1 //===-- ExecuteFunction implementation for Unix-like Systems --------------===//
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 #include "ExecuteFunction.h"
10 #include "llvm/Support/raw_ostream.h"
11 #include <cassert>
12 #include <cstdlib>
13 #include <memory>
14 #include <poll.h>
15 #include <signal.h>
16 #include <sys/wait.h>
17 #include <unistd.h>
18 
19 namespace __llvm_libc {
20 namespace testutils {
21 
22 bool ProcessStatus::exitedNormally() const {
23   return WIFEXITED(PlatformDefined);
24 }
25 
26 int ProcessStatus::getExitCode() const {
27   assert(exitedNormally() && "Abnormal termination, no exit code");
28   return WEXITSTATUS(PlatformDefined);
29 }
30 
31 int ProcessStatus::getFatalSignal() const {
32   if (exitedNormally())
33     return 0;
34   return WTERMSIG(PlatformDefined);
35 }
36 
37 ProcessStatus invokeInSubprocess(FunctionCaller *Func, unsigned timeoutMS) {
38   std::unique_ptr<FunctionCaller> X(Func);
39   int pipeFDs[2];
40   if (::pipe(pipeFDs) == -1)
41     return ProcessStatus::Error("pipe(2) failed");
42 
43   // Don't copy the buffers into the child process and print twice.
44   llvm::outs().flush();
45   llvm::errs().flush();
46   pid_t Pid = ::fork();
47   if (Pid == -1)
48     return ProcessStatus::Error("fork(2) failed");
49 
50   if (!Pid) {
51     (*Func)();
52     std::exit(0);
53   }
54   ::close(pipeFDs[1]);
55 
56   struct pollfd pollFD {
57     pipeFDs[0], 0, 0
58   };
59   // No events requested so this call will only return after the timeout or if
60   // the pipes peer was closed, signaling the process exited.
61   if (::poll(&pollFD, 1, timeoutMS) == -1)
62     return ProcessStatus::Error("poll(2) failed");
63   // If the pipe wasn't closed by the child yet then timeout has expired.
64   if (!(pollFD.revents & POLLHUP)) {
65     ::kill(Pid, SIGKILL);
66     return ProcessStatus::TimedOut();
67   }
68 
69   int WStatus = 0;
70   // Wait on the pid of the subprocess here so it gets collected by the system
71   // and doesn't turn into a zombie.
72   pid_t status = ::waitpid(Pid, &WStatus, 0);
73   if (status == -1)
74     return ProcessStatus::Error("waitpid(2) failed");
75   assert(status == Pid);
76   (void)status;
77   return {WStatus};
78 }
79 
80 const char *signalAsString(int Signum) { return ::strsignal(Signum); }
81 
82 } // namespace testutils
83 } // namespace __llvm_libc
84