diff options
| -rw-r--r-- | 05/main.c | 3 | ||||
| -rw-r--r-- | 05/parse.b | 183 |
2 files changed, 173 insertions, 13 deletions
@@ -3,4 +3,5 @@ long double d; } (*x)(void); */ -typedef long int unsigned Foo[19 + (-3) % 187 - 28 + 5 * 6]; +typedef long int unsigned Foo[3 != 3]; +/* */ @@ -944,6 +944,11 @@ function evaluate_constant_expression local a local b local p + local mask + local type + + type = expr + 4 + type = *4type if *1expr == EXPRESSION_CONSTANT_INT goto eval_constant_int if *1expr == EXPRESSION_IDENTIFIER goto eval_constant_identifier @@ -957,6 +962,14 @@ function evaluate_constant_expression if *1expr == EXPRESSION_MUL goto eval_mul if *1expr == EXPRESSION_DIV goto eval_div if *1expr == EXPRESSION_REMAINDER goto eval_remainder + if *1expr == EXPRESSION_LSHIFT goto eval_lshift + if *1expr == EXPRESSION_RSHIFT goto eval_rshift + if *1expr == EXPRESSION_EQ goto eval_eq + if *1expr == EXPRESSION_NEQ goto eval_neq + if *1expr == EXPRESSION_LT goto eval_lt + if *1expr == EXPRESSION_GT goto eval_gt + if *1expr == EXPRESSION_LEQ goto eval_leq + if *1expr == EXPRESSION_GEQ goto eval_geq byte 0xcc :eval_todo @@ -987,12 +1000,12 @@ function evaluate_constant_expression expr += 8 expr = evaluate_constant_expression(expr, &a) *8p_value = 0 - a - return expr + goto eval_fit_to_type :eval_bitwise_not expr += 8 expr = evaluate_constant_expression(expr, &a) *8p_value = ~a - return expr + goto eval_fit_to_type :eval_logical_not expr += 8 expr = evaluate_constant_expression(expr, &a) @@ -1007,44 +1020,190 @@ function evaluate_constant_expression expr = evaluate_constant_expression(expr, &a) expr = evaluate_constant_expression(expr, &b) *8p_value = a + b - return expr + goto eval_fit_to_type :eval_sub expr += 8 expr = evaluate_constant_expression(expr, &a) expr = evaluate_constant_expression(expr, &b) *8p_value = a - b - return expr + goto eval_fit_to_type :eval_mul expr += 8 expr = evaluate_constant_expression(expr, &a) expr = evaluate_constant_expression(expr, &b) *8p_value = a * b - return expr + goto eval_fit_to_type :eval_div - p = expr + 4 ; pointer to type expr += 8 expr = evaluate_constant_expression(expr, &a) expr = evaluate_constant_expression(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 - return expr + goto eval_fit_to_type :eval_div_unsigned ; must use unsigned division divmod_unsigned(a, b, p_value, &a) - return expr + goto eval_fit_to_type :eval_remainder - p = expr + 4 ; pointer to type expr += 8 expr = evaluate_constant_expression(expr, &a) expr = evaluate_constant_expression(expr, &b) + p = types + type if *1p == TYPE_UNSIGNED_LONG goto eval_rem_unsigned *8p_value = a % b - return expr + goto eval_fit_to_type :eval_rem_unsigned divmod_unsigned(a, b, &a, p_value) - return expr - + goto eval_fit_to_type + :eval_lshift + expr += 8 + expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(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) + p = types + type + p = *1p + p &= 1 ; signed types are odd + if p == 1 goto eval_signed_rshift + *8p_value = a > b + goto eval_fit_to_type + :eval_signed_rshift + local v + mask = a > 63 ; sign bit + + ; sign extension + mask <= b + mask -= 1 + mask <= 64 - b + + v = a > b + v += mask + *8p_value = v + goto eval_fit_to_type + + ; comparison masks: + ; 1 = less than + ; 2 = equal to + ; 4 = greater than + ; e.g. not-equal is 1|4 = 5 because not equal = less than or greater than + :eval_eq + mask = 2 + goto eval_comparison + :eval_neq + mask = 5 + goto eval_comparison + :eval_lt + mask = 1 + goto eval_comparison + :eval_gt + mask = 4 + goto eval_comparison + :eval_leq + mask = 3 + goto eval_comparison + :eval_geq + mask = 6 + goto eval_comparison + :eval_comparison + expr += 8 + expr = evaluate_constant_expression(expr, &a) + expr = evaluate_constant_expression(expr, &b) + + p = types + type + p = *1p + p &= 1 + + if a == b goto eval_comparison_eq + + ; for checking < and >, we care about whether a and b are signed + if p == 1 goto eval_signed_comparison + if a ] b goto eval_comparison_gt + goto eval_comparison_lt + :eval_signed_comparison + if a > b goto eval_comparison_gt + goto eval_comparison_lt + + :eval_comparison_eq + ; a == b + mask &= 2 + goto eval_comparison_done + :eval_comparison_lt + ; a < b + mask &= 1 + goto eval_comparison_done + :eval_comparison_gt + ; a > b + mask &= 4 + goto eval_comparison_done + :eval_comparison_done + if mask != 0 goto eval_comparison1 + *8p_value = 0 + return expr + :eval_comparison1 + *8p_value = 1 + return expr + + :eval_fit_to_type + *8p_value = fit_to_type(*8p_value, type) + return expr + +; value is the output of some arithmetic expression; correct it to be within the range of type. +function fit_to_type + argument value + argument type + local c + local s + c = types + type + c = *1c + if c == TYPE_CHAR goto fit_to_type_char + if c == TYPE_UNSIGNED_CHAR goto fit_to_type_uchar + if c == TYPE_SHORT goto fit_to_type_short + if c == TYPE_UNSIGNED_SHORT goto fit_to_type_ushort + if c == TYPE_INT goto fit_to_type_int + if c == TYPE_UNSIGNED_INT goto fit_to_type_uint + if c == TYPE_LONG goto fit_to_type_long + if c == TYPE_UNSIGNED_LONG goto fit_to_type_ulong + fputs(2, .str_bad_fit_to_type) + exit(1) + :str_bad_fit_to_type + string Bad type passed to fit_to_type. + byte 10 + byte 0 + ; yes, signed integer overflow is undefined behavior and + ; casting to a signed integer is implementation-defined; + ; i'm going to play it safe and implement it properly + :fit_to_type_char + value &= 0xff + s = value > 7 ; sign bit + value += s * 0xffffffffffffff00 ; sign-extend + return value + :fit_to_type_uchar + value &= 0xff + return value + :fit_to_type_short + value &= 0xffff + s = value > 15 ; sign bit + value += s * 0xffffffffffff0000 ; sign-extend + return value + :fit_to_type_ushort + value &= 0xffff + return value + :fit_to_type_int + value &= 0xffffffff + s = value > 31 ; sign bit + value += s * 0xffffffff00000000 ; sign-extend + return value + :fit_to_type_uint + value &= 0xffffffff + return value + :fit_to_type_long + :fit_to_type_ulong + return value ; the "usual conversions" for binary operators, as the C standard calls it function expr_binary_type_usual_conversions argument token ; for errors |