1 #include "cache.h"
2 #include "config.h"
3 #include <stdio.h>
4 #include <subcmd/help.h>
5 #include "../builtin.h"
6 #include "levenshtein.h"
7 
8 static int autocorrect;
9 static struct cmdnames aliases;
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 	/* Also use aliases for command lookup */
17 	if (!prefixcmp(var, "alias."))
18 		add_cmdname(&aliases, var + 6, strlen(var + 6));
19 
20 	return 0;
21 }
22 
23 static int levenshtein_compare(const void *p1, const void *p2)
24 {
25 	const struct cmdname *const *c1 = p1, *const *c2 = p2;
26 	const char *s1 = (*c1)->name, *s2 = (*c2)->name;
27 	int l1 = (*c1)->len;
28 	int l2 = (*c2)->len;
29 	return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
30 }
31 
32 static int add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
33 {
34 	unsigned int i, nr = cmds->cnt + old->cnt;
35 	void *tmp;
36 
37 	if (nr > cmds->alloc) {
38 		/* Choose bigger one to alloc */
39 		if (alloc_nr(cmds->alloc) < nr)
40 			cmds->alloc = nr;
41 		else
42 			cmds->alloc = alloc_nr(cmds->alloc);
43 		tmp = realloc(cmds->names, cmds->alloc * sizeof(*cmds->names));
44 		if (!tmp)
45 			return -1;
46 		cmds->names = tmp;
47 	}
48 	for (i = 0; i < old->cnt; i++)
49 		cmds->names[cmds->cnt++] = old->names[i];
50 	zfree(&old->names);
51 	old->cnt = 0;
52 	return 0;
53 }
54 
55 const char *help_unknown_cmd(const char *cmd)
56 {
57 	unsigned int i, n = 0, best_similarity = 0;
58 	struct cmdnames main_cmds, other_cmds;
59 
60 	memset(&main_cmds, 0, sizeof(main_cmds));
61 	memset(&other_cmds, 0, sizeof(main_cmds));
62 	memset(&aliases, 0, sizeof(aliases));
63 
64 	perf_config(perf_unknown_cmd_config, NULL);
65 
66 	load_command_list("perf-", &main_cmds, &other_cmds);
67 
68 	if (add_cmd_list(&main_cmds, &aliases) < 0 ||
69 	    add_cmd_list(&main_cmds, &other_cmds) < 0) {
70 		fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
71 		goto end;
72 	}
73 	qsort(main_cmds.names, main_cmds.cnt,
74 	      sizeof(main_cmds.names), cmdname_compare);
75 	uniq(&main_cmds);
76 
77 	if (main_cmds.cnt) {
78 		/* This reuses cmdname->len for similarity index */
79 		for (i = 0; i < main_cmds.cnt; ++i)
80 			main_cmds.names[i]->len =
81 				levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
82 
83 		qsort(main_cmds.names, main_cmds.cnt,
84 		      sizeof(*main_cmds.names), levenshtein_compare);
85 
86 		best_similarity = main_cmds.names[0]->len;
87 		n = 1;
88 		while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
89 			++n;
90 	}
91 
92 	if (autocorrect && n == 1) {
93 		const char *assumed = main_cmds.names[0]->name;
94 
95 		main_cmds.names[0] = NULL;
96 		clean_cmdnames(&main_cmds);
97 		fprintf(stderr, "WARNING: You called a perf program named '%s', "
98 			"which does not exist.\n"
99 			"Continuing under the assumption that you meant '%s'\n",
100 			cmd, assumed);
101 		if (autocorrect > 0) {
102 			fprintf(stderr, "in %0.1f seconds automatically...\n",
103 				(float)autocorrect/10.0);
104 			poll(NULL, 0, autocorrect * 100);
105 		}
106 		return assumed;
107 	}
108 
109 	fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
110 
111 	if (main_cmds.cnt && best_similarity < 6) {
112 		fprintf(stderr, "\nDid you mean %s?\n",
113 			n < 2 ? "this": "one of these");
114 
115 		for (i = 0; i < n; i++)
116 			fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
117 	}
118 end:
119 	exit(1);
120 }
121