[compiler-rt] [sanitizer_common] [Darwin] Replace pty with pipe on posix_spawn path for spawning symbolizer (PR #170809)

[Mariusz Borsa via llvm-commits]

================
@@ -281,53 +281,43 @@ int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
                       (size_t)newlen);
 }
 
-static fd_t internal_spawn_impl(const char *argv[], const char *envp[],
-                                pid_t *pid) {
-  fd_t primary_fd = kInvalidFd;
-  fd_t secondary_fd = kInvalidFd;
-
+bool internal_spawn(const char* argv[], const char* envp[], pid_t* pid,
+                    fd_t fd_stdin, fd_t fd_stdout) {
+  // NOTE: Caller ensures that fd_stdin and fd_stdout are not 0, 1, or 2, since
+  // this can break communication.
+  //
+  // NOTE: Caller is responsible for closing fd_stdin after the process has
+  // died.
+
+  int res;
   auto fd_closer = at_scope_exit([&] {
-    internal_close(primary_fd);
-    internal_close(secondary_fd);
+    // NOTE: We intentionally do not close fd_stdin since this can
+    // cause us to receive a fatal SIGPIPE if the process dies.
+    internal_close(fd_stdout);
   });
 
-  // We need a new pseudoterminal to avoid buffering problems. The 'atos' tool
----------------
wrotki wrote:

Ah OK, it was fixed in atos, 5yrs ago. However you should say that explicitly in your PR synopsis, not everyone in open source community can have this context.

https://github.com/llvm/llvm-project/pull/170809