buildroot

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.

​

 * change the USE_PT_GNU_EH_FRAME logic to keep the existing gcc logic

   and only add the musl one as an addition, not as a replacement. Not

   doing this breaks C++ exception handling with glibc, because

   USE_PT_GNU_EH_FRAME doesn't get defined due to the configure script

   not testing dl_iterate_phdr() on any system except Solaris.

​

[Gustavo: remove upstream applied gcc/config/sh/sh.c chunk for 4.9.1]

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"

       ;;

@@ -2338,6 +2341,10 @@