Add wcharP.h to hide internal wchar functions [BZ #18822]hjl/pr18822

For some targets, like i386 and s390, internal IFUNC functions must be
called via PLT with a special register.  Add <wcharP.h> to allow targets,
which don't need a special register to call internal IFUNC functions via
PLT or have internal non-IFUNC wchar functions, to allow direct access to
internal wchar functions within libc.so and libc.a without using GOT nor
PLT.

Tested on i686 and x86-64.  It removed 11 PLT relocations on i686 and
29 PLT relocations on x86-64.

	[BZ #18822]
	* include/wchar.h: Include <wcharP.h>.
	* sysdeps/generic/wcharP.h: New file.
	* sysdeps/i386/wcharP.h: Likewise.
	* sysdeps/x86_64/wcharP.h: Likewise.

4 files changed, 68 insertions, 0 deletions

diff --git a/include/wchar.h b/include/wchar.h
index 1db0ac8278..4160322234 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -2,6 +2,7 @@
 # include <wcsmbs/wchar.h>
 # ifndef _ISOMAC
 
+#include <wcharP.h>
 #include <bits/floatn.h>
 
 extern __typeof (wcscasecmp_l) __wcscasecmp_l;
diff --git a/sysdeps/generic/wcharP.h b/sysdeps/generic/wcharP.h
new file mode 100644
index 0000000000..1a37283bf1
--- /dev/null
+++ b/sysdeps/generic/wcharP.h
@@ -0,0 +1,18 @@
+/* Internal prototrypes for multibyte and wide character functions.
+   Generic version.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
diff --git a/sysdeps/i386/wcharP.h b/sysdeps/i386/wcharP.h
new file mode 100644
index 0000000000..deac12e352
--- /dev/null
+++ b/sysdeps/i386/wcharP.h
@@ -0,0 +1,24 @@
+/* Internal prototrypes for multibyte and wide character functions.
+   i386 version.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+extern __typeof (wcpncpy) __wcpncpy attribute_hidden;
+extern __typeof (wcscat) __wcscat attribute_hidden __attribute_pure__;
+extern __typeof (wcschrnul) __wcschrnul attribute_hidden __attribute_pure__;
+extern __typeof (wcsncpy) __wcsncpy attribute_hidden;
+extern __typeof (wcsnlen) __wcsnlen attribute_hidden __attribute_pure__;
diff --git a/sysdeps/x86_64/wcharP.h b/sysdeps/x86_64/wcharP.h
new file mode 100644
index 0000000000..bd6272db9d
--- /dev/null
+++ b/sysdeps/x86_64/wcharP.h
@@ -0,0 +1,25 @@
+/* Internal prototrypes for multibyte and wide character functions.
+   x86-64 version.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+extern __typeof (wcpncpy) __wcpncpy attribute_hidden;
+extern __typeof (wcscat) __wcscat attribute_hidden __attribute_pure__;
+extern __typeof (wcschrnul) __wcschrnul attribute_hidden __attribute_pure__;
+extern __typeof (wcsncpy) __wcsncpy attribute_hidden;
+extern __typeof (wcslen) __wcslen attribute_hidden __attribute_pure__;
+extern __typeof (wcsnlen) __wcsnlen attribute_hidden __attribute_pure__;