DEADSOFTWARE

Реализованы неявные объявления типов наперёд
[dsw-obn.git] / oberon.c
index 7ca600e205a26e377f25bea0de64ff7ad0c758cf..847e9c77e65a4352cadb204f4948076f8b19ba82 100644 (file)
--- a/oberon.c
+++ b/oberon.c
@@ -172,8 +172,6 @@ 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;
 }
 
@@ -189,7 +187,7 @@ 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;
 
@@ -200,7 +198,7 @@ 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);
        }
@@ -236,6 +234,7 @@ 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)
 {
@@ -247,6 +246,7 @@ 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)
@@ -254,7 +254,6 @@ 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;
 }
 
@@ -279,7 +278,6 @@ 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;
 }
 
@@ -563,7 +561,7 @@ 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_expr_t *
 oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon_expr_t * right)
@@ -809,7 +807,7 @@ 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)
        {
@@ -1203,132 +1201,16 @@ 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_make_pointer(oberon_context_t * ctx, oberon_type_t * type)
-{
-       if(type -> class == OBERON_TYPE_POINTER)
-       {
-               return type;
-       }
-
-       if(type -> class == OBERON_TYPE_INTEGER
-               || type -> class == OBERON_TYPE_BOOLEAN
-               || type -> class == OBERON_TYPE_PROCEDURE
-               || type -> class == OBERON_TYPE_VOID)
-       {
-               oberon_error(ctx, "oberon not support pointers to non structure types");
-       }
-
-       oberon_type_t * newtype;
-       newtype = oberon_new_type_ptr(OBERON_TYPE_POINTER);
-       newtype -> base = type;
-
-       oberon_generator_init_type(ctx, newtype);
-
-       return newtype;
-}
-
-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 == POINTER)
-       {
-               oberon_assert_token(ctx, POINTER);
-               oberon_assert_token(ctx, TO);
-               type = oberon_type(ctx);
-               type = oberon_make_pointer(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);
 }
 
@@ -1368,7 +1250,8 @@ 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);
@@ -1380,24 +1263,18 @@ 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);
                }
        }
 
@@ -1406,32 +1283,24 @@ oberon_formal_pars(oberon_context_t * ctx)
        if(ctx -> token == COLON)
        {
                oberon_assert_token(ctx, COLON);
-               tp -> base = oberon_type(ctx);
+               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);
-       }
-       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);
+               oberon_formal_pars(ctx, signature);
        }
-
-       return signature;
 }
 
 static void
@@ -1471,7 +1340,8 @@ 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);
@@ -1528,6 +1398,140 @@ oberon_const_decl(oberon_context_t * ctx)
        constant -> value = value;
 }
 
+static void
+oberon_make_array_type(oberon_context_t * ctx, int dim, oberon_item_t * size, oberon_type_t * base, oberon_type_t ** type)
+{
+       assert(dim == 1);
+       if(size -> mode != MODE_INTEGER)
+       {
+               oberon_error(ctx, "requires integer constant");
+       }
+
+       oberon_type_t * arr;
+       arr = *type;
+       arr -> class = OBERON_TYPE_ARRAY;
+       arr -> dim = dim;
+       arr -> size = size -> 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_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);
+
+               oberon_item_t * size;
+               size = oberon_const_expr(ctx);
+
+               oberon_assert_token(ctx, OF);
+
+               oberon_type_t * base;
+               base = oberon_new_type_ptr(OBERON_TYPE_VOID);
+               oberon_type(ctx, &base);
+
+               oberon_make_array_type(ctx, 1, size, 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_assert_token(ctx, PROCEDURE);
+               oberon_opt_formal_pars(ctx, type);
+       }
+       else
+       {
+               oberon_error(ctx, "invalid type declaration");
+       }
+}
+
 static void
 oberon_type_decl(oberon_context_t * ctx)
 {
@@ -1536,11 +1540,313 @@ 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)
+       {
+               if(type -> base -> class == OBERON_TYPE_RECORD)
+               {
+                       oberon_generator_init_type(ctx, type -> base);
+                       oberon_generator_init_type(ctx, type);
+               }
+               else
+               {
+                       oberon_initialize_type(ctx, type -> base);
+                       oberon_generator_init_type(ctx, type);
+               }
+       }
+       else if(type -> class == OBERON_TYPE_ARRAY)
+       {
+               oberon_generator_init_type(ctx, type);
+               oberon_initialize_type(ctx, type -> base);              
+       }
+       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
@@ -1576,6 +1882,9 @@ oberon_decl_seq(oberon_context_t * ctx)
                }
        }
 
+       oberon_prevent_recursive_decl(ctx);
+       oberon_initialize_decl(ctx);
+
        while(ctx -> token == PROCEDURE)
        {
                oberon_proc_decl(ctx);