1#include "cache.h"
  2#include <subcmd/help.h>
  3#include "../builtin.h"
  4#include "levenshtein.h"
  5
  6static int autocorrect;
  7static struct cmdnames aliases;
  8
  9static int perf_unknown_cmd_config(const char *var, const char *value,
 10				   void *cb __maybe_unused)
 11{
 12	if (!strcmp(var, "help.autocorrect"))
 13		autocorrect = perf_config_int(var,value);
 14	/* Also use aliases for command lookup */
 15	if (!prefixcmp(var, "alias."))
 16		add_cmdname(&aliases, var + 6, strlen(var + 6));
 17
 18	return 0;
 19}
 20
 21static int levenshtein_compare(const void *p1, const void *p2)
 22{
 23	const struct cmdname *const *c1 = p1, *const *c2 = p2;
 24	const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 25	int l1 = (*c1)->len;
 26	int l2 = (*c2)->len;
 27	return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 28}
 29
 30static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 31{
 32	unsigned int i;
 33
 34	ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 35
 36	for (i = 0; i < old->cnt; i++)
 37		cmds->names[cmds->cnt++] = old->names[i];
 38	zfree(&old->names);
 39	old->cnt = 0;
 40}
 41
 42const char *help_unknown_cmd(const char *cmd)
 43{
 44	unsigned int i, n = 0, best_similarity = 0;
 45	struct cmdnames main_cmds, other_cmds;
 46
 47	memset(&main_cmds, 0, sizeof(main_cmds));
 48	memset(&other_cmds, 0, sizeof(main_cmds));
 49	memset(&aliases, 0, sizeof(aliases));
 50
 51	perf_config(perf_unknown_cmd_config, NULL);
 52
 53	load_command_list("perf-", &main_cmds, &other_cmds);
 54
 55	add_cmd_list(&main_cmds, &aliases);
 56	add_cmd_list(&main_cmds, &other_cmds);
 57	qsort(main_cmds.names, main_cmds.cnt,
 58	      sizeof(main_cmds.names), cmdname_compare);
 59	uniq(&main_cmds);
 60
 61	if (main_cmds.cnt) {
 62		/* This reuses cmdname->len for similarity index */
 63		for (i = 0; i < main_cmds.cnt; ++i)
 64			main_cmds.names[i]->len =
 65				levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
 66
 67		qsort(main_cmds.names, main_cmds.cnt,
 68		      sizeof(*main_cmds.names), levenshtein_compare);
 69
 70		best_similarity = main_cmds.names[0]->len;
 71		n = 1;
 72		while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
 73			++n;
 74	}
 75
 76	if (autocorrect && n == 1) {
 77		const char *assumed = main_cmds.names[0]->name;
 78
 79		main_cmds.names[0] = NULL;
 80		clean_cmdnames(&main_cmds);
 81		fprintf(stderr, "WARNING: You called a perf program named '%s', "
 82			"which does not exist.\n"
 83			"Continuing under the assumption that you meant '%s'\n",
 84			cmd, assumed);
 85		if (autocorrect > 0) {
 86			fprintf(stderr, "in %0.1f seconds automatically...\n",
 87				(float)autocorrect/10.0);
 88			poll(NULL, 0, autocorrect * 100);
 89		}
 90		return assumed;
 91	}
 92
 93	fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
 94
 95	if (main_cmds.cnt && best_similarity < 6) {
 96		fprintf(stderr, "\nDid you mean %s?\n",
 97			n < 2 ? "this": "one of these");
 98
 99		for (i = 0; i < n; i++)
100			fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
101	}
102
103	exit(1);
104}