+ return make_invalid_expression();
+}
+
+static expression_t *parse_array_expression(unsigned precedence,
+ expression_t *left)
+{
+ (void) precedence;
+
+ eat('[');
+
+ expression_t *inside = parse_expression();
+
+ array_access_expression_t *array_access
+ = allocate_ast_zero(sizeof(array_access[0]));
+
+ array_access->expression.type = EXPR_ARRAY_ACCESS;
+
+ type_t *type_left = left->base.datatype;
+ type_t *type_inside = inside->base.datatype;
+ type_t *result_type = NULL;
+
+ if(type_left != NULL && type_inside != NULL) {
+ type_left = skip_typeref(type_left);
+ type_inside = skip_typeref(type_inside);
+
+ if(is_type_pointer(type_left)) {
+ pointer_type_t *pointer = &type_left->pointer;
+ result_type = pointer->points_to;
+ array_access->array_ref = left;
+ array_access->index = inside;
+ } else if(is_type_pointer(type_inside)) {
+ pointer_type_t *pointer = &type_inside->pointer;
+ result_type = pointer->points_to;
+ array_access->array_ref = inside;
+ array_access->index = left;
+ array_access->flipped = true;
+ } else {
+ parser_print_error_prefix();
+ fprintf(stderr, "array access on object with non-pointer types ");
+ print_type_quoted(type_left);
+ fprintf(stderr, ", ");
+ print_type_quoted(type_inside);
+ fprintf(stderr, "\n");
+ }
+ } else {
+ array_access->array_ref = left;
+ array_access->index = inside;
+ }
+
+ if(token.type != ']') {
+ parse_error_expected("Problem while parsing array access", ']', 0);
+ return (expression_t*) array_access;
+ }
+ next_token();
+
+ result_type = automatic_type_conversion(result_type);
+ array_access->expression.datatype = result_type;
+
+ return (expression_t*) array_access;
+}
+
+static bool is_declaration_specifier(const token_t *token,
+ bool only_type_specifiers)
+{
+ switch(token->type) {
+ TYPE_SPECIFIERS
+ return 1;
+ case T_IDENTIFIER:
+ return is_typedef_symbol(token->v.symbol);
+ STORAGE_CLASSES
+ TYPE_QUALIFIERS
+ if(only_type_specifiers)
+ return 0;
+ return 1;
+
+ default:
+ return 0;
+ }
+}
+
+static expression_t *parse_sizeof(unsigned precedence)
+{
+ eat(T_sizeof);
+
+ sizeof_expression_t *sizeof_expression
+ = allocate_ast_zero(sizeof(sizeof_expression[0]));
+ sizeof_expression->expression.type = EXPR_SIZEOF;
+ sizeof_expression->expression.datatype = type_size_t;
+
+ if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
+ next_token();
+ sizeof_expression->type = parse_typename();
+ expect(')');
+ } else {
+ expression_t *expression = parse_sub_expression(precedence);
+ expression->base.datatype = revert_automatic_type_conversion(expression);
+
+ sizeof_expression->type = expression->base.datatype;
+ sizeof_expression->size_expression = expression;
+ }
+
+ return (expression_t*) sizeof_expression;
+}
+
+static expression_t *parse_select_expression(unsigned precedence,
+ expression_t *compound)
+{
+ (void) precedence;
+ assert(token.type == '.' || token.type == T_MINUSGREATER);
+
+ bool is_pointer = (token.type == T_MINUSGREATER);
+ next_token();
+
+ expression_t *select = allocate_expression_zero(EXPR_SELECT);
+ select->select.compound = compound;
+
+ if(token.type != T_IDENTIFIER) {
+ parse_error_expected("while parsing select", T_IDENTIFIER, 0);
+ return select;
+ }
+ symbol_t *symbol = token.v.symbol;
+ select->select.symbol = symbol;
+ next_token();
+
+ type_t *orig_type = compound->base.datatype;
+ if(orig_type == NULL)
+ return make_invalid_expression();
+
+ type_t *type = skip_typeref(orig_type);
+
+ type_t *type_left = type;
+ if(is_pointer) {
+ if(type->type != TYPE_POINTER) {
+ parser_print_error_prefix();
+ fprintf(stderr, "left hand side of '->' is not a pointer, but ");
+ print_type_quoted(orig_type);
+ fputc('\n', stderr);
+ return make_invalid_expression();
+ }
+ pointer_type_t *pointer_type = &type->pointer;
+ type_left = pointer_type->points_to;
+ }
+ type_left = skip_typeref(type_left);
+
+ if(type_left->type != TYPE_COMPOUND_STRUCT
+ && type_left->type != TYPE_COMPOUND_UNION) {
+ parser_print_error_prefix();
+ fprintf(stderr, "request for member '%s' in something not a struct or "
+ "union, but ", symbol->string);
+ print_type_quoted(type_left);
+ fputc('\n', stderr);
+ return make_invalid_expression();
+ }
+
+ compound_type_t *compound_type = &type_left->compound;
+ declaration_t *declaration = compound_type->declaration;
+
+ if(!declaration->init.is_defined) {
+ parser_print_error_prefix();
+ fprintf(stderr, "request for member '%s' of incomplete type ",
+ symbol->string);
+ print_type_quoted(type_left);
+ fputc('\n', stderr);
+ return make_invalid_expression();
+ }
+
+ declaration_t *iter = declaration->context.declarations;
+ for( ; iter != NULL; iter = iter->next) {
+ if(iter->symbol == symbol) {
+ break;
+ }
+ }
+ if(iter == NULL) {
+ parser_print_error_prefix();
+ print_type_quoted(type_left);
+ fprintf(stderr, " has no member named '%s'\n", symbol->string);
+ return make_invalid_expression();
+ }
+
+ /* we always do the auto-type conversions; the & and sizeof parser contains
+ * code to revert this! */
+ type_t *expression_type = automatic_type_conversion(iter->type);
+
+ select->select.compound_entry = iter;
+ select->base.datatype = expression_type;
+ return select;
+}
+
+static expression_t *parse_call_expression(unsigned precedence,
+ expression_t *expression)
+{
+ (void) precedence;
+ expression_t *result = allocate_expression_zero(EXPR_CALL);
+
+ call_expression_t *call = &result->call;
+ call->function = expression;
+
+ function_type_t *function_type = NULL;
+ type_t *orig_type = expression->base.datatype;
+ if(orig_type != NULL) {
+ type_t *type = skip_typeref(orig_type);
+
+ if(is_type_pointer(type)) {
+ pointer_type_t *pointer_type = &type->pointer;
+
+ type = skip_typeref(pointer_type->points_to);
+
+ if (type->type == TYPE_FUNCTION) {
+ function_type = &type->function;
+ call->expression.datatype = function_type->result_type;
+ }
+ }
+ if(function_type == NULL) {
+ parser_print_error_prefix();
+ fputs("called object '", stderr);
+ print_expression(expression);
+ fputs("' (type ", stderr);
+ print_type_quoted(orig_type);
+ fputs(") is not a pointer to a function\n", stderr);
+
+ function_type = NULL;
+ call->expression.datatype = NULL;
+ }
+ }
+
+ /* parse arguments */
+ eat('(');
+
+ if(token.type != ')') {
+ call_argument_t *last_argument = NULL;
+
+ while(true) {
+ call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
+
+ argument->expression = parse_assignment_expression();
+ if(last_argument == NULL) {
+ call->arguments = argument;
+ } else {
+ last_argument->next = argument;
+ }
+ last_argument = argument;
+
+ if(token.type != ',')
+ break;
+ next_token();
+ }
+ }
+ expect(')');
+
+ 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);
+ }
+ /* too few parameters */
+ if(parameter != NULL) {
+ parser_print_error_prefix();
+ 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->base.datatype;
+ type = skip_typeref(type);
+
+ if(type == NULL)
+ continue;
+
+ 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 result;
+}
+
+static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
+
+static expression_t *parse_conditional_expression(unsigned precedence,
+ expression_t *expression)
+{
+ eat('?');
+
+ conditional_expression_t *conditional
+ = allocate_ast_zero(sizeof(conditional[0]));
+ conditional->expression.type = EXPR_CONDITIONAL;
+ conditional->condition = expression;
+
+ /* 6.5.15.2 */
+ type_t *condition_type_orig = conditional->condition->base.datatype;
+ if(condition_type_orig != NULL) {
+ type_t *condition_type = skip_typeref(condition_type_orig);
+ if(condition_type != NULL && !is_type_scalar(condition_type)) {
+ type_error("expected a scalar type",
+ expression->base.source_position, condition_type_orig);
+ }
+ }
+
+ expression_t *const t_expr = parse_expression();
+ conditional->true_expression = t_expr;
+ expect(':');
+ expression_t *const f_expr = parse_sub_expression(precedence);
+ conditional->false_expression = f_expr;
+
+ type_t *const true_type = t_expr->base.datatype;
+ if(true_type == NULL)
+ return (expression_t*) conditional;
+ type_t *const false_type = f_expr->base.datatype;
+ if(false_type == NULL)
+ return (expression_t*) conditional;
+
+ type_t *const skipped_true_type = skip_typeref(true_type);
+ type_t *const skipped_false_type = skip_typeref(false_type);
+
+ /* 6.5.15.3 */
+ if (skipped_true_type == skipped_false_type) {
+ conditional->expression.datatype = skipped_true_type;
+ } else if (is_type_arithmetic(skipped_true_type) &&
+ is_type_arithmetic(skipped_false_type)) {
+ type_t *const result = semantic_arithmetic(skipped_true_type,
+ skipped_false_type);
+ conditional->true_expression = create_implicit_cast(t_expr, result);
+ conditional->false_expression = create_implicit_cast(f_expr, result);
+ conditional->expression.datatype = result;
+ } else if (skipped_true_type->type == TYPE_POINTER &&
+ skipped_false_type->type == TYPE_POINTER &&
+ true /* TODO compatible points_to types */) {
+ /* TODO */
+ } else if(/* (is_null_ptr_const(skipped_true_type) &&
+ skipped_false_type->type == TYPE_POINTER)
+ || (is_null_ptr_const(skipped_false_type) &&
+ skipped_true_type->type == TYPE_POINTER) TODO*/ false) {
+ /* TODO */
+ } else if(/* 1 is pointer to object type, other is void* */ false) {
+ /* TODO */
+ } else {
+ type_error_incompatible("while parsing conditional",
+ expression->base.source_position, true_type,
+ skipped_false_type);
+ }
+
+ return (expression_t*) conditional;
+}
+
+static expression_t *parse_extension(unsigned precedence)
+{
+ eat(T___extension__);
+
+ /* TODO enable extensions */
+
+ return parse_sub_expression(precedence);
+}
+
+static expression_t *parse_builtin_classify_type(const unsigned precedence)
+{
+ eat(T___builtin_classify_type);
+
+ classify_type_expression_t *const classify_type_expr =
+ allocate_ast_zero(sizeof(classify_type_expr[0]));
+ classify_type_expr->expression.type = EXPR_CLASSIFY_TYPE;
+ classify_type_expr->expression.datatype = type_int;
+
+ expect('(');
+ expression_t *const expression = parse_sub_expression(precedence);
+ expect(')');
+ classify_type_expr->type_expression = expression;
+
+ return (expression_t*)classify_type_expr;
+}
+
+static void semantic_incdec(unary_expression_t *expression)
+{
+ type_t *orig_type = expression->value->base.datatype;
+ if(orig_type == NULL)
+ return;
+
+ type_t *type = skip_typeref(orig_type);
+ if(!is_type_arithmetic(type) && type->type != TYPE_POINTER) {
+ /* TODO: improve error message */
+ parser_print_error_prefix();
+ fprintf(stderr, "operation needs an arithmetic or pointer type\n");
+ return;
+ }
+
+ expression->expression.datatype = orig_type;
+}
+
+static void semantic_unexpr_arithmetic(unary_expression_t *expression)
+{
+ type_t *orig_type = expression->value->base.datatype;
+ if(orig_type == NULL)
+ return;
+
+ type_t *type = skip_typeref(orig_type);
+ if(!is_type_arithmetic(type)) {
+ /* TODO: improve error message */
+ parser_print_error_prefix();
+ fprintf(stderr, "operation needs an arithmetic type\n");
+ return;
+ }
+
+ expression->expression.datatype = orig_type;
+}
+
+static void semantic_unexpr_scalar(unary_expression_t *expression)
+{
+ type_t *orig_type = expression->value->base.datatype;
+ if(orig_type == NULL)
+ return;
+
+ type_t *type = skip_typeref(orig_type);
+ if (!is_type_scalar(type)) {
+ parse_error("operand of ! must be of scalar type\n");
+ return;
+ }
+
+ expression->expression.datatype = orig_type;
+}
+
+static void semantic_unexpr_integer(unary_expression_t *expression)
+{
+ type_t *orig_type = expression->value->base.datatype;
+ if(orig_type == NULL)
+ return;
+
+ type_t *type = skip_typeref(orig_type);
+ if (!is_type_integer(type)) {
+ parse_error("operand of ~ must be of integer type\n");
+ return;
+ }
+
+ expression->expression.datatype = orig_type;
+}
+
+static void semantic_dereference(unary_expression_t *expression)
+{
+ type_t *orig_type = expression->value->base.datatype;
+ if(orig_type == NULL)
+ return;
+
+ type_t *type = skip_typeref(orig_type);
+ if(!is_type_pointer(type)) {
+ parser_print_error_prefix();
+ fputs("Unary '*' needs pointer or arrray type, but type ", stderr);
+ print_type_quoted(orig_type);
+ fputs(" given.\n", stderr);
+ return;
+ }
+
+ pointer_type_t *pointer_type = &type->pointer;
+ type_t *result_type = pointer_type->points_to;
+
+ result_type = automatic_type_conversion(result_type);
+ expression->expression.datatype = result_type;
+}
+
+static void semantic_take_addr(unary_expression_t *expression)
+{
+ expression_t *value = expression->value;
+ value->base.datatype = revert_automatic_type_conversion(value);
+
+ type_t *orig_type = value->base.datatype;
+ if(orig_type == NULL)
+ return;
+
+ if(value->type == EXPR_REFERENCE) {
+ reference_expression_t *reference = (reference_expression_t*) value;
+ declaration_t *declaration = reference->declaration;
+ if(declaration != NULL) {
+ declaration->address_taken = 1;
+ }
+ }
+
+ expression->expression.datatype = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
+}
+
+#define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
+static expression_t *parse_##unexpression_type(unsigned precedence) \
+{ \
+ eat(token_type); \
+ \
+ unary_expression_t *unary_expression \
+ = allocate_ast_zero(sizeof(unary_expression[0])); \
+ unary_expression->expression.type = EXPR_UNARY; \
+ unary_expression->type = unexpression_type; \
+ unary_expression->value = parse_sub_expression(precedence); \
+ \
+ sfunc(unary_expression); \
+ \
+ return (expression_t*) unary_expression; \
+}
+
+CREATE_UNARY_EXPRESSION_PARSER('-', UNEXPR_NEGATE, semantic_unexpr_arithmetic)
+CREATE_UNARY_EXPRESSION_PARSER('+', UNEXPR_PLUS, semantic_unexpr_arithmetic)
+CREATE_UNARY_EXPRESSION_PARSER('!', UNEXPR_NOT, semantic_unexpr_scalar)
+CREATE_UNARY_EXPRESSION_PARSER('*', UNEXPR_DEREFERENCE, semantic_dereference)
+CREATE_UNARY_EXPRESSION_PARSER('&', UNEXPR_TAKE_ADDRESS, semantic_take_addr)
+CREATE_UNARY_EXPRESSION_PARSER('~', UNEXPR_BITWISE_NEGATE,
+ semantic_unexpr_integer)
+CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS, UNEXPR_PREFIX_INCREMENT,
+ semantic_incdec)
+CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_PREFIX_DECREMENT,
+ semantic_incdec)
+
+#define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
+ sfunc) \
+static expression_t *parse_##unexpression_type(unsigned precedence, \
+ expression_t *left) \
+{ \
+ (void) precedence; \
+ eat(token_type); \
+ \
+ unary_expression_t *unary_expression \
+ = allocate_ast_zero(sizeof(unary_expression[0])); \
+ unary_expression->expression.type = EXPR_UNARY; \
+ unary_expression->type = unexpression_type; \
+ unary_expression->value = left; \
+ \
+ sfunc(unary_expression); \
+ \
+ return (expression_t*) unary_expression; \
+}
+
+CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS, UNEXPR_POSTFIX_INCREMENT,
+ semantic_incdec)
+CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_POSTFIX_DECREMENT,
+ semantic_incdec)
+
+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);
+ int rank_left = get_rank(type_left);
+ int rank_right = get_rank(type_right);
+ if(rank_left < rank_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 *orig_type_left = left->base.datatype;
+ type_t *orig_type_right = right->base.datatype;
+
+ if(orig_type_left == NULL || orig_type_right == NULL)
+ return;