lldb/tools/lldb-dap/OutputRedirector.cpp

   1 //===-- OutputRedirector.cpp -----------------------------------*- C++ -*-===//
   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 <fcntl.h>
  11 #include <io.h>
  12 #else
  13 #include <unistd.h>
  14 #endif
  15
  16 #include "DAP.h"
  17 #include "OutputRedirector.h"
  18 #include "llvm/ADT/StringRef.h"
  19
  20 using namespace llvm;
  21
  22 namespace lldb_dap {
  23
  24 Error RedirectFd(int fd, std::function<void(llvm::StringRef)> callback) {
  25   int new_fd[2];
  26 #if defined(_WIN32)
  27   if (_pipe(new_fd, 4096, O_TEXT) == -1) {
  28 #else
  29   if (pipe(new_fd) == -1) {
  30 #endif
  31     int error = errno;
  32     return createStringError(inconvertibleErrorCode(),
  33                              "Couldn't create new pipe for fd %d. %s", fd,
  34                              strerror(error));
  35   }
  36
  37   if (dup2(new_fd[1], fd) == -1) {
  38     int error = errno;
  39     return createStringError(inconvertibleErrorCode(),
  40                              "Couldn't override the fd %d. %s", fd,
  41                              strerror(error));
  42   }
  43
  44   int read_fd = new_fd[0];
  45   std::thread t([read_fd, callback]() {
  46     char buffer[OutputBufferSize];
  47     while (true) {
  48       ssize_t bytes_count = read(read_fd, &buffer, sizeof(buffer));
  49       if (bytes_count == 0)
  50         return;
  51       if (bytes_count == -1) {
  52         if (errno == EAGAIN || errno == EINTR)
  53           continue;
  54         break;
  55       }
  56       callback(StringRef(buffer, bytes_count));
  57     }
  58   });
  59   t.detach();
  60   return Error::success();
  61 }
  62
  63 } // namespace lldb_dap