perf_counter tools: add in basic glue from Git

First very raw version at having a central 'perf' command and
a list of subcommands:

  perf top
  perf stat
  perf record
  perf report
  ...

This is done by picking up Git's collection of utility functions,
and hacking them to build fine in this new environment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 366 insertions, 0 deletions

diff --git a/Documentation/perf_counter/help.c b/Documentation/perf_counter/help.c
new file mode 100644
index 000000000000..ec0116721660
--- /dev/null
+++ b/Documentation/perf_counter/help.c
@@ -0,0 +1,366 @@
+#include "cache.h"
+#include "builtin.h"
+#include "exec_cmd.h"
+#include "levenshtein.h"
+#include "help.h"
+
+/* most GUI terminals set COLUMNS (although some don't export it) */
+static int term_columns(void)
+{
+        char *col_string = getenv("COLUMNS");
+        int n_cols;
+
+        if (col_string && (n_cols = atoi(col_string)) > 0)
+                return n_cols;
+
+#ifdef TIOCGWINSZ
+        {
+                struct winsize ws;
+                if (!ioctl(1, TIOCGWINSZ, &ws)) {
+                        if (ws.ws_col)
+                                return ws.ws_col;
+                }
+        }
+#endif
+
+        return 80;
+}
+
+void add_cmdname(struct cmdnames *cmds, const char *name, int len)
+{
+        struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
+
+        ent->len = len;
+        memcpy(ent->name, name, len);
+        ent->name[len] = 0;
+
+        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
+        cmds->names[cmds->cnt++] = ent;
+}
+
+static void clean_cmdnames(struct cmdnames *cmds)
+{
+        int i;
+        for (i = 0; i < cmds->cnt; ++i)
+                free(cmds->names[i]);
+        free(cmds->names);
+        cmds->cnt = 0;
+        cmds->alloc = 0;
+}
+
+static int cmdname_compare(const void *a_, const void *b_)
+{
+        struct cmdname *a = *(struct cmdname **)a_;
+        struct cmdname *b = *(struct cmdname **)b_;
+        return strcmp(a->name, b->name);
+}
+
+static void uniq(struct cmdnames *cmds)
+{
+        int i, j;
+
+        if (!cmds->cnt)
+                return;
+
+        for (i = j = 1; i < cmds->cnt; i++)
+                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
+                        cmds->names[j++] = cmds->names[i];
+
+        cmds->cnt = j;
+}
+
+void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
+{
+        int ci, cj, ei;
+        int cmp;
+
+        ci = cj = ei = 0;
+        while (ci < cmds->cnt && ei < excludes->cnt) {
+                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
+                if (cmp < 0)
+                        cmds->names[cj++] = cmds->names[ci++];
+                else if (cmp == 0)
+                        ci++, ei++;
+                else if (cmp > 0)
+                        ei++;
+        }
+
+        while (ci < cmds->cnt)
+                cmds->names[cj++] = cmds->names[ci++];
+
+        cmds->cnt = cj;
+}
+
+static void pretty_print_string_list(struct cmdnames *cmds, int longest)
+{
+        int cols = 1, rows;
+        int space = longest + 1; /* min 1 SP between words */
+        int max_cols = term_columns() - 1; /* don't print *on* the edge */
+        int i, j;
+
+        if (space < max_cols)
+                cols = max_cols / space;
+        rows = (cmds->cnt + cols - 1) / cols;
+
+        for (i = 0; i < rows; i++) {
+                printf("  ");
+
+                for (j = 0; j < cols; j++) {
+                        int n = j * rows + i;
+                        int size = space;
+                        if (n >= cmds->cnt)
+                                break;
+                        if (j == cols-1 || n + rows >= cmds->cnt)
+                                size = 1;
+                        printf("%-*s", size, cmds->names[n]->name);
+                }
+                putchar('\n');
+        }
+}
+
+static int is_executable(const char *name)
+{
+        struct stat st;
+
+        if (stat(name, &st) || /* stat, not lstat */
+            !S_ISREG(st.st_mode))
+                return 0;
+
+#ifdef __MINGW32__
+        /* cannot trust the executable bit, peek into the file instead */
+        char buf[3] = { 0 };
+        int n;
+        int fd = open(name, O_RDONLY);
+        st.st_mode &= ~S_IXUSR;
+        if (fd >= 0) {
+                n = read(fd, buf, 2);
+                if (n == 2)
+                        /* DOS executables start with "MZ" */
+                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
+                                st.st_mode |= S_IXUSR;
+                close(fd);
+        }
+#endif
+        return st.st_mode & S_IXUSR;
+}
+
+static void list_commands_in_dir(struct cmdnames *cmds,
+                                         const char *path,
+                                         const char *prefix)
+{
+        int prefix_len;
+        DIR *dir = opendir(path);
+        struct dirent *de;
+        struct strbuf buf = STRBUF_INIT;
+        int len;
+
+        if (!dir)
+                return;
+        if (!prefix)
+                prefix = "perf-";
+        prefix_len = strlen(prefix);
+
+        strbuf_addf(&buf, "%s/", path);
+        len = buf.len;
+
+        while ((de = readdir(dir)) != NULL) {
+                int entlen;
+
+                if (prefixcmp(de->d_name, prefix))
+                        continue;
+
+                strbuf_setlen(&buf, len);
+                strbuf_addstr(&buf, de->d_name);
+                if (!is_executable(buf.buf))
+                        continue;
+
+                entlen = strlen(de->d_name) - prefix_len;
+                if (has_extension(de->d_name, ".exe"))
+                        entlen -= 4;
+
+                add_cmdname(cmds, de->d_name + prefix_len, entlen);
+        }
+        closedir(dir);
+        strbuf_release(&buf);
+}
+
+void load_command_list(const char *prefix,
+                struct cmdnames *main_cmds,
+                struct cmdnames *other_cmds)
+{
+        const char *env_path = getenv("PATH");
+        const char *exec_path = perf_exec_path();
+
+        if (exec_path) {
+                list_commands_in_dir(main_cmds, exec_path, prefix);
+                qsort(main_cmds->names, main_cmds->cnt,
+                      sizeof(*main_cmds->names), cmdname_compare);
+                uniq(main_cmds);
+        }
+
+        if (env_path) {
+                char *paths, *path, *colon;
+                path = paths = strdup(env_path);
+                while (1) {
+                        if ((colon = strchr(path, PATH_SEP)))
+                                *colon = 0;
+                        if (!exec_path || strcmp(path, exec_path))
+                                list_commands_in_dir(other_cmds, path, prefix);
+
+                        if (!colon)
+                                break;
+                        path = colon + 1;
+                }
+                free(paths);
+
+                qsort(other_cmds->names, other_cmds->cnt,
+                      sizeof(*other_cmds->names), cmdname_compare);
+                uniq(other_cmds);
+        }
+        exclude_cmds(other_cmds, main_cmds);
+}
+
+void list_commands(const char *title, struct cmdnames *main_cmds,
+                   struct cmdnames *other_cmds)
+{
+        int i, longest = 0;
+
+        for (i = 0; i < main_cmds->cnt; i++)
+                if (longest < main_cmds->names[i]->len)
+                        longest = main_cmds->names[i]->len;
+        for (i = 0; i < other_cmds->cnt; i++)
+                if (longest < other_cmds->names[i]->len)
+                        longest = other_cmds->names[i]->len;
+
+        if (main_cmds->cnt) {
+                const char *exec_path = perf_exec_path();
+                printf("available %s in '%s'\n", title, exec_path);
+                printf("----------------");
+                mput_char('-', strlen(title) + strlen(exec_path));
+                putchar('\n');
+                pretty_print_string_list(main_cmds, longest);
+                putchar('\n');
+        }
+
+        if (other_cmds->cnt) {
+                printf("%s available from elsewhere on your $PATH\n", title);
+                printf("---------------------------------------");
+                mput_char('-', strlen(title));
+                putchar('\n');
+                pretty_print_string_list(other_cmds, longest);
+                putchar('\n');
+        }
+}
+
+int is_in_cmdlist(struct cmdnames *c, const char *s)
+{
+        int i;
+        for (i = 0; i < c->cnt; i++)
+                if (!strcmp(s, c->names[i]->name))
+                        return 1;
+        return 0;
+}
+
+static int autocorrect;
+static struct cmdnames aliases;
+
+static int perf_unknown_cmd_config(const char *var, const char *value, void *cb)
+{
+        if (!strcmp(var, "help.autocorrect"))
+                autocorrect = perf_config_int(var,value);
+        /* Also use aliases for command lookup */
+        if (!prefixcmp(var, "alias."))
+                add_cmdname(&aliases, var + 6, strlen(var + 6));
+
+        return perf_default_config(var, value, cb);
+}
+
+static int levenshtein_compare(const void *p1, const void *p2)
+{
+        const struct cmdname *const *c1 = p1, *const *c2 = p2;
+        const char *s1 = (*c1)->name, *s2 = (*c2)->name;
+        int l1 = (*c1)->len;
+        int l2 = (*c2)->len;
+        return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
+}
+
+static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
+{
+        int i;
+        ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
+
+        for (i = 0; i < old->cnt; i++)
+                cmds->names[cmds->cnt++] = old->names[i];
+        free(old->names);
+        old->cnt = 0;
+        old->names = NULL;
+}
+
+const char *help_unknown_cmd(const char *cmd)
+{
+        int i, n, best_similarity = 0;
+        struct cmdnames main_cmds, other_cmds;
+
+        memset(&main_cmds, 0, sizeof(main_cmds));
+        memset(&other_cmds, 0, sizeof(main_cmds));
+        memset(&aliases, 0, sizeof(aliases));
+
+        perf_config(perf_unknown_cmd_config, NULL);
+
+        load_command_list("perf-", &main_cmds, &other_cmds);
+
+        add_cmd_list(&main_cmds, &aliases);
+        add_cmd_list(&main_cmds, &other_cmds);
+        qsort(main_cmds.names, main_cmds.cnt,
+              sizeof(main_cmds.names), cmdname_compare);
+        uniq(&main_cmds);
+
+        /* This reuses cmdname->len for similarity index */
+        for (i = 0; i < main_cmds.cnt; ++i)
+                main_cmds.names[i]->len =
+                        levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
+
+        qsort(main_cmds.names, main_cmds.cnt,
+              sizeof(*main_cmds.names), levenshtein_compare);
+
+        if (!main_cmds.cnt)
+                die ("Uh oh. Your system reports no Git commands at all.");
+
+        best_similarity = main_cmds.names[0]->len;
+        n = 1;
+        while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
+                ++n;
+        if (autocorrect && n == 1) {
+                const char *assumed = main_cmds.names[0]->name;
+                main_cmds.names[0] = NULL;
+                clean_cmdnames(&main_cmds);
+                fprintf(stderr, "WARNING: You called a Git program named '%s', "
+                        "which does not exist.\n"
+                        "Continuing under the assumption that you meant '%s'\n",
+                        cmd, assumed);
+                if (autocorrect > 0) {
+                        fprintf(stderr, "in %0.1f seconds automatically...\n",
+                                (float)autocorrect/10.0);
+                        poll(NULL, 0, autocorrect * 100);
+                }
+                return assumed;
+        }
+
+        fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
+
+        if (best_similarity < 6) {
+                fprintf(stderr, "\nDid you mean %s?\n",
+                        n < 2 ? "this": "one of these");
+
+                for (i = 0; i < n; i++)
+                        fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
+        }
+
+        exit(1);
+}
+
+int cmd_version(int argc, const char **argv, const char *prefix)
+{
+        printf("perf version %s\n", perf_version_string);
+        return 0;
+}