summaryrefslogtreecommitdiff
path: root/tools/perf/util/expr.y
blob: 432b8560cf51c8bf2d751d409d34fe516ade2582 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/* Simple expression parser */
%{
#include "util.h"
#include "util/debug.h"
#define IN_EXPR_Y 1
#include "expr.h"
#include "smt.h"
#include <string.h>

#define MAXIDLEN 256
%}

%pure-parser
%parse-param { double *final_val }
%parse-param { struct parse_ctx *ctx }
%parse-param { const char **pp }
%lex-param { const char **pp }

%union {
	double num;
	char id[MAXIDLEN+1];
}

%token <num> NUMBER
%token <id> 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 int expr__lex(YYSTYPE *res, const char **pp);

static void expr__error(double *final_val __maybe_unused,
		       struct parse_ctx *ctx __maybe_unused,
		       const char **pp __maybe_unused,
		       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;
}

%}
%%

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; }
	;

%%

static int expr__symbol(YYSTYPE *res, const char *p, const char **pp)
{
	char *dst = res->id;
	const char *s = p;

	if (*p == '#')
		*dst++ = *p++;

	while (isalnum(*p) || *p == '_' || *p == '.' || *p == ':' || *p == '@' || *p == '\\') {
		if (p - s >= MAXIDLEN)
			return -1;
		/*
		 * Allow @ instead of / to be able to specify pmu/event/ without
		 * conflicts with normal division.
		 */
		if (*p == '@')
			*dst++ = '/';
		else if (*p == '\\')
			*dst++ = *++p;
		else
			*dst++ = *p;
		p++;
	}
	*dst = 0;
	*pp = p;
	dst = res->id;
	switch (dst[0]) {
	case 'm':
		if (!strcmp(dst, "min"))
			return MIN;
		if (!strcmp(dst, "max"))
			return MAX;
		break;
	case 'i':
		if (!strcmp(dst, "if"))
			return IF;
		break;
	case 'e':
		if (!strcmp(dst, "else"))
			return ELSE;
		break;
	case '#':
		if (!strcasecmp(dst, "#smt_on"))
			return SMT_ON;
		break;
	}
	return ID;
}

static int expr__lex(YYSTYPE *res, const char **pp)
{
	int tok;
	const char *s;
	const char *p = *pp;

	while (isspace(*p))
		p++;
	s = p;
	switch (*p++) {
	case '#':
	case 'a' ... 'z':
	case 'A' ... 'Z':
		return expr__symbol(res, p - 1, pp);
	case '0' ... '9': case '.':
		res->num = strtod(s, (char **)&p);
		tok = NUMBER;
		break;
	default:
		tok = *s;
		break;
	}
	*pp = p;
	return tok;
}

/* Caller must make sure id is allocated */
void expr__add_id(struct parse_ctx *ctx, const char *name, double val)
{
	int idx;
	assert(ctx->num_ids < MAX_PARSE_ID);
	idx = ctx->num_ids++;
	ctx->ids[idx].name = name;
	ctx->ids[idx].val = val;
}

void expr__ctx_init(struct parse_ctx *ctx)
{
	ctx->num_ids = 0;
}

static bool already_seen(const char *val, const char *one, const char **other,
			 int num_other)
{
	int i;

	if (one && !strcasecmp(one, val))
		return true;
	for (i = 0; i < num_other; i++)
		if (!strcasecmp(other[i], val))
			return true;
	return false;
}

int expr__find_other(const char *p, const char *one, const char ***other,
		     int *num_otherp)
{
	const char *orig = p;
	int err = -1;
	int num_other;

	*other = malloc((EXPR_MAX_OTHER + 1) * sizeof(char *));
	if (!*other)
		return -1;

	num_other = 0;
	for (;;) {
		YYSTYPE val;
		int tok = expr__lex(&val, &p);
		if (tok == 0) {
			err = 0;
			break;
		}
		if (tok == ID && !already_seen(val.id, one, *other, num_other)) {
			if (num_other >= EXPR_MAX_OTHER - 1) {
				pr_debug("Too many extra events in %s\n", orig);
				break;
			}
			(*other)[num_other] = strdup(val.id);
			if (!(*other)[num_other])
				return -1;
			num_other++;
		}
	}
	(*other)[num_other] = NULL;
	*num_otherp = num_other;
	if (err) {
		*num_otherp = 0;
		free(*other);
		*other = NULL;
	}
	return err;
}