[ios/tvos] ARM64 simulator JIT Hack and CMAKE_SYSTEM_VARIANT iOSSimulator

eng/native/build-commons.sh

@@ -94,6 +94,10 @@ build_native()
         cmakeArgs="-DCMAKE_SYSTEM_VARIANT=MacCatalyst $cmakeArgs"
     fi
 
+    if [[ "$targetOS" == "iOSSimulator" || "$targetOS" == "tvOSSimulator" ]]; then
+	cmakeArgs="-DCMAKE_SYSTEM_VARIANT=$targetOS $cmakeArgs"
+    fi
+
     if [[ "$__UseNinja" == 1 ]]; then
         generator="ninja"
         buildTool="$(command -v ninja || command -v ninja-build)"

src/mono/CMakeLists.txt

@@ -213,6 +213,9 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "iOS" OR CMAKE_SYSTEM_NAME STREQUAL "tvOS")
   add_definitions("-DSMALL_CONFIG")
   add_definitions("-D_XOPEN_SOURCE")
   add_definitions("-DHAVE_LARGE_FILE_SUPPORT=1")
+  if (CMAKE_SYSTEM_VARIANT STREQUAL "iOSSimulator" OR CMAKE_SYSTEM_VARIANT STREQUAL "tvOSSimulator")
+    set (HOST_DARWIN_SIMULATOR 1)
+  endif()
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   set(HOST_LINUX 1)
   add_definitions(-D_GNU_SOURCE -D_REENTRANT)

src/mono/cmake/config.h.in

@@ -116,6 +116,9 @@
 /* Host Platform is Mac Catalyst */
 #cmakedefine HOST_MACCAT 1
 
+/* Host Platform is iOS or tvOS simulator */
+#cmakedefine HOST_DARWIN_SIMULATOR 1
+
 /* Use classic Windows API support */
 #cmakedefine HAVE_CLASSIC_WINAPI_SUPPORT 1
 

src/mono/mono/utils/CMakeLists.txt

@@ -33,6 +33,8 @@ set(utils_common_sources
     mono-logger.c
     mono-logger-internals.h
     mono-codeman.c
+    write-protect.c
+    write-protect.h
     mono-counters.c
     mono-compiler.h
     mono-dl.c

src/mono/mono/utils/mono-codeman.c

@@ -28,6 +28,7 @@ static void* mono_code_manager_heap;
 
 #include <mono/utils/mono-os-mutex.h>
 #include <mono/utils/mono-tls.h>
+#include <mono/utils/write-protect.h>
 
 static uintptr_t code_memory_used = 0;
 static size_t dynamic_code_alloc_count;
@@ -668,9 +669,11 @@ mono_codeman_enable_write (void)
 		mono_native_tls_set_value (write_level_tls_id, GINT_TO_POINTER (level));
 		pthread_jit_write_protect_np (0);
 	}
-#elif defined(HOST_MACCAT) && defined(__aarch64__)
-	/* JITing in Catalyst apps is not allowed on Apple Silicon. */
-	g_assert_not_reached ();
+#elif (defined(HOST_IOS) || defined(HOST_TVOS)) && defined(HOST_DARWIN_SIMULATOR) && defined(__aarch64__)
+        int level = GPOINTER_TO_INT (mono_native_tls_get_value (write_level_tls_id));
+        level ++;
+        mono_native_tls_set_value (write_level_tls_id, GINT_TO_POINTER (level));
+        mono_jit_write_protect (0);
 #endif
 }
 
@@ -692,8 +695,12 @@ mono_codeman_disable_write (void)
 		if (level == 0)
 			pthread_jit_write_protect_np (1);
 	}
-#elif defined(HOST_MACCAT) && defined(__aarch64__)
-	/* JITing in Catalyst apps is not allowed on Apple Silicon. */
-	g_assert_not_reached ();
+#elif (defined(HOST_IOS) || defined(HOST_TVOS)) && defined(HOST_DARWIN_SIMULATOR) && defined(__aarch64__)
+		int level = GPOINTER_TO_INT (mono_native_tls_get_value (write_level_tls_id));
+		g_assert (level);
+		level --;
+		mono_native_tls_set_value (write_level_tls_id, GINT_TO_POINTER (level));
+		if (level == 0)
+                        mono_jit_write_protect (1);
 #endif
 }

src/mono/mono/utils/write-protect.c

@@ -0,0 +1,27 @@
+/**
+ * \file
+ */
+
+#include "config.h"
+
+#include "mono-compiler.h"
+#include "write-protect.h"
+
+#if (defined(HOST_IOS) || defined(HOST_TVOS)) && defined (HOST_DARWIN_SIMULATOR) && defined (__aarch64__)
+
+/* our own declaration of pthread_jit_write_protect_np so that we don't see the __API_UNAVAILABLE__ header */
+void
+pthread_jit_write_protect_np (int enabled);
+
+
+void
+mono_jit_write_protect (int enabled)
+{
+        pthread_jit_write_protect_np (enabled);
+}
+
+#else
+
+MONO_EMPTY_SOURCE_FILE (write_protect);
+
+#endif

src/mono/mono/utils/write-protect.h

@@ -0,0 +1,18 @@
+/**
+ * \file
+ */
+
+#ifndef __MONO_WRITE_PROTECT_H__
+#define __MONO_WRITE_PROTECT_H__
+
+#include <mono/utils/mono-publib.h>
+
+#if (defined(HOST_IOS) || defined(HOST_TVOS)) && defined (HOST_DARWIN_SIMULATOR) && defined (__aarch64__)
+
+void
+mono_jit_write_protect (int enabled);
+
+#endif /* defined (HOST_DARWIN_SIMULATOR) && defined (__aarch64__) */
+
+#endif /* __MONO_WRITE_PROTECT_H__ */
+