x1b[0m");
+      }
+      else if (defines.exists('NDKV20+')) {
+         if (defines.exists("PLATFORM_NUMBER")) {
+            Log.warn("The PLATFORM_NUMBER define is deprecated. Please use the HXCPP_ANDROID_PLATFORM define instead.");
+            defines.set("HXCPP_ANDROID_PLATFORM", Std.string(defines.get("PLATFORM_NUMBER")));
+         } else {
+            var platformsJson = root + "/meta/platforms.json";
+
+            var minPlatform:Null<Int> = try {
+               haxe.Json.parse(sys.io.File.getContent(platformsJson)).min;
+            } catch (e) {
+               Log.warn("Unable to determine minimum supported Android platform: " + e.toString());
+               null;
+            };
+
+            if (minPlatform == null) {
+               Log.warn("Defaulting to Android platform 21");
+               minPlatform = 21;
+            }
+
+            // only platform version 21 and above support 64 bit
+            // https://developer.android.com/about/versions/lollipop#Perf
+            if (minPlatform < 21 && (defines.exists('HXCPP_ARM64') || defines.exists('HXCPP_X86_64'))) {
+               minPlatform = 21;
+            }
+
+            defines.set("HXCPP_ANDROID_PLATFORM", Std.string(minPlatform));
+         }
       }
       else {
          globallySetThePlatform(root, defines);
@@ -581,7 +603,7 @@ class Setup
          defines.set("PLATFORM", "android-" + best);
          androidPlatform = best;
       }
-      defines.set("ANDROID_PLATFORM_DEFINE", "HXCPP_ANDROID_PLATFORM=" + androidPlatform);
+      defines.set("HXCPP_ANDROID_PLATFORM", Std.string(androidPlatform));
       if (Log.verbose) Log.println("");
    }