trace.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
   5  * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
   6  * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
   7  * Copyright (C) 2006 Mike McCormack
   8  * Copyright (C) 2006 Christian Couder
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24
  25 #include "cache.h"
  26 #include "quote.h"
  27
  28 /* Get a trace file descriptor from "key" env variable. */
  29 static int get_trace_fd(const char *key, int *need_close)
  30 {
  31         char *trace = getenv(key);
  32
  33         if (!trace || !strcmp(trace, "") ||
  34             !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  35                 return 0;
  36         if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  37                 return STDERR_FILENO;
  38         if (strlen(trace) == 1 && isdigit(*trace))
  39                 return atoi(trace);
  40         if (is_absolute_path(trace)) {
  41                 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  42                 if (fd == -1) {
  43                         fprintf(stderr,
  44                                 "Could not open '%s' for tracing: %s\n"
  45                                 "Defaulting to tracing on stderr...\n",
  46                                 trace, strerror(errno));
  47                         return STDERR_FILENO;
  48                 }
  49                 *need_close = 1;
  50                 return fd;
  51         }
  52
  53         fprintf(stderr, "What does '%s' for %s mean?\n", trace, key);
  54         fprintf(stderr, "If you want to trace into a file, "
  55                 "then please set %s to an absolute pathname "
  56                 "(starting with /).\n", key);
  57         fprintf(stderr, "Defaulting to tracing on stderr...\n");
  58
  59         return STDERR_FILENO;
  60 }
  61
  62 static const char err_msg[] = "Could not trace into fd given by "
  63         "GIT_TRACE environment variable";
  64
  65 static void trace_vprintf(const char *key, const char *fmt, va_list ap)
  66 {
  67         struct strbuf buf = STRBUF_INIT;
  68
  69         if (!trace_want(key))
  70                 return;
  71
  72         set_try_to_free_routine(NULL);  /* is never reset */
  73         strbuf_vaddf(&buf, fmt, ap);
  74         trace_strbuf(key, &buf);
  75         strbuf_release(&buf);
  76 }
  77
  78 __attribute__((format (printf, 2, 3)))
  79 static void trace_printf_key(const char *key, const char *fmt, ...)
  80 {
  81         va_list ap;
  82         va_start(ap, fmt);
  83         trace_vprintf(key, fmt, ap);
  84         va_end(ap);
  85 }
  86
  87 void trace_printf(const char *fmt, ...)
  88 {
  89         va_list ap;
  90         va_start(ap, fmt);
  91         trace_vprintf("GIT_TRACE", fmt, ap);
  92         va_end(ap);
  93 }
  94
  95 void trace_strbuf(const char *key, const struct strbuf *buf)
  96 {
  97         int fd, need_close = 0;
  98
  99         fd = get_trace_fd(key, &need_close);
 100         if (!fd)
 101                 return;
 102
 103         write_or_whine_pipe(fd, buf->buf, buf->len, err_msg);
 104
 105         if (need_close)
 106                 close(fd);
 107 }
 108
 109 void trace_argv_printf(const char **argv, const char *fmt, ...)
 110 {
 111         struct strbuf buf = STRBUF_INIT;
 112         va_list ap;
 113         int fd, need_close = 0;
 114
 115         fd = get_trace_fd("GIT_TRACE", &need_close);
 116         if (!fd)
 117                 return;
 118
 119         set_try_to_free_routine(NULL);  /* is never reset */
 120         va_start(ap, fmt);
 121         strbuf_vaddf(&buf, fmt, ap);
 122         va_end(ap);
 123
 124         sq_quote_argv(&buf, argv, 0);
 125         strbuf_addch(&buf, '\n');
 126         write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
 127         strbuf_release(&buf);
 128
 129         if (need_close)
 130                 close(fd);
 131 }
 132
 133 static const char *quote_crnl(const char *path)
 134 {
 135         static char new_path[PATH_MAX];
 136         const char *p2 = path;
 137         char *p1 = new_path;
 138
 139         if (!path)
 140                 return NULL;
 141
 142         while (*p2) {
 143                 switch (*p2) {
 144                 case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
 145                 case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
 146                 case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
 147                 default:
 148                         *p1++ = *p2;
 149                 }
 150                 p2++;
 151         }
 152         *p1 = '\0';
 153         return new_path;
 154 }
 155
 156 /* FIXME: move prefix to startup_info struct and get rid of this arg */
 157 void trace_repo_setup(const char *prefix)
 158 {
 159         static const char *key = "GIT_TRACE_SETUP";
 160         const char *git_work_tree;
 161         char cwd[PATH_MAX];
 162
 163         if (!trace_want(key))
 164                 return;
 165
 166         if (!getcwd(cwd, PATH_MAX))
 167                 die("Unable to get current working directory");
 168
 169         if (!(git_work_tree = get_git_work_tree()))
 170                 git_work_tree = "(null)";
 171
 172         if (!prefix)
 173                 prefix = "(null)";
 174
 175         trace_printf_key(key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 176         trace_printf_key(key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 177         trace_printf_key(key, "setup: cwd: %s\n", quote_crnl(cwd));
 178         trace_printf_key(key, "setup: prefix: %s\n", quote_crnl(prefix));
 179 }
 180
 181 int trace_want(const char *key)
 182 {
 183         const char *trace = getenv(key);
 184
 185         if (!trace || !strcmp(trace, "") ||
 186             !strcmp(trace, "0") || !strcasecmp(trace, "false"))
 187                 return 0;
 188         return 1;
 189 }