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Процедуры можно вызывать со скобками :)
[dsw-obn.git] / oberon.c
index 440364361e45956f86091d3022fd50b3099f1026..98928fbe7c4e1629b2519b0f505e54fb921ef63b 100644 (file)
--- a/oberon.c
+++ b/oberon.c
@@ -64,51 +64,137 @@ oberon_error(oberon_context_t * ctx, const char * fmt, ...)
 //   TABLE
 // ======================================================================= 
 
-static oberon_type_t *
-oberon_find_type(oberon_context_t * ctx, char * name)
+static oberon_scope_t *
+oberon_open_scope(oberon_context_t * ctx)
+{
+       oberon_scope_t * scope = malloc(sizeof *scope);
+       memset(scope, 0, sizeof *scope);
+
+       oberon_object_t * list = malloc(sizeof *list);
+       memset(list, 0, sizeof *list);
+
+       scope -> ctx = ctx;
+       scope -> list = list;
+       scope -> up = ctx -> decl;
+
+       ctx -> decl = scope;
+       return scope;
+}
+
+static void
+oberon_close_scope(oberon_scope_t * scope)
+{
+       oberon_context_t * ctx = scope -> ctx;
+       ctx -> decl = scope -> up;
+}
+
+static oberon_object_t *
+oberon_define_object(oberon_scope_t * scope, char * name, int class)
 {
-       oberon_type_t * x = ctx -> types;
+       oberon_object_t * x = scope -> list;
        while(x -> next && strcmp(x -> next -> name, name) != 0)
        {
                x = x -> next;
        }
 
-       return x -> next;
+       if(x -> next)
+       {
+               oberon_error(scope -> ctx, "already defined");
+       }
+
+       oberon_object_t * newvar = malloc(sizeof *newvar);
+       memset(newvar, 0, sizeof *newvar);
+       newvar -> name = name;
+       newvar -> class = class;
+
+       x -> next = newvar;
+
+       return newvar;
 }
 
-static oberon_var_t *
-oberon_find_var(oberon_context_t * ctx, char * name)
+static oberon_object_t *
+oberon_find_object_in_list(oberon_object_t * list, char * name)
 {
-       oberon_var_t * x = ctx -> mod -> vars;
+       oberon_object_t * x = list;
        while(x -> next && strcmp(x -> next -> name, name) != 0)
        {
                x = x -> next;
        }
-
        return x -> next;
 }
 
+static oberon_object_t *
+oberon_find_object(oberon_scope_t * scope, char * name)
+{
+       oberon_object_t * result = NULL;
+
+       oberon_scope_t * s = scope;
+       while(result == NULL && s != NULL)
+       {
+               result = oberon_find_object_in_list(s -> list, name);
+               s = s -> up;
+       }
+
+       if(result == NULL)
+       {
+               oberon_error(scope -> ctx, "undefined ident %s", name);
+       }
+
+       return result;
+}
+
 static void
-oberon_define_var(oberon_context_t * ctx, char * name, oberon_type_t * type)
+oberon_define_type(oberon_scope_t * scope, char * name, oberon_type_t * type)
 {
-       oberon_var_t * x = ctx -> mod -> vars;
-       while(x -> next && strcmp(x -> next -> name, name) != 0)
+       oberon_object_t * id;
+       id = oberon_define_object(scope, name, OBERON_CLASS_TYPE);
+       id -> type = type;
+       oberon_generator_init_type(scope -> ctx, type);
+}
+
+static oberon_type_t *
+oberon_find_type(oberon_scope_t * scope, char * name)
+{
+       oberon_object_t * x = oberon_find_object(scope, name);
+       if(x -> class != OBERON_CLASS_TYPE)
        {
-               x = x -> next;
+               oberon_error(scope -> ctx, "%s not a type", name);
        }
 
-       if(x -> next)
+       return x -> type;
+}
+
+static void
+oberon_define_var(oberon_scope_t * scope, char * name, oberon_type_t * type)
+{
+       oberon_object_t * var;
+       var = oberon_define_object(scope, name, OBERON_CLASS_VAR);
+       var -> type = type;
+       oberon_generator_init_var(scope -> ctx, var);
+}
+
+/*
+static oberon_object_t *
+oberon_find_var(oberon_scope_t * scope, char * name)
+{
+       oberon_object_t * x = oberon_find_object(scope, name);
+
+       if(x -> class != OBERON_CLASS_VAR)
        {
-               oberon_error(ctx, "already defined");
+               oberon_error(scope -> ctx, "%s not a var", name);
        }
 
-       oberon_var_t * newvar = malloc(sizeof *newvar);
-       memset(newvar, 0, sizeof *newvar);
-       newvar -> name = name;
-       newvar -> type = type;
-       oberon_generator_init_var(ctx, newvar);
+       return x;
+}
+*/
 
-       x -> next = newvar;
+static oberon_object_t *
+oberon_define_proc(oberon_scope_t * scope, char * name)
+{
+       oberon_object_t * proc;
+       proc = oberon_define_object(scope, name, OBERON_CLASS_PROC);
+       oberon_generator_init_proc(scope -> ctx, proc);
+       return proc;
 }
 
 // =======================================================================
@@ -416,20 +502,34 @@ static oberon_expr_t *
 oberon_factor(oberon_context_t * ctx)
 {
        char * name;
-       oberon_var_t * var;
+       oberon_object_t * var;
        oberon_expr_t * expr;
 
        switch(ctx -> token)
        {
                case IDENT:
                        name = oberon_assert_ident(ctx);
-                       var = oberon_find_var(ctx, name);
-                       if(var == NULL)
+                       var = oberon_find_object(ctx -> decl, name);
+                       if(var -> class == OBERON_CLASS_VAR)
                        {
-                               oberon_error(ctx, "undefined variable %s", name);
+                               expr = oberon_new_item(MODE_VAR, var -> type);
                        }
-                       expr = oberon_new_item(MODE_VAR, var -> type);
+                       else if(var -> class == OBERON_CLASS_PROC)
+                       {
+                               expr = oberon_new_item(MODE_CALL, var -> type);
+                       }
+                       else
+                       {
+                               oberon_error(ctx, "invalid designator");
+                       }
+
                        expr -> item.var = var;
+                       if(ctx -> token == LPAREN)
+                       {
+                               oberon_assert_token(ctx, LPAREN);
+                               expr -> item.mode = MODE_CALL;
+                               oberon_assert_token(ctx, RPAREN);
+                       }
                        break;
                case INTEGER:
                        expr = oberon_new_item(MODE_INTEGER, ctx -> int_type);
@@ -721,13 +821,7 @@ static oberon_type_t *
 oberon_type(oberon_context_t * ctx)
 {
        char * name = oberon_assert_ident(ctx);
-       oberon_type_t * type = oberon_find_type(ctx, name);
-
-       if(type == NULL)
-       {
-               oberon_error(ctx, "undefined type");
-       }
-
+       oberon_type_t * type = oberon_find_type(ctx -> decl, name);
        return type;
 }
 
@@ -737,19 +831,26 @@ oberon_var_decl(oberon_context_t * ctx)
        char * name = oberon_assert_ident(ctx);
        oberon_assert_token(ctx, COLON);
        oberon_type_t * type = oberon_type(ctx);
-       oberon_define_var(ctx, name, type);
+       oberon_define_var(ctx -> decl, name, type);
 }
 
 static void
 oberon_make_procedure_begin(oberon_context_t * ctx, char * name)
 {
-       
+       oberon_object_t * proc;
+       proc = oberon_define_proc(ctx -> decl, name);
+
+       oberon_open_scope(ctx);
+
+       oberon_generate_begin_proc(ctx, proc);
 }
 
 static void
 oberon_make_procedure_end(oberon_context_t * ctx)
 {
+       oberon_generate_end_proc(ctx);
 
+       oberon_close_scope(ctx -> decl);
 }
 
 static void
@@ -818,6 +919,29 @@ oberon_assign(oberon_context_t * ctx, oberon_expr_t * src, oberon_expr_t * dst)
        oberon_generate_assign(ctx, src, dst);
 }
 
+static void
+oberon_make_call(oberon_context_t * ctx, oberon_expr_t * desig)
+{
+       if(desig -> is_item == 0)
+       {
+               oberon_error(ctx, "expected item");
+       }
+
+       if(desig -> item.mode != MODE_CALL)
+       {
+               oberon_error(ctx, "expected mode CALL");
+       }
+
+       if(desig -> item.var -> class != OBERON_CLASS_PROC)
+       {
+               oberon_error(ctx, "only procedures can be called");
+       }
+
+       // TODO check arguments
+
+       oberon_generate_call_proc(ctx, desig);
+}
+
 static void
 oberon_statement(oberon_context_t * ctx)
 {
@@ -827,9 +951,16 @@ oberon_statement(oberon_context_t * ctx)
        if(ctx -> token == IDENT)
        {
                item1 = oberon_expr(ctx);
-               oberon_assert_token(ctx, ASSIGN);
-               item2 = oberon_expr(ctx);
-               oberon_assign(ctx, item2, item1);
+               if(ctx -> token == ASSIGN)
+               {
+                       oberon_assert_token(ctx, ASSIGN);
+                       item2 = oberon_expr(ctx);
+                       oberon_assign(ctx, item2, item1);
+               }
+               else
+               {
+                       oberon_make_call(ctx, item1);
+               }
        }
 }
 
@@ -880,43 +1011,40 @@ oberon_parse_module(oberon_context_t * ctx)
 // =======================================================================
 
 static oberon_type_t *
-oberon_register_global_type_ret(oberon_context_t * ctx, oberon_type_t * type)
+oberon_new_type_ptr(int class)
 {
-       oberon_type_t * x = ctx -> types;
-       while(x -> next && strcmp(x -> next -> name, type -> name) != 0)
-       {
-               x = x -> next;
-       }
-
-       if(x -> next)
-       {
-               oberon_error(ctx, "already defined");
-       }
+       oberon_type_t * x = malloc(sizeof *x);
+       memset(x, 0, sizeof *x);
+       x -> class = class;
+       return x;
+}
 
-       // TODO: copy type name (not a pointer)
-       oberon_type_t * newtype = malloc(sizeof *newtype);
-       memcpy(newtype, type, sizeof *newtype);
-       newtype -> next = NULL;
-       oberon_generator_init_type(ctx, newtype);
+static oberon_type_t *
+oberon_new_type_integer(int size)
+{
+       oberon_type_t * x;
+       x = oberon_new_type_ptr(OBERON_TYPE_INTEGER);
+       x -> size = size;
+       return x;
+}
 
-       x -> next = newtype;
-       return newtype; 
+static oberon_type_t *
+oberon_new_type_boolean(int size)
+{
+       oberon_type_t * x;
+       x = oberon_new_type_ptr(OBERON_TYPE_BOOLEAN);
+       x -> size = size;
+       return x;
 }
 
 static void
 register_default_types(oberon_context_t * ctx)
 {
-       static oberon_type_t integer = { "INTEGER", OBERON_TYPE_INTEGER, sizeof(int) };
-       static oberon_type_t boolean = { "BOOLEAN", OBERON_TYPE_BOOLEAN, sizeof(int) };
+       ctx -> int_type = oberon_new_type_integer(sizeof(int));
+       ctx -> bool_type = oberon_new_type_boolean(sizeof(int));
 
-       ctx -> int_type = oberon_register_global_type_ret(ctx, &integer);
-       ctx -> bool_type = oberon_register_global_type_ret(ctx, &boolean);
-}
-
-void
-oberon_register_global_type(oberon_context_t * ctx, oberon_type_t * type)
-{
-       oberon_register_global_type_ret(ctx, type);
+       oberon_define_type(ctx -> world_scope, "INTEGER", ctx -> int_type);
+       oberon_define_type(ctx -> world_scope, "BOOLEAN", ctx -> bool_type);
 }
 
 oberon_context_t *
@@ -925,9 +1053,9 @@ oberon_create_context()
        oberon_context_t * ctx = malloc(sizeof *ctx);
        memset(ctx, 0, sizeof *ctx);
 
-       oberon_type_t * types = malloc(sizeof *types);
-       memset(types, 0, sizeof *types);
-       ctx -> types = types;
+       oberon_scope_t * world_scope;
+       world_scope = oberon_open_scope(ctx);
+       ctx -> world_scope = world_scope;
 
        oberon_generator_init_context(ctx);
 
@@ -948,15 +1076,17 @@ oberon_compile_module(oberon_context_t * ctx, const char * code)
 {
        oberon_module_t * mod = malloc(sizeof *mod);
        memset(mod, 0, sizeof *mod);
-       oberon_var_t * vars = malloc(sizeof *vars);
-       memset(vars, 0, sizeof *vars);
        ctx -> mod = mod;
-       ctx -> mod -> vars = vars;
+
+       oberon_scope_t * module_scope;
+       module_scope = oberon_open_scope(ctx);
+       mod -> decl = module_scope;
 
        oberon_init_scaner(ctx, code);
        oberon_parse_module(ctx);
 
        oberon_generate_code(ctx);
+
+       ctx -> mod = NULL;
        return mod;
 }
-