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

   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 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         memset(&aliases, 0, sizeof(aliases));
  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, &aliases) < 0 ||
  67             add_cmd_list(&main_cmds, &other_cmds) < 0) {
  68                 fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
  69                 goto end;
  70         }
  71         qsort(main_cmds.names, main_cmds.cnt,
  72               sizeof(main_cmds.names), cmdname_compare);
  73         uniq(&main_cmds);
  74
  75         if (main_cmds.cnt) {
  76                 /* This reuses cmdname->len for similarity index */
  77                 for (i = 0; i < main_cmds.cnt; ++i)
  78                         main_cmds.names[i]->len =
  79                                 levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
  80
  81                 qsort(main_cmds.names, main_cmds.cnt,
  82                       sizeof(*main_cmds.names), levenshtein_compare);
  83
  84                 best_similarity = main_cmds.names[0]->len;
  85                 n = 1;
  86                 while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
  87                         ++n;
  88         }
  89
  90         if (autocorrect && n == 1) {
  91                 const char *assumed = main_cmds.names[0]->name;
  92
  93                 main_cmds.names[0] = NULL;
  94                 clean_cmdnames(&main_cmds);
  95                 fprintf(stderr, "WARNING: You called a perf program named '%s', "
  96                         "which does not exist.\n"
  97                         "Continuing under the assumption that you meant '%s'\n",
  98                         cmd, assumed);
  99                 if (autocorrect > 0) {
 100                         fprintf(stderr, "in %0.1f seconds automatically...\n",
 101                                 (float)autocorrect/10.0);
 102                         poll(NULL, 0, autocorrect * 100);
 103                 }
 104                 return assumed;
 105         }
 106
 107         fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
 108
 109         if (main_cmds.cnt && best_similarity < 6) {
 110                 fprintf(stderr, "\nDid you mean %s?\n",
 111                         n < 2 ? "this": "one of these");
 112
 113                 for (i = 0; i < n; i++)
 114                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 115         }
 116 end:
 117         exit(1);
 118 }