[PseudoTerminal][NFC] Use llvm errno helpers

[xbolva00]

Summary

LLVM provide (str)errno helpers, so convert code to use it.

Also fixes warning:
/home/xbolva00/LLVM/llvm/tools/lldb/source/Host/common/PseudoTerminal.cpp:248:25: warning: ignoring return value of ‘char* strerror_r(int, char*, size_t)’, declared with attribute warn_unused_result [-Wunused-result]

::strerror_r(errno, error_str, error_len);

[xbolva00]

• Moved variable into #if block

[xbolva00]

• Removed include errno.h

[JDevlieghere]

Any chance we could wrap this in a helper function?

[xbolva00]

• Added helper function

[JDevlieghere]

LGTM, thx!

source/Host/common/PseudoTerminal.cpp

 //===-- PseudoTerminal.cpp --------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "lldb/Host/PseudoTerminal.h"
 #include "lldb/Host/Config.h"
 
-#include <errno.h>
+#include "llvm/Support/Errno.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #if defined(TIOCSCTTY)
 #include <sys/ioctl.h>
 #endif
 
 #include "lldb/Host/PosixApi.h"
 
 #if defined(__ANDROID__)
 int posix_openpt(int flags);
 #endif
 
 using namespace lldb_private;
 
 //----------------------------------------------------------------------
+// Write string describing error number
+//----------------------------------------------------------------------
+static void ErrnoToStr(char *error_str, size_t error_len) {
+  std::string strerror = llvm::sys::StrError();
+  ::snprintf(error_str, error_len, "%s", strerror.c_str());
+}
+
+//----------------------------------------------------------------------
 // PseudoTerminal constructor
 //----------------------------------------------------------------------
 PseudoTerminal::PseudoTerminal()
     : m_master_fd(invalid_fd), m_slave_fd(invalid_fd) {}
 
 //----------------------------------------------------------------------
 // Destructor
 //
bool PseudoTerminal::OpenFirstAvailableMaster(int oflag, char *error_str,
   if (error_str)
     error_str[0] = '\0';
 
 #if !defined(LLDB_DISABLE_POSIX)
   // Open the master side of a pseudo terminal
   m_master_fd = ::posix_openpt(oflag);
   if (m_master_fd < 0) {
     if (error_str)
-      ::strerror_r(errno, error_str, error_len);
+      ErrnoToStr(error_str, error_len);
     return false;
   }
 
   // Grant access to the slave pseudo terminal
   if (::grantpt(m_master_fd) < 0) {
     if (error_str)
-      ::strerror_r(errno, error_str, error_len);
+      ErrnoToStr(error_str, error_len);
     CloseMasterFileDescriptor();
     return false;
   }
 
   // Clear the lock flag on the slave pseudo terminal
   if (::unlockpt(m_master_fd) < 0) {
     if (error_str)
-      ::strerror_r(errno, error_str, error_len);
+      ErrnoToStr(error_str, error_len);
     CloseMasterFileDescriptor();
     return false;
   }
 
   return true;
 #else
   if (error_str)
     ::snprintf(error_str, error_len, "%s", "pseudo terminal not supported");
bool PseudoTerminal::OpenSlave(int oflag, char *error_str, size_t error_len) {
 
   if (slave_name == nullptr)
     return false;
 
   m_slave_fd = ::open(slave_name, oflag);
 
   if (m_slave_fd < 0) {
     if (error_str)
-      ::strerror_r(errno, error_str, error_len);
+      ErrnoToStr(error_str, error_len);
     return false;
   }
 
   return true;
 }
 
 //----------------------------------------------------------------------
 // Get the name of the slave pseudo terminal. A master pseudo terminal should
if (m_master_fd < 0) {
     if (error_str)
       ::snprintf(error_str, error_len, "%s",
                  "master file descriptor is invalid");
     return nullptr;
   }
   const char *slave_name = ::ptsname(m_master_fd);
 
   if (error_str && slave_name == nullptr)
-    ::strerror_r(errno, error_str, error_len);
+    ErrnoToStr(error_str, error_len);
 
   return slave_name;
 }
 
 //----------------------------------------------------------------------
 // Fork a child process and have its stdio routed to a pseudo terminal.
 //
 // In the parent process when a valid pid is returned, the master file
#if !defined(LLDB_DISABLE_POSIX)
   flags |= O_CLOEXEC;
   if (OpenFirstAvailableMaster(flags, error_str, error_len)) {
     // Successfully opened our master pseudo terminal
 
     pid = ::fork();
     if (pid < 0) {
       // Fork failed
       if (error_str)
-        ::strerror_r(errno, error_str, error_len);
+        ErrnoToStr(error_str, error_len);
     } else if (pid == 0) {
       // Child Process
       ::setsid();
 
       if (OpenSlave(O_RDWR, error_str, error_len)) {
         // Successfully opened slave
 
         // Master FD should have O_CLOEXEC set, but let's close it just in
         // case...
         CloseMasterFileDescriptor();
 
 #if defined(TIOCSCTTY)
         // Acquire the controlling terminal
         if (::ioctl(m_slave_fd, TIOCSCTTY, (char *)0) < 0) {
           if (error_str)
-            ::strerror_r(errno, error_str, error_len);
+            ErrnoToStr(error_str, error_len);
         }
 #endif
         // Duplicate all stdio file descriptors to the slave pseudo terminal
         if (::dup2(m_slave_fd, STDIN_FILENO) != STDIN_FILENO) {
           if (error_str && !error_str[0])
-            ::strerror_r(errno, error_str, error_len);
+            ErrnoToStr(error_str, error_len);
         }
 
         if (::dup2(m_slave_fd, STDOUT_FILENO) != STDOUT_FILENO) {
           if (error_str && !error_str[0])
-            ::strerror_r(errno, error_str, error_len);
+            ErrnoToStr(error_str, error_len);
         }
 
         if (::dup2(m_slave_fd, STDERR_FILENO) != STDERR_FILENO) {
           if (error_str && !error_str[0])
-            ::strerror_r(errno, error_str, error_len);
+            ErrnoToStr(error_str, error_len);
         }
       }
     } else {
       // Parent Process
       // Do nothing and let the pid get returned!
     }
   }
 #endif