libgcc/libgcov-driver-system.c

   1 /* Routines required for instrumenting a program.  */
   2 /* Compile this one with gcc.  */
   3 /* Copyright (C) 1989-2021 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #if !IN_GCOV_TOOL
  27 /* Configured via the GCOV_ERROR_FILE environment variable;
  28    it will either be stderr, or a file of the user's choosing.
  29    Non-static to prevent multiple gcov-aware shared objects from
  30    instantiating their own copies. */
  31 FILE *__gcov_error_file = NULL;
  32 #endif
  33
  34 /* A utility function to populate the __gcov_error_file pointer.
  35    This should NOT be called outside of the gcov system driver code. */
  36
  37 static FILE *
  38 get_gcov_error_file (void)
  39 {
  40 #if IN_GCOV_TOOL
  41   return stderr;
  42 #else
  43   if (!__gcov_error_file)
  44     {
  45       const char *gcov_error_filename = getenv ("GCOV_ERROR_FILE");
  46
  47       if (gcov_error_filename)
  48         __gcov_error_file = fopen (gcov_error_filename, "a");
  49       if (!__gcov_error_file)
  50         __gcov_error_file = stderr;
  51     }
  52   return __gcov_error_file;
  53 #endif
  54 }
  55
  56 /* A utility function for outputting errors.  */
  57
  58 static int __attribute__((format(printf, 1, 2)))
  59 gcov_error (const char *fmt, ...)
  60 {
  61   int ret;
  62   va_list argp;
  63
  64   va_start (argp, fmt);
  65   FILE *f = get_gcov_error_file ();
  66   ret = vfprintf (f, fmt, argp);
  67   va_end (argp);
  68
  69   if (getenv ("GCOV_EXIT_AT_ERROR"))
  70     {
  71       fprintf (f, "profiling:exiting after an error\n");
  72       exit (1);
  73     }
  74
  75   return ret;
  76 }
  77
  78 #if !IN_GCOV_TOOL
  79 static void
  80 gcov_error_exit (void)
  81 {
  82   if (__gcov_error_file && __gcov_error_file != stderr)
  83     {
  84       fclose (__gcov_error_file);
  85       __gcov_error_file = NULL;
  86     }
  87 }
  88 #endif
  89
  90 /* Make sure path component of the given FILENAME exists, create
  91    missing directories. FILENAME must be writable.
  92    Returns zero on success, or -1 if an error occurred.  */
  93
  94 static int
  95 create_file_directory (char *filename)
  96 {
  97 #if !defined(TARGET_POSIX_IO) && !defined(_WIN32)
  98   (void) filename;
  99   return -1;
 100 #else
 101   char *s;
 102
 103   s = filename;
 104
 105   if (HAS_DRIVE_SPEC(s))
 106     s += 2;
 107   if (IS_DIR_SEPARATOR(*s))
 108     ++s;
 109   for (; *s != '\0'; s++)
 110     if (IS_DIR_SEPARATOR(*s))
 111       {
 112         char sep = *s;
 113         *s  = '\0';
 114
 115         /* Try to make directory if it doesn't already exist.  */
 116         if (access (filename, F_OK) == -1
 117 #ifdef TARGET_POSIX_IO
 118             && mkdir (filename, 0777) == -1
 119 #else
 120 #ifdef mkdir
 121 #undef mkdir
 122 #endif
 123             && mkdir (filename) == -1
 124 #endif
 125             /* The directory might have been made by another process.  */
 126             && errno != EEXIST)
 127           {
 128             gcov_error ("profiling:%s:Cannot create directory\n", filename);
 129             *s = sep;
 130             return -1;
 131           };
 132
 133         *s = sep;
 134       };
 135   return 0;
 136 #endif
 137 }
 138
 139 /* Replace filename variables in FILENAME.  We currently support expansion:
 140
 141    %p - process ID
 142    %q{ENV} - value of environment variable ENV
 143    */
 144
 145 static char *
 146 replace_filename_variables (char *filename)
 147 {
 148   char buffer[16];
 149   char empty[] = "";
 150   for (char *p = filename; *p != '\0'; p++)
 151     {
 152       unsigned length = strlen (filename);
 153       if (*p == '%' && *(p + 1) != '\0')
 154         {
 155           unsigned start = p - filename;
 156           p++;
 157           char *replacement = NULL;
 158           switch (*p)
 159             {
 160             case 'p':
 161               sprintf (buffer, "%d", getpid ());
 162               replacement = buffer;
 163               p++;
 164               break;
 165             case 'q':
 166               if (*(p + 1) == '{')
 167                 {
 168                   p += 2;
 169                   char *e = strchr (p, '}');
 170                   if (e)
 171                     {
 172                       *e = '\0';
 173                       replacement = getenv (p);
 174                       if (replacement == NULL)
 175                         replacement = empty;
 176                       p = e + 1;
 177                     }
 178                   else
 179                     return filename;
 180                 }
 181               break;
 182             default:
 183               return filename;
 184             }
 185
 186           /* Concat beginning of the path, replacement and
 187              ending of the path.  */
 188           unsigned end = length - (p - filename);
 189           unsigned repl_length = replacement != NULL ? strlen (replacement) : 0;
 190
 191           char *buffer = (char *)xmalloc (start + end + repl_length + 1);
 192           char *buffer_ptr = buffer;
 193           buffer_ptr = (char *)memcpy (buffer_ptr, filename, start);
 194           buffer_ptr += start;
 195           if (replacement != NULL)
 196             buffer_ptr = (char *)memcpy (buffer_ptr, replacement, repl_length);
 197           buffer_ptr += repl_length;
 198           buffer_ptr = (char *)memcpy (buffer_ptr, p, end);
 199           buffer_ptr += end;
 200           *buffer_ptr = '\0';
 201
 202           free (filename);
 203           filename = buffer;
 204           p = buffer + start + repl_length;
 205         }
 206     }
 207
 208   return filename;
 209 }
 210
 211 static void
 212 allocate_filename_struct (struct gcov_filename *gf)
 213 {
 214   const char *gcov_prefix;
 215   size_t prefix_length;
 216   int strip = 0;
 217   gf->filename = NULL;
 218
 219   {
 220     /* Check if the level of dirs to strip off specified. */
 221     char *tmp = getenv("GCOV_PREFIX_STRIP");
 222     if (tmp)
 223       {
 224         strip = atoi (tmp);
 225         /* Do not consider negative values. */
 226         if (strip < 0)
 227           strip = 0;
 228       }
 229   }
 230   gf->strip = strip;
 231
 232   /* Get file name relocation prefix.  Non-absolute values are ignored. */
 233   gcov_prefix = getenv("GCOV_PREFIX");
 234   prefix_length = gcov_prefix ? strlen (gcov_prefix) : 0;
 235
 236   /* Remove an unnecessary trailing '/' */
 237   if (prefix_length && IS_DIR_SEPARATOR (gcov_prefix[prefix_length - 1]))
 238     prefix_length--;
 239
 240   /* If no prefix was specified and a prefix stip, then we assume
 241      relative.  */
 242   if (!prefix_length && gf->strip)
 243     {
 244       gcov_prefix = ".";
 245       prefix_length = 1;
 246     }
 247
 248   /* Allocate and initialize the filename scratch space.  */
 249   if (prefix_length)
 250     {
 251       gf->prefix = (char *) xmalloc (prefix_length + 1);
 252       char *p = (char *) memcpy (gf->prefix, gcov_prefix, prefix_length);
 253       *(p + prefix_length) = '\0';
 254     }
 255   else
 256     gf->prefix = NULL;
 257 }
 258
 259 /* Open a gcda file specified by GI_FILENAME.
 260    Return -1 on error.  Return 0 on success.  */
 261
 262 static int
 263 gcov_exit_open_gcda_file (struct gcov_info *gi_ptr,
 264                           struct gcov_filename *gf)
 265 {
 266   int append_slash = 0;
 267   const char *fname = gi_ptr->filename;
 268
 269   /* Build relocated filename, stripping off leading
 270      directories from the initial filename if requested. */
 271   if (gf->strip > 0)
 272     {
 273       const char *probe = fname;
 274       int level;
 275
 276       /* Remove a leading separator, without counting it.  */
 277       if (IS_DIR_SEPARATOR (*probe))
 278         probe++;
 279
 280       /* Skip selected directory levels.  If we fall off the end, we
 281          keep the final part.  */
 282       for (level = gf->strip; *probe && level; probe++)
 283         if (IS_DIR_SEPARATOR (*probe))
 284           {
 285             fname = probe;
 286             level--;
 287           }
 288     }
 289
 290   /* Update complete filename with stripped original. */
 291   if (gf->prefix)
 292     {
 293       /* Avoid to add multiple drive letters into combined path.  */
 294       if (HAS_DRIVE_SPEC(fname))
 295         fname += 2;
 296
 297       if (!IS_DIR_SEPARATOR (*fname))
 298         append_slash = 1;
 299     }
 300
 301   size_t prefix_length = gf->prefix ? strlen (gf->prefix) : 0;
 302   gf->filename = (char *) xmalloc (prefix_length + strlen (fname) + 2);
 303   *gf->filename = '\0';
 304   if (prefix_length)
 305     strcat (gf->filename, gf->prefix);
 306   if (append_slash)
 307     *gf->filename++ = '/';
 308   strcat (gf->filename, fname);
 309
 310   gf->filename = replace_filename_variables (gf->filename);
 311
 312   if (!gcov_open (gf->filename))
 313     {
 314       /* Open failed likely due to missed directory.
 315          Create directory and retry to open file. */
 316       if (create_file_directory (gf->filename))
 317         {
 318           fprintf (stderr, "profiling:%s:Skip\n", gf->filename);
 319           return -1;
 320         }
 321       if (!gcov_open (gf->filename))
 322         {
 323           fprintf (stderr, "profiling:%s:Cannot open\n", gf->filename);
 324           return -1;
 325         }
 326     }
 327
 328   return 0;
 329 }