Bump to NDK r27 (#9020)

Changes: https://github.com/android/ndk/wiki/Changelog-r27

NDK r27 has been released.  The most important change affecting us is that we should start building
all our native libraries with [16k page alignment](https://github.com/android/ndk/wiki/Changelog-r27#announcements),
support for which is already in `main` and will be refined once #9075 is merged.

Notable changes:

  * NDK switched to LLVM 18.0.1 as its toolchain
  * A RISC-V sysroot (AKA riscv64, or rv64) has been added. It is not supported. It is present to aid bringup for
    OS vendors, but it's not yet a supported Android ABI. It will not be built by default.
  * Added APP_SUPPORT_FLEXIBLE_PAGE_SIZES for ndk-build and ANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES for CMake. 
  * The unsupported libclang, libclang-cpp, libLLVM, and libLTO libraries were removed to save space.

Author: grendello

build-tools/xaprepare/xaprepare/ConfigAndData/BuildAndroidPlatforms.cs

@@ -5,8 +5,8 @@ namespace Xamarin.Android.Prepare
 {
 	class BuildAndroidPlatforms
 	{
-		public const string AndroidNdkVersion = "26d";
-		public const string AndroidNdkPkgRevision = "26.3.11579264";
+		public const string AndroidNdkVersion = "27";
+		public const string AndroidNdkPkgRevision = "27.0.12077973";
 		public const int NdkMinimumAPI = 21;
 		public const int NdkMinimumAPILegacy32 = 21;
 

src-ThirdParty/llvm/verbose_abort.cpp

@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <__config>
+#include <__verbose_abort>
+#include <cstdarg>
+#include <cstdio>
+#include <cstdlib>
+
+#ifdef __BIONIC__
+#  include <android/api-level.h>
+#  if __ANDROID_API__ >= 21
+#    include <syslog.h>
+extern "C" void android_set_abort_message(const char* msg);
+#  else
+#    include <assert.h>
+#  endif // __ANDROID_API__ >= 21
+#endif   // __BIONIC__
+
+#if defined(__APPLE__) && __has_include(<CrashReporterClient.h>)
+#  include <CrashReporterClient.h>
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+_LIBCPP_WEAK void __libcpp_verbose_abort(char const* format, ...) {
+  // Write message to stderr. We do this before formatting into a
+  // buffer so that we still get some information out if that fails.
+  {
+    va_list list;
+    va_start(list, format);
+    std::vfprintf(stderr, format, list);
+    va_end(list);
+  }
+
+  // Format the arguments into an allocated buffer for CrashReport & friends.
+  // We leak the buffer on purpose, since we're about to abort() anyway.
+  char* buffer;
+  (void)buffer;
+  va_list list;
+  va_start(list, format);
+
+#if defined(__APPLE__) && __has_include(<CrashReporterClient.h>)
+  // Note that we should technically synchronize accesses here (by e.g. taking a lock),
+  // however concretely we're only setting a pointer, so the likelihood of a race here
+  // is low.
+  vasprintf(&buffer, format, list);
+  CRSetCrashLogMessage(buffer);
+#elif defined(__BIONIC__)
+  vasprintf(&buffer, format, list);
+
+#  if __ANDROID_API__ >= 21
+  // Show error in tombstone.
+  android_set_abort_message(buffer);
+
+  // Show error in logcat.
+  openlog("libc++", 0, 0);
+  syslog(LOG_CRIT, "%s", buffer);
+  closelog();
+#  else
+  // The good error reporting wasn't available in Android until L. Since we're
+  // about to abort anyway, just call __assert2, which will log _somewhere_
+  // (tombstone and/or logcat) in older releases.
+  __assert2(__FILE__, __LINE__, __func__, buffer);
+#  endif // __ANDROID_API__ >= 21
+#endif
+  va_end(list);
+
+  std::abort();
+}
+
+_LIBCPP_END_NAMESPACE_STD

src/native/CMakePresets.json.in

@@ -18,6 +18,7 @@
             "cacheVariables": {
                 "ANDROID_NDK": "@AndroidNdkDirectory@",
                 "ANDROID_TOOLCHAIN": "clang",
+                "ANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES": "ON",
                 "CMAKE_EXPORT_COMPILE_COMMANDS": "ON",
                 "CMAKE_MAKE_PROGRAM": "@NinjaPath@",
                 "OUTPUT_PATH": "@OutputPath@",

src/native/monodroid/CMakeLists.txt

@@ -133,6 +133,7 @@ target_compile_options(
   ${XAMARIN_MONO_ANDROID_LIB}
   PRIVATE
   ${XA_DEFAULT_SYMBOL_VISIBILITY}
+  ${XA_COMMON_CXX_ARGS}
 )
 
 target_include_directories(

src/native/monodroid/embedded-assemblies.hh

@@ -389,7 +389,7 @@ namespace xamarin::android::internal {
 		bool                   need_to_scan_more_apks = true;
 
 		AssemblyStoreIndexEntry *assembly_store_hashes;
-		std::mutex             assembly_decompress_mutex;
+		xamarin::android::mutex  assembly_decompress_mutex;
 	};
 }
 

src/native/monodroid/monodroid-glue-internal.hh

@@ -346,15 +346,15 @@ namespace xamarin::android::internal
 		jnienv_register_jni_natives_fn jnienv_register_jni_natives = nullptr;
 		MonoAssemblyLoadContextGCHandle default_alc = nullptr;
 
-		static std::mutex             pinvoke_map_write_lock;
+		static xamarin::android::mutex             pinvoke_map_write_lock;
 		static pinvoke_library_map    other_pinvoke_map;
 		static MonoCoreRuntimeProperties monovm_core_properties;
 		MonovmRuntimeConfigArguments  runtime_config_args;
 
 		static void *system_native_library_handle;
 		static void *system_security_cryptography_native_android_library_handle;
 		static void *system_io_compression_native_library_handle;
-		static std::mutex   dso_handle_write_lock;
+		static xamarin::android::mutex   dso_handle_write_lock;
 	};
 }
 #endif

src/native/monodroid/monodroid-glue.cc

@@ -77,7 +77,7 @@ using namespace microsoft::java_interop;
 using namespace xamarin::android;
 using namespace xamarin::android::internal;
 
-std::mutex MonodroidRuntime::pinvoke_map_write_lock;
+xamarin::android::mutex MonodroidRuntime::pinvoke_map_write_lock;
 
 MonoCoreRuntimeProperties MonodroidRuntime::monovm_core_properties = {
 	.trusted_platform_assemblies = nullptr,
@@ -86,7 +86,7 @@ MonoCoreRuntimeProperties MonodroidRuntime::monovm_core_properties = {
 	.pinvoke_override = &MonodroidRuntime::monodroid_pinvoke_override
 };
 
-std::mutex MonodroidRuntime::dso_handle_write_lock;
+xamarin::android::mutex MonodroidRuntime::dso_handle_write_lock;
 bool MonodroidRuntime::startup_in_progress = true;
 
 void

src/native/monodroid/monodroid-tracing.cc

@@ -15,7 +15,7 @@ namespace {
 	decltype(xa_get_java_backtrace)* _xa_get_java_backtrace;
 	decltype(xa_get_interesting_signal_handlers)* _xa_get_interesting_signal_handlers;
 	bool tracing_init_done;
-	std::mutex tracing_init_lock {};
+	xamarin::android::mutex tracing_init_lock {};
 }
 
 void

src/native/monodroid/startup-aware-lock.hh

@@ -8,7 +8,7 @@ namespace xamarin::android::internal
 	class StartupAwareLock final
 	{
 	public:
-		explicit StartupAwareLock (std::mutex &m)
+		explicit StartupAwareLock (xamarin::android::mutex &m)
 			: lock (m)
 		{
 			if (MonodroidRuntime::is_startup_in_progress ()) {
@@ -34,7 +34,7 @@ namespace xamarin::android::internal
 		StartupAwareLock& operator= (StartupAwareLock const&) = delete;
 
 	private:
-		std::mutex& lock;
+		xamarin::android::mutex& lock;
 	};
 }
 #endif

src/native/monodroid/timing-internal.hh

@@ -440,7 +440,7 @@ namespace xamarin::android::internal
 
 	private:
 		std::atomic_size_t next_event_index = 0;
-		std::mutex event_vector_realloc_mutex;
+		xamarin::android::mutex event_vector_realloc_mutex;
 		std::vector<TimingEvent> events;
 
 		static TimingEvent init_time;