c70ced4738
ysyx_22040000 李心杨 Linux calcite 6.1.71 #1-NixOS SMP PREEMPT_DYNAMIC Fri Jan 5 14:18:41 UTC 2024 x86_64 GNU/Linux 11:18:05 up 0:12, 2 users, load average: 0.53, 0.27, 0.14
45 lines
929 B
Text
45 lines
929 B
Text
%code requires {
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#include <common.h>
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}
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%{
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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extern int yylex(void);
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void yyerror(uint32_t *result, const char *err) {
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fprintf(stderr, "Error: %s\n", err);
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}
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%}
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%token NUMBER HEX_NUMBER
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%start input
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%define api.value.type { word_t }
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%parse-param { uint32_t *result }
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%left '-' '+'
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%left '*' '/'
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%%
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input
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: expression { *result = $1; }
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;
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expression
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: number { $$ = $1; }
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| expression '+' expression { $$ = $1 + $3; }
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| expression '-' expression { $$ = $1 - $3; }
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| expression '*' expression { $$ = $1 * $3; }
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| expression '/' expression {
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if($3 == 0) {
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fprintf(stderr, "Error: divide by zero at %u / %u\n", $1, $3);
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YYABORT;
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};
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$$ = $1 / $3;
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}
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| '-' number { $$ = -$2; }
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| '(' expression ')' { $$ = $2; }
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number
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: NUMBER
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| HEX_NUMBER
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%%
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