gcc/jit/jit-tempdir.c

   1 /* Managing temporary directories and their content within libgccjit.so
   2    Copyright (C) 2014-2020 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24
  25 #include "jit-tempdir.h"
  26
  27
  28 /* Construct a tempdir path template suitable for use by mkdtemp
  29    e.g. "/tmp/libgccjit-XXXXXX", but respecting the rules in
  30    libiberty's choose_tempdir rather than hardcoding "/tmp/".
  31
  32    The memory is allocated using malloc and must be freed.
  33    Aborts the process if allocation fails. */
  34
  35 static char *
  36 make_tempdir_path_template ()
  37 {
  38   const char *tmpdir_buf;
  39   size_t tmpdir_len;
  40   const char *file_template_buf;
  41   size_t file_template_len;
  42   char *result;
  43
  44   /* The result of choose_tmpdir is a cached buffer within libiberty, so
  45      we must *not* free it.  */
  46   tmpdir_buf = choose_tmpdir ();
  47
  48   /* choose_tmpdir aborts on malloc failure.  */
  49   gcc_assert (tmpdir_buf);
  50
  51   tmpdir_len = strlen (tmpdir_buf);
  52   /* tmpdir_buf should now have a dir separator as the final byte.  */
  53   gcc_assert (tmpdir_len > 0);
  54   gcc_assert (tmpdir_buf[tmpdir_len - 1] == DIR_SEPARATOR);
  55
  56   file_template_buf = "libgccjit-XXXXXX";
  57   file_template_len = strlen (file_template_buf);
  58
  59   result = XNEWVEC (char, tmpdir_len + file_template_len + 1);
  60   strcpy (result, tmpdir_buf);
  61   strcpy (result + tmpdir_len, file_template_buf);
  62
  63   return result;
  64 }
  65
  66 /* The constructor for the jit::tempdir object.
  67    The real work is done by the jit::tempdir::create method.  */
  68
  69 gcc::jit::tempdir::tempdir (logger *logger, int keep_intermediates)
  70   : log_user (logger),
  71     m_keep_intermediates (keep_intermediates),
  72     m_path_template (NULL),
  73     m_path_tempdir (NULL),
  74     m_path_c_file (NULL),
  75     m_path_s_file (NULL),
  76     m_path_so_file (NULL)
  77 {
  78   JIT_LOG_SCOPE (get_logger ());
  79 }
  80
  81 /* Do the real work of creating the on-disk tempdir.
  82    We do this here, rather than in the jit::tempdir constructor
  83    so that we can handle failure without needing exceptions.  */
  84
  85 bool
  86 gcc::jit::tempdir::create ()
  87 {
  88   JIT_LOG_SCOPE (get_logger ());
  89
  90   m_path_template = make_tempdir_path_template ();
  91   if (!m_path_template)
  92     return false;
  93
  94   log ("m_path_template: %s", m_path_template);
  95
  96   /* Create tempdir using mkdtemp.  This is created with 0700 perms and
  97      is unique.  Hence no other (non-root) users should have access to
  98      the paths within it.  */
  99   m_path_tempdir = mkdtemp (m_path_template);
 100   if (!m_path_tempdir)
 101     return false;
 102   log ("m_path_tempdir: %s", m_path_tempdir);
 103
 104   m_path_c_file = concat (m_path_tempdir, "/fake.c", NULL);
 105   m_path_s_file = concat (m_path_tempdir, "/fake.s", NULL);
 106   m_path_so_file = concat (m_path_tempdir, "/fake.so", NULL);
 107
 108   /* Success.  */
 109   return true;
 110 }
 111
 112 /* The destructor for the jit::tempdir object, which
 113    cleans up the filesystem directory and its contents
 114    (unless keep_intermediates was set).  */
 115
 116 gcc::jit::tempdir::~tempdir ()
 117 {
 118   JIT_LOG_SCOPE (get_logger ());
 119
 120   if (m_keep_intermediates)
 121     fprintf (stderr, "intermediate files written to %s\n", m_path_tempdir);
 122   else
 123     {
 124       /* Clean up .s/.so.  */
 125       if (m_path_s_file)
 126         {
 127           log ("unlinking .s file: %s", m_path_s_file);
 128           unlink (m_path_s_file);
 129         }
 130       if (m_path_so_file)
 131         {
 132           log ("unlinking .so file: %s", m_path_so_file);
 133           unlink (m_path_so_file);
 134         }
 135
 136       /* Clean up any other tempfiles.  */
 137       int i;
 138       char *tempfile;
 139       FOR_EACH_VEC_ELT (m_tempfiles, i, tempfile)
 140         {
 141           log ("unlinking tempfile: %s", tempfile);
 142           unlink (tempfile);
 143         }
 144
 145       /* The tempdir should now be empty; remove it.  */
 146       if (m_path_tempdir)
 147         {
 148           log ("removing tempdir: %s", m_path_tempdir);
 149           rmdir (m_path_tempdir);
 150         }
 151     }
 152
 153   free (m_path_template);
 154   /* m_path_tempdir aliases m_path_template, or is NULL, so don't
 155      attempt to free it .  */
 156   free (m_path_c_file);
 157   free (m_path_s_file);
 158   free (m_path_so_file);
 159
 160   int i;
 161   char *tempfile;
 162   FOR_EACH_VEC_ELT (m_tempfiles, i, tempfile)
 163     free (tempfile);
 164 }