From: Zoltan Varga <vargaz@gmail.com>
Date: Thu, 31 Aug 2017 11:17:02 +0000 (-0400)
Subject: [sdb] Fix support for async debugging in optimized mode, roslyn generates valuetype... 
X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=mono.git;a=commitdiff_plain;h=19046502886ad7697b4c6642337441a7fdafd28a

[sdb] Fix support for async debugging in optimized mode, roslyn generates valuetype IAsyncStateMethod implementations. Fixes #58728. (#5476)
---

diff --git a/mono/mini/debugger-agent.c b/mono/mini/debugger-agent.c
index dae5ed21a1c..4a2637c1943 100644
--- a/mono/mini/debugger-agent.c
+++ b/mono/mini/debugger-agent.c
@@ -4746,25 +4746,17 @@ breakpoint_matches_assembly (MonoBreakpoint *bp, MonoAssembly *assembly)
 	return bp->method && bp->method->klass->image->assembly == assembly;
 }
 
-static MonoObject*
-get_this (StackFrame *frame)
+static gpointer
+get_this_addr (StackFrame *frame)
 {
 	//Logic inspiered by "add_var" method and took out path that happens in async method for getting this
 	MonoDebugVarInfo *var = frame->jit->this_var;
 	if ((var->index & MONO_DEBUG_VAR_ADDRESS_MODE_FLAGS) != MONO_DEBUG_VAR_ADDRESS_MODE_REGOFFSET)
 		return NULL;
 
-	guint8 * addr = (guint8 *)mono_arch_context_get_int_reg (&frame->ctx, var->index & ~MONO_DEBUG_VAR_ADDRESS_MODE_FLAGS);
+	guint8 *addr = (guint8 *)mono_arch_context_get_int_reg (&frame->ctx, var->index & ~MONO_DEBUG_VAR_ADDRESS_MODE_FLAGS);
 	addr += (gint32)var->offset;
-	return *(MonoObject**)addr;
-}
-
-//This ID is used to figure out if breakpoint hit on resumeOffset belongs to us or not
-//since thread probably changed...
-static int
-get_this_async_id (StackFrame *frame)
-{
-	return get_objid (get_this (frame));
+	return addr;
 }
 
 static MonoMethod*
@@ -4779,25 +4771,100 @@ get_set_notification_method (MonoClass* async_builder_class)
 	return set_notification_method;
 }
 
-static void
-set_set_notification_for_wait_completion_flag (StackFrame *frame)
+static MonoMethod*
+get_object_id_for_debugger_method (MonoClass* async_builder_class)
+{
+	MonoError error;
+	GPtrArray *array = mono_class_get_methods_by_name (async_builder_class, "get_ObjectIdForDebugger", 0x24, FALSE, FALSE, &error);
+	mono_error_assert_ok (&error);
+	g_assert (array->len == 1);
+	MonoMethod *method = (MonoMethod *)g_ptr_array_index (array, 0);
+	g_ptr_array_free (array, TRUE);
+	return method;
+}
+
+/* Return the address of the AsyncMethodBuilder struct belonging to the state machine method pointed to by FRAME */
+static gpointer
+get_async_method_builder (StackFrame *frame)
 {
-	MonoObject* obj = get_this (frame);
-	g_assert (obj);
-	MonoClassField *builder_field = mono_class_get_field_from_name (obj->vtable->klass, "<>t__builder");
+	MonoObject *this_obj;
+	MonoClassField *builder_field;
+	gpointer builder;
+	guint8 *this_addr;
+
+	builder_field = mono_class_get_field_from_name (frame->method->klass, "<>t__builder");
 	g_assert (builder_field);
-	MonoObject* builder;
+
+	this_addr = get_this_addr (frame);
+	if (!this_addr)
+		return NULL;
+
+	if (frame->method->klass->valuetype) {
+		guint8 *vtaddr = *(guint8**)this_addr;
+		builder = (char*)vtaddr + builder_field->offset - sizeof (MonoObject);
+	} else {
+		this_obj = *(MonoObject**)this_addr;
+		builder = (char*)this_obj + builder_field->offset;
+	}
+
+	return builder;
+}
+
+//This ID is used to figure out if breakpoint hit on resumeOffset belongs to us or not
+//since thread probably changed...
+static int
+get_this_async_id (StackFrame *frame)
+{
+	MonoClassField *builder_field;
+	gpointer builder;
+	MonoMethod *method;
+	MonoObject *ex;
 	MonoError error;
-	builder = mono_field_get_value_object_checked (frame->domain, builder_field, obj, &error);
+	MonoObject *obj;
+	gboolean old_disable_breakpoints = FALSE;
+	DebuggerTlsData *tls;
+
+	/*
+	 * FRAME points to a method in a state machine class/struct.
+	 * Call the ObjectIdForDebugger method of the associated method builder type.
+	 */
+	builder = get_async_method_builder (frame);
+	if (!builder)
+		return 0;
+
+	builder_field = mono_class_get_field_from_name (frame->method->klass, "<>t__builder");
+	g_assert (builder_field);
+
+	tls = (DebuggerTlsData *)mono_native_tls_get_value (debugger_tls_id);
+	if (tls) {
+		old_disable_breakpoints = tls->disable_breakpoints;
+		tls->disable_breakpoints = TRUE;
+	}
+
+	method = get_object_id_for_debugger_method (mono_class_from_mono_type (builder_field->type));
+	obj = mono_runtime_try_invoke (method, builder, NULL, &ex, &error);
 	mono_error_assert_ok (&error);
+
+	if (tls)
+		tls->disable_breakpoints = old_disable_breakpoints;
+
+	return get_objid (obj);
+}
+
+static void
+set_set_notification_for_wait_completion_flag (StackFrame *frame)
+{
+	MonoClassField *builder_field = mono_class_get_field_from_name (frame->method->klass, "<>t__builder");
+	g_assert (builder_field);
+	gpointer builder = get_async_method_builder (frame);
 	g_assert (builder);
 
 	void* args [1];
 	gboolean arg = TRUE;
+	MonoError error;
 	args [0] = &arg;
-	mono_runtime_invoke_checked (get_set_notification_method (builder->vtable->klass), mono_object_unbox (builder), args, &error);
+	mono_runtime_invoke_checked (get_set_notification_method (mono_class_from_mono_type (builder_field->type)), builder, args, &error);
 	mono_error_assert_ok (&error);
-	mono_field_set_value (obj, builder_field, mono_object_unbox (builder));
 }
 
 static MonoMethod* notify_debugger_of_wait_completion_method_cache = NULL;