1 #include "cache.h"
2 #include "config.h"
3 #include <poll.h>
4 #include <stdio.h>
5 #include <subcmd/help.h>
6 #include "../builtin.h"
7 #include "levenshtein.h"
8 
9 static int autocorrect;
10 
11 static int perf_unknown_cmd_config(const char *var, const char *value,
12 				   void *cb __maybe_unused)
13 {
14 	if (!strcmp(var, "help.autocorrect"))
15 		autocorrect = perf_config_int(var,value);
16 
17 	return 0;
18 }
19 
20 static int levenshtein_compare(const void *p1, const void *p2)
21 {
22 	const struct cmdname *const *c1 = p1, *const *c2 = p2;
23 	const char *s1 = (*c1)->name, *s2 = (*c2)->name;
24 	int l1 = (*c1)->len;
25 	int l2 = (*c2)->len;
26 	return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
27 }
28 
29 static int add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
30 {
31 	unsigned int i, nr = cmds->cnt + old->cnt;
32 	void *tmp;
33 
34 	if (nr > cmds->alloc) {
35 		/* Choose bigger one to alloc */
36 		if (alloc_nr(cmds->alloc) < nr)
37 			cmds->alloc = nr;
38 		else
39 			cmds->alloc = alloc_nr(cmds->alloc);
40 		tmp = realloc(cmds->names, cmds->alloc * sizeof(*cmds->names));
41 		if (!tmp)
42 			return -1;
43 		cmds->names = tmp;
44 	}
45 	for (i = 0; i < old->cnt; i++)
46 		cmds->names[cmds->cnt++] = old->names[i];
47 	zfree(&old->names);
48 	old->cnt = 0;
49 	return 0;
50 }
51 
52 const char *help_unknown_cmd(const char *cmd)
53 {
54 	unsigned int i, n = 0, best_similarity = 0;
55 	struct cmdnames main_cmds, other_cmds;
56 
57 	memset(&main_cmds, 0, sizeof(main_cmds));
58 	memset(&other_cmds, 0, sizeof(main_cmds));
59 
60 	perf_config(perf_unknown_cmd_config, NULL);
61 
62 	load_command_list("perf-", &main_cmds, &other_cmds);
63 
64 	if (add_cmd_list(&main_cmds, &other_cmds) < 0) {
65 		fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
66 		goto end;
67 	}
68 	qsort(main_cmds.names, main_cmds.cnt,
69 	      sizeof(main_cmds.names), cmdname_compare);
70 	uniq(&main_cmds);
71 
72 	if (main_cmds.cnt) {
73 		/* This reuses cmdname->len for similarity index */
74 		for (i = 0; i < main_cmds.cnt; ++i)
75 			main_cmds.names[i]->len =
76 				levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
77 
78 		qsort(main_cmds.names, main_cmds.cnt,
79 		      sizeof(*main_cmds.names), levenshtein_compare);
80 
81 		best_similarity = main_cmds.names[0]->len;
82 		n = 1;
83 		while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
84 			++n;
85 	}
86 
87 	if (autocorrect && n == 1) {
88 		const char *assumed = main_cmds.names[0]->name;
89 
90 		main_cmds.names[0] = NULL;
91 		clean_cmdnames(&main_cmds);
92 		fprintf(stderr, "WARNING: You called a perf program named '%s', "
93 			"which does not exist.\n"
94 			"Continuing under the assumption that you meant '%s'\n",
95 			cmd, assumed);
96 		if (autocorrect > 0) {
97 			fprintf(stderr, "in %0.1f seconds automatically...\n",
98 				(float)autocorrect/10.0);
99 			poll(NULL, 0, autocorrect * 100);
100 		}
101 		return assumed;
102 	}
103 
104 	fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
105 
106 	if (main_cmds.cnt && best_similarity < 6) {
107 		fprintf(stderr, "\nDid you mean %s?\n",
108 			n < 2 ? "this": "one of these");
109 
110 		for (i = 0; i < n; i++)
111 			fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
112 	}
113 end:
114 	exit(1);
115 }
116