xref: /openbmc/linux/tools/perf/util/expr.c (revision 4eb5928d)
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 static size_t key_hash(const void *key, void *ctx __maybe_unused)
21 {
22 	const char *str = (const char *)key;
23 	size_t hash = 0;
24 
25 	while (*str != '\0') {
26 		hash *= 31;
27 		hash += *str;
28 		str++;
29 	}
30 	return hash;
31 }
32 
33 static bool key_equal(const void *key1, const void *key2,
34 		    void *ctx __maybe_unused)
35 {
36 	return !strcmp((const char *)key1, (const char *)key2);
37 }
38 
39 /* Caller must make sure id is allocated */
40 int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
41 {
42 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
43 	char *old_key = NULL;
44 	int ret;
45 
46 	data_ptr = malloc(sizeof(*data_ptr));
47 	if (!data_ptr)
48 		return -ENOMEM;
49 
50 	data_ptr->parent = ctx->parent;
51 
52 	ret = hashmap__set(&ctx->ids, id, data_ptr,
53 			   (const void **)&old_key, (void **)&old_data);
54 	if (ret)
55 		free(data_ptr);
56 	free(old_key);
57 	free(old_data);
58 	return ret;
59 }
60 
61 /* Caller must make sure id is allocated */
62 int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
63 {
64 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
65 	char *old_key = NULL;
66 	int ret;
67 
68 	data_ptr = malloc(sizeof(*data_ptr));
69 	if (!data_ptr)
70 		return -ENOMEM;
71 	data_ptr->val = val;
72 	data_ptr->is_ref = false;
73 
74 	ret = hashmap__set(&ctx->ids, id, data_ptr,
75 			   (const void **)&old_key, (void **)&old_data);
76 	if (ret)
77 		free(data_ptr);
78 	free(old_key);
79 	free(old_data);
80 	return ret;
81 }
82 
83 int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref)
84 {
85 	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
86 	char *old_key = NULL;
87 	char *name, *p;
88 	int ret;
89 
90 	data_ptr = zalloc(sizeof(*data_ptr));
91 	if (!data_ptr)
92 		return -ENOMEM;
93 
94 	name = strdup(ref->metric_name);
95 	if (!name) {
96 		free(data_ptr);
97 		return -ENOMEM;
98 	}
99 
100 	/*
101 	 * The jevents tool converts all metric expressions
102 	 * to lowercase, including metric references, hence
103 	 * we need to add lowercase name for metric, so it's
104 	 * properly found.
105 	 */
106 	for (p = name; *p; p++)
107 		*p = tolower(*p);
108 
109 	/*
110 	 * Intentionally passing just const char pointers,
111 	 * originally from 'struct pmu_event' object.
112 	 * We don't need to change them, so there's no
113 	 * need to create our own copy.
114 	 */
115 	data_ptr->ref.metric_name = ref->metric_name;
116 	data_ptr->ref.metric_expr = ref->metric_expr;
117 	data_ptr->ref.counted = false;
118 	data_ptr->is_ref = true;
119 
120 	ret = hashmap__set(&ctx->ids, name, data_ptr,
121 			   (const void **)&old_key, (void **)&old_data);
122 	if (ret)
123 		free(data_ptr);
124 
125 	pr_debug2("adding ref metric %s: %s\n",
126 		  ref->metric_name, ref->metric_expr);
127 
128 	free(old_key);
129 	free(old_data);
130 	return ret;
131 }
132 
133 int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
134 		 struct expr_id_data **data)
135 {
136 	return hashmap__find(&ctx->ids, id, (void **)data) ? 0 : -1;
137 }
138 
139 int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
140 		     struct expr_id_data **datap)
141 {
142 	struct expr_id_data *data;
143 
144 	if (expr__get_id(ctx, id, datap) || !*datap) {
145 		pr_debug("%s not found\n", id);
146 		return -1;
147 	}
148 
149 	data = *datap;
150 
151 	pr_debug2("lookup: is_ref %d, counted %d, val %f: %s\n",
152 		  data->is_ref, data->ref.counted, data->val, id);
153 
154 	if (data->is_ref && !data->ref.counted) {
155 		data->ref.counted = true;
156 		pr_debug("processing metric: %s ENTRY\n", id);
157 		if (expr__parse(&data->val, ctx, data->ref.metric_expr, 1)) {
158 			pr_debug("%s failed to count\n", id);
159 			return -1;
160 		}
161 		pr_debug("processing metric: %s EXIT: %f\n", id, data->val);
162 	}
163 
164 	return 0;
165 }
166 
167 void expr__del_id(struct expr_parse_ctx *ctx, const char *id)
168 {
169 	struct expr_id_data *old_val = NULL;
170 	char *old_key = NULL;
171 
172 	hashmap__delete(&ctx->ids, id,
173 			(const void **)&old_key, (void **)&old_val);
174 	free(old_key);
175 	free(old_val);
176 }
177 
178 void expr__ctx_init(struct expr_parse_ctx *ctx)
179 {
180 	hashmap__init(&ctx->ids, key_hash, key_equal, NULL);
181 }
182 
183 void expr__ctx_clear(struct expr_parse_ctx *ctx)
184 {
185 	struct hashmap_entry *cur;
186 	size_t bkt;
187 
188 	hashmap__for_each_entry((&ctx->ids), cur, bkt) {
189 		free((char *)cur->key);
190 		free(cur->value);
191 	}
192 	hashmap__clear(&ctx->ids);
193 }
194 
195 static int
196 __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
197 	      int start, int runtime)
198 {
199 	struct expr_scanner_ctx scanner_ctx = {
200 		.start_token = start,
201 		.runtime = runtime,
202 	};
203 	YY_BUFFER_STATE buffer;
204 	void *scanner;
205 	int ret;
206 
207 	pr_debug2("parsing metric: %s\n", expr);
208 
209 	ret = expr_lex_init_extra(&scanner_ctx, &scanner);
210 	if (ret)
211 		return ret;
212 
213 	buffer = expr__scan_string(expr, scanner);
214 
215 #ifdef PARSER_DEBUG
216 	expr_debug = 1;
217 	expr_set_debug(1, scanner);
218 #endif
219 
220 	ret = expr_parse(val, ctx, scanner);
221 
222 	expr__flush_buffer(buffer, scanner);
223 	expr__delete_buffer(buffer, scanner);
224 	expr_lex_destroy(scanner);
225 	return ret;
226 }
227 
228 int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
229 		const char *expr, int runtime)
230 {
231 	return __expr__parse(final_val, ctx, expr, EXPR_PARSE, runtime) ? -1 : 0;
232 }
233 
234 int expr__find_other(const char *expr, const char *one,
235 		     struct expr_parse_ctx *ctx, int runtime)
236 {
237 	int ret = __expr__parse(NULL, ctx, expr, EXPR_OTHER, runtime);
238 
239 	if (one)
240 		expr__del_id(ctx, one);
241 
242 	return ret;
243 }
244