X-Git-Url: http://deadsoftware.ru/gitweb?a=blobdiff_plain;f=oberon.c;h=3837bf5b92702c744bcf7b883ff73395826063a8;hb=518cba11c21426f922afef90048f5f9c8130fed2;hp=2b4e09f5e8a3ca7e95e4923a6d4773fa9e5202bf;hpb=42da6ba15843521d2b18994d863f2ec3d2672a97;p=dsw-obn.git

diff --git a/oberon.c b/oberon.c
index 2b4e09f..3837bf5 100644
--- a/oberon.c
+++ b/oberon.c
@@ -48,7 +48,11 @@ enum {
 	OF,
 	LBRACE,
 	RBRACE,
-	RECORD
+	RECORD,
+	POINTER,
+	TO,
+	UPARROW,
+	NIL
 };
 
 // =======================================================================
@@ -170,8 +174,6 @@ oberon_define_field(oberon_context_t * ctx, oberon_type_t * rec, char *  name, o
 	field -> type = type;
 
 	rec -> num_decl += 1;
-	oberon_generator_init_var(ctx, field);
-
 	x -> next = field;
 }
 
@@ -187,7 +189,7 @@ oberon_find_object_in_list(oberon_object_t * list, char * name)
 }
 
 static oberon_object_t *
-oberon_find_object(oberon_scope_t * scope, char * name)
+oberon_find_object(oberon_scope_t * scope, char * name, int check_it)
 {
 	oberon_object_t * result = NULL;
 
@@ -198,7 +200,7 @@ oberon_find_object(oberon_scope_t * scope, char * name)
 		s = s -> up;
 	}
 
-	if(result == NULL)
+	if(check_it && result == NULL)
 	{
 		oberon_error(scope -> ctx, "undefined ident %s", name);
 	}
@@ -234,6 +236,7 @@ oberon_define_type(oberon_scope_t * scope, char * name, oberon_type_t * type)
 	return id;
 }
 
+/*
 static oberon_type_t *
 oberon_find_type(oberon_scope_t * scope, char * name)
 {
@@ -245,6 +248,7 @@ oberon_find_type(oberon_scope_t * scope, char * name)
 
 	return x -> type;
 }
+*/
 
 static oberon_object_t *
 oberon_define_var(oberon_scope_t * scope, int class, char * name, oberon_type_t * type)
@@ -252,7 +256,6 @@ oberon_define_var(oberon_scope_t * scope, int class, char * name, oberon_type_t
 	oberon_object_t * var;
 	var = oberon_define_object(scope, name, class);
 	var -> type = type;
-	oberon_generator_init_var(scope -> ctx, var);
 	return var;
 }
 
@@ -277,7 +280,6 @@ oberon_define_proc(oberon_scope_t * scope, char * name, oberon_type_t * signatur
 	oberon_object_t * proc;
 	proc = oberon_define_object(scope, name, OBERON_CLASS_PROC);
 	proc -> type = signature;
-	oberon_generator_init_proc(scope -> ctx, proc);
 	return proc;
 }
 
@@ -387,6 +389,18 @@ oberon_read_ident(oberon_context_t * ctx)
 	{
 		ctx -> token = RECORD;
 	}
+	else if(strcmp(ident, "POINTER") == 0)
+	{
+		ctx -> token = POINTER;
+	}
+	else if(strcmp(ident, "TO") == 0)
+	{
+		ctx -> token = TO;
+	}
+	else if(strcmp(ident, "NIL") == 0)
+	{
+		ctx -> token = NIL;
+	}
 }
 
 static void
@@ -519,6 +533,10 @@ oberon_read_symbol(oberon_context_t * ctx)
 			ctx -> token = RBRACE;
 			oberon_get_char(ctx);
 			break;
+		case '^':
+			ctx -> token = UPARROW;
+			oberon_get_char(ctx);
+			break;
 		default:
 			oberon_error(ctx, "invalid char");
 			break;
@@ -553,7 +571,8 @@ static void oberon_expect_token(oberon_context_t * ctx, int token);
 static oberon_expr_t * oberon_expr(oberon_context_t * ctx);
 static void oberon_assert_token(oberon_context_t * ctx, int token);
 static char * oberon_assert_ident(oberon_context_t * ctx);
-static oberon_type_t * oberon_type(oberon_context_t * ctx);
+static void oberon_type(oberon_context_t * ctx, oberon_type_t ** type);
+static oberon_item_t * oberon_const_expr(oberon_context_t * ctx);
 
 static oberon_expr_t *
 oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon_expr_t * right)
@@ -620,7 +639,7 @@ oberon_make_unary_op(oberon_context_t * ctx, int token, oberon_expr_t * a)
 }
 
 static void
-oberon_expr_list(oberon_context_t * ctx, int * num_expr, oberon_expr_t ** first)
+oberon_expr_list(oberon_context_t * ctx, int * num_expr, oberon_expr_t ** first, int const_expr)
 {
 	oberon_expr_t * last;
 
@@ -630,7 +649,16 @@ oberon_expr_list(oberon_context_t * ctx, int * num_expr, oberon_expr_t ** first)
 	{
 		oberon_assert_token(ctx, COMMA);
 		oberon_expr_t * current;
-		current = oberon_expr(ctx);
+
+		if(const_expr)
+		{
+			current = (oberon_expr_t *) oberon_const_expr(ctx);
+		}
+		else
+		{
+			current = oberon_expr(ctx);
+		}
+
 		last -> next = current;
 		last = current;
 		*num_expr += 1;
@@ -645,7 +673,6 @@ oberon_autocast_to(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t *
 		oberon_error(ctx, "incompatible types");
 	}
 
-
 	if(pref -> class == OBERON_TYPE_INTEGER)
 	{
 		if(expr -> result -> class > pref -> class)
@@ -653,6 +680,24 @@ oberon_autocast_to(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t *
 			oberon_error(ctx, "incompatible size");
 		}
 	}
+	else if(pref -> class == OBERON_TYPE_RECORD)
+	{
+		if(expr -> result != pref)
+		{
+			printf("oberon_autocast_to: rec %p != %p\n", expr -> result, pref);
+			oberon_error(ctx, "incompatible record types");
+		}
+	}
+	else if(pref -> class == OBERON_TYPE_POINTER)
+	{
+		if(expr -> result -> base != pref -> base)
+		{
+			if(expr -> result -> base -> class != OBERON_TYPE_VOID)
+			{
+				oberon_error(ctx, "incompatible pointer types");
+			}
+		}
+	}
 
 	// TODO cast
 
@@ -694,6 +739,24 @@ oberon_autocast_call(oberon_context_t * ctx, oberon_expr_t * desig)
 	oberon_object_t * param = fn -> decl;
 	for(int i = 0; i < num_args; i++)
 	{
+		if(param -> class == OBERON_CLASS_VAR_PARAM)
+		{
+			if(arg -> is_item)
+			{
+				switch(arg -> item.mode)
+				{
+					case MODE_VAR:
+					case MODE_INDEX:
+					case MODE_FIELD:
+					// Допустимо разыменование?
+					//case MODE_DEREF:
+						break;
+					default:
+						oberon_error(ctx, "var-parameter accept only variables");
+						break;
+				}
+			}
+		}
 		oberon_autocast_to(ctx, arg, param -> type);
 		arg = arg -> next;
 		param = param -> next;
@@ -710,51 +773,65 @@ oberon_autocast_call(oberon_context_t * ctx, oberon_expr_t * desig)
 	|| ((x) == TRUE) \
 	|| ((x) == FALSE))
 
-#define ISSELECTOR(x) \
-	(((x) == LBRACE) \
-	|| ((x) == DOT))
-
 static oberon_expr_t *
-oberon_make_array_selector(oberon_context_t * ctx, oberon_expr_t * desig, int num_indexes, oberon_expr_t * indexes)
+oberno_make_dereferencing(oberon_context_t * ctx, oberon_expr_t * expr)
 {
-	assert(desig -> is_item == 1);
-
-	if(desig -> item.mode != MODE_VAR)
+	if(expr -> result -> class != OBERON_TYPE_POINTER)
 	{
-		oberon_error(ctx, "not MODE_VAR");
+		oberon_error(ctx, "not a pointer");
 	}
 
-	int class = desig -> item.var -> class;
-	switch(class)
+	assert(expr -> is_item);
+
+	oberon_expr_t * selector;
+	selector = oberon_new_item(MODE_DEREF, expr -> result -> base);
+	selector -> item.parent = (oberon_item_t *) expr;
+
+	return selector;
+}
+
+static oberon_expr_t *
+oberon_make_array_selector(oberon_context_t * ctx, oberon_expr_t * desig, oberon_expr_t * index)
+{
+	if(desig -> result -> class == OBERON_TYPE_POINTER)
 	{
-		case OBERON_CLASS_VAR:
-		case OBERON_CLASS_VAR_PARAM:
-		case OBERON_CLASS_PARAM:
-			break;
-		default:
-			oberon_error(ctx, "not variable");
-			break;
+		desig = oberno_make_dereferencing(ctx, desig);
 	}
 
-	oberon_type_t * type = desig -> item.var -> type;
-	if(type -> class != OBERON_TYPE_ARRAY)
+	assert(desig -> is_item);
+
+	if(desig -> result -> class != OBERON_TYPE_ARRAY)
 	{
 		oberon_error(ctx, "not array");
 	}
 
-	int dim = desig -> item.var -> type -> dim;
-	if(num_indexes != dim)
+	oberon_type_t * base;
+	base = desig -> result -> base;
+
+	if(index -> result -> class != OBERON_TYPE_INTEGER)
 	{
-		oberon_error(ctx, "dimesions not matched");
+		oberon_error(ctx, "index must be integer");
 	}
 
-	oberon_type_t * base = desig -> item.var -> type -> base;
+	// Статическая проверка границ массива
+	if(index -> is_item)
+	{
+		if(index -> item.mode == MODE_INTEGER)
+		{
+			int arr_size = desig -> result -> size;
+			int index_int = index -> item.integer;
+			if(index_int < 0 || index_int > arr_size - 1)
+			{
+				oberon_error(ctx, "not in range (dimension size 0..%i)", arr_size - 1);
+			}
+		}
+	}
 
 	oberon_expr_t * selector;
 	selector = oberon_new_item(MODE_INDEX, base);
 	selector -> item.parent = (oberon_item_t *) desig;
-	selector -> item.num_args = num_indexes;
-	selector -> item.args = indexes;
+	selector -> item.num_args = 1;
+	selector -> item.args = index;
 
 	return selector;
 }
@@ -762,10 +839,14 @@ oberon_make_array_selector(oberon_context_t * ctx, oberon_expr_t * desig, int nu
 static oberon_expr_t *
 oberon_make_record_selector(oberon_context_t * ctx, oberon_expr_t * expr, char * name)
 {
+	if(expr -> result -> class == OBERON_TYPE_POINTER)
+	{
+		expr = oberno_make_dereferencing(ctx, expr);
+	}
+
 	assert(expr -> is_item == 1);
 
-	int class = expr -> result -> class;
-	if(class != OBERON_TYPE_RECORD)
+	if(expr -> result -> class != OBERON_TYPE_RECORD)
 	{
 		oberon_error(ctx, "not record");
 	}
@@ -783,6 +864,11 @@ oberon_make_record_selector(oberon_context_t * ctx, oberon_expr_t * expr, char *
 	return selector;
 }
 
+#define ISSELECTOR(x) \
+	(((x) == LBRACE) \
+	|| ((x) == DOT) \
+	|| ((x) == UPARROW))
+
 static oberon_expr_t *
 oberon_designator(oberon_context_t * ctx)
 {
@@ -791,7 +877,7 @@ oberon_designator(oberon_context_t * ctx)
 	oberon_expr_t * expr;
 
 	name = oberon_assert_ident(ctx);
-	var = oberon_find_object(ctx -> decl, name);
+	var = oberon_find_object(ctx -> decl, name, 1);
 
 	switch(var -> class)
 	{
@@ -826,9 +912,18 @@ oberon_designator(oberon_context_t * ctx)
 				oberon_assert_token(ctx, LBRACE);
 				int num_indexes = 0;
 				oberon_expr_t * indexes = NULL;
-				oberon_expr_list(ctx, &num_indexes, &indexes);
+				oberon_expr_list(ctx, &num_indexes, &indexes, 0);
 				oberon_assert_token(ctx, RBRACE);
-				expr = oberon_make_array_selector(ctx, expr, num_indexes, indexes);
+
+				for(int i = 0; i < num_indexes; i++)
+				{
+					expr = oberon_make_array_selector(ctx, expr, indexes);
+					indexes = indexes -> next;
+				}
+				break;
+			case UPARROW:
+				oberon_assert_token(ctx, UPARROW);
+				expr = oberno_make_dereferencing(ctx, expr);
 				break;
 			default:
 				oberon_error(ctx, "oberon_designator: wat");
@@ -857,7 +952,7 @@ oberon_opt_proc_parens(oberon_context_t * ctx, oberon_expr_t * expr)
 
 		if(ISEXPR(ctx -> token))
 		{
-			oberon_expr_list(ctx, &num_args, &arguments);
+			oberon_expr_list(ctx, &num_args, &arguments, 0);
 		}
 
 		expr -> result = expr -> item.var -> type -> base;
@@ -908,6 +1003,10 @@ oberon_factor(oberon_context_t * ctx)
 			expr = oberon_factor(ctx);
 			expr = oberon_make_unary_op(ctx, NOT, expr);
 			break;
+		case NIL:
+			oberon_assert_token(ctx, NIL);
+			expr = oberon_new_item(MODE_NIL, ctx -> void_ptr_type);
+			break;
 		default:
 			oberon_error(ctx, "invalid expression");
 	}
@@ -1158,6 +1257,7 @@ oberon_const_expr(oberon_context_t * ctx)
 //   PARSER
 // =======================================================================
 
+static void oberon_decl_seq(oberon_context_t * ctx);
 static void oberon_statement_seq(oberon_context_t * ctx);
 
 static void
@@ -1185,100 +1285,16 @@ oberon_assert_ident(oberon_context_t * ctx)
 	return ident;
 }
 
-static oberon_type_t *
-oberon_make_array_type(oberon_context_t * ctx, int dim, oberon_item_t * size, oberon_type_t * base)
-{
-	assert(dim == 1);
-	oberon_type_t * newtype;
-
-	if(size -> mode != MODE_INTEGER)
-	{
-		oberon_error(ctx, "requires integer constant");
-	}
-
-	newtype = oberon_new_type_ptr(OBERON_TYPE_ARRAY);
-	newtype -> dim = dim;
-	newtype -> size = size -> integer;
-	newtype -> base = base;
-	oberon_generator_init_type(ctx, newtype);
-
-	return newtype;
-}
-
 static void
-oberon_field_list(oberon_context_t * ctx, oberon_type_t * rec)
-{
-	if(ctx -> token == IDENT)
-	{
-		char * name;
-		oberon_type_t * type;
-		name = oberon_assert_ident(ctx);
-		oberon_assert_token(ctx, COLON);
-		type = oberon_type(ctx);
-		oberon_define_field(ctx, rec, name, type);
-	}
-}
-
-static oberon_type_t * oberon_opt_formal_pars(oberon_context_t * ctx, int class);
-
-static oberon_type_t *
-oberon_type(oberon_context_t * ctx)
+oberon_var_decl(oberon_context_t * ctx)
 {
+	char * name;
 	oberon_type_t * type;
+	type = oberon_new_type_ptr(OBERON_TYPE_VOID);
 
-	if(ctx -> token == IDENT)
-	{
-		char * name = oberon_assert_ident(ctx);
-		type = oberon_find_type(ctx -> decl, name);
-	}
-	else if(ctx -> token == ARRAY)
-	{
-		oberon_assert_token(ctx, ARRAY);
-		oberon_item_t * size = oberon_const_expr(ctx);
-		oberon_assert_token(ctx, OF);
-		oberon_type_t * base = oberon_type(ctx);
-		type = oberon_make_array_type(ctx, 1, size, base);
-	}
-	else if(ctx -> token == RECORD)
-	{
-		type = oberon_new_type_ptr(OBERON_TYPE_RECORD);
-		oberon_object_t * list = malloc(sizeof *list);
-	        memset(list, 0, sizeof *list);
-		type -> num_decl = 0;
-		type -> base = NULL;
-		type -> decl = list;
-
-		oberon_assert_token(ctx, RECORD);
-		oberon_field_list(ctx, type);
-		while(ctx -> token == SEMICOLON)
-		{
-			oberon_assert_token(ctx, SEMICOLON);
-			oberon_field_list(ctx, type);
-		}
-		oberon_assert_token(ctx, END);
-
-		type -> decl = type -> decl -> next;
-		oberon_generator_init_type(ctx, type);
-	}
-	else if(ctx -> token == PROCEDURE)
-	{
-		oberon_assert_token(ctx, PROCEDURE);
-		type = oberon_opt_formal_pars(ctx, OBERON_TYPE_PROCEDURE);
-	}
-	else
-	{
-		oberon_error(ctx, "invalid type declaration");
-	}
-
-	return type;
-}
-
-static void
-oberon_var_decl(oberon_context_t * ctx)
-{
-	char * name = oberon_assert_ident(ctx);
+	name = oberon_assert_ident(ctx);
 	oberon_assert_token(ctx, COLON);
-	oberon_type_t * type = oberon_type(ctx);
+	oberon_type(ctx, &type);
 	oberon_define_var(ctx -> decl, OBERON_CLASS_VAR, name, type);
 }
 
@@ -1318,7 +1334,8 @@ oberon_fp_section(oberon_context_t * ctx, int * num_decl)
 	oberon_assert_token(ctx, COLON);
 
 	oberon_type_t * type;
-	type = oberon_type(ctx);
+	type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+	oberon_type(ctx, &type);
 
 	oberon_object_t * first;
 	first = oberon_make_param(ctx, modifer_token, name, type);
@@ -1330,24 +1347,18 @@ oberon_fp_section(oberon_context_t * ctx, int * num_decl)
 #define ISFPSECTION \
 	((ctx -> token == VAR) || (ctx -> token == IDENT))
 
-static oberon_type_t *
-oberon_formal_pars(oberon_context_t * ctx)
+static void
+oberon_formal_pars(oberon_context_t * ctx, oberon_type_t * signature)
 {
-	oberon_type_t * tp;
-	tp = oberon_new_type_ptr(OBERON_TYPE_PROCEDURE);
-	tp -> num_decl = 0;
-	tp -> base = ctx -> void_type;
-	tp -> decl = NULL;
-
 	oberon_assert_token(ctx, LPAREN);
 
 	if(ISFPSECTION)
 	{
-		tp -> decl = oberon_fp_section(ctx, &tp -> num_decl);
+		signature -> decl = oberon_fp_section(ctx, &signature -> num_decl);
 		while(ctx -> token == SEMICOLON)
 		{
 			oberon_assert_token(ctx, SEMICOLON);
-			oberon_fp_section(ctx, &tp -> num_decl);
+			oberon_fp_section(ctx, &signature -> num_decl);
 		}
 	}
 
@@ -1356,32 +1367,25 @@ oberon_formal_pars(oberon_context_t * ctx)
 	if(ctx -> token == COLON)
 	{
 		oberon_assert_token(ctx, COLON);
-		tp -> base = oberon_type(ctx);
+		// TODO get by qualident
+		oberon_type(ctx, &signature -> base);
 	}
-
-	oberon_generator_init_type(ctx, tp);
-	return tp;
 }
 
-static oberon_type_t *
-oberon_opt_formal_pars(oberon_context_t * ctx, int class)
+static void
+oberon_opt_formal_pars(oberon_context_t * ctx, oberon_type_t ** type)
 {
 	oberon_type_t * signature;
+	signature = *type;
+	signature -> class = OBERON_TYPE_PROCEDURE;
+	signature -> num_decl = 0;
+	signature -> base = ctx -> void_type;
+	signature -> decl = NULL;
 
 	if(ctx -> token == LPAREN)
 	{
-		signature = oberon_formal_pars(ctx);
+		oberon_formal_pars(ctx, signature);
 	}
-	else
-	{
-		signature = oberon_new_type_ptr(class);
-		signature -> num_decl = 0;
-		signature -> base = ctx -> void_type;
-		signature -> decl = NULL;
-		oberon_generator_init_type(ctx, signature);
-	}
-
-	return signature;
 }
 
 static void
@@ -1421,7 +1425,8 @@ oberon_proc_decl(oberon_context_t * ctx)
 	oberon_open_scope(ctx);
 
 	oberon_type_t * signature;
-	signature = oberon_opt_formal_pars(ctx, OBERON_TYPE_PROCEDURE);
+	signature = oberon_new_type_ptr(OBERON_TYPE_VOID);
+	oberon_opt_formal_pars(ctx, &signature);
 
 	oberon_object_t * proc;
 	proc = oberon_define_proc(this_proc_def_scope, name, signature);
@@ -1431,9 +1436,11 @@ oberon_proc_decl(oberon_context_t * ctx)
 
 	oberon_assert_token(ctx, SEMICOLON);
 
-	oberon_generate_begin_proc(ctx, proc);
+	oberon_decl_seq(ctx);
+	oberon_generator_init_type(ctx, signature);
+	oberon_generator_init_proc(ctx, proc);
 
-	// TODO declarations
+	oberon_generate_begin_proc(ctx, proc);
 
 	if(ctx -> token == BEGIN)
 	{
@@ -1478,6 +1485,163 @@ oberon_const_decl(oberon_context_t * ctx)
 	constant -> value = value;
 }
 
+static void
+oberon_make_array_type(oberon_context_t * ctx, oberon_expr_t * size, oberon_type_t * base, oberon_type_t ** type)
+{
+	if(size -> is_item == 0)
+	{
+		oberon_error(ctx, "requires constant");
+	}
+
+	if(size -> item.mode != MODE_INTEGER)
+	{
+		oberon_error(ctx, "requires integer constant");
+	}
+
+	oberon_type_t * arr;
+	arr = *type;
+	arr -> class = OBERON_TYPE_ARRAY;
+	arr -> size = size -> item.integer;
+	arr -> base = base;
+}
+
+static void
+oberon_field_list(oberon_context_t * ctx, oberon_type_t * rec)
+{
+	if(ctx -> token == IDENT)
+	{
+		char * name;
+		oberon_type_t * type;
+		type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+
+		name = oberon_assert_ident(ctx);
+		oberon_assert_token(ctx, COLON);
+		oberon_type(ctx, &type);
+		oberon_define_field(ctx, rec, name, type);
+	}
+}
+
+static void
+oberon_qualident_type(oberon_context_t * ctx, oberon_type_t ** type)
+{
+	char * name;
+	oberon_object_t * to;
+
+	name = oberon_assert_ident(ctx);
+	to = oberon_find_object(ctx -> decl, name, 0);
+
+	if(to != NULL)
+	{
+		if(to -> class != OBERON_CLASS_TYPE)
+		{
+			oberon_error(ctx, "not a type");
+		}
+	}
+	else
+	{
+		to = oberon_define_object(ctx -> decl, name, OBERON_CLASS_TYPE);
+		to -> type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+	}
+
+	*type = to -> type;
+}
+
+static void oberon_opt_formal_pars(oberon_context_t * ctx, oberon_type_t ** type);
+
+/*
+ * Правило граматики "type". Указатель type должен указывать на существующий объект!
+ */
+
+static void
+oberon_make_multiarray(oberon_context_t * ctx, oberon_expr_t * sizes, oberon_type_t * base, oberon_type_t ** type)
+{
+	if(sizes == NULL)
+	{
+		*type = base;
+		return;
+	}
+
+	oberon_type_t * dim;
+	dim = oberon_new_type_ptr(OBERON_TYPE_VOID);
+
+	oberon_make_multiarray(ctx, sizes -> next, base, &dim);
+
+	oberon_make_array_type(ctx, sizes, dim, type);
+}
+
+static void
+oberon_type(oberon_context_t * ctx, oberon_type_t ** type)
+{
+	if(ctx -> token == IDENT)
+	{
+		oberon_qualident_type(ctx, type);
+	}
+	else if(ctx -> token == ARRAY)
+	{
+		oberon_assert_token(ctx, ARRAY);
+
+		int num_sizes = 0;
+		oberon_expr_t * sizes;
+		oberon_expr_list(ctx, &num_sizes, &sizes, 1);
+
+		oberon_assert_token(ctx, OF);
+
+		oberon_type_t * base;
+		base = oberon_new_type_ptr(OBERON_TYPE_VOID);
+		oberon_type(ctx, &base);
+
+		oberon_make_multiarray(ctx, sizes, base, type);
+	}
+	else if(ctx -> token == RECORD)
+	{
+		oberon_type_t * rec;
+		rec = *type;
+		rec -> class = OBERON_TYPE_RECORD;
+		oberon_object_t * list = malloc(sizeof *list);
+	        memset(list, 0, sizeof *list);
+		rec -> num_decl = 0;
+		rec -> base = NULL;
+		rec -> decl = list;
+
+		oberon_assert_token(ctx, RECORD);
+		oberon_field_list(ctx, rec);
+		while(ctx -> token == SEMICOLON)
+		{
+			oberon_assert_token(ctx, SEMICOLON);
+			oberon_field_list(ctx, rec);
+		}
+		oberon_assert_token(ctx, END);
+
+		rec -> decl = rec -> decl -> next;
+		*type = rec;
+	}
+	else if(ctx -> token == POINTER)
+	{
+		oberon_assert_token(ctx, POINTER);
+		oberon_assert_token(ctx, TO);
+
+		oberon_type_t * base;
+		base = oberon_new_type_ptr(OBERON_TYPE_VOID);
+		oberon_type(ctx, &base);
+
+		oberon_type_t * ptr;
+		ptr = *type;
+		ptr -> class = OBERON_TYPE_POINTER;
+		ptr -> base = base;
+	}
+	else if(ctx -> token == PROCEDURE)
+	{
+		oberon_open_scope(ctx);
+		oberon_assert_token(ctx, PROCEDURE);
+		oberon_opt_formal_pars(ctx, type);
+		oberon_close_scope(ctx -> decl);
+	}
+	else
+	{
+		oberon_error(ctx, "invalid type declaration");
+	}
+}
+
 static void
 oberon_type_decl(oberon_context_t * ctx)
 {
@@ -1486,11 +1650,305 @@ oberon_type_decl(oberon_context_t * ctx)
 	oberon_type_t * type;
 
 	name = oberon_assert_ident(ctx);
+
+	newtype = oberon_find_object(ctx -> decl, name, 0);
+	if(newtype == NULL)
+	{
+		newtype = oberon_define_object(ctx -> decl, name, OBERON_CLASS_TYPE);
+		newtype -> type = oberon_new_type_ptr(OBERON_TYPE_VOID);
+		assert(newtype -> type);
+	}
+	else
+	{
+		if(newtype -> class != OBERON_CLASS_TYPE)
+		{
+			oberon_error(ctx, "mult definition");
+		}
+
+		if(newtype -> linked)
+		{
+			oberon_error(ctx, "mult definition - already linked");
+		}
+	}
+
 	oberon_assert_token(ctx, EQUAL);
-	type = oberon_type(ctx);
 
-	newtype = oberon_define_object(ctx -> decl, name, OBERON_CLASS_TYPE);
+	type = newtype -> type;
+	oberon_type(ctx, &type);
+
+	if(type -> class == OBERON_TYPE_VOID)
+	{
+		oberon_error(ctx, "recursive alias declaration");
+	}
+
 	newtype -> type = type;
+	newtype -> linked = 1;
+}
+
+static void oberon_prevent_recursive_object(oberon_context_t * ctx, oberon_object_t * x);
+static void oberon_prevent_recursive_type(oberon_context_t * ctx, oberon_type_t * type);
+
+static void
+oberon_prevent_recursive_pointer(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class != OBERON_TYPE_POINTER
+		&& type -> class != OBERON_TYPE_ARRAY)
+	{
+		return;
+	}
+
+	if(type -> recursive)
+	{
+		oberon_error(ctx, "recursive pointer declaration");
+	}
+
+	if(type -> base -> class == OBERON_TYPE_POINTER)
+	{
+		oberon_error(ctx, "attempt to make pointer to pointer");
+	}
+
+	type -> recursive = 1;
+
+	oberon_prevent_recursive_pointer(ctx, type -> base);
+
+	type -> recursive = 0;
+}
+
+static void
+oberon_prevent_recursive_record(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class != OBERON_TYPE_RECORD)
+	{
+		return;
+	}
+
+	if(type -> recursive)
+	{
+		oberon_error(ctx, "recursive record declaration");
+	}
+
+	type -> recursive = 1;
+
+	int num_fields = type -> num_decl;
+	oberon_object_t * field = type -> decl;
+	for(int i = 0; i < num_fields; i++)
+	{
+		oberon_prevent_recursive_object(ctx, field);
+		field = field -> next;
+	}
+
+	type -> recursive = 0;	
+}
+static void
+oberon_prevent_recursive_procedure(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class != OBERON_TYPE_PROCEDURE)
+	{
+		return;
+	}
+
+	if(type -> recursive)
+	{
+		oberon_error(ctx, "recursive procedure declaration");
+	}
+
+	type -> recursive = 1;
+
+	int num_fields = type -> num_decl;
+	oberon_object_t * field = type -> decl;
+	for(int i = 0; i < num_fields; i++)
+	{
+		oberon_prevent_recursive_object(ctx, field);
+		field = field -> next;
+	}
+
+	type -> recursive = 0;	
+}
+
+static void
+oberon_prevent_recursive_array(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class != OBERON_TYPE_ARRAY)
+	{
+		return;
+	}
+
+	if(type -> recursive)
+	{
+		oberon_error(ctx, "recursive array declaration");
+	}
+
+	type -> recursive = 1;
+
+	oberon_prevent_recursive_type(ctx, type -> base);
+
+	type -> recursive = 0;
+}
+
+static void
+oberon_prevent_recursive_type(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class == OBERON_TYPE_POINTER)
+	{
+		oberon_prevent_recursive_pointer(ctx, type);
+	}
+	else if(type -> class == OBERON_TYPE_RECORD)
+	{
+		oberon_prevent_recursive_record(ctx, type);
+	}
+	else if(type -> class == OBERON_TYPE_ARRAY)
+	{
+		oberon_prevent_recursive_array(ctx, type);
+	}
+	else if(type -> class == OBERON_TYPE_PROCEDURE)
+	{
+		oberon_prevent_recursive_procedure(ctx, type);
+	}
+}
+
+static void
+oberon_prevent_recursive_object(oberon_context_t * ctx, oberon_object_t * x)
+{
+	switch(x -> class)
+	{
+		case OBERON_CLASS_VAR:
+		case OBERON_CLASS_TYPE:
+		case OBERON_CLASS_PARAM:
+		case OBERON_CLASS_VAR_PARAM:
+		case OBERON_CLASS_FIELD:
+			oberon_prevent_recursive_type(ctx, x -> type);
+			break;
+		case OBERON_CLASS_CONST:
+		case OBERON_CLASS_PROC:
+			break;
+		default:
+			oberon_error(ctx, "oberon_prevent_recursive_object: wat");
+			break;
+	}
+}
+
+static void
+oberon_prevent_recursive_decl(oberon_context_t * ctx)
+{
+	oberon_object_t * x = ctx -> decl -> list -> next;
+
+	while(x)
+	{
+		oberon_prevent_recursive_object(ctx, x);
+		x = x -> next;
+	}
+}
+
+static void oberon_initialize_object(oberon_context_t * ctx, oberon_object_t * x);
+static void oberon_initialize_type(oberon_context_t * ctx, oberon_type_t * type);
+
+static void
+oberon_initialize_record_fields(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class != OBERON_TYPE_RECORD)
+	{
+		return;
+	}
+
+	int num_fields = type -> num_decl;
+	oberon_object_t * field = type -> decl;
+	for(int i = 0; i < num_fields; i++)
+	{
+		if(field -> type -> class == OBERON_TYPE_POINTER)
+		{
+			oberon_initialize_type(ctx, field -> type);
+		}
+
+		oberon_initialize_object(ctx, field);
+		field = field -> next;
+	}
+
+	oberon_generator_init_record(ctx, type);
+}
+
+static void
+oberon_initialize_type(oberon_context_t * ctx, oberon_type_t * type)
+{
+	if(type -> class == OBERON_TYPE_VOID)
+	{
+		oberon_error(ctx, "undeclarated type");
+	}
+
+	if(type -> initialized)
+	{
+		return;
+	}
+
+	type -> initialized = 1;
+
+	if(type -> class == OBERON_TYPE_POINTER)
+	{
+		oberon_initialize_type(ctx, type -> base);
+		oberon_generator_init_type(ctx, type);
+	}
+	else if(type -> class == OBERON_TYPE_ARRAY)
+	{
+		oberon_initialize_type(ctx, type -> base);		
+		oberon_generator_init_type(ctx, type);
+	}
+	else if(type -> class == OBERON_TYPE_RECORD)
+	{
+		oberon_generator_init_type(ctx, type);
+		oberon_initialize_record_fields(ctx, type);
+	}
+	else if(type -> class == OBERON_TYPE_PROCEDURE)
+	{
+		int num_fields = type -> num_decl;
+		oberon_object_t * field = type -> decl;
+		for(int i = 0; i < num_fields; i++)
+		{
+			oberon_initialize_object(ctx, field);
+			field = field -> next;
+		}		
+
+		oberon_generator_init_type(ctx, type);
+	}
+	else
+	{
+		oberon_generator_init_type(ctx, type);
+	}
+}
+
+static void
+oberon_initialize_object(oberon_context_t * ctx, oberon_object_t * x)
+{
+	printf("oberon_initialize_object: name %s class %i\n", x -> name, x -> class);
+	switch(x -> class)
+	{
+		case OBERON_CLASS_TYPE:
+			oberon_initialize_type(ctx, x -> type);
+			break;
+		case OBERON_CLASS_VAR:
+		case OBERON_CLASS_PARAM:
+		case OBERON_CLASS_VAR_PARAM:
+		case OBERON_CLASS_FIELD:
+			oberon_initialize_type(ctx, x -> type);
+			oberon_generator_init_var(ctx, x);
+			break;
+		case OBERON_CLASS_CONST:
+		case OBERON_CLASS_PROC:
+			break;
+		default:
+			oberon_error(ctx, "oberon_prevent_recursive_object: wat");
+			break;
+	}
+}
+
+static void
+oberon_initialize_decl(oberon_context_t * ctx)
+{
+	oberon_object_t * x = ctx -> decl -> list;
+
+	while(x -> next)
+	{
+		oberon_initialize_object(ctx, x -> next);
+		x = x -> next;
+	}	
 }
 
 static void
@@ -1526,6 +1984,9 @@ oberon_decl_seq(oberon_context_t * ctx)
 		}
 	}
 
+	oberon_prevent_recursive_decl(ctx);
+	oberon_initialize_decl(ctx);
+
 	while(ctx -> token == PROCEDURE)
 	{
 		oberon_proc_decl(ctx);
@@ -1543,6 +2004,11 @@ oberon_assign(oberon_context_t * ctx, oberon_expr_t * src, oberon_expr_t * dst)
 static void
 oberon_make_call(oberon_context_t * ctx, oberon_expr_t * desig)
 {
+	if(desig -> result -> class != OBERON_TYPE_VOID)
+	{
+		oberon_error(ctx, "procedure with result");
+	}
+
 	oberon_autocast_call(ctx, desig);
 	oberon_generate_call_proc(ctx, desig);
 }
@@ -1636,6 +2102,10 @@ register_default_types(oberon_context_t * ctx)
 	ctx -> void_type = oberon_new_type_ptr(OBERON_TYPE_VOID);
 	oberon_generator_init_type(ctx, ctx -> void_type);
 
+	ctx -> void_ptr_type = oberon_new_type_ptr(OBERON_TYPE_POINTER);
+	ctx -> void_ptr_type -> base = ctx -> void_type;
+	oberon_generator_init_type(ctx, ctx -> void_ptr_type);
+
 	ctx -> int_type = oberon_new_type_integer(sizeof(int));
 	oberon_define_type(ctx -> world_scope, "INTEGER", ctx -> int_type);