tools/perf/util/help-unknown-cmd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "cache.h"
   3 #include "config.h"
   4 #include <poll.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <subcmd/help.h>
   8 #include "../builtin.h"
   9 #include "levenshtein.h"
  10 #include <linux/zalloc.h>
  11
  12 static int autocorrect;
  13
  14 static int perf_unknown_cmd_config(const char *var, const char *value,
  15                                    void *cb __maybe_unused)
  16 {
  17         if (!strcmp(var, "help.autocorrect"))
  18                 return perf_config_int(&autocorrect, var,value);
  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, struct cmdnames *main_cmds)
  56 {
  57         unsigned int i, n = 0, best_similarity = 0;
  58         struct cmdnames other_cmds;
  59
  60         memset(&other_cmds, 0, sizeof(other_cmds));
  61
  62         perf_config(perf_unknown_cmd_config, NULL);
  63
  64         load_command_list("perf-", main_cmds, &other_cmds);
  65
  66         if (add_cmd_list(main_cmds, &other_cmds) < 0) {
  67                 fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
  68                 goto end;
  69         }
  70         qsort(main_cmds->names, main_cmds->cnt,
  71               sizeof(main_cmds->names), cmdname_compare);
  72         uniq(main_cmds);
  73
  74         if (main_cmds->cnt) {
  75                 /* This reuses cmdname->len for similarity index */
  76                 for (i = 0; i < main_cmds->cnt; ++i) {
  77                         main_cmds->names[i]->len =
  78                                 levenshtein(cmd, main_cmds->names[i]->name,
  79                                         /*swap_penalty=*/0,
  80                                         /*substition_penality=*/2,
  81                                         /*insertion_penality=*/1,
  82                                         /*deletion_penalty=*/1);
  83                 }
  84                 qsort(main_cmds->names, main_cmds->cnt,
  85                       sizeof(*main_cmds->names), levenshtein_compare);
  86
  87                 best_similarity = main_cmds->names[0]->len;
  88                 n = 1;
  89                 while (n < main_cmds->cnt && best_similarity == main_cmds->names[n]->len)
  90                         ++n;
  91         }
  92
  93         if (autocorrect && n == 1) {
  94                 const char *assumed = main_cmds->names[0]->name;
  95
  96                 main_cmds->names[0] = NULL;
  97                 clean_cmdnames(&other_cmds);
  98                 fprintf(stderr, "WARNING: You called a perf program named '%s', "
  99                         "which does not exist.\n"
 100                         "Continuing under the assumption that you meant '%s'\n",
 101                         cmd, assumed);
 102                 if (autocorrect > 0) {
 103                         fprintf(stderr, "in %0.1f seconds automatically...\n",
 104                                 (float)autocorrect/10.0);
 105                         poll(NULL, 0, autocorrect * 100);
 106                 }
 107                 return assumed;
 108         }
 109
 110         fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
 111
 112         if (main_cmds->cnt && best_similarity < 6) {
 113                 fprintf(stderr, "\nDid you mean %s?\n",
 114                         n < 2 ? "this": "one of these");
 115
 116                 for (i = 0; i < n; i++)
 117                         fprintf(stderr, "\t%s\n", main_cmds->names[i]->name);
 118         }
 119 end:
 120         clean_cmdnames(&other_cmds);
 121         return NULL;
 122 }