chore(3p/nix): Clean up some unused defines

third_party/nix/src/libstore/local-store.cc

@@ -320,16 +320,6 @@ void LocalStore::openDB(State& state, bool create) {
     throw Error(format("cannot open Nix database '%1%'") % dbPath);
   }
 
-#ifdef __CYGWIN__
-  /* The cygwin version of sqlite3 has a patch which calls
-     SetDllDirectory("/usr/bin") on init. It was intended to fix extension
-     loading, which we don't use, and the effect of SetDllDirectory is
-     inherited by child processes, and causes libraries to be loaded from
-     /usr/bin instead of $PATH. This breaks quite a few things (e.g.
-     checkPhase on openssh), so we set it back to default behaviour. */
-  SetDllDirectoryW(L"");
-#endif
-
   if (sqlite3_busy_timeout(db, 60 * 60 * 1000) != SQLITE_OK) {
     throwSQLiteError(db, "setting timeout");
   }
@@ -381,7 +371,6 @@ void LocalStore::openDB(State& state, bool create) {
 /* To improve purity, users may want to make the Nix store a read-only
    bind mount.  So make the Nix store writable for this process. */
 void LocalStore::makeStoreWritable() {
-#if __linux__
   if (getuid() != 0) {
     return;
   }
@@ -401,7 +390,6 @@ void LocalStore::makeStoreWritable() {
       throw SysError(format("remounting %1% writable") % realStoreDir);
     }
   }
-#endif
 }
 
 const time_t mtimeStore = 1; /* 1 second into the epoch */

third_party/nix/src/libstore/remote-store.cc

@@ -90,13 +90,7 @@ ref<RemoteStore::Connection> UDSRemoteStore::openConnection() {
   auto conn = make_ref<Connection>();
 
   /* Connect to a daemon that does the privileged work for us. */
-  conn->fd = socket(PF_UNIX,
-                    SOCK_STREAM
-#ifdef SOCK_CLOEXEC
-                        | SOCK_CLOEXEC
-#endif
-                    ,
-                    0);
+  conn->fd = socket(PF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
   if (!conn->fd) {
     throw SysError("cannot create Unix domain socket");
   }

third_party/nix/src/libutil/compression.cc

@@ -214,7 +214,6 @@ struct XzCompressionSink : CompressionSink {
     bool done = false;
 
     if (parallel) {
-#ifdef HAVE_LZMA_MT
       lzma_mt mt_options = {};
       mt_options.flags = 0;
       mt_options.timeout = 300;  // Using the same setting as the xz cmd line
@@ -230,10 +229,6 @@ struct XzCompressionSink : CompressionSink {
       // number of threads.
       ret = lzma_stream_encoder_mt(&strm, &mt_options);
       done = true;
-#else
-      LOG(ERROR) << "parallel XZ compression requested but not supported, "
-                 << "falling back to single-threaded compression";
-#endif
     }
 
     if (!done) {

third_party/nix/src/nix/repl.cc

@@ -7,22 +7,8 @@
 
 #include <absl/strings/ascii.h>
 #include <absl/strings/match.h>
-#include <glog/logging.h>
-
-#ifdef READLINE
-#include <readline/history.h>
-#include <readline/readline.h>
-#else
-// editline < 1.15.2 don't wrap their API for C++ usage
-// (added in
-// https://github.com/troglobit/editline/commit/91398ceb3427b730995357e9d120539fb9bb7461).
-// This results in linker errors due to to name-mangling of editline C symbols.
-// For compatibility with these versions, we wrap the API here
-// (wrapping multiple times on newer versions is no problem).
-extern "C" {
 #include <editline.h>
-}
-#endif
+#include <glog/logging.h>
 
 #include "libexpr/common-eval-args.hh"
 #include "libexpr/eval-inline.hh"
@@ -242,15 +228,11 @@ void NixRepl::mainLoop(const std::vector<std::string>& files) {
   // Allow nix-repl specific settings in .inputrc
   rl_readline_name = "nix-repl";
   createDirs(dirOf(historyFile));
-#ifndef READLINE
   el_hist_size = 1000;
-#endif
   read_history(historyFile.c_str());
   curRepl = this;
-#ifndef READLINE
   rl_set_complete_func(completionCallback);
   rl_set_list_possib_func(listPossibleCallback);
-#endif
 
   std::string input;