gcc: add musl support patch for gcc 4.7.3

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gcc/4.7.3/900-musl-support.patch

@@ -0,0 +1,638 @@
+Add musl support to gcc
+
+This patch comes from the musl-cross project at
+https://bitbucket.org/GregorR/musl-cross/src. Compared to the upstream version:
+
+ * the config.sub modifications have been removed, because Buildroot
+   already overwrites all config.sub with a more recent config.sub
+   that has musl support.
+
+ * change to ensure that a dummy dynamic linker path
+   MUSL_DYNAMIC_LINKER<foo> is defined for all architectures,
+   otherwise building gcc for architectures not supported by musl was
+   causing build failure. Bug reported upstream at
+   https://bitbucket.org/GregorR/musl-gcc-patches/issue/4/musl-gcc-patches-break-the-build-on.
+
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+---
+
+# HG changeset patch
+# Parent f50bb54f331f73405131a30b4f353cfda1c70304
+Use the generic implementation of libstdc++ primitives when we're on musl, not the glibc one.
+
+Index: b/libstdc++-v3/configure.host
+===================================================================
+--- a/libstdc++-v3/configure.host
++++ b/libstdc++-v3/configure.host
+@@ -243,6 +243,13 @@
+     os_include_dir="os/bsd/freebsd"
+     ;;
+   gnu* | linux* | kfreebsd*-gnu | knetbsd*-gnu)
++    # check for musl by target
++    case "${host_os}" in
++      *-musl*)
++        os_include_dir="os/generic"
++        ;;
++      *)
++
+     if [ "$uclibc" = "yes" ]; then
+       os_include_dir="os/uclibc"
+     elif [ "$bionic" = "yes" ]; then
+@@ -251,6 +258,9 @@
+       os_include_dir="os/gnu-linux"
+     fi
+     ;;
++
++    esac
++    ;;
+   hpux*)
+     os_include_dir="os/hpux"
+     ;;
+Index: b/gcc/config.gcc
+===================================================================
+--- a/gcc/config.gcc
++++ b/gcc/config.gcc
+@@ -522,7 +522,7 @@
+ esac
+ 
+ # Common C libraries.
+-tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3"
++tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3 LIBC_MUSL=4"
+ 
+ # Common parts for widely ported systems.
+ case ${target} in
+@@ -625,6 +625,9 @@
+     *-*-*uclibc*)
+       tm_defines="$tm_defines DEFAULT_LIBC=LIBC_UCLIBC"
+       ;;
++    *-*-*musl*)
++      tm_defines="$tm_defines DEFAULT_LIBC=LIBC_MUSL"
++      ;;
+     *)
+       tm_defines="$tm_defines DEFAULT_LIBC=LIBC_GLIBC"
+       ;;
+@@ -2092,6 +2095,10 @@
+ 	    powerpc*-*-linux*paired*)
+ 		tm_file="${tm_file} rs6000/750cl.h" ;;
+ 	esac
++        case ${target} in
++            *-linux*-musl*)
++                enable_secureplt=yes ;;
++        esac
+ 	if test x${enable_secureplt} = xyes; then
+ 		tm_file="rs6000/secureplt.h ${tm_file}"
+ 	fi
+Index: b/gcc/config/linux.h
+===================================================================
+--- a/gcc/config/linux.h
++++ b/gcc/config/linux.h
+@@ -33,10 +33,12 @@
+ #define OPTION_GLIBC  (DEFAULT_LIBC == LIBC_GLIBC)
+ #define OPTION_UCLIBC (DEFAULT_LIBC == LIBC_UCLIBC)
+ #define OPTION_BIONIC (DEFAULT_LIBC == LIBC_BIONIC)
++#define OPTION_MUSL   (DEFAULT_LIBC == LIBC_MUSL)
+ #else
+ #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
+ #define OPTION_UCLIBC (linux_libc == LIBC_UCLIBC)
+ #define OPTION_BIONIC (linux_libc == LIBC_BIONIC)
++#define OPTION_MUSL   (linux_libc == LIBC_MUSL)
+ #endif
+ 
+ #define GNU_USER_TARGET_OS_CPP_BUILTINS()			\
+@@ -54,18 +56,21 @@
+    uClibc or Bionic is the default C library and whether
+    -muclibc or -mglibc or -mbionic has been passed to change the default.  */
+ 
+-#define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LD1, LD2, LD3)	\
+-  "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:" LD1 "}}"
++#define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LIBC4, LD1, LD2, LD3, LD4)	\
++  "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:%{" LIBC4 ":" LD4 ";:" LD1 "}}}"
+ 
+ #if DEFAULT_LIBC == LIBC_GLIBC
+-#define CHOOSE_DYNAMIC_LINKER(G, U, B) \
+-  CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", G, U, B)
++#define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
++  CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", "mmusl", G, U, B, M)
+ #elif DEFAULT_LIBC == LIBC_UCLIBC
+-#define CHOOSE_DYNAMIC_LINKER(G, U, B) \
+-  CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", U, G, B)
++#define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
++  CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", "mmusl", U, G, B, M)
+ #elif DEFAULT_LIBC == LIBC_BIONIC
+-#define CHOOSE_DYNAMIC_LINKER(G, U, B) \
+-  CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", B, G, U)
++#define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
++  CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", "mmusl", B, G, U, M)
++#elif DEFAULT_LIBC == LIBC_MUSL
++#define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
++  CHOOSE_DYNAMIC_LINKER1 ("mmusl", "mglibc", "muclibc", "mbionic", M, G, U, B)
+ #else
+ #error "Unsupported DEFAULT_LIBC"
+ #endif /* DEFAULT_LIBC */
+@@ -83,23 +88,32 @@
+ #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
+ #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
+ 
++/* Musl dynamic linker paths must be defined on a per-architecture
++   basis, for each architecture supported by Musl. However, in order
++   to let other architectures continue to build with other C
++   libraries, we provide a dummy definition of the following defines. */
++#define MUSL_DYNAMIC_LINKER "invalid"
++#define MUSL_DYNAMIC_LINKER32 "invalid"
++#define MUSL_DYNAMIC_LINKER64 "invalid"
++#define MUSL_DYNAMIC_LINKERX32 "invalid"
++
+ #define GNU_USER_DYNAMIC_LINKER						\
+   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,	\
+-			 BIONIC_DYNAMIC_LINKER)
++			 BIONIC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
+ #define GNU_USER_DYNAMIC_LINKER32					\
+   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
+-			 BIONIC_DYNAMIC_LINKER32)
++			 BIONIC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
+ #define GNU_USER_DYNAMIC_LINKER64					\
+   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
+-			 BIONIC_DYNAMIC_LINKER64)
++			 BIONIC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
+ #define GNU_USER_DYNAMIC_LINKERX32					\
+   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
+-			 BIONIC_DYNAMIC_LINKERX32)
++			 BIONIC_DYNAMIC_LINKERX32, MUSL_DYNAMIC_LINKERX32)
+ 
+ /* Determine whether the entire c99 runtime
+    is present in the runtime library.  */
+ #undef TARGET_C99_FUNCTIONS
+-#define TARGET_C99_FUNCTIONS (OPTION_GLIBC)
++#define TARGET_C99_FUNCTIONS (OPTION_GLIBC || OPTION_MUSL)
+ 
+ /* Whether we have sincos that follows the GNU extension.  */
+ #undef TARGET_HAS_SINCOS
+@@ -108,3 +122,74 @@
+ /* Whether we have Bionic libc runtime */
+ #undef TARGET_HAS_BIONIC
+ #define TARGET_HAS_BIONIC (OPTION_BIONIC)
++
++/* musl avoids problematic includes by rearranging the include directories.
++ * Unfortunately, this is mostly duplicated from cppdefault.c */
++#if DEFAULT_LIBC == LIBC_MUSL
++#define INCLUDE_DEFAULTS_MUSL_GPP			\
++    { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1,		\
++      GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },		\
++    { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1,		\
++      GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 1 },		\
++    { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1,	\
++      GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },
++
++#ifdef LOCAL_INCLUDE_DIR
++#define INCLUDE_DEFAULTS_MUSL_LOCAL			\
++    { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 2 },		\
++    { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 0 },
++#else
++#define INCLUDE_DEFAULTS_MUSL_LOCAL
++#endif
++
++#ifdef PREFIX_INCLUDE_DIR
++#define INCLUDE_DEFAULTS_MUSL_PREFIX			\
++    { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0},
++#else
++#define INCLUDE_DEFAULTS_MUSL_PREFIX
++#endif
++
++#ifdef CROSS_INCLUDE_DIR
++#define INCLUDE_DEFAULTS_MUSL_CROSS			\
++    { CROSS_INCLUDE_DIR, "GCC", 0, 0, 0, 0},
++#else
++#define INCLUDE_DEFAULTS_MUSL_CROSS
++#endif
++
++#ifdef TOOL_INCLUDE_DIR
++#define INCLUDE_DEFAULTS_MUSL_TOOL			\
++    { TOOL_INCLUDE_DIR, "BINUTILS", 0, 1, 0, 0},
++#else
++#define INCLUDE_DEFAULTS_MUSL_TOOL
++#endif
++
++#ifdef NATIVE_SYSTEM_HEADER_DIR
++#define INCLUDE_DEFAULTS_MUSL_NATIVE			\
++    { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 2 },	\
++    { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 0 },
++#else
++#define INCLUDE_DEFAULTS_MUSL_NATIVE
++#endif
++
++#if defined (CROSS_DIRECTORY_STRUCTURE) && !defined (TARGET_SYSTEM_ROOT)
++# undef INCLUDE_DEFAULTS_MUSL_LOCAL
++# define INCLUDE_DEFAULTS_MUSL_LOCAL
++# undef INCLUDE_DEFAULTS_MUSL_NATIVE
++# define INCLUDE_DEFAULTS_MUSL_NATIVE
++#else
++# undef INCLUDE_DEFAULTS_MUSL_CROSS
++# define INCLUDE_DEFAULTS_MUSL_CROSS
++#endif
++
++#undef INCLUDE_DEFAULTS
++#define INCLUDE_DEFAULTS				\
++  {							\
++    INCLUDE_DEFAULTS_MUSL_GPP				\
++    INCLUDE_DEFAULTS_MUSL_PREFIX			\
++    INCLUDE_DEFAULTS_MUSL_CROSS				\
++    INCLUDE_DEFAULTS_MUSL_TOOL				\
++    INCLUDE_DEFAULTS_MUSL_NATIVE			\
++    { GCC_INCLUDE_DIR, "GCC", 0, 1, 0, 0 },		\
++    { 0, 0, 0, 0, 0, 0 }				\
++  }
++#endif
+Index: b/gcc/config/linux.opt
+===================================================================
+--- a/gcc/config/linux.opt
++++ b/gcc/config/linux.opt
+@@ -30,3 +30,7 @@
+ muclibc
+ Target Report RejectNegative Var(linux_libc,LIBC_UCLIBC) Negative(mbionic)
+ Use uClibc C library
++
++mmusl
++Target Report RejectNegative Var(linux_libc,LIBC_MUSL) Negative(mglibc)
++Use musl C library
+Index: b/gcc/ginclude/stddef.h
+===================================================================
+--- a/gcc/ginclude/stddef.h
++++ b/gcc/ginclude/stddef.h
+@@ -184,6 +184,7 @@
+ #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 @@
+ #define ___int_size_t_h
+ #define _GCC_SIZE_T
+ #define _SIZET_
++#define __DEFINED_size_t /* musl */
+ #if (defined (__FreeBSD__) && (__FreeBSD__ >= 5)) \
+   || defined(__FreeBSD_kernel__)
+ /* __size_t is a typedef on FreeBSD 5, must not trash it. */
+@@ -215,6 +217,7 @@
+ 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 */
+Index: b/libgomp/config/posix/time.c
+===================================================================
+--- a/libgomp/config/posix/time.c
++++ b/libgomp/config/posix/time.c
+@@ -28,6 +28,8 @@
+    The following implementation uses the most simple POSIX routines.
+    If present, POSIX 4 clocks should be used instead.  */
+ 
++#define _POSIX_C_SOURCE 199309L /* for clocks */
++
+ #include "libgomp.h"
+ #include <unistd.h>
+ #if TIME_WITH_SYS_TIME
+Index: b/libgcc/unwind-dw2-fde-dip.c
+===================================================================
+--- a/libgcc/unwind-dw2-fde-dip.c
++++ b/libgcc/unwind-dw2-fde-dip.c
+@@ -47,28 +47,13 @@
+ #include "unwind-compat.h"
+ #include "gthr.h"
+ 
+-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+-    && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
+-	|| (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
+-# define USE_PT_GNU_EH_FRAME
+-#endif
+-
+-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+-    && defined(__FreeBSD__) && __FreeBSD__ >= 7
+-# define ElfW __ElfN
+-# define USE_PT_GNU_EH_FRAME
+-#endif
+-
+-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+-    && defined(__OpenBSD__)
+-# define ElfW(type) Elf_##type
+-# define USE_PT_GNU_EH_FRAME
+-#endif
+-
+-#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+-    && defined(TARGET_DL_ITERATE_PHDR) \
+-    && defined(__sun__) && defined(__svr4__)
++#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) && defined(TARGET_DL_ITERATE_PHDR)
+ # define USE_PT_GNU_EH_FRAME
++# ifdef __OpenBSD__
++#  define ElfW(type) Elf_##typ
++# elif defined(__FreeBSD__) && __FreeBSD__ >= 7
++#  define ElfW __ElfN
++# endif
+ #endif
+ 
+ #if defined(USE_PT_GNU_EH_FRAME)
+Index: b/gcc/configure
+===================================================================
+--- a/gcc/configure
++++ b/gcc/configure
+@@ -26787,6 +26787,9 @@
+ 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.
+@@ -26820,6 +26823,7 @@
+ 	 # <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 "$LINENO" "__stack_chk_fail" "ac_cv_func___stack_chk_fail"
+@@ -26902,6 +26906,9 @@
+       gcc_cv_target_dl_iterate_phdr=no
+     fi
+     ;;
++  *-linux-musl*)
++    gcc_cv_target_dl_iterate_phdr=yes
++    ;;
+ esac
+ 
+ if test x$gcc_cv_target_dl_iterate_phdr = xyes; then
+Index: b/gcc/configure.ac
+===================================================================
+--- a/gcc/configure.ac
++++ b/gcc/configure.ac
+@@ -4664,6 +4664,9 @@
+       gcc_cv_libc_provides_ssp,
+       [gcc_cv_libc_provides_ssp=no
+     case "$target" in
++       *-*-musl*)
++         # All versions of musl provide stack protector
++	 gcc_cv_libc_provides_ssp=yes;;
+        *-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
+       [# glibc 2.4 and later provides __stack_chk_fail and
+       # either __stack_chk_guard, or TLS access to stack guard canary.
+@@ -4697,6 +4700,7 @@
+ 	 # <http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html>) and for now
+ 	 # simply assert that glibc does provide this, which is true for all
+ 	 # realistically usable GNU/Hurd configurations.
++	 # All supported versions of musl provide it as well
+ 	 gcc_cv_libc_provides_ssp=yes;;
+        *-*-darwin* | *-*-freebsd*)
+ 	 AC_CHECK_FUNC(__stack_chk_fail,[gcc_cv_libc_provides_ssp=yes],
+@@ -4762,6 +4766,9 @@
+       gcc_cv_target_dl_iterate_phdr=no
+     fi
+     ;;
++  *-linux-musl*)
++    gcc_cv_target_dl_iterate_phdr=yes
++    ;;
+ esac
+ GCC_TARGET_TEMPLATE([TARGET_DL_ITERATE_PHDR])
+ if test x$gcc_cv_target_dl_iterate_phdr = xyes; then
+Index: b/fixincludes/mkfixinc.sh
+===================================================================
+--- a/fixincludes/mkfixinc.sh
++++ b/fixincludes/mkfixinc.sh
+@@ -20,7 +20,8 @@
+     powerpc-*-eabi*    | \
+     powerpc-*-rtems*   | \
+     powerpcle-*-eabisim* | \
+-    powerpcle-*-eabi* )
++    powerpcle-*-eabi* | \
++    *-musl* )
+ 	#  IF there is no include fixing,
+ 	#  THEN create a no-op fixer and exit
+ 	(echo "#! /bin/sh" ; echo "exit 0" ) > ${target}
+Index: b/gcc/config/i386/linux.h
+===================================================================
+--- a/gcc/config/i386/linux.h
++++ b/gcc/config/i386/linux.h
+@@ -22,3 +22,5 @@
+ 
+ #define GNU_USER_LINK_EMULATION "elf_i386"
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux.so.2"
++#undef MUSL_DYNAMIC_LINKER
++#define MUSL_DYNAMIC_LINKER "/lib/ld-musl-i386.so.1"
+Index: b/gcc/config/i386/linux64.h
+===================================================================
+--- a/gcc/config/i386/linux64.h
++++ b/gcc/config/i386/linux64.h
+@@ -31,3 +31,10 @@
+ #define GLIBC_DYNAMIC_LINKER32 "/lib/ld-linux.so.2"
+ #define GLIBC_DYNAMIC_LINKER64 "/lib64/ld-linux-x86-64.so.2"
+ #define GLIBC_DYNAMIC_LINKERX32 "/libx32/ld-linux-x32.so.2"
++
++#undef MUSL_DYNAMIC_LINKER32
++#undef MUSL_DYNAMIC_LINKER64
++#undef MUSL_DYNAMIC_LINKERX32
++#define MUSL_DYNAMIC_LINKER32 "/lib/ld-musl-i386.so.1"
++#define MUSL_DYNAMIC_LINKER64 "/lib/ld-musl-x86_64.so.1"
++#define MUSL_DYNAMIC_LINKERX32 "/lib/ld-musl-x32.so.1"
+Index: b/libitm/config/linux/x86/tls.h
+===================================================================
+--- a/libitm/config/linux/x86/tls.h
++++ b/libitm/config/linux/x86/tls.h
+@@ -25,16 +25,19 @@
+ #ifndef LIBITM_X86_TLS_H
+ #define LIBITM_X86_TLS_H 1
+ 
+-#if defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 10)
++#if defined(__GLIBC_PREREQ)
++#if __GLIBC_PREREQ(2, 10)
+ /* Use slots in the TCB head rather than __thread lookups.
+    GLIBC has reserved words 10 through 13 for TM.  */
+ #define HAVE_ARCH_GTM_THREAD 1
+ #define HAVE_ARCH_GTM_THREAD_DISP 1
+ #endif
++#endif
+ 
+ #include "config/generic/tls.h"
+ 
+-#if defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 10)
++#if defined(__GLIBC_PREREQ)
++#if __GLIBC_PREREQ(2, 10)
+ namespace GTM HIDDEN {
+ 
+ #ifdef __x86_64__
+@@ -101,5 +104,6 @@
+ 
+ } // namespace GTM
+ #endif /* >= GLIBC 2.10 */
++#endif
+ 
+ #endif // LIBITM_X86_TLS_H
+Index: b/gcc/config/arm/linux-eabi.h
+===================================================================
+--- a/gcc/config/arm/linux-eabi.h
++++ b/gcc/config/arm/linux-eabi.h
+@@ -64,6 +64,23 @@
+ #undef  GLIBC_DYNAMIC_LINKER
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux.so.3"
+ 
++/* For ARM musl currently supports four dynamic linkers:
++   - ld-musl-arm.so.1 - for the EABI-derived soft-float ABI
++   - ld-musl-armhf.so.1 - for the EABI-derived hard-float ABI
++   - ld-musl-armeb.so.1 - for the EABI-derived soft-float ABI, EB
++   - ld-musl-armebhf.so.1 - for the EABI-derived hard-float ABI, EB
++   musl does not support the legacy OABI mode.
++   All the dynamic linkers live in /lib.
++   We default to soft-float, EL. */
++#undef  MUSL_DYNAMIC_LINKER
++#if TARGET_BIG_ENDIAN_DEFAULT
++#define MUSL_DYNAMIC_LINKER_E "%{mlittle-endian:;:eb}"
++#else
++#define MUSL_DYNAMIC_LINKER_E "%{mbig-endian:eb}"
++#endif
++#define MUSL_DYNAMIC_LINKER \
++  "/lib/ld-musl-arm" MUSL_DYNAMIC_LINKER_E "%{mfloat-abi=hard:hf}.so.1"
++
+ /* At this point, bpabi.h will have clobbered LINK_SPEC.  We want to
+    use the GNU/Linux version, not the generic BPABI version.  */
+ #undef  LINK_SPEC
+Index: b/libitm/config/arm/hwcap.cc
+===================================================================
+--- a/libitm/config/arm/hwcap.cc
++++ b/libitm/config/arm/hwcap.cc
+@@ -40,7 +40,11 @@
+ 
+ #ifdef __linux__
+ #include <unistd.h>
++#ifdef __GLIBC__
+ #include <sys/fcntl.h>
++#else
++#include <fcntl.h>
++#endif
+ #include <elf.h>
+ 
+ static void __attribute__((constructor))
+Index: b/gcc/config/mips/linux.h
+===================================================================
+--- a/gcc/config/mips/linux.h
++++ b/gcc/config/mips/linux.h
+@@ -19,3 +19,11 @@
+ <http://www.gnu.org/licenses/>.  */
+ 
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
++
++#if TARGET_ENDIAN_DEFAULT == 0 /* LE */
++#define MUSL_DYNAMIC_LINKER_E "%{EB:;:el}"
++#else
++#define MUSL_DYNAMIC_LINKER_E "%{EL:el}"
++#endif
++#undef MUSL_DYNAMIC_LINKER
++#define MUSL_DYNAMIC_LINKER "/lib/ld-musl-mips" MUSL_DYNAMIC_LINKER_E ".so.1"
+Index: b/gcc/config/rs6000/linux64.h
+===================================================================
+--- a/gcc/config/rs6000/linux64.h
++++ b/gcc/config/rs6000/linux64.h
+@@ -362,17 +362,23 @@
+ #define GLIBC_DYNAMIC_LINKER64 "/lib64/ld64.so.1"
+ #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
+ #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
++#undef MUSL_DYNAMIC_LINKER32
++#undef MUSL_DYNAMIC_LINKER64
++#define MUSL_DYNAMIC_LINKER32 "/lib/ld-musl-powerpc.so.1"
++#define MUSL_DYNAMIC_LINKER64 "/lib/ld-musl-powerpc64.so.1"
+ #if DEFAULT_LIBC == LIBC_UCLIBC
+-#define CHOOSE_DYNAMIC_LINKER(G, U) "%{mglibc:" G ";:" U "}"
++#define CHOOSE_DYNAMIC_LINKER(G, U, M) "%{mglibc:" G ";:%{mmusl:" M ";:" U "}}"
+ #elif DEFAULT_LIBC == LIBC_GLIBC
+-#define CHOOSE_DYNAMIC_LINKER(G, U) "%{muclibc:" U ";:" G "}"
++#define CHOOSE_DYNAMIC_LINKER(G, U, M) "%{muclibc:" U ";:%{mmusl:" M ";:" G "}}"
++#elif DEFAULT_LIBC == LIBC_MUSL
++#define CHOOSE_DYNAMIC_LINKER(G, U, M) "%{mglibc:" G ";:%{muclibc:" U ";:" M "}}"
+ #else
+ #error "Unsupported DEFAULT_LIBC"
+ #endif
+ #define GNU_USER_DYNAMIC_LINKER32 \
+-  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32)
++  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
+ #define GNU_USER_DYNAMIC_LINKER64 \
+-  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64)
++  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
+ 
+ 
+ #define LINK_OS_LINUX_SPEC32 "-m elf32ppclinux %{!shared: %{!static: \
+Index: b/gcc/config/rs6000/secureplt.h
+===================================================================
+--- a/gcc/config/rs6000/secureplt.h
++++ b/gcc/config/rs6000/secureplt.h
+@@ -18,3 +18,4 @@
+ <http://www.gnu.org/licenses/>.  */
+ 
+ #define CC1_SECURE_PLT_DEFAULT_SPEC "-msecure-plt"
++#define LINK_SECURE_PLT_DEFAULT_SPEC "--secure-plt"
+Index: b/gcc/config/rs6000/sysv4.h
+===================================================================
+--- a/gcc/config/rs6000/sysv4.h
++++ b/gcc/config/rs6000/sysv4.h
+@@ -566,6 +566,9 @@
+ #ifndef CC1_SECURE_PLT_DEFAULT_SPEC
+ #define CC1_SECURE_PLT_DEFAULT_SPEC ""
+ #endif
++#ifndef LINK_SECURE_PLT_DEFAULT_SPEC
++#define LINK_SECURE_PLT_DEFAULT_SPEC ""
++#endif
+ 
+ /* Pass -G xxx to the compiler and set correct endian mode.  */
+ #define	CC1_SPEC "%{G*} %(cc1_cpu) \
+@@ -626,7 +629,8 @@
+ %{mlittle: --oformat elf32-powerpcle } %{mlittle-endian: --oformat elf32-powerpcle } \
+ %{!mlittle: %{!mlittle-endian: %{!mbig: %{!mbig-endian: \
+     %{mcall-i960-old: --oformat elf32-powerpcle} \
+-  }}}}"
++  }}}} \
++%{!mbss-plt: %{!msecure-plt: %(link_secure_plt_default)}}"
+ 
+ /* Any specific OS flags.  */
+ #define LINK_OS_SPEC "\
+@@ -804,15 +808,19 @@
+ 
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
+ #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
++#undef MUSL_DYNAMIC_LINKER
++#define MUSL_DYNAMIC_LINKER "/lib/ld-musl-powerpc.so.1"
+ #if DEFAULT_LIBC == LIBC_UCLIBC
+-#define CHOOSE_DYNAMIC_LINKER(G, U) "%{mglibc:" G ";:" U "}"
++#define CHOOSE_DYNAMIC_LINKER(G, U, M) "%{mglibc:" G ";:%{mmusl:" M ";:" U "}}"
++#elif DEFAULT_LIBC == LIBC_MUSL
++#define CHOOSE_DYNAMIC_LINKER(G, U, M) "%{mglibc:" G ";:%{muclibc:" U ";:" M "}}"
+ #elif !defined (DEFAULT_LIBC) || DEFAULT_LIBC == LIBC_GLIBC
+-#define CHOOSE_DYNAMIC_LINKER(G, U) "%{muclibc:" U ";:" G "}"
++#define CHOOSE_DYNAMIC_LINKER(G, U, M) "%{muclibc:" U ";:%{mmusl:" M ";:" G "}}"
+ #else
+ #error "Unsupported DEFAULT_LIBC"
+ #endif
+ #define GNU_USER_DYNAMIC_LINKER \
+-  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER)
++  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
+ 
+ #define LINK_OS_LINUX_SPEC "-m elf32ppclinux %{!shared: %{!static: \
+   %{rdynamic:-export-dynamic} \
+@@ -938,6 +946,7 @@
+   { "cc1_endian_little",	CC1_ENDIAN_LITTLE_SPEC },		\
+   { "cc1_endian_default",	CC1_ENDIAN_DEFAULT_SPEC },		\
+   { "cc1_secure_plt_default",	CC1_SECURE_PLT_DEFAULT_SPEC },		\
++  { "link_secure_plt_default",	LINK_SECURE_PLT_DEFAULT_SPEC },		\
+   { "cpp_os_ads",		CPP_OS_ADS_SPEC },			\
+   { "cpp_os_yellowknife",	CPP_OS_YELLOWKNIFE_SPEC },		\
+   { "cpp_os_mvme",		CPP_OS_MVME_SPEC },			\
+Index: b/gcc/config/mips/linux64.h
+===================================================================
+--- a/gcc/config/mips/linux64.h
++++ b/gcc/config/mips/linux64.h
+@@ -30,4 +30,4 @@
+ #define BIONIC_DYNAMIC_LINKERN32 "/system/bin/linker32"
+ #define GNU_USER_DYNAMIC_LINKERN32 \
+   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERN32, UCLIBC_DYNAMIC_LINKERN32, \
+-			 BIONIC_DYNAMIC_LINKERN32)
++			 BIONIC_DYNAMIC_LINKERN32, MUSL_DYNAMIC_LINKER)