LXR linux/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
  12static int autocorrect;
  13
  14static 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
  23static 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
  32static 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
  55const 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
  63        perf_config(perf_unknown_cmd_config, NULL);
  64
  65        load_command_list("perf-", &main_cmds, &other_cmds);
  66
  67        if (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        }
 116end:
 117        exit(1);
 118}
 119