Merge branch '2753-vasprintf-loop' into 'main'

glib/tests: Add test to check that we abort on low-memory

See merge request GNOME/glib!2992

glib/tests/meson.build

@@ -292,6 +292,15 @@ test_extra_programs = {
   'test-spawn-echo' : {},
 }
 
+if have_dlopen_dlsym
+  test_extra_programs += {
+    'messages-low-memory' : {
+      'dependencies' : libdl_dep,
+      'override_options' : ['b_asneeded=false'],
+    },
+  }
+endif
+
 if host_machine.system() == 'windows'
   # test-spawn-sleep helper binary required by the spawn tests above
   test_extra_programs += {
@@ -335,6 +344,7 @@ foreach program_name, extra_args : test_extra_programs
       sources: [source, extra_sources],
       c_args : test_cargs,
       cpp_args: test_cpp_args,
+      override_options : extra_args.get('override_options', []),
       dependencies : test_deps + extra_args.get('dependencies', []),
       install_dir : installed_tests_execdir,
       install_tag : 'tests',
@@ -368,6 +378,7 @@ foreach test_name, extra_args : glib_tests
     c_args : test_cargs + extra_args.get('c_args', []),
     cpp_args : test_cpp_args + extra_args.get('cpp_args', []),
     link_args : extra_args.get('link_args', []),
+    override_options : extra_args.get('override_options', []),
     dependencies : test_deps + extra_args.get('dependencies', []),
     install_dir: installed_tests_execdir,
     install_tag: 'tests',
@@ -410,6 +421,14 @@ python_tests = {
   },
 }
 
+if 'messages-low-memory' in test_extra_programs
+  python_tests += {
+    'messages-low-memory.py' : {
+      'extra_programs': ['messages-low-memory'],
+    },
+  }
+endif
+
 foreach test_name, extra_args : python_tests
   depends = [extra_args.get('depends', [])]
   suite = ['glib', 'no-valgrind']

glib/tests/messages-low-memory.c

@@ -0,0 +1,88 @@
+/* Unit tests for gmessages on low-memory
+ *
+ * Copyright (C) 2022 Marco Trevisan
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Marco Trevisan <marco.trevisan@canonical.com>
+ */
+
+#include "config.h"
+
+#include <dlfcn.h>
+#include <glib.h>
+
+static gboolean malloc_eom = FALSE;
+static gboolean our_malloc_called = FALSE;
+
+#ifdef ENOMEM
+/* Wrapper around malloc() which returns `ENOMEM` if the test variable
+ * `malloc_eom` is set.
+ * Otherwise passes through to the normal malloc() in libc.
+ */
+
+void *
+malloc (size_t size)
+{
+  static void *(*real_malloc)(size_t);
+  if (!real_malloc)
+      real_malloc = dlsym (RTLD_NEXT, "malloc");
+
+  if (malloc_eom)
+    {
+      our_malloc_called = TRUE;
+      errno = ENOMEM;
+      return NULL;
+    }
+
+  return real_malloc (size);
+}
+#endif
+
+int
+main (int   argc,
+      char *argv[])
+{
+  g_setenv ("LC_ALL", "C", TRUE);
+
+#ifndef ENOMEM
+  g_message ("ENOMEM Not defined, test skipped");
+  return 77;
+#endif
+
+  g_message ("Simulates a situation in which we were crashing because "
+             "of low-memory, leading malloc to fail instead of aborting");
+  g_message ("bug: https://gitlab.gnome.org/GNOME/glib/-/issues/2753");
+
+  /* Setting `malloc_eom` to true should cause the override `malloc()`
+   * in this file to fail on the allocation on the next line. */
+  malloc_eom = TRUE;
+  g_message ("Memory is exhausted, but we'll write anyway: %u", 123);
+
+#ifndef __linux__
+  if (!our_malloc_called)
+    {
+      /* For some reasons this doesn't work darwin systems, so ignore the result
+       * for non-linux, while we want to ensure the test is valid at least there
+       */
+      g_message ("Our malloc implementation has not been called, the test "
+                 "has not been performed");
+      return 77;
+    }
+#endif
+
+  return 0;
+}

glib/tests/messages-low-memory.py

@@ -0,0 +1,101 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright © 2022 Emmanuel Fleury <emmanuel.fleury@gmail.com>
+# Copyright © 2022 Marco Trevisan <mail@3v1n0.net>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+# MA  02110-1301  USA
+
+""" Integration tests for g_message functions on low-memory. """
+
+import collections
+import os
+import subprocess
+import unittest
+
+import taptestrunner
+
+Result = collections.namedtuple("Result", ("info", "out", "err"))
+
+
+class TestMessagesLowMemory(unittest.TestCase):
+    """Integration test for checking g_message()’s behavior on low memory.
+
+    This can be run when installed or uninstalled. When uninstalled,
+    it requires G_TEST_BUILDDIR and G_TEST_SRCDIR to be set.
+
+    The idea with this test harness is to test if g_message and friends
+    assert instead of crashing if memory is exhausted, printing the expected
+    error message.
+    """
+
+    test_binary = "messages-low-memory"
+
+    def setUp(self):
+        ext = ""
+        if os.name == "nt":
+            ext = ".exe"
+        if "G_TEST_BUILDDIR" in os.environ:
+            self._test_binary = os.path.join(
+                os.environ["G_TEST_BUILDDIR"], self.test_binary + ext
+            )
+        else:
+            self._test_binary = os.path.join(
+                os.path.dirname(__file__), self.test_binary + ext
+            )
+        print("messages-low-memory:", self._test_binary)
+
+    def runTestBinary(self, *args):
+        print("Running:", *args)
+
+        env = os.environ.copy()
+        env["LC_ALL"] = "C.UTF-8"
+        print("Environment:", env)
+
+        # We want to ensure consistent line endings...
+        info = subprocess.run(
+            *args,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            env=env,
+            universal_newlines=True,
+        )
+        out = info.stdout.strip()
+        err = info.stderr.strip()
+
+        result = Result(info, out, err)
+
+        print("Return code:", result.info.returncode)
+        print("Output:", result.out)
+        print("Error:", result.err)
+        return result
+
+    def test_message_memory_allocation_failure(self):
+        """Test running g_message() when memory is exhausted."""
+        result = self.runTestBinary(self._test_binary)
+
+        if result.info.returncode == 77:
+            self.skipTest("Not supported")
+
+        if os.name == "nt":
+            self.assertEqual(result.info.returncode, 3)
+        else:
+            self.assertEqual(result.info.returncode, -6)
+        self.assertIn("failed to allocate memory", result.err)
+
+
+if __name__ == "__main__":
+    unittest.main(testRunner=taptestrunner.TAPTestRunner())