From 150fbb9dd8d29199427e5f0318c11f21e713a5f7 Mon Sep 17 00:00:00 2001 From: pommicket Date: Mon, 24 Jan 2022 18:27:09 -0500 Subject: casts --- 05/parse.b | 152 ++++++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 95 insertions(+), 57 deletions(-) (limited to '05/parse.b') diff --git a/05/parse.b b/05/parse.b index 2df9db1..c424ee5 100644 --- a/05/parse.b +++ b/05/parse.b @@ -288,6 +288,15 @@ function parse_type_to prefix_end = p goto parse_type_loop :parse_array_type + local prev_types + local prev_types_bytes_used + ; little hack to avoid screwing up types like double[sizeof(int)] + ; temporarily switch out types array to parse the cast's type + prev_types = types + prev_types_bytes_used = types_bytes_used + types = malloc(4000) + types_init(types, &types_bytes_used) + local expr expr = malloc(4000) *1out = TYPE_ARRAY @@ -296,11 +305,16 @@ function parse_type_to token_skip_to_matching_rsquare(&p) suffix += 16 ; skip [ parse_expression(suffix, p, expr) - evaluate_constant_expression(expr, &n) + print_expression(expr) + putc(10) + evaluate_constant_expression(*8p_token, expr, &n) if n < 0 goto bad_array_size *8out = n out += 8 free(expr) + free(types) + types = prev_types + types_bytes_used = prev_types_bytes_used suffix = p + 16 goto parse_type_loop :bad_array_size @@ -782,13 +796,13 @@ function parse_expression return out :expr_binary_bad_types bad_types_to_operator(tokens, *4a, *4b) - ;@TODO: casts :parse_expr_unary if c == KEYWORD_SIZEOF goto parse_sizeof *1out = unary_op_to_expression_type(c) c = *1out + if c == EXPRESSION_CAST goto parse_cast out += 8 a = out + 4 ; type of operand p = tokens + 16 @@ -808,6 +822,22 @@ function parse_expression string Bad unary symbol (this shouldn't happen). byte 10 byte 0 + :parse_cast + p = best + 16 + a = parse_type(&p, &c) + if c != 0 goto bad_cast ; e.g. (int x)5 + if *1p != SYMBOL_RPAREN goto bad_cast ; e.g. (int ,)5 + out += 4 + *4out = a + out += 4 + p += 16 + out = parse_expression(p, tokens_end, out) + return out + :bad_cast + token_error(tokens, .str_bad_cast) + :str_bad_cast + string Bad cast. + byte 0 :unary_address_of *4type = type_create_pointer(*4a) return out @@ -842,14 +872,6 @@ function parse_expression byte 0 :parse_sizeof - ; little hack to avoid screwing up types like double[sizeof(int)] - ; temporarily switch out types array to parse the sizeof's type - local prev_types - local prev_types_bytes_used - prev_types = types - prev_types_bytes_used = types_bytes_used - types = malloc(4000) - types_init(types, &types_bytes_used) *1out = EXPRESSION_CONSTANT_INT out += 4 *1out = TYPE_UNSIGNED_LONG @@ -874,9 +896,6 @@ function parse_expression *8out = type_sizeof(*4p) free(temp) :parse_sizeof_finish - free(types) - types = prev_types - types_bytes_used = prev_types_bytes_used out += 8 return out @@ -1094,8 +1113,10 @@ function type_sizeof ; @NONSTANDARD: doesn't handle floats, but really why would you use floats in an array size ; e.g. SomeType x[(int)3.3]; ; this is also used for #if evaluation +; tokens is used for error messages (e.g. if this "constant" expression is *x or something) ; NOTE: this returns the end of the expression, not the value (which is stored in *8p_value) function evaluate_constant_expression + argument token argument expr argument p_value local a @@ -1116,7 +1137,7 @@ function evaluate_constant_expression if c == EXPRESSION_UNARY_MINUS goto eval_unary_minus if c == EXPRESSION_BITWISE_NOT goto eval_bitwise_not if c == EXPRESSION_LOGICAL_NOT goto eval_logical_not - if c == EXPRESSION_CAST goto eval_todo ; @TODO + if c == EXPRESSION_CAST goto eval_cast if c == EXPRESSION_ADD goto eval_add if c == EXPRESSION_SUB goto eval_sub if c == EXPRESSION_MUL goto eval_mul @@ -1137,16 +1158,25 @@ function evaluate_constant_expression if c == EXPRESSION_LOGICAL_OR goto eval_logical_or if c == EXPRESSION_CONDITIONAL goto eval_conditional - byte 0xcc - :eval_todo - fputs(2, .str_eval_todo) - exit(1) - :str_eval_todo - string evaluate_constant_expression does not support this kind of expression yet (see @TODOs). - byte 10 + token_error(token, .str_eval_bad_exprtype) + + :str_eval_bad_exprtype + string Can't evaluate constant expression. byte 0 - + :eval_cast + p = types + type + if *1p == TYPE_VOID goto eval_cast_bad_type + if *1p > TYPE_UNSIGNED_LONG goto eval_cast_bad_type + expr += 8 + ; @NONSTANDARD: we don't support, for example, int x[(int)(float)5]; + expr = evaluate_constant_expression(token, expr, p_value) + goto eval_fit_to_type + :eval_cast_bad_type + token_error(token, .str_eval_cast_bad_type) + :str_eval_cast_bad_type + string Bad type for constant cast (note: floating-point casts are not supported even though they are standard). + byte 0 :eval_constant_identifier ; @TODO: enum values fputs(2, .str_constant_identifier) @@ -1162,45 +1192,45 @@ function evaluate_constant_expression return expr :eval_unary_plus expr += 8 - expr = evaluate_constant_expression(expr, p_value) + expr = evaluate_constant_expression(token, expr, p_value) return expr :eval_unary_minus expr += 8 - expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(token, expr, &a) *8p_value = 0 - a goto eval_fit_to_type :eval_bitwise_not expr += 8 - expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(token, expr, &a) *8p_value = ~a goto eval_fit_to_type :eval_logical_not expr += 8 - expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(token, expr, &a) if a == 0 goto eval_value_1 goto eval_value_0 :eval_add expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a + b goto eval_fit_to_type :eval_sub expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a - b goto eval_fit_to_type :eval_mul expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a * b goto eval_fit_to_type :eval_div expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) if *1p == TYPE_UNSIGNED_LONG goto eval_div_unsigned ; division is signed or uses a small type, so we can use 64-bit signed division *8p_value = a / b @@ -1211,8 +1241,8 @@ function evaluate_constant_expression goto eval_fit_to_type :eval_remainder expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) p = types + type if *1p == TYPE_UNSIGNED_LONG goto eval_rem_unsigned *8p_value = a % b @@ -1222,14 +1252,14 @@ function evaluate_constant_expression goto eval_fit_to_type :eval_lshift expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a < b goto eval_fit_to_type :eval_rshift expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) p = types + type p = *1p p &= 1 ; signed types are odd @@ -1275,8 +1305,8 @@ function evaluate_constant_expression goto eval_comparison :eval_comparison expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) p = types + type p = *1p @@ -1309,41 +1339,41 @@ function evaluate_constant_expression goto eval_value_0 :eval_bitwise_and expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a & b goto eval_fit_to_type :eval_bitwise_or expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a | b goto eval_fit_to_type :eval_bitwise_xor expr += 8 - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) *8p_value = a ^ b goto eval_fit_to_type :eval_logical_and expr += 8 - expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(token, expr, &a) if a == 0 goto eval_value_0 - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &b) if b == 0 goto eval_value_0 goto eval_value_1 :eval_logical_or expr += 8 - expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(token, expr, &a) if a != 0 goto eval_value_1 - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &b) if b != 0 goto eval_value_1 goto eval_value_0 :eval_conditional expr += 8 - expr = evaluate_constant_expression(expr, &mask) - expr = evaluate_constant_expression(expr, &a) - expr = evaluate_constant_expression(expr, &b) + expr = evaluate_constant_expression(token, expr, &mask) + expr = evaluate_constant_expression(token, expr, &a) + expr = evaluate_constant_expression(token, expr, &b) if mask == 0 goto eval_conditional_b *8p_value = a goto eval_fit_to_type @@ -1557,6 +1587,7 @@ function operator_precedence if op == SYMBOL_MINUS goto return_0xe0 if op == SYMBOL_TILDE goto return_0xe0 if op == SYMBOL_NOT goto return_0xe0 + if op == SYMBOL_LPAREN goto return_0xe8 ; casts return 0xffff @@ -1570,6 +1601,7 @@ function unary_op_to_expression_type if op == SYMBOL_MINUS goto return_EXPRESSION_UNARY_MINUS if op == SYMBOL_TILDE goto return_EXPRESSION_BITWISE_NOT if op == SYMBOL_NOT goto return_EXPRESSION_LOGICAL_NOT + if op == SYMBOL_LPAREN goto return_EXPRESSION_CAST return 0 :return_EXPRESSION_PRE_INCREMENT @@ -1588,7 +1620,8 @@ function unary_op_to_expression_type return EXPRESSION_BITWISE_NOT :return_EXPRESSION_LOGICAL_NOT return EXPRESSION_LOGICAL_NOT - +:return_EXPRESSION_CAST + return EXPRESSION_CAST ; is this operator right-associative? most C operators are left associative, ; but += / -= / etc. are not @@ -1755,6 +1788,7 @@ function print_expression if c == EXPRESSION_UNARY_MINUS goto print_unary_minus if c == EXPRESSION_BITWISE_NOT goto print_bitwise_not if c == EXPRESSION_LOGICAL_NOT goto print_logical_not + if c == EXPRESSION_CAST goto print_cast b = binop_expression_type_to_symbol(c) if b != 0 goto print_expr_binop @@ -1766,7 +1800,11 @@ function print_expression string Bad expression passed to print_expression. byte 10 byte 0 - + :print_cast + ; we've already printed the type + expression += 8 + expression = print_expression(expression) + return expression :print_expr_int expression += 8 putn(*8expression) -- cgit v1.2.3