---- a/gcc/ginclude/stddef.h
-+++ b/gcc/ginclude/stddef.h
-@@ -184,6 +184,7 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
- #ifndef _GCC_SIZE_T
- #ifndef _SIZET_
- #ifndef __size_t
-+#ifndef __DEFINED_size_t /* musl */
- #define __size_t__ /* BeOS */
- #define __SIZE_T__ /* Cray Unicos/Mk */
- #define _SIZE_T
-@@ -200,6 +201,7 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
- #define ___int_size_t_h
- #define _GCC_SIZE_T
- #define _SIZET_
-+#define __DEFINED_size_t /* musl */
- #if (defined (__FreeBSD__) && (__FreeBSD__ >= 5)) \
- || defined(__DragonFly__) \
- || defined(__FreeBSD_kernel__)
-@@ -218,6 +220,7 @@ typedef __SIZE_TYPE__ size_t;
- typedef long ssize_t;
- #endif /* __BEOS__ */
- #endif /* !(defined (__GNUG__) && defined (size_t)) */
-+#endif /* __DEFINED_size_t */
- #endif /* __size_t */
- #endif /* _SIZET_ */
- #endif /* _GCC_SIZE_T */
+--- a/gcc/configure
++++ b/gcc/configure
+@@ -27742,6 +27742,9 @@ if test "${gcc_cv_libc_provides_ssp+set}
+ else
+ gcc_cv_libc_provides_ssp=no
+ case "$target" in
++ *-*-musl*)
++ # All versions of musl provide stack protector
++ gcc_cv_libc_provides_ssp=yes;;
+ *-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
+ # glibc 2.4 and later provides __stack_chk_fail and
+ # either __stack_chk_guard, or TLS access to stack guard canary.
+@@ -27774,6 +27777,7 @@ fi
+ # <http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html>) and for now
+ # simply assert that glibc does provide this, which is true for all
+ # realistically usable GNU/Hurd configurations.
++ # All supported versions of musl provide it as well
+ gcc_cv_libc_provides_ssp=yes;;
+ *-*-darwin* | *-*-freebsd*)
+ ac_fn_c_check_func "$LINENO" "__stack_chk_fail" "ac_cv_func___stack_chk_fail"
+@@ -27870,6 +27874,9 @@ case "$target" in
+ gcc_cv_target_dl_iterate_phdr=no
+ fi
+ ;;
++ *-linux-musl*)
++ gcc_cv_target_dl_iterate_phdr=yes
++ ;;
+ esac
+
+ if test x$gcc_cv_target_dl_iterate_phdr = xyes; then
+--- a/gcc/configure.ac
++++ b/gcc/configure.ac
+@@ -5229,6 +5229,9 @@ AC_CACHE_CHECK(__stack_chk_fail in targe
+ gcc_cv_libc_provides_ssp,
+ [gcc_cv_libc_provides_ssp=no
+ case "$target" in
++ *-*-musl*)
++ # All versions of musl provide stack protector
++ gcc_cv_libc_provides_ssp=yes;;
+ *-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
+ # glibc 2.4 and later provides __stack_chk_fail and
+ # either __stack_chk_guard, or TLS access to stack guard canary.
+@@ -5255,6 +5258,7 @@ AC_CACHE_CHECK(__stack_chk_fail in targe
+ # <http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html>) and for now
+ # simply assert that glibc does provide this, which is true for all
+ # realistically usable GNU/Hurd configurations.
++ # All supported versions of musl provide it as well
+ gcc_cv_libc_provides_ssp=yes;;
+ *-*-darwin* | *-*-freebsd*)
+ AC_CHECK_FUNC(__stack_chk_fail,[gcc_cv_libc_provides_ssp=yes],
+@@ -5328,6 +5332,9 @@ case "$target" in
+ gcc_cv_target_dl_iterate_phdr=no
+ fi
+ ;;
++ *-linux-musl*)
++ gcc_cv_target_dl_iterate_phdr=yes
++ ;;
+ esac
+ GCC_TARGET_TEMPLATE([TARGET_DL_ITERATE_PHDR])
+ if test x$gcc_cv_target_dl_iterate_phdr = xyes; then
+--- a/gcc/doc/invoke.texi
++++ b/gcc/doc/invoke.texi
+@@ -667,7 +667,7 @@ Objective-C and Objective-C++ Dialects}.
+ -mcpu=@var{cpu}}
+
+ @emph{GNU/Linux Options}
+-@gccoptlist{-mglibc -muclibc -mbionic -mandroid @gol
++@gccoptlist{-mglibc -muclibc -mmusl -mbionic -mandroid @gol
+ -tno-android-cc -tno-android-ld}
+
+ @emph{H8/300 Options}
+@@ -15324,13 +15324,19 @@ These @samp{-m} options are defined for
+ @item -mglibc
+ @opindex mglibc
+ Use the GNU C library. This is the default except
+-on @samp{*-*-linux-*uclibc*} and @samp{*-*-linux-*android*} targets.
++on @samp{*-*-linux-*uclibc*}, @samp{*-*-linux-*musl*} and
++@samp{*-*-linux-*android*} targets.
+
+ @item -muclibc
+ @opindex muclibc
+ Use uClibc C library. This is the default on
+ @samp{*-*-linux-*uclibc*} targets.
+
++@item -mmusl
++@opindex mmusl
++Use the musl C library. This is the default on
++@samp{*-*-linux-*musl*} targets.
++
+ @item -mbionic
+ @opindex mbionic
+ Use Bionic C library. This is the default on