This is an optimization which produces improved launching time. There should be no functionality change. Clients should see no ABI differences.

llvm-svn: 177443

1 files changed, 8 insertions, 6 deletions

diff --git a/libcxx/src/iostream.cpp b/libcxx/src/iostream.cpp
index f5b959b4bb9..7fc71df44a4 100644
--- a/libcxx/src/iostream.cpp
+++ b/libcxx/src/iostream.cpp
@@ -13,6 +13,8 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+static mbstate_t state_types[6] = {};
+
 _ALIGNAS_TYPE (__stdinbuf<char> ) static char __cin [sizeof(__stdinbuf <char>)];
 _ALIGNAS_TYPE (__stdoutbuf<char>) static char __cout[sizeof(__stdoutbuf<char>)];
 _ALIGNAS_TYPE (__stdoutbuf<char>) static char __cerr[sizeof(__stdoutbuf<char>)];
@@ -33,17 +35,17 @@ ios_base::Init __start_std_streams;
 
 ios_base::Init::Init()
 {
-    istream* cin_ptr  = ::new(cin)  istream(::new(__cin)  __stdinbuf <char>(stdin) );
-    ostream* cout_ptr = ::new(cout) ostream(::new(__cout) __stdoutbuf<char>(stdout));
-    ostream* cerr_ptr = ::new(cerr) ostream(::new(__cerr) __stdoutbuf<char>(stderr));
+    istream* cin_ptr  = ::new(cin)  istream(::new(__cin)  __stdinbuf <char>(stdin, state_types+0) );
+    ostream* cout_ptr = ::new(cout) ostream(::new(__cout) __stdoutbuf<char>(stdout, state_types+1));
+    ostream* cerr_ptr = ::new(cerr) ostream(::new(__cerr) __stdoutbuf<char>(stderr, state_types+2));
                         ::new(clog) ostream(cerr_ptr->rdbuf());
     cin_ptr->tie(cout_ptr);
     _VSTD::unitbuf(*cerr_ptr);
     cerr_ptr->tie(cout_ptr);
 
-    wistream* wcin_ptr  = ::new(wcin)  wistream(::new(__wcin)  __stdinbuf <wchar_t>(stdin) );
-    wostream* wcout_ptr = ::new(wcout) wostream(::new(__wcout) __stdoutbuf<wchar_t>(stdout));
-    wostream* wcerr_ptr = ::new(wcerr) wostream(::new(__wcerr) __stdoutbuf<wchar_t>(stderr));
+    wistream* wcin_ptr  = ::new(wcin)  wistream(::new(__wcin)  __stdinbuf <wchar_t>(stdin, state_types+3) );
+    wostream* wcout_ptr = ::new(wcout) wostream(::new(__wcout) __stdoutbuf<wchar_t>(stdout, state_types+4));
+    wostream* wcerr_ptr = ::new(wcerr) wostream(::new(__wcerr) __stdoutbuf<wchar_t>(stderr, state_types+5));
                           ::new(wclog) wostream(wcerr_ptr->rdbuf());
     wcin_ptr->tie(wcout_ptr);
     _VSTD::unitbuf(*wcerr_ptr);