fix uninitialized variable breaking implicitely defined functions
[cparser] / parser.c
index fdb85bd..e042b89 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -25,21 +25,27 @@ typedef struct {
        unsigned short namespace;
 } stack_entry_t;
 
-static token_t               token;
-static token_t               lookahead_buffer[MAX_LOOKAHEAD];
-static int                   lookahead_bufpos;
-static stack_entry_t        *environment_stack = NULL;
-static context_t            *global_context    = NULL;
-static context_t            *context           = NULL;
-static declaration_t        *last_declaration  = NULL;
-static struct obstack        temp_obst;
-
-static type_t               *type_int        = NULL;
-static type_t               *type_double     = NULL;
-static type_t               *type_const_char = NULL;
-static type_t               *type_string     = NULL;
-static type_t               *type_void       = NULL;
-static type_t               *type_size_t     = NULL;
+static token_t         token;
+static token_t         lookahead_buffer[MAX_LOOKAHEAD];
+static int             lookahead_bufpos;
+static stack_entry_t  *environment_stack = NULL;
+static context_t      *global_context    = NULL;
+static context_t      *context           = NULL;
+static declaration_t  *last_declaration  = NULL;
+static declaration_t  *current_function  = NULL;
+static struct obstack  temp_obst;
+static bool            found_error;
+
+static type_t         *type_int         = NULL;
+static type_t         *type_uint        = NULL;
+static type_t         *type_long_double = NULL;
+static type_t         *type_double      = NULL;
+static type_t         *type_float       = NULL;
+static type_t         *type_const_char  = NULL;
+static type_t         *type_string      = NULL;
+static type_t         *type_void        = NULL;
+static type_t         *type_size_t      = NULL;
+static type_t         *type_ptrdiff_t   = NULL;
 
 static statement_t *parse_compound_statement(void);
 static statement_t *parse_statement(void);
@@ -156,6 +162,7 @@ static inline const token_t *look_ahead(int num)
 
 static void error(void)
 {
+       found_error = true;
 #ifdef ABORT_ON_ERROR
        abort();
 #endif
@@ -179,8 +186,7 @@ static void parser_print_error_prefix_pos(
 
 static void parser_print_error_prefix(void)
 {
-       parser_print_prefix_pos(token.source_position);
-       error();
+       parser_print_error_prefix_pos(token.source_position);
 }
 
 static void parse_error(const char *message)
@@ -189,7 +195,6 @@ static void parse_error(const char *message)
        fprintf(stderr, "parse error: %s\n", message);
 }
 
-__attribute__((unused))
 static void parse_warning(const char *message)
 {
        parser_print_prefix_pos(token.source_position);
@@ -225,6 +230,28 @@ static void parse_error_expected(const char *message, ...)
        fprintf(stderr, "\n");
 }
 
+static void type_error(const char *msg, const source_position_t source_position,
+                       type_t *type)
+{
+       parser_print_error_prefix_pos(source_position);
+       fprintf(stderr, "%s, but found type ", msg);
+       print_type(type);
+       fputc('\n', stderr);
+       error();
+}
+
+static void type_error_incompatible(const char *msg,
+               const source_position_t source_position, type_t *type1, type_t *type2)
+{
+       parser_print_error_prefix_pos(source_position);
+       fprintf(stderr, "%s, incompatible types: ", msg);
+       print_type(type1);
+       fprintf(stderr, " - ");
+       print_type(type2);
+       fprintf(stderr, ")\n");
+       error();
+}
+
 static void eat_block(void)
 {
        if(token.type == '{')
@@ -460,6 +487,109 @@ static void environment_pop_to(size_t new_top)
 }
 
 
+static int get_rank(const type_t *type)
+{
+       /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
+        * and esp. footnote 108). However we can't fold constants (yet), so we
+        * can't decide wether unsigned int is possible, while int always works.
+        * (unsigned int would be preferable when possible... for stuff like
+        *  struct { enum { ... } bla : 4; } ) */
+       if(type->type == TYPE_ENUM)
+               return ATOMIC_TYPE_INT;
+
+       assert(type->type == TYPE_ATOMIC);
+       atomic_type_t      *atomic_type = (atomic_type_t*) type;
+       atomic_type_type_t  atype       = atomic_type->atype;
+       return atype;
+}
+
+static type_t *promote_integer(type_t *type)
+{
+       if(get_rank(type) < ATOMIC_TYPE_INT)
+               type = type_int;
+
+       return type;
+}
+
+static expression_t *create_cast_expression(expression_t *expression,
+                                            type_t *dest_type)
+{
+       unary_expression_t *cast = allocate_ast_zero(sizeof(cast[0]));
+
+       cast->expression.type     = EXPR_UNARY;
+       cast->type                = UNEXPR_CAST;
+       cast->value               = expression;
+       cast->expression.datatype = dest_type;
+
+       return (expression_t*) cast;
+}
+
+static expression_t *create_implicit_cast(expression_t *expression,
+                                          type_t *dest_type)
+{
+       assert(expression->datatype != NULL);
+       type_t *source_type = expression->datatype;
+
+       source_type = skip_typeref(source_type);
+       dest_type   = skip_typeref(dest_type);
+
+       if(expression->datatype == dest_type)
+               return expression;
+
+       if(dest_type->type == TYPE_ATOMIC) {
+               if(source_type->type != TYPE_ATOMIC)
+                       panic("casting of non-atomic types not implemented yet");
+
+               if(is_type_floating(dest_type) && !is_type_scalar(source_type)) {
+                       type_error_incompatible("can't cast types",
+                                               expression->source_position,
+                                               source_type, dest_type);
+                       return expression;
+               }
+
+               return create_cast_expression(expression, dest_type);
+       }
+       if(dest_type->type == TYPE_POINTER) {
+               if(source_type->type == TYPE_POINTER) {
+                       if(!pointers_compatible(source_type, dest_type)) {
+                               type_error_incompatible("can't implicitely cast types",
+                                               expression->source_position,
+                                               source_type, dest_type);
+                       } else {
+                               return create_cast_expression(expression, dest_type);
+                       }
+               }
+       }
+
+       panic("casting of non-atomic types not implemented yet");
+}
+
+static void semantic_assign(type_t *orig_type_left, expression_t **right,
+                            const char *context)
+{
+       type_t *orig_type_right = (*right)->datatype;
+       type_t *type_left       = skip_typeref(orig_type_left);
+       type_t *type_right      = skip_typeref(orig_type_right);
+
+       if(type_left == type_right) {
+               /* fine */
+       } else if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
+               *right = create_implicit_cast(*right, type_left);
+       } else if(type_left->type == TYPE_POINTER
+                       && type_right->type == TYPE_POINTER) {
+               /* TODO */
+       } else {
+               /* TODO: improve error message */
+               parser_print_error_prefix();
+               fprintf(stderr, "incompatible types in %s\n", context);
+               parser_print_error_prefix();
+               print_type(type_left);
+               fputs(" <- ", stderr);
+               print_type(type_right);
+               fputs("\n", stderr);
+       }
+
+}
 
 static expression_t *parse_constant_expression(void)
 {
@@ -591,35 +721,42 @@ static designator_t *parse_designation(void)
        }
 }
 
-static initializer_t *parse_initializer_list(void);
+static initializer_t *parse_initializer_list(type_t *type);
 
-static initializer_t *parse_initializer(void)
+static initializer_t *parse_initializer(type_t *type)
 {
        designator_t *designator = parse_designation();
 
        initializer_t *result;
        if(token.type == '{') {
-               result = parse_initializer_list();
+               result = parse_initializer_list(type);
        } else {
                result          = allocate_ast_zero(sizeof(result[0]));
                result->type    = INITIALIZER_VALUE;
                result->v.value = parse_assignment_expression();
+
+               if(type != NULL) {
+                       semantic_assign(type, &result->v.value, "initializer");
+               }
        }
        result->designator = designator;
 
        return result;
 }
 
-static initializer_t *parse_initializer_list(void)
+static initializer_t *parse_initializer_list(type_t *type)
 {
        eat('{');
 
+       /* TODO: semantic */
+       (void) type;
+
        initializer_t *result = allocate_ast_zero(sizeof(result[0]));
        result->type = INITIALIZER_LIST;
 
        initializer_t *last = NULL;
        while(1) {
-               initializer_t *initializer = parse_initializer();
+               initializer_t *initializer = parse_initializer(NULL);
                if(last != NULL) {
                        last->next = initializer;
                } else {
@@ -743,7 +880,7 @@ static void parse_enum_entries(void)
 
                if(token.type == '=') {
                        next_token();
-                       entry->init.initializer = parse_initializer();
+                       entry->init.initializer = parse_initializer(type_int);
                }
 
                record_declaration(entry);
@@ -888,6 +1025,8 @@ static type_t *create_builtin_type(symbol_t *symbol)
        builtin_type_t *type = allocate_type_zero(sizeof(type[0]));
        type->type.type      = TYPE_BUILTIN;
        type->symbol         = symbol;
+       /* TODO... */
+       type->real_type      = type_int;
 
        return (type_t*) type;
 }
@@ -1614,7 +1753,7 @@ static void parse_init_declarators(const declaration_specifiers_t *specifiers)
                                parser_error_multiple_definition(declaration, ndeclaration);
                        }
 
-                       ndeclaration->init.initializer = parse_initializer();
+                       ndeclaration->init.initializer = parse_initializer(declaration->type);
                } else if(token.type == '{') {
                        if(declaration->type->type != TYPE_FUNCTION) {
                                parser_print_error_prefix();
@@ -1642,9 +1781,14 @@ static void parse_init_declarators(const declaration_specifiers_t *specifiers)
                        for( ; parameter != NULL; parameter = parameter->next) {
                                environment_push(parameter);
                        }
+                       declaration_t *old_current_function = current_function;
+                       current_function                    = declaration;
 
                        statement_t *statement = parse_compound_statement();
 
+                       assert(current_function == declaration);
+                       old_current_function = current_function;
+
                        assert(context == &declaration->context);
                        set_context(last_context);
                        environment_pop_to(top);
@@ -1817,7 +1961,8 @@ static expression_t *parse_float_const(void)
 static declaration_t *create_implicit_function(symbol_t *symbol,
                const source_position_t source_position)
 {
-       function_type_t *function_type = allocate_type_zero(sizeof(function_type));
+       function_type_t *function_type
+               = allocate_type_zero(sizeof(function_type[0]));
 
        function_type->type.type              = TYPE_FUNCTION;
        function_type->result_type            = type_int;
@@ -1893,7 +2038,7 @@ static void check_cast_allowed(expression_t *expression, type_t *dest_type)
 {
        (void) expression;
        (void) dest_type;
-       /* TODO check if cast is allowed and issue warnings/errors */
+       /* TODO check if explicit cast is allowed and issue warnings/errors */
 }
 
 static expression_t *parse_cast(void)
@@ -2243,9 +2388,26 @@ static expression_t *parse_call_expression(unsigned precedence,
 {
        (void) precedence;
        call_expression_t *call = allocate_ast_zero(sizeof(call[0]));
+       call->expression.type   = EXPR_CALL;
+       call->function          = expression;
 
-       call->expression.type     = EXPR_CALL;
-       call->function            = expression;
+       function_type_t *function_type;
+       type_t          *type = expression->datatype;
+       if(type->type != TYPE_FUNCTION) {
+               /* TODO calling pointers to functions is ok */
+               parser_print_error_prefix();
+               fputs("called object '", stderr);
+               print_expression(expression);
+               fputs("' (type ", stderr);
+               print_type(type);
+               fputs("is not a function\n", stderr);
+
+               function_type             = NULL;
+               call->expression.datatype = NULL;
+       } else {
+               function_type             = (function_type_t*) type;
+               call->expression.datatype = function_type->result_type;
+       }
 
        /* parse arguments */
        eat('(');
@@ -2271,51 +2433,50 @@ static expression_t *parse_call_expression(unsigned precedence,
        }
        expect(')');
 
-       type_t *type = expression->datatype;
-       if(type != NULL) {
-               /* we can call pointer to function */
-               if(type->type == TYPE_POINTER) {
-                       pointer_type_t *pointer = (pointer_type_t*) type;
-                       type = pointer->points_to;
+       if(function_type != NULL) {
+               function_parameter_t *parameter = function_type->parameters;
+               call_argument_t      *argument  = call->arguments;
+               for( ; parameter != NULL && argument != NULL;
+                               parameter = parameter->next, argument = argument->next) {
+                       type_t *expected_type = parameter->type;
+                       /* TODO report context in error messages */
+                       argument->expression  = create_implicit_cast(argument->expression,
+                                                                    expected_type);
                }
-
-               if(type == NULL || type->type != TYPE_FUNCTION) {
+               /* too few parameters */
+               if(parameter != NULL) {
                        parser_print_error_prefix();
-                       fprintf(stderr, "expected a function type for call but found "
-                               "type ");
-                       print_type(expression->datatype);
-                       fprintf(stderr, "\n");
-               } else {
-                       function_type_t *function_type = (function_type_t*) type;
-                       call->expression.datatype      = function_type->result_type;
+                       fprintf(stderr, "too few arguments to function '");
+                       print_expression(expression);
+                       fprintf(stderr, "'\n");
+               } else if(argument != NULL) {
+                       /* too many parameters */
+                       if(!function_type->variadic
+                                       && !function_type->unspecified_parameters) {
+                               parser_print_error_prefix();
+                               fprintf(stderr, "too many arguments to function '");
+                               print_expression(expression);
+                               fprintf(stderr, "'\n");
+                       } else {
+                               /* do default promotion */
+                               for( ; argument != NULL; argument = argument->next) {
+                                       type_t *type = argument->expression->datatype;
+
+                                       if(is_type_integer(type)) {
+                                               type = promote_integer(type);
+                                       } else if(type == type_float) {
+                                               type = type_double;
+                                       }
+                                       argument->expression
+                                               = create_implicit_cast(argument->expression, type);
+                               }
+                       }
                }
        }
 
        return (expression_t*) call;
 }
 
-static void type_error(const char *msg, const source_position_t source_position,
-                       type_t *type)
-{
-       parser_print_error_prefix_pos(source_position);
-       fprintf(stderr, "%s, but found type ", msg);
-       print_type(type);
-       fputc('\n', stderr);
-       error();
-}
-
-static void type_error_incompatible(const char *msg,
-               const source_position_t source_position, type_t *type1, type_t *type2)
-{
-       parser_print_error_prefix_pos(source_position);
-       fprintf(stderr, "%s, incompatible types: ", msg);
-       print_type(type1);
-       fprintf(stderr, " - ");
-       print_type(type2);
-       fprintf(stderr, ")\n");
-       error();
-}
-
 static type_t *get_type_after_conversion(const type_t *type1,
                                          const type_t *type2)
 {
@@ -2397,8 +2558,13 @@ static type_t *get_unexpr_arithmetic_type(const expression_t *expression)
 
 static type_t *get_unexpr_dereference_type(const expression_t *expression)
 {
-       (void) expression;
-       /* TODO... */
+       type_t *expression_type = expression->datatype;
+
+       if(expression_type->type == TYPE_POINTER) {
+               pointer_type_t *pointer_type = (pointer_type_t*) expression_type;
+               return pointer_type->points_to;
+       }
+       panic("deref TODO...");
        return NULL;
 }
 
@@ -2460,103 +2626,257 @@ CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_POSTFIX_INCREMENT,
 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_POSTFIX_DECREMENT,
                                        get_unexpr_arithmetic_type)
 
-static type_t *get_binexpr_int_type(const expression_t *left,
-                                    const expression_t *right)
+static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
+{
+       /* TODO: handle complex + imaginary types */
+
+       /* § 6.3.1.8 Usual arithmetic conversions */
+       if(type_left == type_long_double || type_right == type_long_double) {
+               return type_long_double;
+       } else if(type_left == type_double || type_right == type_double) {
+               return type_double;
+       } else if(type_left == type_float || type_right == type_float) {
+               return type_float;
+       }
+
+       type_right = promote_integer(type_right);
+       type_left  = promote_integer(type_left);
+
+       if(type_left == type_right)
+               return type_left;
+
+       bool signed_left  = is_type_signed(type_left);
+       bool signed_right = is_type_signed(type_right);
+       if(get_rank(type_left) < get_rank(type_right)) {
+               if(signed_left == signed_right || !signed_right) {
+                       return type_right;
+               } else {
+                       return type_left;
+               }
+       } else {
+               if(signed_left == signed_right || !signed_left) {
+                       return type_left;
+               } else {
+                       return type_right;
+               }
+       }
+}
+
+static void semantic_binexpr_arithmetic(binary_expression_t *expression)
+{
+       expression_t *left       = expression->left;
+       expression_t *right      = expression->right;
+       type_t       *type_left  = skip_typeref(left->datatype);
+       type_t       *type_right = skip_typeref(right->datatype);
+
+       if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
+               /* TODO: improve error message */
+               parser_print_error_prefix();
+               fprintf(stderr, "operation needs arithmetic types\n");
+               return;
+       }
+
+       type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
+       expression->left  = create_implicit_cast(left, arithmetic_type);
+       expression->right = create_implicit_cast(right, arithmetic_type);
+       expression->expression.datatype = arithmetic_type;
+}
+
+static void semantic_add(binary_expression_t *expression)
+{
+       expression_t *left            = expression->left;
+       expression_t *right           = expression->right;
+       type_t       *orig_type_left  = left->datatype;
+       type_t       *orig_type_right = right->datatype;
+       type_t       *type_left       = skip_typeref(orig_type_left);
+       type_t       *type_right      = skip_typeref(orig_type_right);
+
+       /* § 5.6.5 */
+       if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
+               type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
+               expression->left  = create_implicit_cast(left, arithmetic_type);
+               expression->right = create_implicit_cast(right, arithmetic_type);
+               expression->expression.datatype = arithmetic_type;
+               return;
+       } else if(type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
+               expression->expression.datatype = type_left;
+       } else if(type_right->type == TYPE_POINTER && is_type_integer(type_left)) {
+               expression->expression.datatype = type_right;
+       } else {
+               parser_print_error_prefix();
+               fprintf(stderr, "invalid operands to binary + (");
+               print_type(orig_type_left);
+               fprintf(stderr, ", ");
+               print_type(orig_type_right);
+               fprintf(stderr, ")\n");
+       }
+}
+
+static void semantic_sub(binary_expression_t *expression)
+{
+       expression_t *left            = expression->left;
+       expression_t *right           = expression->right;
+       type_t       *orig_type_left  = left->datatype;
+       type_t       *orig_type_right = right->datatype;
+       type_t       *type_left       = skip_typeref(orig_type_left);
+       type_t       *type_right      = skip_typeref(orig_type_right);
+
+       /* § 5.6.5 */
+       if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
+               type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
+               expression->left  = create_implicit_cast(left, arithmetic_type);
+               expression->right = create_implicit_cast(right, arithmetic_type);
+               expression->expression.datatype = arithmetic_type;
+               return;
+       } else if(type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
+               expression->expression.datatype = type_left;
+       } else if(type_left->type == TYPE_POINTER &&
+                       type_right->type == TYPE_POINTER) {
+               if(!pointers_compatible(type_left, type_right)) {
+                       parser_print_error_prefix();
+                       fprintf(stderr, "pointers to incompatible objects to binary - (");
+                       print_type(orig_type_left);
+                       fprintf(stderr, ", ");
+                       print_type(orig_type_right);
+                       fprintf(stderr, ")\n");
+               } else {
+                       expression->expression.datatype = type_ptrdiff_t;
+               }
+       } else {
+               parser_print_error_prefix();
+               fprintf(stderr, "invalid operands to binary - (");
+               print_type(orig_type_left);
+               fprintf(stderr, ", ");
+               print_type(orig_type_right);
+               fprintf(stderr, ")\n");
+       }
+}
+
+static void semantic_comparison(binary_expression_t *expression)
 {
-       (void) left;
-       (void) right;
-       return type_int;
+       expression_t *left       = expression->left;
+       expression_t *right      = expression->right;
+       type_t       *type_left  = left->datatype;
+       type_t       *type_right = right->datatype;
+
+       /* TODO non-arithmetic types */
+       if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
+               type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
+               expression->left  = create_implicit_cast(left, arithmetic_type);
+               expression->right = create_implicit_cast(right, arithmetic_type);
+               expression->expression.datatype = arithmetic_type;
+       }
+       expression->expression.datatype = type_int;
 }
 
-static type_t *get_binexpr_arithmetic_type(const expression_t *left,
-                                            const expression_t *right)
+static void semantic_arithmetic_assign(binary_expression_t *expression)
 {
-       (void) right;
-       return left->datatype;
+       expression_t *left       = expression->left;
+       expression_t *right      = expression->right;
+       type_t       *type_left  = left->datatype;
+       type_t       *type_right = right->datatype;
+
+       if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
+               /* TODO: improve error message */
+               parser_print_error_prefix();
+               fprintf(stderr, "operation needs arithmetic types\n");
+               return;
+       }
+
+       /* combined instructions are tricky. We can't create an implicit cast on
+        * the left side, because we need the uncasted form for the store.
+        * The ast2firm pass has to know that left_type must be right_type
+        * for the arithmeitc operation and create a cast by itself */
+       type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
+       expression->right       = create_implicit_cast(right, arithmetic_type);
+       expression->expression.datatype = type_left;
 }
 
-static type_t *get_binexpr_arithmetic_assign_type(const expression_t *left,
-                                                  const expression_t *right)
+static void semantic_logical_op(binary_expression_t *expression)
 {
-       (void) right;
        /* TODO */
-       return left->datatype;
-}
-
-static type_t *get_binexpr_right_type(const expression_t *left,
-                                       const expression_t *right)
-{
-       (void) left;
-       return right->datatype;
-}
-
-#define CREATE_BINEXPR_PARSER(token_type, binexpression_type, tfunc)    \
-static expression_t *parse_##binexpression_type(unsigned precedence,    \
-                                                expression_t *left)     \
-{                                                                       \
-       eat(token_type);                                                    \
-                                                                        \
-       expression_t *right = parse_sub_expression(precedence);             \
-                                                                        \
-       binary_expression_t *binexpr                                        \
-               = allocate_ast_zero(sizeof(binexpr[0]));                        \
-       binexpr->expression.type     = EXPR_BINARY;                         \
-       binexpr->type                = binexpression_type;                  \
-       binexpr->left                = left;                                \
-       binexpr->right               = right;                               \
-       binexpr->expression.datatype = tfunc(left, right);                  \
-                                                                        \
-       return (expression_t*) binexpr;                                     \
-}
-
-CREATE_BINEXPR_PARSER(',', BINEXPR_COMMA,   get_binexpr_right_type)
-CREATE_BINEXPR_PARSER('*', BINEXPR_MUL,     get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('/', BINEXPR_DIV,     get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('%', BINEXPR_MOD,     get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('+', BINEXPR_ADD,     get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('-', BINEXPR_SUB,     get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('<', BINEXPR_LESS,    get_binexpr_int_type)
-CREATE_BINEXPR_PARSER('>', BINEXPR_GREATER, get_binexpr_int_type)
-CREATE_BINEXPR_PARSER('=', BINEXPR_ASSIGN,  get_binexpr_right_type)
-CREATE_BINEXPR_PARSER(T_EQUALEQUAL, BINEXPR_EQUAL,
-                      get_binexpr_int_type)
+       expression->expression.datatype = type_int;
+}
+
+static void semantic_binexpr_assign(binary_expression_t *expression)
+{
+       expression_t *left       = expression->left;
+       type_t       *type_left  = left->datatype;
+
+       semantic_assign(type_left, &expression->right, "assignment");
+
+       expression->expression.datatype = type_left;
+}
+
+static void semantic_comma(binary_expression_t *expression)
+{
+       expression->expression.datatype = expression->right->datatype;
+}
+
+#define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr) \
+static expression_t *parse_##binexpression_type(unsigned precedence,     \
+                                                expression_t *left)      \
+{                                                                        \
+       eat(token_type);                                                     \
+                                                                         \
+       expression_t *right = parse_sub_expression(precedence + lr);         \
+                                                                         \
+       binary_expression_t *binexpr                                         \
+               = allocate_ast_zero(sizeof(binexpr[0]));                         \
+       binexpr->expression.type     = EXPR_BINARY;                          \
+       binexpr->type                = binexpression_type;                   \
+       binexpr->left                = left;                                 \
+       binexpr->right               = right;                                \
+       sfunc(binexpr);                                                      \
+                                                                         \
+       return (expression_t*) binexpr;                                      \
+}
+
+CREATE_BINEXPR_PARSER(',', BINEXPR_COMMA,          semantic_comma, 1)
+CREATE_BINEXPR_PARSER('*', BINEXPR_MUL,            semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('/', BINEXPR_DIV,            semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('%', BINEXPR_MOD,            semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('+', BINEXPR_ADD,            semantic_add, 1)
+CREATE_BINEXPR_PARSER('-', BINEXPR_SUB,            semantic_sub, 1)
+CREATE_BINEXPR_PARSER('<', BINEXPR_LESS,           semantic_comparison, 1)
+CREATE_BINEXPR_PARSER('>', BINEXPR_GREATER,        semantic_comparison, 1)
+CREATE_BINEXPR_PARSER('=', BINEXPR_ASSIGN,         semantic_binexpr_assign, 0)
+CREATE_BINEXPR_PARSER(T_EQUALEQUAL, BINEXPR_EQUAL, semantic_comparison, 1)
 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, BINEXPR_NOTEQUAL,
-                      get_binexpr_int_type)
-CREATE_BINEXPR_PARSER(T_LESSEQUAL, BINEXPR_LESSEQUAL,
-                      get_binexpr_int_type)
+                      semantic_comparison, 1)
+CREATE_BINEXPR_PARSER(T_LESSEQUAL, BINEXPR_LESSEQUAL, semantic_comparison, 1)
 CREATE_BINEXPR_PARSER(T_GREATEREQUAL, BINEXPR_GREATEREQUAL,
-                      get_binexpr_int_type)
-CREATE_BINEXPR_PARSER('&', BINEXPR_BITWISE_AND, get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('|', BINEXPR_BITWISE_OR,  get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER('^', BINEXPR_BITWISE_XOR, get_binexpr_arithmetic_type)
-CREATE_BINEXPR_PARSER(T_ANDAND, BINEXPR_LOGICAL_AND,
-                      get_binexpr_int_type)
-CREATE_BINEXPR_PARSER(T_PIPEPIPE, BINEXPR_LOGICAL_OR,
-                      get_binexpr_int_type)
+                      semantic_comparison, 1)
+CREATE_BINEXPR_PARSER('&', BINEXPR_BITWISE_AND,    semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('|', BINEXPR_BITWISE_OR,     semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('^', BINEXPR_BITWISE_XOR,    semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER(T_ANDAND, BINEXPR_LOGICAL_AND,  semantic_logical_op, 1)
+CREATE_BINEXPR_PARSER(T_PIPEPIPE, BINEXPR_LOGICAL_OR, semantic_logical_op, 1)
+/* TODO shift has a bit special semantic */
 CREATE_BINEXPR_PARSER(T_LESSLESS, BINEXPR_SHIFTLEFT,
-                      get_binexpr_arithmetic_type)
+                      semantic_binexpr_arithmetic, 1)
 CREATE_BINEXPR_PARSER(T_GREATERGREATER, BINEXPR_SHIFTRIGHT,
-                      get_binexpr_arithmetic_type)
+                      semantic_binexpr_arithmetic, 1)
 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, BINEXPR_ADD_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, BINEXPR_SUB_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, BINEXPR_MUL_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, BINEXPR_DIV_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, BINEXPR_MOD_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, BINEXPR_SHIFTLEFT_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, BINEXPR_SHIFTRIGHT_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_ANDEQUAL, BINEXPR_BITWISE_AND_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, BINEXPR_BITWISE_OR_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 CREATE_BINEXPR_PARSER(T_CARETEQUAL, BINEXPR_BITWISE_XOR_ASSIGN,
-                      get_binexpr_arithmetic_assign_type)
+                      semantic_arithmetic_assign, 0)
 
 static expression_t *parse_sub_expression(unsigned precedence)
 {
@@ -2899,9 +3219,30 @@ static statement_t *parse_return(void)
 
        statement->statement.type            = STATEMENT_RETURN;
        statement->statement.source_position = token.source_position;
+
+       assert(current_function->type->type == TYPE_FUNCTION);
+       function_type_t *function_type = (function_type_t*) current_function->type;
+       type_t          *return_type   = function_type->result_type;
+
+       expression_t *return_value;
        if(token.type != ';') {
-               statement->return_value = parse_expression();
+               return_value = parse_expression();
+
+               if(return_type == type_void && return_value->datatype != type_void) {
+                       parse_warning("'return' with a value, in function returning void");
+                       return_value = NULL;
+               } else {
+                       semantic_assign(return_type, &return_value, "'return'");
+               }
+       } else {
+               return_value = NULL;
+               if(return_type != type_void) {
+                       parse_warning("'return' without value, in function returning "
+                                     "non-void");
+               }
        }
+       statement->return_value = return_value;
+
        expect(';');
 
        return (statement_t*) statement;
@@ -3113,8 +3454,10 @@ static translation_unit_t *parse_translation_unit(void)
 translation_unit_t *parse(void)
 {
        environment_stack = NEW_ARR_F(stack_entry_t, 0);
+       found_error       = false;
 
        type_set_output(stderr);
+       ast_set_output(stderr);
 
        lookahead_bufpos = 0;
        for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
@@ -3124,6 +3467,9 @@ translation_unit_t *parse(void)
 
        DEL_ARR_F(environment_stack);
 
+       if(found_error)
+               return NULL;
+
        return unit;
 }
 
@@ -3132,12 +3478,16 @@ void init_parser(void)
        init_expression_parsers();
        obstack_init(&temp_obst);
 
-       type_int        = make_atomic_type(ATOMIC_TYPE_INT, 0);
-       type_double     = make_atomic_type(ATOMIC_TYPE_DOUBLE, 0);
-       type_size_t     = make_atomic_type(ATOMIC_TYPE_UINT, 0);
-       type_const_char = make_atomic_type(ATOMIC_TYPE_CHAR, TYPE_QUALIFIER_CONST);
-       type_void       = make_atomic_type(ATOMIC_TYPE_VOID, 0);
-       type_string     = make_pointer_type(type_const_char, 0);
+       type_int         = make_atomic_type(ATOMIC_TYPE_INT, 0);
+       type_uint        = make_atomic_type(ATOMIC_TYPE_UINT, 0);
+       type_long_double = make_atomic_type(ATOMIC_TYPE_LONG_DOUBLE, 0);
+       type_double      = make_atomic_type(ATOMIC_TYPE_DOUBLE, 0);
+       type_float       = make_atomic_type(ATOMIC_TYPE_FLOAT, 0);
+       type_size_t      = make_atomic_type(ATOMIC_TYPE_ULONG, 0);
+       type_ptrdiff_t   = make_atomic_type(ATOMIC_TYPE_LONG, 0);
+       type_const_char  = make_atomic_type(ATOMIC_TYPE_CHAR, TYPE_QUALIFIER_CONST);
+       type_void        = make_atomic_type(ATOMIC_TYPE_VOID, 0);
+       type_string      = make_pointer_type(type_const_char, 0);
 }
 
 void exit_parser(void)