unittests/Support/SignalsTest.cpp

   1 //========- unittests/Support/SignalsTest.cpp - Signal handling test =========//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #if !defined(_WIN32)
  10 #include <unistd.h>
  11 #include <sysexits.h>
  12 #include <signal.h>
  13 #endif // !defined(_WIN32)
  14
  15 #include "llvm/Support/Signals.h"
  16
  17 #include "gtest/gtest.h"
  18
  19 using namespace llvm;
  20
  21 #if !defined(_WIN32)
  22 TEST(SignalTest, IgnoreMultipleSIGPIPEs) {
  23   // Ignore SIGPIPE.
  24   signal(SIGPIPE, SIG_IGN);
  25
  26   // Disable exit-on-SIGPIPE.
  27   sys::SetPipeSignalFunction(nullptr);
  28
  29   // Create unidirectional read/write pipes.
  30   int fds[2];
  31   int err = pipe(fds);
  32   if (err != 0)
  33     return; // If we can't make pipes, this isn't testing anything.
  34
  35   // Close the read pipe.
  36   close(fds[0]);
  37
  38   // Attempt to write to the write pipe. Currently we're asserting that the
  39   // write fails, which isn't great.
  40   //
  41   // What we really want is a death test that checks that this block exits
  42   // with a special exit "success" code, as opposed to unexpectedly exiting due
  43   // to a kill-by-SIGNAL or due to the default SIGPIPE handler.
  44   //
  45   // Unfortunately llvm's unit tests aren't set up to support death tests well.
  46   // For one, death tests are flaky in a multithreaded context. And sigactions
  47   // inherited from llvm-lit interfere with what's being tested.
  48   const void *buf = (const void *)&fds;
  49   err = write(fds[1], buf, 1);
  50   ASSERT_EQ(err, -1);
  51   err = write(fds[1], buf, 1);
  52   ASSERT_EQ(err, -1);
  53 }
  54 #endif // !defined(_WIN32)