Commit 1da65232 authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Peter Korsgaard
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libunwind: fix C library dependency 



The libunwind package currently dependency on glibc *or* uclibc
snapshot. However, we are going to remove the support for uclibc
snapshot, and uClibc-ng has equivalent functionality as uclibc
snapshot. Moreover, musl is also capable of building libunwind for
certain architectures.

Therefore, this commit reworks the architecture dependencies of
libunwind, to make it available on all architectures for which it is
supported, depending on the capabilities of the different C libraries,
and the implementation of libunwind on each architecture.

On some architectures, libunwind uses the C library *context()
functions, which are not provided by musl at all, and not provided by
uClibc on all architectures. But on some other architectures,
libunwind does not use the C library *context() functions, which
explains why it can be built with musl on such architectures.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarPeter Korsgaard <peter@korsgaard.com>
parent 711c0387

package/libunwind/Config.in

+24 −7
Original line number Diff line number Diff line 
# libunwind is only available for a certain subset of the

# architectures (as visible in the list of architectures supported

# with the glibc C library below).

#

# In addition to this, on some architectures libunwind requires the

# *context() function from the C library, which are only available on

# certain architectures in uClibc, and not available at all on

# musl. But on some other architectures, libunwind works without using

# the *context() functions, which allows it to be built with musl.

config BR2_PACKAGE_LIBUNWIND_ARCH_SUPPORTS

	bool

	default y if BR2_TOOLCHAIN_USES_GLIBC && \

		(BR2_arm || BR2_armeb || BR2_mips || BR2_mipsel || BR2_mips64 || \

		 BR2_mips64el || BR2_powerpc || BR2_sh || BR2_sh64 || BR2_i386 || BR2_x86_64)

	default y if BR2_TOOLCHAIN_USES_UCLIBC && \

		(BR2_arm || BR2_armeb || BR2_i386 || BR2_mips || BR2_mipsel || \

		 BR2_mips64 || BR2_mips64el || BR2_x86_64)

	default y if BR2_TOOLCHAIN_USES_MUSL && \

		(BR2_arm || BR2_armeb || BR2_i386 || BR2_x86_64)



config BR2_PACKAGE_LIBUNWIND

	bool "libunwind"

	depends on BR2_TOOLCHAIN_HAS_THREADS

	depends on (BR2_UCLIBC_VERSION_SNAPSHOT || BR2_TOOLCHAIN_USES_GLIBC) # {g,s}etcontext

	depends on BR2_arm || BR2_armeb || BR2_mips || BR2_mipsel || BR2_mips64 || \

		BR2_mips64el || BR2_powerpc || BR2_sh || BR2_sh64 || BR2_i386 || BR2_x86_64

	depends on BR2_PACKAGE_LIBUNWIND_ARCH_SUPPORTS

	help

	  C API to determine the call-chain of a program.



	  http://www.nongnu.org/libunwind/index.html



comment "libunwind needs a uclibc snapshot or (e)glibc toolchain w/ threads"

	depends on BR2_arm || BR2_armeb || BR2_mips || BR2_mipsel || BR2_mips64 || \

		BR2_mips64el || BR2_powerpc || BR2_sh || BR2_sh64 || BR2_i386 || BR2_x86_64

	depends on !BR2_TOOLCHAIN_HAS_THREADS || !(BR2_UCLIBC_VERSION_SNAPSHOT || BR2_TOOLCHAIN_USES_GLIBC)
 
comment "libunwind needs a toolchain w/ threads"

	depends on BR2_PACKAGE_LIBUNWIND_ARCH_SUPPORTS

	depends on !BR2_TOOLCHAIN_HAS_THREADS