gcc: add musl support patch to gcc 4.9.0
authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Mon, 5 May 2014 21:17:04 +0000 (23:17 +0200)
committerPeter Korsgaard <peter@korsgaard.com>
Mon, 5 May 2014 21:52:36 +0000 (23:52 +0200)
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
package/gcc/4.9.0/900-musl-support.patch [new file with mode: 0644]

diff --git a/package/gcc/4.9.0/900-musl-support.patch b/package/gcc/4.9.0/900-musl-support.patch
new file mode 100644 (file)
index 0000000..958940e
--- /dev/null
@@ -0,0 +1,710 @@
+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>
+---
+
+Index: b/fixincludes/mkfixinc.sh
+===================================================================
+--- a/fixincludes/mkfixinc.sh
++++ b/fixincludes/mkfixinc.sh
+@@ -19,7 +19,8 @@
+     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" ) > ${target}
+Index: b/gcc/config.gcc
+===================================================================
+--- a/gcc/config.gcc
++++ b/gcc/config.gcc
+@@ -594,7 +594,7 @@
+ esac
+ # Common C libraries.
+-tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3"
++tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3 LIBC_MUSL=4"
+ # 32-bit x86 processors supported by --with-arch=.  Each processor
+ # MUST be separated by exactly one space.
+@@ -719,6 +719,9 @@
+     *-*-*uclibc*)
+       tm_defines="$tm_defines DEFAULT_LIBC=LIBC_UCLIBC"
+       ;;
++    *-*-*musl*)
++      tm_defines="$tm_defines DEFAULT_LIBC=LIBC_MUSL"
++      ;;
+     *)
+       tm_defines="$tm_defines DEFAULT_LIBC=LIBC_GLIBC"
+       ;;
+@@ -2323,6 +2326,10 @@
+           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/aarch64/aarch64-linux.h
+===================================================================
+--- a/gcc/config/aarch64/aarch64-linux.h
++++ b/gcc/config/aarch64/aarch64-linux.h
+@@ -22,6 +22,8 @@
+ #define GCC_AARCH64_LINUX_H
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux-aarch64%{mbig-endian:_be}.so.1"
++#undef MUSL_DYNAMIC_LINKER
++#define MUSL_DYNAMIC_LINKER "/lib/ld-musl-aarch64.so.1"
+ #define CPP_SPEC "%{pthread:-D_REENTRANT}"
+Index: b/gcc/config/arm/linux-eabi.h
+===================================================================
+--- a/gcc/config/arm/linux-eabi.h
++++ b/gcc/config/arm/linux-eabi.h
+@@ -77,6 +77,23 @@
+     %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \
+     %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}"
++/* 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/gcc/config/i386/linux.h
+===================================================================
+--- a/gcc/config/i386/linux.h
++++ b/gcc/config/i386/linux.h
+@@ -21,3 +21,5 @@
+ #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
+@@ -30,3 +30,10 @@
+ #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
++#define MUSL_DYNAMIC_LINKER32 "/lib/ld-musl-i386.so.1"
++#undef MUSL_DYNAMIC_LINKER64
++#define MUSL_DYNAMIC_LINKER64 "/lib/ld-musl-x86_64.so.1"
++#undef MUSL_DYNAMIC_LINKERX32
++#define MUSL_DYNAMIC_LINKERX32 "/lib/ld-musl-x32.so.1"
+Index: b/gcc/config/linux.h
+===================================================================
+--- a/gcc/config/linux.h
++++ b/gcc/config/linux.h
+@@ -32,10 +32,12 @@
+ #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()                     \
+@@ -53,18 +55,21 @@
+    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 */
+@@ -82,23 +87,103 @@
+ #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_LINKER32)
+ /* 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
++
+ #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
+ /* This is a *uclinux* target.  We don't define below macros to normal linux
+    versions, because doing so would require *uclinux* targets to include
+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/config/microblaze/linux.h
+===================================================================
+--- a/gcc/config/microblaze/linux.h
++++ b/gcc/config/microblaze/linux.h
+@@ -25,7 +25,23 @@
+ #undef TLS_NEEDS_GOT
+ #define TLS_NEEDS_GOT 1
+-#define DYNAMIC_LINKER "/lib/ld.so.1"
++#if TARGET_BIG_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-microblaze" MUSL_DYNAMIC_LINKER_E ".so.1"
++#define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
++
++#if DEFAULT_LIBC == LIBC_MUSL
++#define DYNAMIC_LINKER MUSL_DYNAMIC_LINKER
++#else
++#define DYNAMIC_LINKER GLIBC_DYNAMIC_LINKER
++#endif
++
++
+ #undef  SUBTARGET_EXTRA_SPECS
+ #define SUBTARGET_EXTRA_SPECS \
+   { "dynamic_linker", DYNAMIC_LINKER }
+Index: b/gcc/config/rs6000/linux64.h
+===================================================================
+--- a/gcc/config/rs6000/linux64.h
++++ b/gcc/config/rs6000/linux64.h
+@@ -375,17 +375,23 @@
+ #endif
+ #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
+ #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
++#undef MUSL_DYNAMIC_LINKER32
++#define MUSL_DYNAMIC_LINKER32 "/lib/ld-musl-powerpc.so.1"
++#undef MUSL_DYNAMIC_LINKER64
++#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)
+ #undef  DEFAULT_ASM_ENDIAN
+ #if (TARGET_DEFAULT & MASK_LITTLE_ENDIAN)
+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
+@@ -537,6 +537,9 @@
+ #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.  */
+ #define       CC1_SPEC "%{G*} %(cc1_cpu)" \
+@@ -585,7 +588,8 @@
+ /* Override the default target of the linker.  */
+ #define       LINK_TARGET_SPEC \
+-  ENDIAN_SELECT("", " --oformat elf32-powerpcle", "")
++  ENDIAN_SELECT("", " --oformat elf32-powerpcle", "") \
++  "%{!mbss-plt: %{!msecure-plt: %(link_secure_plt_default)}}"
+ /* Any specific OS flags.  */
+ #define LINK_OS_SPEC "\
+@@ -763,15 +767,18 @@
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld.so.1"
+ #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
++#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} \
+@@ -894,6 +901,7 @@
+   { "link_os_openbsd",                LINK_OS_OPENBSD_SPEC },                 \
+   { "link_os_default",                LINK_OS_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/sh/linux.h
+===================================================================
+--- a/gcc/config/sh/linux.h
++++ b/gcc/config/sh/linux.h
+@@ -43,7 +43,15 @@
+ #define TARGET_ASM_FILE_END file_end_indicate_exec_stack
++#if TARGET_BIG_ENDIAN_DEFAULT /* BE */
++#define MUSL_DYNAMIC_LINKER_E "eb"
++#else
++#define MUSL_DYNAMIC_LINKER_E
++#endif
++
+ #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux.so.2"
++#undef MUSL_DYNAMIC_LINKER
++#define MUSL_DYNAMIC_LINKER "/lib/ld-musl-sh" MUSL_DYNAMIC_LINKER_E ".so.1"
+ #undef SUBTARGET_LINK_EMUL_SUFFIX
+ #define SUBTARGET_LINK_EMUL_SUFFIX "_linux"
+Index: b/gcc/config/sh/sh.c
+===================================================================
+--- a/gcc/config/sh/sh.c
++++ b/gcc/config/sh/sh.c
+@@ -70,10 +70,6 @@
+ #include "pass_manager.h"
+ #include "context.h"
+-#include <sstream>
+-#include <vector>
+-#include <algorithm>
+-
+ int code_for_indirect_jump_scratch = CODE_FOR_indirect_jump_scratch;
+ /* These are some macros to abstract register modes.  */
+Index: b/gcc/configure
+===================================================================
+--- a/gcc/configure
++++ b/gcc/configure
+@@ -27300,6 +27300,9 @@
+ 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.
+@@ -27332,6 +27335,7 @@
+        # <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 "$LINENO" "__stack_chk_fail" "ac_cv_func___stack_chk_fail"
+@@ -27421,6 +27425,9 @@
+       gcc_cv_target_dl_iterate_phdr=no
+     fi
+     ;;
++  *-linux-musl*)
++    gcc_cv_target_dl_iterate_phdr=yes
++    ;;
+ esac
+ if test x$gcc_cv_target_dl_iterate_phdr = xyes; then
+Index: b/gcc/configure.ac
+===================================================================
+--- a/gcc/configure.ac
++++ b/gcc/configure.ac
+@@ -5001,6 +5001,9 @@
+       gcc_cv_libc_provides_ssp,
+       [gcc_cv_libc_provides_ssp=no
+     case "$target" in
++       *-*-musl*)
++         # All versions of musl provide stack protector
++       gcc_cv_libc_provides_ssp=yes;;
+        *-*-linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu)
+       # glibc 2.4 and later provides __stack_chk_fail and
+       # either __stack_chk_guard, or TLS access to stack guard canary.
+@@ -5027,6 +5030,7 @@
+        # <http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html>) and for now
+        # simply assert that glibc does provide this, which is true for all
+        # realistically usable GNU/Hurd configurations.
++       # All supported versions of musl provide it as well
+        gcc_cv_libc_provides_ssp=yes;;
+        *-*-darwin* | *-*-freebsd*)
+        AC_CHECK_FUNC(__stack_chk_fail,[gcc_cv_libc_provides_ssp=yes],
+@@ -5093,6 +5097,9 @@
+       gcc_cv_target_dl_iterate_phdr=no
+     fi
+     ;;
++  *-linux-musl*)
++    gcc_cv_target_dl_iterate_phdr=yes
++    ;;
+ esac
+ GCC_TARGET_TEMPLATE([TARGET_DL_ITERATE_PHDR])
+ if test x$gcc_cv_target_dl_iterate_phdr = xyes; then
+Index: b/gcc/ginclude/stddef.h
+===================================================================
+--- a/gcc/ginclude/stddef.h
++++ b/gcc/ginclude/stddef.h
+@@ -181,6 +181,7 @@
+ #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
+@@ -197,6 +198,7 @@
+ #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. */
+@@ -214,6 +216,7 @@
+ 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/libgcc/unwind-dw2-fde-dip.c
+===================================================================
+--- a/libgcc/unwind-dw2-fde-dip.c
++++ b/libgcc/unwind-dw2-fde-dip.c
+@@ -46,33 +46,13 @@
+ #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(__BIONIC__)
+-# 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_##type
++# elif defined(__FreeBSD__) && __FreeBSD__ >= 7
++#  define ElfW __ElfN
++# endif
+ #endif
+ #if defined(USE_PT_GNU_EH_FRAME)
+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/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/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/libstdc++-v3/configure.host
+===================================================================
+--- a/libstdc++-v3/configure.host
++++ b/libstdc++-v3/configure.host
+@@ -264,6 +264,13 @@
+     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
+@@ -272,6 +279,9 @@
+       os_include_dir="os/gnu-linux"
+     fi
+     ;;
++
++    esac
++    ;;
+   hpux*)
+     os_include_dir="os/hpux"
+     ;;
+Index: b/gcc/config/mips/linux64.h
+===================================================================
+--- a/gcc/config/mips/linux64.h
++++ b/gcc/config/mips/linux64.h
+@@ -41,4 +41,4 @@
+ #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)
+Index: b/gcc/config/mips/linux.h
+===================================================================
+--- a/gcc/config/mips/linux.h
++++ b/gcc/config/mips/linux.h
+@@ -23,3 +23,11 @@
+ #undef UCLIBC_DYNAMIC_LINKER
+ #define UCLIBC_DYNAMIC_LINKER \
+   "%{mnan=2008:/lib/ld-uClibc-mipsn8.so.0;:/lib/ld-uClibc.so.0}"
++
++#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"