xref: /linux/tools/perf/util/expr.c (revision de6e0b198239857943db395377dc1d2ddd6c05df)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdbool.h>
3 #include <assert.h>
4 #include <errno.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include "metricgroup.h"
8 #include "debug.h"
9 #include "expr.h"
10 #include "expr-bison.h"
11 #include "expr-flex.h"
12 #include <linux/kernel.h>
13 #include <linux/zalloc.h>
14 #include <ctype.h>
15 
16 #ifdef PARSER_DEBUG
17 extern int expr_debug;
18 #endif
19 
20 struct expr_id_data {
21 	union {
22 		double val;
23 		struct {
24 			double val;
25 			const char *metric_name;
26 			const char *metric_expr;
27 		} ref;
28 		struct expr_id	*parent;
29 	};
30 
31 	enum {
32 		/* Holding a double value. */
33 		EXPR_ID_DATA__VALUE,
34 		/* Reference to another metric. */
35 		EXPR_ID_DATA__REF,
36 		/* A reference but the value has been computed. */
37 		EXPR_ID_DATA__REF_VALUE,
38 		/* A parent is remembered for the recursion check. */
39 		EXPR_ID_DATA__PARENT,
40 	} kind;
41 };
42 
43 static size_t key_hash(const void *key, void *ctx __maybe_unused)
44 {
45 	const char *str = (const char *)key;
46 	size_t hash = 0;
47 
48 	while (*str != '\0') {
49 		hash *= 31;
50 		hash += *str;
51 		str++;
52 	}
53 	return hash;
54 }
55 
56 static bool key_equal(const void *key1, const void *key2,
57 		    void *ctx __maybe_unused)
58 {
59 	return !strcmp((const char *)key1, (const char *)key2);
60 }
61 
62 /* Caller must make sure id is allocated */
63 int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
64 {
65 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
66 	char *old_key = NULL;
67 	int ret;
68 
69 	data_ptr = malloc(sizeof(*data_ptr));
70 	if (!data_ptr)
71 		return -ENOMEM;
72 
73 	data_ptr->parent = ctx->parent;
74 	data_ptr->kind = EXPR_ID_DATA__PARENT;
75 
76 	ret = hashmap__set(&ctx->ids, id, data_ptr,
77 			   (const void **)&old_key, (void **)&old_data);
78 	if (ret)
79 		free(data_ptr);
80 	free(old_key);
81 	free(old_data);
82 	return ret;
83 }
84 
85 /* Caller must make sure id is allocated */
86 int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
87 {
88 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
89 	char *old_key = NULL;
90 	int ret;
91 
92 	data_ptr = malloc(sizeof(*data_ptr));
93 	if (!data_ptr)
94 		return -ENOMEM;
95 	data_ptr->val = val;
96 	data_ptr->kind = EXPR_ID_DATA__VALUE;
97 
98 	ret = hashmap__set(&ctx->ids, id, data_ptr,
99 			   (const void **)&old_key, (void **)&old_data);
100 	if (ret)
101 		free(data_ptr);
102 	free(old_key);
103 	free(old_data);
104 	return ret;
105 }
106 
107 int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref)
108 {
109 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
110 	char *old_key = NULL;
111 	char *name, *p;
112 	int ret;
113 
114 	data_ptr = zalloc(sizeof(*data_ptr));
115 	if (!data_ptr)
116 		return -ENOMEM;
117 
118 	name = strdup(ref->metric_name);
119 	if (!name) {
120 		free(data_ptr);
121 		return -ENOMEM;
122 	}
123 
124 	/*
125 	 * The jevents tool converts all metric expressions
126 	 * to lowercase, including metric references, hence
127 	 * we need to add lowercase name for metric, so it's
128 	 * properly found.
129 	 */
130 	for (p = name; *p; p++)
131 		*p = tolower(*p);
132 
133 	/*
134 	 * Intentionally passing just const char pointers,
135 	 * originally from 'struct pmu_event' object.
136 	 * We don't need to change them, so there's no
137 	 * need to create our own copy.
138 	 */
139 	data_ptr->ref.metric_name = ref->metric_name;
140 	data_ptr->ref.metric_expr = ref->metric_expr;
141 	data_ptr->kind = EXPR_ID_DATA__REF;
142 
143 	ret = hashmap__set(&ctx->ids, name, data_ptr,
144 			   (const void **)&old_key, (void **)&old_data);
145 	if (ret)
146 		free(data_ptr);
147 
148 	pr_debug2("adding ref metric %s: %s\n",
149 		  ref->metric_name, ref->metric_expr);
150 
151 	free(old_key);
152 	free(old_data);
153 	return ret;
154 }
155 
156 int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
157 		 struct expr_id_data **data)
158 {
159 	return hashmap__find(&ctx->ids, id, (void **)data) ? 0 : -1;
160 }
161 
162 int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
163 		     struct expr_id_data **datap)
164 {
165 	struct expr_id_data *data;
166 
167 	if (expr__get_id(ctx, id, datap) || !*datap) {
168 		pr_debug("%s not found\n", id);
169 		return -1;
170 	}
171 
172 	data = *datap;
173 
174 	switch (data->kind) {
175 	case EXPR_ID_DATA__VALUE:
176 		pr_debug2("lookup(%s): val %f\n", id, data->val);
177 		break;
178 	case EXPR_ID_DATA__PARENT:
179 		pr_debug2("lookup(%s): parent %s\n", id, data->parent->id);
180 		break;
181 	case EXPR_ID_DATA__REF:
182 		pr_debug2("lookup(%s): ref metric name %s\n", id,
183 			data->ref.metric_name);
184 		pr_debug("processing metric: %s ENTRY\n", id);
185 		data->kind = EXPR_ID_DATA__REF_VALUE;
186 		if (expr__parse(&data->ref.val, ctx, data->ref.metric_expr, 1)) {
187 			pr_debug("%s failed to count\n", id);
188 			return -1;
189 		}
190 		pr_debug("processing metric: %s EXIT: %f\n", id, data->val);
191 		break;
192 	case EXPR_ID_DATA__REF_VALUE:
193 		pr_debug2("lookup(%s): ref val %f metric name %s\n", id,
194 			data->ref.val, data->ref.metric_name);
195 		break;
196 	default:
197 		assert(0);  /* Unreachable. */
198 	}
199 
200 	return 0;
201 }
202 
203 void expr__del_id(struct expr_parse_ctx *ctx, const char *id)
204 {
205 	struct expr_id_data *old_val = NULL;
206 	char *old_key = NULL;
207 
208 	hashmap__delete(&ctx->ids, id,
209 			(const void **)&old_key, (void **)&old_val);
210 	free(old_key);
211 	free(old_val);
212 }
213 
214 void expr__ctx_init(struct expr_parse_ctx *ctx)
215 {
216 	hashmap__init(&ctx->ids, key_hash, key_equal, NULL);
217 }
218 
219 void expr__ctx_clear(struct expr_parse_ctx *ctx)
220 {
221 	struct hashmap_entry *cur;
222 	size_t bkt;
223 
224 	hashmap__for_each_entry((&ctx->ids), cur, bkt) {
225 		free((char *)cur->key);
226 		free(cur->value);
227 	}
228 	hashmap__clear(&ctx->ids);
229 }
230 
231 static int
232 __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
233 	      int start, int runtime)
234 {
235 	struct expr_scanner_ctx scanner_ctx = {
236 		.start_token = start,
237 		.runtime = runtime,
238 	};
239 	YY_BUFFER_STATE buffer;
240 	void *scanner;
241 	int ret;
242 
243 	pr_debug2("parsing metric: %s\n", expr);
244 
245 	ret = expr_lex_init_extra(&scanner_ctx, &scanner);
246 	if (ret)
247 		return ret;
248 
249 	buffer = expr__scan_string(expr, scanner);
250 
251 #ifdef PARSER_DEBUG
252 	expr_debug = 1;
253 	expr_set_debug(1, scanner);
254 #endif
255 
256 	ret = expr_parse(val, ctx, scanner);
257 
258 	expr__flush_buffer(buffer, scanner);
259 	expr__delete_buffer(buffer, scanner);
260 	expr_lex_destroy(scanner);
261 	return ret;
262 }
263 
264 int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
265 		const char *expr, int runtime)
266 {
267 	return __expr__parse(final_val, ctx, expr, EXPR_PARSE, runtime) ? -1 : 0;
268 }
269 
270 int expr__find_other(const char *expr, const char *one,
271 		     struct expr_parse_ctx *ctx, int runtime)
272 {
273 	int ret = __expr__parse(NULL, ctx, expr, EXPR_OTHER, runtime);
274 
275 	if (one)
276 		expr__del_id(ctx, one);
277 
278 	return ret;
279 }
280 
281 double expr_id_data__value(const struct expr_id_data *data)
282 {
283 	if (data->kind == EXPR_ID_DATA__VALUE)
284 		return data->val;
285 	assert(data->kind == EXPR_ID_DATA__REF_VALUE);
286 	return data->ref.val;
287 }
288 
289 struct expr_id *expr_id_data__parent(struct expr_id_data *data)
290 {
291 	assert(data->kind == EXPR_ID_DATA__PARENT);
292 	return data->parent;
293 }
294