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