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 /* Stolen from "imap-send.c". */
  29 static int git_vasprintf(char **strp, const char *fmt, va_list ap)
  30 {
  31         int len;
  32         char tmp[1024];
  33
  34         if ((len = vsnprintf(tmp, sizeof(tmp), fmt, ap)) < 0 ||
  35             !(*strp = xmalloc(len + 1)))
  36                 return -1;
  37         if (len >= (int)sizeof(tmp))
  38                 vsprintf(*strp, fmt, ap);
  39         else
  40                 memcpy(*strp, tmp, len + 1);
  41         return len;
  42 }
  43
  44 /* Stolen from "imap-send.c". */
  45 int nfvasprintf(char **str, const char *fmt, va_list va)
  46 {
  47         int ret = git_vasprintf(str, fmt, va);
  48         if (ret < 0)
  49                 die("Fatal: Out of memory\n");
  50         return ret;
  51 }
  52
  53 /* Get a trace file descriptor from GIT_TRACE env variable. */
  54 static int get_trace_fd(int *need_close)
  55 {
  56         char *trace = getenv("GIT_TRACE");
  57
  58         if (!trace || !strcmp(trace, "") ||
  59             !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  60                 return 0;
  61         if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  62                 return STDERR_FILENO;
  63         if (strlen(trace) == 1 && isdigit(*trace))
  64                 return atoi(trace);
  65         if (*trace == '/') {
  66                 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  67                 if (fd == -1) {
  68                         fprintf(stderr,
  69                                 "Could not open '%s' for tracing: %s\n"
  70                                 "Defaulting to tracing on stderr...\n",
  71                                 trace, strerror(errno));
  72                         return STDERR_FILENO;
  73                 }
  74                 *need_close = 1;
  75                 return fd;
  76         }
  77
  78         fprintf(stderr, "What does '%s' for GIT_TRACE means ?\n", trace);
  79         fprintf(stderr, "If you want to trace into a file, "
  80                 "then please set GIT_TRACE to an absolute pathname "
  81                 "(starting with /).\n");
  82         fprintf(stderr, "Defaulting to tracing on stderr...\n");
  83
  84         return STDERR_FILENO;
  85 }
  86
  87 static const char err_msg[] = "Could not trace into fd given by "
  88         "GIT_TRACE environment variable";
  89
  90 void trace_printf(const char *format, ...)
  91 {
  92         char *trace_str;
  93         va_list rest;
  94         int need_close = 0;
  95         int fd = get_trace_fd(&need_close);
  96
  97         if (!fd)
  98                 return;
  99
 100         va_start(rest, format);
 101         nfvasprintf(&trace_str, format, rest);
 102         va_end(rest);
 103
 104         write_or_whine(fd, trace_str, strlen(trace_str), err_msg);
 105
 106         free(trace_str);
 107
 108         if (need_close)
 109                 close(fd);
 110 }
 111
 112 void trace_argv_printf(const char **argv, int count, const char *format, ...)
 113 {
 114         char *argv_str, *format_str, *trace_str;
 115         size_t argv_len, format_len, trace_len;
 116         va_list rest;
 117         int need_close = 0;
 118         int fd = get_trace_fd(&need_close);
 119
 120         if (!fd)
 121                 return;
 122
 123         /* Get the argv string. */
 124         argv_str = sq_quote_argv(argv, count);
 125         argv_len = strlen(argv_str);
 126
 127         /* Get the formated string. */
 128         va_start(rest, format);
 129         nfvasprintf(&format_str, format, rest);
 130         va_end(rest);
 131
 132         /* Allocate buffer for trace string. */
 133         format_len = strlen(format_str);
 134         trace_len = argv_len + format_len + 1; /* + 1 for \n */
 135         trace_str = xmalloc(trace_len + 1);
 136
 137         /* Copy everything into the trace string. */
 138         strncpy(trace_str, format_str, format_len);
 139         strncpy(trace_str + format_len, argv_str, argv_len);
 140         strcpy(trace_str + trace_len - 1, "\n");
 141
 142         write_or_whine(fd, trace_str, trace_len, err_msg);
 143
 144         free(argv_str);
 145         free(format_str);
 146         free(trace_str);
 147
 148         if (need_close)
 149                 close(fd);
 150 }