diff --git a/gnu/dist/gcc/gcc/c-opts.c b/gnu/dist/gcc/gcc/c-opts.c
index 77a468ab1847..5714b2de7f96 100644
--- a/gnu/dist/gcc/gcc/c-opts.c
+++ b/gnu/dist/gcc/gcc/c-opts.c
@@ -1731,6 +1731,10 @@ Switches:\n\
-iwithprefix
Add to the end of the system include path\n\
-iwithprefixbefore Add to the end of the main include path\n\
-isystem Add to the start of the system include path\n\
+"), stdout);
+ fputs (_("\
+ -isystem-cxx Add to the start of the system C++ include\n\
+ path\n\
"), stdout);
fputs (_("\
-idirafter Add to the end of the system include path\n\
diff --git a/gnu/dist/gcc/gcc/cppinit.c b/gnu/dist/gcc/gcc/cppinit.c
index d8e622bca4e4..aa6e7459d146 100644
--- a/gnu/dist/gcc/gcc/cppinit.c
+++ b/gnu/dist/gcc/gcc/cppinit.c
@@ -1179,6 +1179,7 @@ new_pending_directive (pend, text, handler)
DEF_OPT("include", no_fil, OPT_include) \
DEF_OPT("iprefix", no_pth, OPT_iprefix) \
DEF_OPT("isystem", no_dir, OPT_isystem) \
+ DEF_OPT("isystem-cxx", no_dir, OPT_isystemcxx) \
DEF_OPT("iwithprefix", no_dir, OPT_iwithprefix) \
DEF_OPT("iwithprefixbefore", no_dir, OPT_iwithprefixbefore)
@@ -1362,6 +1363,11 @@ cpp_handle_option (pfile, argc, argv)
include directory. */
append_include_chain (pfile, xstrdup (arg), SYSTEM, 0);
break;
+ case OPT_isystemcxx:
+ /* Add directory to beginning of system C++ include path, as a system
+ include directory. */
+ append_include_chain (pfile, xstrdup (arg), SYSTEM, 1);
+ break;
case OPT_include:
case OPT_imacros:
{
diff --git a/gnu/dist/gcc/gcc/gcc.h b/gnu/dist/gcc/gcc/gcc.h
index 06691bd9f6b7..c9d204f89fdd 100644
--- a/gnu/dist/gcc/gcc/gcc.h
+++ b/gnu/dist/gcc/gcc/gcc.h
@@ -48,8 +48,8 @@ struct spec_function
|| !strcmp (STR, "imacros") || !strcmp (STR, "aux-info") \
|| !strcmp (STR, "idirafter") || !strcmp (STR, "iprefix") \
|| !strcmp (STR, "iwithprefix") || !strcmp (STR, "iwithprefixbefore") \
- || !strcmp (STR, "isystem") || !strcmp (STR, "-param") \
- || !strcmp (STR, "specs") \
+ || !strcmp (STR, "isystem") || !strcmp (STR, "isystem-cxx") \
+ || !strcmp (STR, "-param") || !strcmp (STR, "specs") \
|| !strcmp (STR, "MF") || !strcmp (STR, "MT") || !strcmp (STR, "MQ"))