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