[lldb] Check for and use ptsname_r if available

ptsname is not thread-safe. ptsname_r is available on most (but not all)
systems -- use it preferentially.

In the patch I also improve the thread-safety of the ptsname fallback
path by wrapping it in a mutex. This should guarantee the safety of a
typical ptsname implementation using a single static buffer, as long as
all callers go through this function.

I also remove the error arguments, as the only way this function can
fail is if the "primary" fd is not valid. This is a programmer error as
this requirement is documented, and all callers ensure that is the case.

Differential Revision: https://reviews.llvm.org/D88728

1 files changed, 1 insertions, 1 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 8dea8b9..9adf25f 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -818,7 +818,7 @@ Status ProcessGDBRemote::DoLaunch(lldb_private::Module *exe_module,
         // does a lot of output.
         if ((!stdin_file_spec || !stdout_file_spec || !stderr_file_spec) &&
             pty.OpenFirstAvailablePrimary(O_RDWR | O_NOCTTY, nullptr, 0)) {
-          FileSpec secondary_name{pty.GetSecondaryName(nullptr, 0)};
+          FileSpec secondary_name(pty.GetSecondaryName());
 
           if (!stdin_file_spec)
             stdin_file_spec = secondary_name;