tools/perf/util/expr.y

   1 /* Simple expression parser */
   2 %{
   3 #define YYDEBUG 1
   4 #include <stdio.h>
   5 #include "util.h"
   6 #include "util/debug.h"
   7 #include <stdlib.h> // strtod()
   8 #define IN_EXPR_Y 1
   9 #include "expr.h"
  10 #include "smt.h"
  11 #include <string.h>
  12
  13 %}
  14
  15 %define api.pure full
  16
  17 %parse-param { double *final_val }
  18 %parse-param { struct parse_ctx *ctx }
  19 %parse-param {void *scanner}
  20 %lex-param {void* scanner}
  21
  22 %union {
  23         double   num;
  24         char    *str;
  25 }
  26
  27 %token EXPR_PARSE EXPR_OTHER EXPR_ERROR
  28 %token <num> NUMBER
  29 %token <str> ID
  30 %token MIN MAX IF ELSE SMT_ON
  31 %left MIN MAX IF
  32 %left '|'
  33 %left '^'
  34 %left '&'
  35 %left '-' '+'
  36 %left '*' '/' '%'
  37 %left NEG NOT
  38 %type <num> expr if_expr
  39
  40 %{
  41 static void expr_error(double *final_val __maybe_unused,
  42                        struct parse_ctx *ctx __maybe_unused,
  43                        void *scanner,
  44                        const char *s)
  45 {
  46         pr_debug("%s\n", s);
  47 }
  48
  49 static int lookup_id(struct parse_ctx *ctx, char *id, double *val)
  50 {
  51         int i;
  52
  53         for (i = 0; i < ctx->num_ids; i++) {
  54                 if (!strcasecmp(ctx->ids[i].name, id)) {
  55                         *val = ctx->ids[i].val;
  56                         return 0;
  57                 }
  58         }
  59         return -1;
  60 }
  61
  62 %}
  63 %%
  64
  65 start:
  66 EXPR_PARSE all_expr
  67 |
  68 EXPR_OTHER all_other
  69
  70 all_other: all_other other
  71 |
  72
  73 other: ID
  74 {
  75         if (ctx->num_ids + 1 >= EXPR_MAX_OTHER) {
  76                 pr_err("failed: way too many variables");
  77                 YYABORT;
  78         }
  79
  80         ctx->ids[ctx->num_ids++].name = $1;
  81 }
  82 |
  83 MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')'
  84
  85
  86 all_expr: if_expr                       { *final_val = $1; }
  87         ;
  88
  89 if_expr:
  90         expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
  91         | expr
  92         ;
  93
  94 expr:     NUMBER
  95         | ID                    { if (lookup_id(ctx, $1, &$$) < 0) {
  96                                         pr_debug("%s not found\n", $1);
  97                                         YYABORT;
  98                                   }
  99                                 }
 100         | expr '|' expr         { $$ = (long)$1 | (long)$3; }
 101         | expr '&' expr         { $$ = (long)$1 & (long)$3; }
 102         | expr '^' expr         { $$ = (long)$1 ^ (long)$3; }
 103         | expr '+' expr         { $$ = $1 + $3; }
 104         | expr '-' expr         { $$ = $1 - $3; }
 105         | expr '*' expr         { $$ = $1 * $3; }
 106         | expr '/' expr         { if ($3 == 0) YYABORT; $$ = $1 / $3; }
 107         | expr '%' expr         { if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; }
 108         | '-' expr %prec NEG    { $$ = -$2; }
 109         | '(' if_expr ')'       { $$ = $2; }
 110         | MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
 111         | MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
 112         | SMT_ON                 { $$ = smt_on() > 0; }
 113         ;
 114
 115 %%