Files
erofs-linux/tools/perf/util/expr.y
T
Jiri Olsa 26226a9772 perf expr: Move expr lexer to flex
Adding expr flex code instead of the manual parser code. So it's easily
extensible in upcoming changes.

The new flex code is in flex.l object and gets compiled like all the
other flexers we use.  It's defined as flex reentrant parser.

It's used by both expr__parse and expr__find_other interfaces by
separating the starting point.

There's no intended change of functionality ;-) the test expr is
passing.

Signed-off-by: Jiri Olsa <[email protected]>
Reviewed-by: Andi Kleen <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2020-03-09 21:43:24 -03:00

116 lines
2.2 KiB
Plaintext

/* Simple expression parser */
%{
#define YYDEBUG 1
#include <stdio.h>
#include "util.h"
#include "util/debug.h"
#include <stdlib.h> // strtod()
#define IN_EXPR_Y 1
#include "expr.h"
#include "smt.h"
#include <string.h>
%}
%define api.pure full
%parse-param { double *final_val }
%parse-param { struct parse_ctx *ctx }
%parse-param {void *scanner}
%lex-param {void* scanner}
%union {
double num;
char *str;
}
%token EXPR_PARSE EXPR_OTHER EXPR_ERROR
%token <num> NUMBER
%token <str> ID
%token MIN MAX IF ELSE SMT_ON
%left MIN MAX IF
%left '|'
%left '^'
%left '&'
%left '-' '+'
%left '*' '/' '%'
%left NEG NOT
%type <num> expr if_expr
%{
static void expr_error(double *final_val __maybe_unused,
struct parse_ctx *ctx __maybe_unused,
void *scanner,
const char *s)
{
pr_debug("%s\n", s);
}
static int lookup_id(struct parse_ctx *ctx, char *id, double *val)
{
int i;
for (i = 0; i < ctx->num_ids; i++) {
if (!strcasecmp(ctx->ids[i].name, id)) {
*val = ctx->ids[i].val;
return 0;
}
}
return -1;
}
%}
%%
start:
EXPR_PARSE all_expr
|
EXPR_OTHER all_other
all_other: all_other other
|
other: ID
{
if (ctx->num_ids + 1 >= EXPR_MAX_OTHER) {
pr_err("failed: way too many variables");
YYABORT;
}
ctx->ids[ctx->num_ids++].name = $1;
}
|
MIN | MAX | IF | ELSE | SMT_ON | NUMBER | '|' | '^' | '&' | '-' | '+' | '*' | '/' | '%' | '(' | ')'
all_expr: if_expr { *final_val = $1; }
;
if_expr:
expr IF expr ELSE expr { $$ = $3 ? $1 : $5; }
| expr
;
expr: NUMBER
| ID { if (lookup_id(ctx, $1, &$$) < 0) {
pr_debug("%s not found\n", $1);
YYABORT;
}
}
| expr '|' expr { $$ = (long)$1 | (long)$3; }
| expr '&' expr { $$ = (long)$1 & (long)$3; }
| expr '^' expr { $$ = (long)$1 ^ (long)$3; }
| expr '+' expr { $$ = $1 + $3; }
| expr '-' expr { $$ = $1 - $3; }
| expr '*' expr { $$ = $1 * $3; }
| expr '/' expr { if ($3 == 0) YYABORT; $$ = $1 / $3; }
| expr '%' expr { if ((long)$3 == 0) YYABORT; $$ = (long)$1 % (long)$3; }
| '-' expr %prec NEG { $$ = -$2; }
| '(' if_expr ')' { $$ = $2; }
| MIN '(' expr ',' expr ')' { $$ = $3 < $5 ? $3 : $5; }
| MAX '(' expr ',' expr ')' { $$ = $3 > $5 ? $3 : $5; }
| SMT_ON { $$ = smt_on() > 0; }
;
%%