More embedding samples.

svn path=/trunk/mono/; revision=30034

3 files changed, 409 insertions, 1 deletions

diff --git a/samples/Makefile.am b/samples/Makefile.am
index 0d535d35449..d6769d8d70a 100644
--- a/samples/Makefile.am
+++ b/samples/Makefile.am
@@ -3,4 +3,6 @@ dist-hook:
 	mkdir $(distdir)/embed
 	mkdir $(distdir)/profiler
 	cp $(srcdir)/profiler/sample.c $(distdir)/profiler
-	cp $(srcdir)/embed/test.cs $(srcdir)/embed/teste.c $(distdir)/embed
\ No newline at end of file
+	cp $(srcdir)/embed/test.cs $(srcdir)/embed/teste.c $(distdir)/embed
+	cp $(srcdir)/embed/test-metadata.c $(distdir)/embed
+	cp $(srcdir)/embed/test-invoke.c $(srcdir)/embed/invoke.cs $(distdir)/embed
diff --git a/samples/embed/invoke.cs b/samples/embed/invoke.cs
new file mode 100644
index 00000000000..19e2775d3a5
--- /dev/null
+++ b/samples/embed/invoke.cs
@@ -0,0 +1,50 @@
+using System;
+
+namespace Embed {
+	class MyType {
+		int val = 5;
+		string str = "hello";
+
+		MyType () {
+			Console.WriteLine ("In ctor val is: {0}", val);
+			Console.WriteLine ("In ctor str is: {0}", str);
+		}
+		
+		MyType (int v, byte[] array) {
+			Console.WriteLine ("In ctor (int, byte[]) got value: {0}, array len: {1}", v, array.Length);
+		}
+
+		void method () {
+			Console.WriteLine ("In method val is {0}", val);
+			Console.WriteLine ("In method str is: {0}", str);
+		}
+
+		int Value {
+			get {
+				return val;
+			}
+		}
+
+		string Message {
+			get {
+				return str;
+			}
+		}
+
+		void Values (ref int v, ref string s) {
+			Console.WriteLine ("In Values () v is {0}", v);
+			Console.WriteLine ("In Values () s is: {0}", s);
+			v = val;
+			s = str;
+		}
+
+		static void Fail () {
+			throw new Exception ();
+		}
+		
+		static void Main () {
+			/* we do nothing here... */
+		}
+	}
+}
+
diff --git a/samples/embed/test-invoke.c b/samples/embed/test-invoke.c
new file mode 100644
index 00000000000..899a6b228a8
--- /dev/null
+++ b/samples/embed/test-invoke.c
@@ -0,0 +1,356 @@
+#include <mono/jit/jit.h>
+#include <mono/metadata/environment.h>
+#include <mono/metadata/assembly.h>
+#include <mono/metadata/debug-helpers.h>
+#include <string.h>
+#include <stdlib.h>
+
+/*
+ * Simple mono embedding example.
+ * We show how to create objects and invoke methods and set fields in them.
+ * Compile with: 
+ * 	gcc -Wall -o test-invoke test-invoke.c `pkg-config --cflags --libs mono` -lm
+ * 	mcs invoke.cs
+ * Run with:
+ * 	./test-invoke invoke.exe
+ */
+
+typedef struct
+{
+	MonoDomain *domain;
+	const char *file;
+	int argc;
+	char **argv;
+} MainThreadArgs;
+
+static void
+access_valuetype_field (MonoObject *obj)
+{
+	MonoClass *klass;
+	MonoClassField *field;
+	int val;
+
+	klass = mono_object_get_class (obj);
+
+	/* Now we'll change the value of the 'val' field (see invoke.cs) */
+	field = mono_class_get_field_from_name (klass, "val");
+
+	/* This time we also add a bit of error checking... */
+	if (!field) {
+		fprintf (stderr, "Can't find field val in MyType\n");
+		exit (1);
+	}
+	/* Check that val is an int (if you're paranoid or if you need to 
+	 * show how this API is used) 
+	 */
+	if (mono_type_get_type (mono_field_get_type (field)) != MONO_TYPE_I4) {
+		fprintf (stderr, "Field val is not a 32 bit integer\n");
+		exit (1);
+	}
+	
+	/* Note we pass a pointer to the value */
+	mono_field_get_value (obj, field, &val);
+	printf ("Value of field is: %d\n", val);
+	val = 10;
+
+	/* Note we pass a pointer to the value here as well */
+	mono_field_set_value (obj, field, &val);
+
+}
+
+static void
+access_reference_field (MonoObject *obj)
+{
+	MonoClass *klass;
+	MonoDomain *domain;
+	MonoClassField *str;
+	MonoString *strval;
+	char *p;
+
+	klass = mono_object_get_class (obj);
+	domain = mono_object_get_domain (obj);
+
+	/* Now we'll see that a reference type is handled slightly differently.
+	 * First, get the MonoClassField representing it.
+	 */
+	str = mono_class_get_field_from_name (klass, "str");
+	
+	/* No change here, we always pass a pointer */
+	mono_field_get_value (obj, str, &strval);
+	
+	/* get the string in UTF-8 encoding to print it */
+	p = mono_string_to_utf8 (strval);
+	printf ("Value of str is: %s\n", p);
+	/* we need to free the result from mono_string_to_utf8 () */
+	g_free (p);
+
+	/* string are immutable, so we need to create a different string */
+	strval = mono_string_new (domain, "hello from the embedding API");
+
+	/* Here is the slight difference: for reference types we pass 
+	 * the pointer directly, instead of a pointer to the value.
+	 */
+	mono_field_set_value (obj, str, strval);
+
+}
+
+/* Demostrate how to call methods */
+static void
+call_methods (MonoObject *obj)
+{
+	MonoClass *klass;
+	MonoDomain *domain;
+	MonoMethod *method = NULL, *m = NULL, *ctor = NULL, *fail = NULL, *mvalues;
+	MonoProperty *prop;
+	MonoObject *result, *exception;
+	MonoString *str;
+	char *p;
+	gpointer iter;
+	gpointer args [2];
+	int val;
+
+	klass = mono_object_get_class (obj);
+	domain = mono_object_get_domain (obj);
+
+	/* retrieve all the methods we need */
+	iter = NULL;
+	while ((m = mono_class_get_methods (klass, &iter))) {
+		if (strcmp (mono_method_get_name (m), "method") == 0) {
+			method = m;
+		} else if (strcmp (mono_method_get_name (m), "Fail") == 0) {
+			fail = m;
+		} else if (strcmp (mono_method_get_name (m), "Values") == 0) {
+			mvalues = m;
+		} else if (strcmp (mono_method_get_name (m), ".ctor") == 0) {
+			/* Check it's the ctor that takes two args:
+			 * as you see a contrsuctor is a method like any other.
+			 */
+			MonoMethodSignature * sig = mono_method_signature (m);
+			if (mono_signature_get_param_count (sig) == 2) {
+				ctor = m;
+			}
+		}
+	}
+	/* Now we'll call method () on obj: since it takes no arguments 
+	 * we can pass NULL as the third argument to mono_runtime_invoke ().
+	 * The method will print the updated value.
+	 */
+	mono_runtime_invoke (method, obj, NULL, NULL);
+
+	/* mono_object_new () doesn't call any constructor: this means that
+	 * we'll have to invoke the constructor if needed ourselves. Note:
+	 * invoking a constructor is no different than calling any other method,
+	 * so we'll still call mono_runtime_invoke (). This also means that we 
+	 * can invoke a constructor at any time, like now.
+	 * First, setup the array of arguments and their values.
+	 */
+
+	/* As usual, we use the address of the data for valuetype arguments */
+	val = 7;
+	args [0] = &val;
+	/* and the pointer for reference types: mono_array_new () returns a MonoArray* */
+	args [1] = mono_array_new (domain, mono_get_byte_class (), 256);
+	mono_runtime_invoke (ctor, obj, args, NULL);
+
+	/* A property exists only as a metadata entity, so getting or setting the value
+	 * is nothing more than calling mono_runtime_invoke () on the getter or setter method.
+	 */
+	prop = mono_class_get_property_from_name (klass, "Value");
+	method = mono_property_get_get_method (prop);
+	result = mono_runtime_invoke (method, obj, NULL, NULL);
+	/* mono_runtime_invoke () always boxes the return value if it's a valuetype */
+	val = *(int*)mono_object_unbox (result);
+	
+	printf ("Value of val from property is: %d\n", val);
+	
+	/* we also have an helper method: note that reference types are returned as is */
+	prop = mono_class_get_property_from_name (klass, "Message");
+	str = (MonoString*)mono_property_get_value (prop, obj, NULL, NULL);
+	/* get the string in UTF-8 encoding to print it */
+	p = mono_string_to_utf8 (str);
+	printf ("Value of str from property is: %s\n", p);
+	/* we need to free the result from mono_string_to_utf8 () */
+	g_free (p);
+
+	/* Now we'll show two things:
+	 * 1) static methods are invoked with mono_runtime_invoke () as well,
+	 * we just pass NULL as the second argument.
+	 * 2) we can catch exceptions thrown by the called method.
+	 * Note: fail is declared as static void Fail () in invoke.cs.
+	 * We first set result to NULL: if after the invocation it will have
+	 * a different value, it will be the exception that was thrown from 
+	 * the Fail () method. Note that if an exception was thrown, the return 
+	 * value (if any) is undefined and can't be used in any way (yes, the above 
+	 * invocations don't have this type of error checking to make things simpler).
+	 */
+	exception = NULL;
+	mono_runtime_invoke (fail, NULL, NULL, &exception);
+	if (exception) {
+		printf ("An exception was thrown in Fail ()\n");
+	}
+
+	/* Now let's see how to handle methods that take by ref arguments:
+	 * Valuetypes continue to be passed as pointers to the data.
+	 * Reference arguments passed by ref (ref or out is the same)
+	 * are handled the same way: a pointer to the pointer is used
+	 * (so that the result can be read back).
+	 * Small note: in this case (a System.Int32 valuetype) we can just
+	 * use &val where val is a C 32 bit integer. In the general case 
+	 * unmanaged code doesn't know the size of a valuetype, since the 
+	 * runtime may decide to lay it out in what it thinks is a better way 
+	 * (unless ExplicitLayout is set). To avoid issues, the best thing is to
+	 * create an object of the valuetype's class and retrieve the pointer 
+	 * to the data with the mono_object_unbox () function.
+	 */
+	val = 100;
+	str = mono_string_new (domain, "another string");
+	args [0] = &val;
+	args [1] = &str;
+	mono_runtime_invoke (mvalues, obj, args, NULL);
+	/* get the string in UTF-8 encoding to print it */
+	p = mono_string_to_utf8 (str);
+	printf ("Values of str/val from Values () are: %s/%d\n", p, val);
+	/* we need to free the result from mono_string_to_utf8 () */
+	g_free (p);
+}
+
+static void
+more_methods (MonoDomain *domain)
+{
+	MonoClass *klass;
+	MonoMethodDesc* mdesc;
+	MonoMethod *method, *vtmethod;
+	MonoString *str;
+	MonoObject *obj;
+	char *p;
+	int val;
+
+	/* Now let's call an instance method on a valuetype. There are two
+	 * different case:
+	 * 1) calling a virtual method defined in a base class, like ToString (): 
+	 * we need to pass the value boxed in an object
+	 * 2) calling a normal instance method: in this case
+	 * we pass the address to the valuetype as the second argument 
+	 * instead of an object.
+	 * First some initialization.
+	 */
+	val = 25;
+	klass = mono_get_int32_class ();
+	obj = mono_value_box (domain, klass, &val);
+
+	/* A different way to search for a method */
+	mdesc = mono_method_desc_new (":ToString()", FALSE);
+	vtmethod = mono_method_desc_search_in_class (mdesc, klass);
+
+	str = (MonoString*)mono_runtime_invoke (vtmethod, &val, NULL, NULL);
+	/* get the string in UTF-8 encoding to print it */
+	p = mono_string_to_utf8 (str);
+	printf ("25.ToString (): %s\n", p);
+	/* we need to free the result from mono_string_to_utf8 () */
+	g_free (p);
+
+	/* Now: see how the result is different if we search for the ToString ()
+	 * method in System.Object: mono_runtime_invoke () doesn't do any sort of
+	 * virtual method invocation: it calls the exact method that it was given 
+	 * to execute. If a virtual call is needed, mono_object_get_virtual_method ()
+	 * can be called.
+	 */
+	method = mono_method_desc_search_in_class (mdesc, mono_get_object_class ());
+	str = (MonoString*)mono_runtime_invoke (method, obj, NULL, NULL);
+	/* get the string in UTF-8 encoding to print it */
+	p = mono_string_to_utf8 (str);
+	printf ("25.ToString (), from System.Object: %s\n", p);
+	/* we need to free the result from mono_string_to_utf8 () */
+	g_free (p);
+
+	/* Now get the method that overrides ToString () in obj */
+	vtmethod = mono_object_get_virtual_method (obj, method);
+	if (mono_class_is_valuetype (mono_method_get_class (vtmethod))) {
+		printf ("Need to unbox this for call to virtual ToString () for %s\n", mono_class_get_name (klass));
+	}
+
+	mono_method_desc_free (mdesc);
+}
+
+static void
+create_object (MonoDomain *domain, MonoImage *image)
+{
+	MonoClass *klass;
+	MonoObject *obj;
+
+	klass = mono_class_from_name (image, "Embed", "MyType");
+	if (!klass) {
+		fprintf (stderr, "Can't find MyType in assembly %s\n", mono_image_get_filename (image));
+		exit (1);
+	}
+
+	obj = mono_object_new (domain, klass);
+	/* mono_object_new () only allocates the storage: 
+	 * it doesn't run any constructor. Tell the runtime to run
+	 * the default argumentless constructor.
+	 */
+	mono_runtime_object_init (obj);
+
+	access_valuetype_field (obj);
+	access_reference_field (obj);
+
+	call_methods (obj);
+	more_methods (domain);
+}
+
+static void main_thread_handler (gpointer user_data)
+{
+	MainThreadArgs *main_args=(MainThreadArgs *)user_data;
+	MonoAssembly *assembly;
+
+	/* Loading an assembly makes the runtime setup everything
+	 * needed to execute it. If we're just interested in the metadata
+	 * we'd use mono_image_load (), instead and we'd get a MonoImage*.
+	 */
+	assembly = mono_domain_assembly_open (main_args->domain,
+					      main_args->file);
+	if (!assembly)
+		exit (2);
+	/*
+	 * mono_jit_exec() will run the Main() method in the assembly.
+	 * The return value needs to be looked up from
+	 * System.Environment.ExitCode.
+	 */
+	mono_jit_exec (main_args->domain, assembly, main_args->argc,
+		       main_args->argv);
+
+	create_object (main_args->domain, mono_assembly_get_image (assembly));
+}
+
+int 
+main (int argc, char* argv[]) {
+	MonoDomain *domain;
+	const char *file;
+	int retval;
+	MainThreadArgs main_args;
+	
+	if (argc < 2){
+		fprintf (stderr, "Please provide an assembly to load\n");
+		return 1;
+	}
+	file = argv [1];
+	/*
+	 * mono_jit_init() creates a domain: each assembly is
+	 * loaded and run in a MonoDomain.
+	 */
+	domain = mono_jit_init (file);
+
+	main_args.domain=domain;
+	main_args.file=file;
+	main_args.argc=argc-1;
+	main_args.argv=argv+1;
+	
+	mono_runtime_exec_managed_code (domain, main_thread_handler,
+					&main_args);
+	
+	retval=mono_environment_exitcode_get ();
+	
+	mono_jit_cleanup (domain);
+	return retval;
+}
+