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
 17extern int expr_debug;
 18#endif
 19
 20struct 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
 43static 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
 56static 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 */
 63int 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 */
 86int 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
107int 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
156int 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
162int 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
203void 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
214void expr__ctx_init(struct expr_parse_ctx *ctx)
215{
216	hashmap__init(&ctx->ids, key_hash, key_equal, NULL);
217}
218
219void 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
231static 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
264int 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
270int 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
281double 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
289struct 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}