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(struct trace_key *key)
  30 {
  31         static struct trace_key trace_default = { "GIT_TRACE" };
  32         const char *trace;
  33
  34         /* use default "GIT_TRACE" if NULL */
  35         if (!key)
  36                 key = &trace_default;
  37
  38         /* don't open twice */
  39         if (key->initialized)
  40                 return key->fd;
  41
  42         trace = getenv(key->key);
  43
  44         if (!trace || !strcmp(trace, "") ||
  45             !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  46                 key->fd = 0;
  47         else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  48                 key->fd = STDERR_FILENO;
  49         else if (strlen(trace) == 1 && isdigit(*trace))
  50                 key->fd = atoi(trace);
  51         else if (is_absolute_path(trace)) {
  52                 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  53                 if (fd == -1) {
  54                         fprintf(stderr,
  55                                 "Could not open '%s' for tracing: %s\n"
  56                                 "Defaulting to tracing on stderr...\n",
  57                                 trace, strerror(errno));
  58                         key->fd = STDERR_FILENO;
  59                 } else {
  60                         key->fd = fd;
  61                         key->need_close = 1;
  62                 }
  63         } else {
  64                 fprintf(stderr, "What does '%s' for %s mean?\n"
  65                         "If you want to trace into a file, then please set "
  66                         "%s to an absolute pathname (starting with /).\n"
  67                         "Defaulting to tracing on stderr...\n",
  68                         trace, key->key, key->key);
  69                 key->fd = STDERR_FILENO;
  70         }
  71
  72         key->initialized = 1;
  73         return key->fd;
  74 }
  75
  76 void trace_disable(struct trace_key *key)
  77 {
  78         if (key->need_close)
  79                 close(key->fd);
  80         key->fd = 0;
  81         key->initialized = 1;
  82         key->need_close = 0;
  83 }
  84
  85 static const char err_msg[] = "Could not trace into fd given by "
  86         "GIT_TRACE environment variable";
  87
  88 static int prepare_trace_line(struct trace_key *key, struct strbuf *buf)
  89 {
  90         static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
  91
  92         if (!trace_want(key))
  93                 return 0;
  94
  95         set_try_to_free_routine(NULL);  /* is never reset */
  96
  97         /* unit tests may want to disable additional trace output */
  98         if (trace_want(&trace_bare))
  99                 return 1;
 100
 101         /* add line prefix here */
 102
 103         return 1;
 104 }
 105
 106 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 107 {
 108         /* append newline if missing */
 109         if (buf->len && buf->buf[buf->len - 1] != '\n')
 110                 strbuf_addch(buf, '\n');
 111
 112         write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
 113         strbuf_release(buf);
 114 }
 115
 116 static void trace_vprintf(struct trace_key *key, const char *format, va_list ap)
 117 {
 118         struct strbuf buf = STRBUF_INIT;
 119
 120         if (!prepare_trace_line(key, &buf))
 121                 return;
 122
 123         strbuf_vaddf(&buf, format, ap);
 124         print_trace_line(key, &buf);
 125 }
 126
 127 void trace_printf_key(struct trace_key *key, const char *format, ...)
 128 {
 129         va_list ap;
 130         va_start(ap, format);
 131         trace_vprintf(key, format, ap);
 132         va_end(ap);
 133 }
 134
 135 void trace_printf(const char *format, ...)
 136 {
 137         va_list ap;
 138         va_start(ap, format);
 139         trace_vprintf(NULL, format, ap);
 140         va_end(ap);
 141 }
 142
 143 void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 144 {
 145         struct strbuf buf = STRBUF_INIT;
 146
 147         if (!prepare_trace_line(key, &buf))
 148                 return;
 149
 150         strbuf_addbuf(&buf, data);
 151         print_trace_line(key, &buf);
 152 }
 153
 154 void trace_argv_printf(const char **argv, const char *format, ...)
 155 {
 156         struct strbuf buf = STRBUF_INIT;
 157         va_list ap;
 158
 159         if (!prepare_trace_line(NULL, &buf))
 160                 return;
 161
 162         va_start(ap, format);
 163         strbuf_vaddf(&buf, format, ap);
 164         va_end(ap);
 165
 166         sq_quote_argv(&buf, argv, 0);
 167         print_trace_line(NULL, &buf);
 168 }
 169
 170 static const char *quote_crnl(const char *path)
 171 {
 172         static char new_path[PATH_MAX];
 173         const char *p2 = path;
 174         char *p1 = new_path;
 175
 176         if (!path)
 177                 return NULL;
 178
 179         while (*p2) {
 180                 switch (*p2) {
 181                 case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
 182                 case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
 183                 case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
 184                 default:
 185                         *p1++ = *p2;
 186                 }
 187                 p2++;
 188         }
 189         *p1 = '\0';
 190         return new_path;
 191 }
 192
 193 /* FIXME: move prefix to startup_info struct and get rid of this arg */
 194 void trace_repo_setup(const char *prefix)
 195 {
 196         static struct trace_key key = TRACE_KEY_INIT(SETUP);
 197         const char *git_work_tree;
 198         char cwd[PATH_MAX];
 199
 200         if (!trace_want(&key))
 201                 return;
 202
 203         if (!getcwd(cwd, PATH_MAX))
 204                 die("Unable to get current working directory");
 205
 206         if (!(git_work_tree = get_git_work_tree()))
 207                 git_work_tree = "(null)";
 208
 209         if (!prefix)
 210                 prefix = "(null)";
 211
 212         trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 213         trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 214         trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 215         trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 216 }
 217
 218 int trace_want(struct trace_key *key)
 219 {
 220         return !!get_trace_fd(key);
 221 }