Merge from bittboy/buildroot@db180c0

toolchain/Config.in

@@ -0,0 +1,659 @@
+menu "Toolchain"
+
+# Invisible option that makes sure the toolchain package always gets
+# built
+config BR2_TOOLCHAIN
+	bool
+	default y
+
+# Should be selected for glibc or eglibc
+config BR2_TOOLCHAIN_USES_GLIBC
+	bool
+	select BR2_USE_WCHAR
+	select BR2_ENABLE_LOCALE
+	select BR2_TOOLCHAIN_HAS_FULL_GETTEXT
+	select BR2_TOOLCHAIN_HAS_THREADS
+	select BR2_TOOLCHAIN_HAS_THREADS_DEBUG
+	select BR2_TOOLCHAIN_HAS_THREADS_NPTL
+	select BR2_TOOLCHAIN_HAS_UCONTEXT
+	select BR2_TOOLCHAIN_SUPPORTS_PIE
+
+config BR2_TOOLCHAIN_USES_UCLIBC
+	bool
+	# ucontext is only available for a subset of the supported
+	# architectures
+	select BR2_TOOLCHAIN_HAS_UCONTEXT if BR2_ARM_CPU_HAS_ARM || BR2_i386 \
+		|| BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el \
+		|| BR2_sparc || BR2_x86_64
+	select BR2_TOOLCHAIN_SUPPORTS_PIE if !BR2_m68k && !BR2_microblaze && !BR2_STATIC_LIBS
+
+config BR2_TOOLCHAIN_USES_MUSL
+	bool
+	select BR2_USE_WCHAR
+	select BR2_ENABLE_LOCALE
+	select BR2_TOOLCHAIN_HAS_THREADS
+	select BR2_TOOLCHAIN_HAS_THREADS_DEBUG
+	select BR2_TOOLCHAIN_HAS_THREADS_NPTL
+	select BR2_TOOLCHAIN_HAS_UCONTEXT
+	select BR2_TOOLCHAIN_SUPPORTS_PIE if !BR2_STATIC_LIBS
+
+choice
+	prompt "Toolchain type"
+	help
+	  Select whether to use the toolchain provided by buildroot
+	  or an external toolchain.
+
+	  Some vendors provide toolchains in binary form, some in
+	  source form.
+
+config BR2_TOOLCHAIN_BUILDROOT
+	bool "Buildroot toolchain"
+	depends on BR2_ARCH_HAS_TOOLCHAIN_BUILDROOT
+
+config BR2_TOOLCHAIN_EXTERNAL
+	bool "External toolchain"
+	help
+	  Select if you want to use an existing cross-compiling
+	  toolchain. Buildroot can either download automatically a
+	  toolchain, or use an already installed toolchain.
+
+endchoice
+
+source "toolchain/toolchain-buildroot/Config.in"
+source "toolchain/toolchain-external/Config.in"
+
+# Generic toolchain options
+
+# we want gdb config in the middle of both source and external
+# toolchains, but mconf won't let us source the same file twice,
+# so put it here instead
+source "package/gdb/Config.in.host"
+
+comment "Toolchain Generic Options"
+
+# https://sourceware.org/bugzilla/show_bug.cgi?id=19615
+# Affect toolchains built with binutils 2.26 (fixed in binutils 2.26.1).
+config BR2_TOOLCHAIN_HAS_BINUTILS_BUG_19615
+	bool
+
+# https://sourceware.org/bugzilla/show_bug.cgi?id=20006
+# Affect toolchains built with binutils 2.26 (fixed in binutils 2.26.1).
+config BR2_TOOLCHAIN_HAS_BINUTILS_BUG_20006
+	bool
+
+# Atomic types can be:
+#  - never lock-free
+#  - sometimes lock-free
+#  - always lock-free
+# see https://en.cppreference.com/w/c/atomic/ATOMIC_LOCK_FREE_consts
+#
+# On most architectures, gcc provides "always lock-free" atomic types,
+# but a few architectures are limited to "sometimes lock-free"
+# types. This hidden option allows to know if the architecture
+# provides "always lock-free" atomic types.
+config BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS
+	bool
+	default y
+	depends on !BR2_nios2
+	depends on !BR2_ARM_CPU_ARMV4
+	depends on !BR2_ARM_CPU_ARMV5
+	depends on !BR2_sparc_v8
+	depends on !BR2_m68k_cf5208
+
+# GCC uses thunk functions to adjust the 'this' pointer when calling
+# C++ member functions in classes derived with multiple inheritance.
+# Generation of thunk functions requires support from the compiler
+# back end. In the absence of that support target-independent code
+# in the C++ front end is used to generate thunk functions, but it
+# does not support vararg functions.
+# or1k will support it in the gcc mainline starting with gcc-9.
+config BR2_TOOLCHAIN_SUPPORTS_VARIADIC_MI_THUNK
+	bool
+	default y
+	depends on !BR2_or1k
+	depends on !BR2_xtensa
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63261. This bug no
+# longer exists in gcc 8.x.
+config BR2_TOOLCHAIN_HAS_GCC_BUG_63261
+	bool
+	default y if BR2_microblaze
+	depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_8
+
+# Prior to gcc 7.x, exception_ptr, nested_exception and future from
+# libstdc++ would only be provided on architectures that support
+# always lock-free atomic ints. See
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64735. This issue has
+# been removed in GCC 7.x, where exception propagation is now
+# supported without lock-free atomic int.
+config BR2_TOOLCHAIN_HAS_GCC_BUG_64735
+	bool
+	default y if !BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS && \
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_7
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68485. This bug still
+# exists in gcc 9.x
+config BR2_TOOLCHAIN_HAS_GCC_BUG_68485
+	bool
+	default y if BR2_microblaze
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85180. This bug no
+# longer exists in gcc 8.x.
+config BR2_TOOLCHAIN_HAS_GCC_BUG_85180
+	bool
+	default y if BR2_microblaze
+	depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_8
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85862
+# An infinite loop exists in the find_base_term() logic of 6.x
+# on microblaze.  http://autobuild.buildroot.net/results/158e8ebb39713e1b436a5cc1a1916f46c30694df/
+config BR2_TOOLCHAIN_HAS_GCC_BUG_85862
+	bool
+	default y if BR2_microblaze
+	depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_7
+
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90620
+# ICE: in do_output_reload, at reload1.c:7978 on microblaze.
+# It's still not fixed in gcc 9.x
+config BR2_TOOLCHAIN_HAS_GCC_BUG_90620
+	bool
+	default y if BR2_microblaze
+
+config BR2_TOOLCHAIN_HAS_NATIVE_RPC
+	bool
+
+config BR2_USE_WCHAR
+	bool
+
+config BR2_ENABLE_LOCALE
+	bool
+
+config BR2_INSTALL_LIBSTDCPP
+	bool
+
+config BR2_TOOLCHAIN_HAS_FORTRAN
+	bool
+
+config BR2_TOOLCHAIN_HAS_THREADS
+	bool
+
+config BR2_TOOLCHAIN_HAS_THREADS_DEBUG
+	bool
+
+config BR2_TOOLCHAIN_HAS_THREADS_NPTL
+	bool
+
+config BR2_TOOLCHAIN_HAS_SSP
+	bool
+
+config BR2_TOOLCHAIN_HAS_UCONTEXT
+	bool
+
+config BR2_TOOLCHAIN_HAS_OPENMP
+	bool
+
+config BR2_TOOLCHAIN_SUPPORTS_PIE
+	bool
+
+config BR2_TOOLCHAIN_GLIBC_GCONV_LIBS_COPY
+	bool "Copy gconv libraries"
+	depends on BR2_TOOLCHAIN_USES_GLIBC
+	help
+	  The gconv libraries are used to convert between different
+	  character sets (charsets).
+
+	  Say 'y' if you need to store and/or display different
+	  charsets.
+
+config BR2_TOOLCHAIN_GLIBC_GCONV_LIBS_LIST
+	string "Gconv libraries to copy"
+	depends on BR2_TOOLCHAIN_GLIBC_GCONV_LIBS_COPY
+	help
+	  Set to the list of gconv libraries to copy.
+	  Leave empty to copy all gconv libraries.
+
+	  Specify only the basename of the libraries, leave
+	  out the .so extension. Eg.:
+	    IBM850 ISO8859-15 UNICODE
+
+	  Note: the full set of gconv libs are ~8MiB (on ARM).
+
+# This boolean is true if the toolchain provides a built-in full
+# featured gettext implementation (glibc), and false if only a stub
+# gettext implementation is provided (uclibc, musl)
+config BR2_TOOLCHAIN_HAS_FULL_GETTEXT
+	bool
+
+config BR2_USE_MMU
+	bool "Enable MMU support" if BR2_ARCH_HAS_MMU_OPTIONAL
+	default y if BR2_ARCH_HAS_MMU_OPTIONAL || BR2_ARCH_HAS_MMU_MANDATORY
+	help
+	  If your target has a MMU, you should say Y here.  If you
+	  are unsure, just say Y.
+
+config BR2_TARGET_OPTIMIZATION
+	string "Target Optimizations"
+	default ""
+	help
+	  Optimizations to use when building for the target host.
+	  NOTE: gcc optimization level is defined in build options.
+
+config BR2_TARGET_LDFLAGS
+	string "Target linker options"
+	help
+	  Extra options to pass to the linker when building for the
+	  target.
+
+	  Note that options with a '$' sign (eg.
+	  -Wl,-rpath='$ORIGIN/../lib') are not supported.
+
+config BR2_ECLIPSE_REGISTER
+	bool "Register toolchain within Eclipse Buildroot plug-in"
+	help
+	  This options tells Buildroot to generate the necessary
+	  configuration files to make your toolchain appear within
+	  Eclipse, through the Eclipse Buildroot plugin.
+
+# Options for packages to depend on, if they require at least a
+# specific version of the kernel headers.
+# Toolchains should choose the adequate option (ie. the highest
+# version, not all of them).
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0
+	bool
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_1
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_1
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_3
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_4
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_3
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_5
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_4
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_6
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_5
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_7
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_6
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_7
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_9
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_9
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_11
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_11
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_13
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_14
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_13
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_15
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_14
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_16
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_15
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_17
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_16
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_18
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_17
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_19
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_18
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_0
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_19
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_1
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_0
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_2
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_1
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_3
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_2
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_4
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_3
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_5
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_4
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_6
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_5
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_7
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_6
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_8
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_7
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_9
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_8
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_10
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_9
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_10
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_12
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_13
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_12
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_14
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_13
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_15
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_14
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_16
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_15
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_17
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_16
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_18
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_17
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_19
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_18
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_20
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_19
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_20
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0
+
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_2
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1
+
+# This order guarantees that the highest version is set, as kconfig
+# stops affecting a value on the first matching default.
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST
+	string
+	default "5.2"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_2
+	default "5.1"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_1
+	default "5.0"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_0
+	default "4.20" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_20
+	default "4.19" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_19
+	default "4.18" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_18
+	default "4.17" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_17
+	default "4.16" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_16
+	default "4.15" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_15
+	default "4.14" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_14
+	default "4.13" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_13
+	default "4.12" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_12
+	default "4.11" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
+	default "4.10" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_10
+	default "4.9"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_9
+	default "4.8"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_8
+	default "4.7"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_7
+	default "4.6"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_6
+	default "4.5"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_5
+	default "4.4"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_4
+	default "4.3"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_3
+	default "4.2"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_2
+	default "4.1"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_1
+	default "4.0"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_0
+	default "3.19" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_19
+	default "3.18" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_18
+	default "3.17" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_17
+	default "3.16" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_16
+	default "3.15" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_15
+	default "3.14" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_14
+	default "3.13" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_13
+	default "3.12" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12
+	default "3.11" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_11
+	default "3.10" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10
+	default "3.9"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_9
+	default "3.8"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8
+	default "3.7"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_7
+	default "3.6"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_6
+	default "3.5"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_5
+	default "3.4"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_4
+	default "3.3"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_3
+	default "3.2"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
+	default "3.1"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_1
+	default "3.0"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0
+	default "2.6"
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_3
+	bool
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_3
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_5
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_6
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_5
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_7
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_6
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_7
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_5
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_6
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_5
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_7
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_6
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_8
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_7
+
+config BR2_TOOLCHAIN_GCC_AT_LEAST_9
+	bool
+	select BR2_TOOLCHAIN_GCC_AT_LEAST_8
+
+# This order guarantees that the highest version is set, as kconfig
+# stops affecting a value on the first matching default.
+config BR2_TOOLCHAIN_GCC_AT_LEAST
+	string
+	default "9"	if BR2_TOOLCHAIN_GCC_AT_LEAST_9
+	default "8"	if BR2_TOOLCHAIN_GCC_AT_LEAST_8
+	default "7"	if BR2_TOOLCHAIN_GCC_AT_LEAST_7
+	default "6"	if BR2_TOOLCHAIN_GCC_AT_LEAST_6
+	default "5"	if BR2_TOOLCHAIN_GCC_AT_LEAST_5
+	default "4.9"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+	default "4.8"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
+	default "4.7"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_7
+	default "4.6"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_6
+	default "4.5"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_5
+	default "4.4"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
+	default "4.3"	if BR2_TOOLCHAIN_GCC_AT_LEAST_4_3
+
+config BR2_TOOLCHAIN_HAS_MNAN_OPTION
+	bool
+	default y if BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
+
+config BR2_TOOLCHAIN_HAS_SYNC_1
+	bool
+	default y
+	depends on !BR2_m68k_cf
+	depends on !BR2_microblaze
+	depends on !BR2_sparc
+	depends on !(BR2_arc && !BR2_ARC_ATOMIC_EXT)
+
+config BR2_TOOLCHAIN_HAS_SYNC_2
+	bool
+	default y if BR2_TOOLCHAIN_HAS_SYNC_1
+
+config BR2_TOOLCHAIN_HAS_SYNC_4
+	bool
+	default y
+	depends on !BR2_m68k_cf
+	depends on !BR2_sparc
+	depends on !(BR2_arc && !BR2_ARC_ATOMIC_EXT)
+
+# The availability of __sync for 8-byte types on ARM is somewhat
+# complicated:
+#
+#  - It appeared in gcc starting with gcc 4.7.
+#
+#  - On ARMv7, there is no problem, it can be directly implemented in
+#    userspace.
+#
+#  - On < ARMv7, it requires help from the kernel. Unfortunately, the
+#    libgcc code implementing 8-byte __sync with the help from the
+#    kernel calls __write() when a failure occurs, which is a function
+#    internal to glibc, not available in uClibc and musl. This means
+#    that the 8-byte __sync operations are not available on < ARMv7
+#    with uClibc and musl. This problem was fixed as part of gcc
+#    PR68059, which was backported to the gcc 5 branch, but isn't yet
+#    part of any gcc 5.x release.
+#
+config BR2_TOOLCHAIN_ARM_HAS_SYNC_8
+	bool
+	default y
+	depends on BR2_arm || BR2_armeb
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_7
+	depends on BR2_TOOLCHAIN_USES_GLIBC || BR2_ARM_CPU_ARMV7A
+
+# 8-byte intrinsics available on most x86 CPUs, except a few old ones
+config BR2_TOOLCHAIN_X86_HAS_SYNC_8
+	bool
+	default y
+	depends on BR2_i386
+	depends on !BR2_x86_i486
+	depends on !BR2_x86_c3
+	depends on !BR2_x86_winchip_c6
+	depends on !BR2_x86_winchip2
+
+# 8-byte intrinsics available:
+#  - On all 64 bits architecture
+#  - On a certain combinations of ARM platforms
+#  - On certain x86 32 bits CPUs
+config BR2_TOOLCHAIN_HAS_SYNC_8
+	bool
+	default y if BR2_ARCH_IS_64
+	default y if BR2_TOOLCHAIN_ARM_HAS_SYNC_8
+	default y if BR2_TOOLCHAIN_X86_HAS_SYNC_8
+
+# libatomic is available since gcc 4.8, when thread support is
+# enabled. Also, libatomic doesn't recognize "uclinux" as a valid OS
+# part of the tuple, and is therefore not build on uclinux targets,
+# which is why BR2_BINFMT_FLAT configurations are excluded.
+config BR2_TOOLCHAIN_HAS_LIBATOMIC
+	bool
+	default y if BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 && \
+		BR2_TOOLCHAIN_HAS_THREADS && \
+		!BR2_BINFMT_FLAT
+
+# __atomic intrinsics are available:
+# - with gcc 4.8, either through built-ins or libatomic, on all
+#   architectures. Since we don't want to separate the cases where
+#   libatomic is needed vs. not needed, we simplify thing and only
+#   support situations where libatomic is available, even if on some
+#   architectures libatomic is not strictly needed as all __atomic
+#   intrinsics might be built-in. The only case where libatomic is
+#   missing entirely is when the toolchain does not have support for
+#   threads. However, a package that does not need threads but still
+#   uses atomics is quite a corner case, which does not warrant the
+#   added complexity.
+# - with gcc 4.7, libatomic did not exist, so only built-ins are
+#   available. This means that __atomic can only be used in a subset
+#   of the architectures
+config BR2_TOOLCHAIN_HAS_ATOMIC
+	bool
+	default y if BR2_TOOLCHAIN_HAS_LIBATOMIC
+	default y if BR2_TOOLCHAIN_GCC_AT_LEAST_4_7 && BR2_arm
+	default y if BR2_TOOLCHAIN_GCC_AT_LEAST_4_7 && BR2_armeb
+	default y if BR2_TOOLCHAIN_GCC_AT_LEAST_4_7 && BR2_xtensa
+	default y if BR2_TOOLCHAIN_GCC_AT_LEAST_4_7 && BR2_ARCH_IS_64
+
+# - libquadmath is not needed/available on all architectures (but gcc
+#   correctly handles this already).
+# - At least, libquadmath is available on:
+#   - i*86
+#   - x86_64
+# - When available, libquadmath requires wchar support.
+config BR2_TOOLCHAIN_HAS_LIBQUADMATH
+	bool
+	default y if BR2_i386 || BR2_x86_64
+
+endmenu