1 #include "cache.h"
2 #include <subcmd/help.h>
3 #include "../builtin.h"
4 #include "levenshtein.h"
5 
6 static int autocorrect;
7 static struct cmdnames aliases;
8 
9 static 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 
21 static 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 
30 static 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 
42 const 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 }
105