1 /* Managing temporary directories and their content within libgccjit.so
2    Copyright (C) 2014-2016 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 *
make_tempdir_path_template()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 
tempdir(logger * logger,int keep_intermediates)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
create()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 
~tempdir()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 }
165