Update the Android NDK to r27c and update to 16kb alignment (#3096)

* Update the Android NDK to r27c

* Set the max page size to be 16kb

* https://developer.android.com/guide/practices/page-sizes
* https://android-developers.googleblog.com/2024/08/adding-16-kb-page-size-to-android.html

* Add a test

Author: mattleibow

native/android/build.cake

@@ -8,6 +8,30 @@ DirectoryPath ANDROID_NDK_HOME = Argument("ndk", EnvironmentVariable("ANDROID_ND
 string SUPPORT_VULKAN_VAR = Argument ("supportVulkan", EnvironmentVariable ("SUPPORT_VULKAN") ?? "true");
 bool SUPPORT_VULKAN = SUPPORT_VULKAN_VAR == "1" || SUPPORT_VULKAN_VAR.ToLower () == "true";
 
+Information("Android NDK Path: {0}", ANDROID_NDK_HOME);
+Information("Building Vulkan: {0}", SUPPORT_VULKAN);
+
+void CheckAlignment(FilePath so)
+{
+    Information($"Making sure that everything is 16 KB aligned...");
+
+    var prebuilt = ANDROID_NDK_HOME.CombineWithFilePath("toolchains/llvm/prebuilt").FullPath;
+    var objdump = GetFiles($"{prebuilt}/*/bin/llvm-objdump*").FirstOrDefault() ?? throw new Exception("Could not find llvm-objdump");
+    RunProcess(objdump.FullPath, $"-p {so}", out var stdout);
+
+    var loads = stdout
+        .Where(l => l.Trim().StartsWith("LOAD"))
+        .ToList();
+
+    if (loads.Any(l => !l.Trim().EndsWith("align 2**14"))) {
+        Information(String.Join(Environment.NewLine + "    ", stdout));
+        throw new Exception($"{so} contained a LOAD that was not 16 KB aligned.");
+    } else {
+        Information("Everything is 16 KB aligned:");
+        Information(String.Join(Environment.NewLine, loads));
+    }
+}
+
 Task("libSkiaSharp")
     .IsDependentOn("git-sync-deps")
     .WithCriteria(IsRunningOnMacOs() || IsRunningOnWindows())
@@ -38,12 +62,15 @@ Task("libSkiaSharp")
             $"skia_use_vulkan={SUPPORT_VULKAN} ".ToLower () +
             $"skia_enable_skottie=true " +
             $"extra_cflags=[ '-DSKIA_C_DLL', '-DHAVE_SYSCALL_GETRANDOM', '-DXML_DEV_URANDOM' ] " +
+            $"extra_ldflags=[ '-Wl,-z,max-page-size=16384' ] " +
             $"ndk='{ANDROID_NDK_HOME}' " +
             $"ndk_api=21");
 
+        var so = SKIA_PATH.CombineWithFilePath($"out/android/{arch}/libSkiaSharp.so");
         var outDir = OUTPUT_PATH.Combine(arch);
         EnsureDirectoryExists(outDir);
-        CopyFileToDirectory(SKIA_PATH.CombineWithFilePath($"out/android/{arch}/libSkiaSharp.so"), outDir);
+        CopyFileToDirectory(so, outDir);
+        CheckAlignment(so);
     }
 });
 
@@ -68,9 +95,11 @@ Task("libHarfBuzzSharp")
             WorkingDirectory = "libHarfBuzzSharp",
         });
 
+        var so = $"libHarfBuzzSharp/libs/{arch}/libHarfBuzzSharp.so";
         var outDir = OUTPUT_PATH.Combine(arch);
         EnsureDirectoryExists(outDir);
-        CopyFileToDirectory($"libHarfBuzzSharp/libs/{arch}/libHarfBuzzSharp.so", outDir);
+        CopyFileToDirectory(so, outDir);
+        CheckAlignment(so);
     }
 });
 

native/android/libHarfBuzzSharp/jni/Application.mk

@@ -3,3 +3,4 @@ APP_PLATFORM := android-21
 NDK_TOOLCHAIN_VERSION := clang
 APP_STL := c++_static
 APP_OPTIM := release
+APP_SUPPORT_FLEXIBLE_PAGE_SIZES := true

native/android/libHarfBuzzSharp/jni/HarfBuzzSharp.mk

@@ -10,7 +10,7 @@ LOCAL_MODULE           := HarfBuzzSharp
 
 LOCAL_C_INCLUDES       := . $(src_root) $(ext_root)
 
-LOCAL_LDFLAGS          := -s -Wl,--gc-sections
+LOCAL_LDFLAGS          := -s -Wl,--gc-sections -Wl,-z,max-page-size=16384
 
 LOCAL_CFLAGS           := -DNDEBUG                                                                  \
                           -DHAVE_CONFIG_OVERRIDE_H -DHAVE_OT -DHB_NO_FALLBACK_SHAPE                 \

scripts/install-android-ndk.ps1

@@ -1,5 +1,5 @@
 Param(
-    [string] $Version = "r25c",
+    [string] $Version = "r27c",
     [string] $InstallDestination = $null
 )