support/support_record_failure.c

   1 /* Global test failure counter.
   2    Copyright (C) 2016-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <support/check.h>
  20 #include <support/support.h>
  21 #include <support/test-driver.h>
  22
  23 #include <stdbool.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <sys/mman.h>
  27 #include <unistd.h>
  28
  29 /* This structure keeps track of test failures.  The counter is
  30    incremented on each failure.  The failed member is set to true if a
  31    failure is detected, so that even if the counter wraps around to
  32    zero, the failure of a test can be detected.
  33
  34    The init constructor function below puts *state on a shared
  35    annonymous mapping, so that failure reports from subprocesses
  36    propagate to the parent process.  */
  37 struct test_failures
  38 {
  39   unsigned int counter;
  40   unsigned int failed;
  41 };
  42 static struct test_failures *state;
  43
  44 static __attribute__ ((constructor)) void
  45 init (void)
  46 {
  47   void *ptr = mmap (NULL, sizeof (*state), PROT_READ | PROT_WRITE,
  48                     MAP_ANONYMOUS | MAP_SHARED, -1, 0);
  49   if (ptr == MAP_FAILED)
  50     {
  51       printf ("error: could not map %zu bytes: %m\n", sizeof (*state));
  52       exit (1);
  53     }
  54   /* Zero-initialization of the struct is sufficient.  */
  55   state = ptr;
  56 }
  57
  58 void
  59 support_record_failure (void)
  60 {
  61   if (state == NULL)
  62     {
  63       write_message
  64         ("error: support_record_failure called without initialization\n");
  65       _exit (1);
  66     }
  67   /* Relaxed MO is sufficient because we are only interested in the
  68      values themselves, in isolation.  */
  69   __atomic_store_n (&state->failed, 1, __ATOMIC_RELEASE);
  70   __atomic_add_fetch (&state->counter, 1, __ATOMIC_RELEASE);
  71 }
  72
  73 int
  74 support_report_failure (int status)
  75 {
  76   if (state == NULL)
  77     {
  78       write_message
  79         ("error: support_report_failure called without initialization\n");
  80       return 1;
  81     }
  82
  83   /* Relaxed MO is sufficient because acquire test result reporting
  84      assumes that exiting from the main thread happens before the
  85      error reporting via support_record_failure, which requires some
  86      form of external synchronization.  */
  87   bool failed = __atomic_load_n (&state->failed, __ATOMIC_RELAXED);
  88   if (failed)
  89     printf ("error: %u test failures\n",
  90             __atomic_load_n (&state->counter, __ATOMIC_RELAXED));
  91
  92   if ((status == 0 || status == EXIT_UNSUPPORTED) && failed)
  93     /* If we have a recorded failure, it overrides a non-failure
  94        report from the test function.  */
  95     status = 1;
  96   return status;
  97 }
  98
  99 void
 100 support_record_failure_reset (void)
 101 {
 102   /* Only used for testing the test framework, with external
 103      synchronization, but use release MO for consistency.  */
 104   __atomic_store_n (&state->failed, 0, __ATOMIC_RELAXED);
 105   __atomic_add_fetch (&state->counter, 0, __ATOMIC_RELAXED);
 106 }
 107
 108 int
 109 support_record_failure_is_failed (void)
 110 {
 111   /* Relaxed MO is sufficient because we need (blocking) external
 112      synchronization for reliable test error reporting anyway.  */
 113   return __atomic_load_n (&state->failed, __ATOMIC_RELAXED);
 114 }