crosstool-ng/config/libc/glibc.in

# This file contains the common configuration options
# that apply to both glibc.

## depends on ! WINDOWS && ! BARE_METAL && ARCH_USE_MMU
## select LIBC_SUPPORT_THREADS_NATIVE
## select CC_CORE_PASSES_NEEDED
# TBD: select GETTEXT for build only, not for host
## select GETTEXT_NEEDED
## select BINUTILS_FORCE_LD_BFD_DEFAULT

## help The de-facto standard for Linux distributions.
## help Feature-rich, but large...  Most useful for desktop-like systems.

# GLIBC and kernel are special when it comes to obsoletion. Users
# of crosstool-ng depend on the ability to build new toolchains matching
# the kernel/libc versions of a particular target system, and LTS releases
# are still using quite ancient versions. Please do not retire versions
# (including versions in between) until the EOL dates indicated in version.desc.

if GLIBC_USE_PORTS_EXTERNAL
source "config/versions/glibc-ports.in"
endif

# Glibc has some dependencies on the kernel headers:
config GLIBC_DEP_KERNEL_HEADERS_VERSION
	def_bool y
	select LINUX_REQUIRE_3_2_or_later if GLIBC_2_24_or_later

# Glibc 2.26 requires at least binutils 2.25.
# Also, binutils 2.30 fail while compiling aarch64 glibc; fixed in 2.27
# and backported to 2.26. For other versions, require binutils older than
# 2.30 (if the patch is backported, binutils 2.23 will break).
config GLIBC_DEP_BINUTILS
    def_bool y
    select BINUTILS_REQUIRE_2_25_or_later if GLIBC_2_26_or_later
    select BINUTILS_REQUIRE_older_than_2_30 if GLIBC_older_than_2_26 && ARCH_ARM && ARCH_64

config GLIBC_DEP_GCC
    def_bool y
    select GCC_REQUIRE_4_9_or_later if GLIBC_2_26_or_later

config THREADS
    default "nptl"

config GLIBC_BUILD_SSP
    def_bool y
    depends on GLIBC_2_25_or_later

# Known add-ons and when they exist(ed)
#   crypt           external in 2.1, no longer an add-on since 2.2
#   libidn          external in 2.3.4 .. 2.10, still an add-on
#   linuxthreads    external in 2.0.1 .. 2.5,  no longer available since 2.6 [*]
#   localedata      external in 2.0.1 .. 2.0.6, no longer an add-on since 2.1 [*]
#   ports           external in 2.3.4 .. 2.16, no longer an add-on since 2.20
#   nptl            never external, no longer an add-on since 2.20
#
# Given the list of currently supported glibc releases, we only need to worry about
# 'libidn', 'ports' and 'nptl' add-ons. Of these, only 'ports' can be an external
# tarball; and only 'libidn' is user-selectable ('ports' & 'nptl' are selected
# by crosstool-NG, as dictated by the architecture and thread model).
#
# I had trouble locating the sources in the repository for some of the released
# versions. E.g., there is a 2.5 version of linuxthreads, but the tag for 2.5 in Git
# does not have the linuxthreads directory at all. Similarly, 2.0.6 tag did not have
# localedata. Since these releases are no longer supported by crosstool-NG, this is
# of pure historical interest now, however.

config GLIBC_HAS_NPTL_ADDON
    def_bool y
    depends on !GLIBC_2_20_or_later

config GLIBC_HAS_PORTS_ADDON
    def_bool y
    depends on !GLIBC_2_20_or_later

config GLIBC_HAS_PORTS_ADDON_EXTERNAL
    def_bool y
    depends on !GLIBC_2_17_or_later

# In case it folds into main distribution in some future release, too
config GLIBC_HAS_LIBIDN_ADDON
    def_bool y

# Some architectures require the ports addon. List them one by one here:
# This list must be carefully in sync with the architectures names
# we can find in config/arch/*
config GLIBC_USE_PORTS_ADDON
    def_bool y
    depends on ARCH_ALPHA || ARCH_ARM || ARCH_M68K || ARCH_MIPS || ARCH_POWERPC
    depends on GLIBC_HAS_PORTS_ADDON

config GLIBC_USE_PORTS_EXTERNAL
    def_bool y
    depends on GLIBC_USE_PORTS_ADDON && GLIBC_HAS_PORTS_ADDON_EXTERNAL

config GLIBC_USE_NPTL_ADDON
    def_bool y
    depends on THREADS_NATIVE && GLIBC_HAS_NPTL_ADDON

config GLIBC_USE_LIBIDN_ADDON
    bool "Build libidn add-on"
    help
      Enables the libidn add-on in GNU libc.

# SPARCv8 support retired in 2.23
config GLIBC_NO_SPARC_V8
    def_bool y
    depends on GLIBC_2_23_or_later

# 2.14 obsoleted Sun RPC code, making it unavailable *at all* for compiling/linking
# (only remained as versioned symbols for previously linked binaries). They backpedaled
# in 2.16, adding an option to enable that code. Crosstool-NG backports that code
# to 2.14/2.15, but there is no harm in throwing this option even if that patch
# is not applied.
config GLIBC_HAS_OBSOLETE_RPC
    def_bool y
    depends on GLIBC_2_14_or_later

config GLIBC_EXTRA_CONFIG_ARRAY
    string
    prompt "extra config"
    default ""
    help
      Extra flags to pass onto ./configure when configuring.

      You can enter multiple arguments here, and arguments can contain spaces
      if they are properly quoted (or escaped, but prefer quotes). Eg.:
          --with-foo="1st arg with 4 spaces" --with-bar=2nd-arg-without-space

config GLIBC_CONFIGPARMS
    string
    prompt "Extra config params (READ HELP)"
    default "" if ! ARCH_SH
    default "no-z-defs=yes" if ARCH_SH
    help
      Some architectures need to set options in the file configparms.
      This is the case for sh3/4, which really need to set configparms
      to "no-z-defs=yes" as of gcc-3.4/glibc-2.3.2.
      
      Unless you are building a toolchain for sh3/4, you should leave that empty.
      
      Note: If you need to pass more than one value, separate them with
            '\n'. Eg.:  var1=val1\nvar2=val2

config GLIBC_EXTRA_CFLAGS
    string
    prompt "extra target CFLAGS"
    default ""
    help
      Extra target CFLAGS to use when building.

config GLIBC_ENABLE_OBSOLETE_RPC
    bool "Enable obsolete (Sun) RPC"
    default y
    depends on GLIBC_HAS_OBSOLETE_RPC
    help
      Allow building applications using obsolete (Sun) RPC.

config GLIBC_ENABLE_FORTIFIED_BUILD
    bool
    prompt "Enable fortified build (EXPERIMENTAL)"
    depends on EXPERIMENTAL
    help
      If you say 'y' here, then glibc will be using fortified versions
      of functions with format arguments (eg. vsyslog, printf...), and
      do a sanity check on the format at runtime, to avoid some of the
      common format string attacks.
      
      This is currently not supported, and will most probably result in
      a broken build, with an error message like:
        ../misc/syslog.c: In function '__vsyslog_chk':
        ../misc/syslog.c:123: sorry, unimplemented: inlining failed in
        call to 'syslog': function body not available
      
      If you are brave enough and want to debug the issue, then say 'y'
      here. Otherwise, be still and say 'n' (the default). ;-)


config GLIBC_DISABLE_VERSIONING
    bool
    prompt "Disable symbols versioning"
    help
      Do not include versioning information in the library objects.

config GLIBC_OLDEST_ABI
    string
    prompt "Oldest supported ABI"
    default ""
    help
      Set the oldest ABI supported by the C library.
      
      Setting this option, for example, to 2.2 will provide ABI support
      back to (e)glibc-2.2.

      If this option is not set, (e)glibc will choose for you.

config GLIBC_FORCE_UNWIND
    bool
    prompt "Force unwind support (READ HELP!)"
    default y
    help
      If your toolchain fails building while building the C library
      start files, or the complete C library, with a message like:
        configure: error: forced unwind support is required
      
      then you may try changing this option. Otherwise, leave it to
      the default 'y'.
      
      The issue seems to be related to building NPTL on old versions
      of glibc on some architectures
      (seen on s390, s390x and x86_64).

config GLIBC_LOCALES
    bool
    prompt "Build and install locales"
    help
      Whether to build and install the libc locale files for the target,
      which is required in order to support internationalization.

if LIBC_GLIBC && GLIBC_LOCALES
comment "WARNING!                                                      "
comment "|  The built locales will be usable if and only if the build  "
comment "|  machine and the target:                                    "
comment "|   - have the same endianness,                               "
comment "|   - and have the same alignment requirements for uint32_t.  "
comment "|  You will have to check by yourself (for now).              "
comment "WARNING!                                                      "
comment "|  Building GLIBC locales requires that GLIBC supports        "
comment "|  the build machine as the target.                           "
endif # LIBC_GLIBC && GLIBC_LOCALES

if KERNEL_LINUX

choice GLIBC_SUPPORTED_KERNEL
    bool
    prompt "Minimum supported kernel version"
    default GLIBC_KERNEL_VERSION_AS_HEADERS

config GLIBC_KERNEL_VERSION_NONE
    bool
    prompt "Let ./configure decide"
    help
      Let ./configure decide what minimum kernel version glibc will be
      able to run against.
      
      This will include legacy compatibility code for older kernels in
      the C library, thus ensuring that it will run on a large number
      of old kernels.
      
      The minimum kernel version supported will be dependent upon the
      target you build for. For example:
        alpha*-*-linux-gnu      Requires Linux 2.6.9 for NPTL
        sh[34]-*-linux-gnu      Requires Linux 2.6.11
        powerpc*                Requires Linux 2.4.19
        arm*-*-linux-*gnueabi   Requires Linux 2.6.16

config GLIBC_KERNEL_VERSION_AS_HEADERS
    bool
    prompt "Same as kernel headers (default)"
    help
      Normally, you'll want glibc to run against the same kernel
      version as the one used for the headers.
      
      This is the default.
      
      If enabled, crosstool-ng will use the chosen version of kernel
      headers for the glibc minimum kernel version supported, which is
      what gets passed to "--enable-kernel=" when configuring glibc.
      
      Enabling this will ensure that no legacy compatibility code for
      older kernels is built into your C libraries, but it will
      be unable to run on kernel versions older than whichever kernel
      headers version you've built the toolchain for.
      
      If you know for sure that your toolchain will never need to build
      applications that will run under a kernel version older than your
      chosen kernel headers version (CT_KERNEL_VERSION), you can choose
      "y" here.

config GLIBC_KERNEL_VERSION_CHOSEN
    bool
    prompt "Specific kernel version"
    help
      Specify the earliest Linux kernel version you want glibc to
      include support for.  This does not have to match the kernel
      headers version used for your toolchain.  This controls what is
      passed to the "--enable-kernel=" option to the glibc configure
      script.

      If you want to be able to statically link programs with your
      toolchain's C library, make sure this kernel version is lower than
      all kernels you wish to support to avoid "FATAL: kernel too old"
      errors.  The higher the version you specify, the less legacy code
      will be built into libc.

      Most people can leave this at the default value of "2.6.9".

if GLIBC_KERNEL_VERSION_CHOSEN

config GLIBC_MIN_KERNEL_VERSION
    string
    prompt "Minimum kernel version to support"
    default "2.6.9"
    help
      Enter here the lowest kernel version glibc will be able to run against.
      
      The minimum kernel version supported will be dependent upon the
      target you build for. For example:
        alpha*-*-linux-gnu      Requires Linux 2.6.9 for NPTL
        sh[34]-*-linux-gnu      Requires Linux 2.6.11
        powerpc*                Requires Linux 2.4.19
        arm*-*-linux-*gnueabi   Requires Linux 2.6.16
      
      Note that no sanity check is performed by crosstool-NG to ensure
      that the value you enter here is appropriate for your target.

endif # GLIBC_KERNEL_VERSION_CHOSEN

endchoice

config GLIBC_MIN_KERNEL
    string
    default ""                            if GLIBC_KERNEL_VERSION_NONE
    default LINUX_VERSION                 if GLIBC_KERNEL_VERSION_AS_HEADERS
    default GLIBC_MIN_KERNEL_VERSION      if GLIBC_KERNEL_VERSION_CHOSEN

if GLIBC_BUILD_SSP
choice
    bool "Stack-smashing protection (SSP) in glibc"
    default GLIBC_SSP_DEFAULT

config GLIBC_SSP_DEFAULT
    bool "default"
    help
      Glibc's configure script determines the stack protection level.

config GLIBC_SSP_NO
    bool "no"
    help
      Glibc functions are not protected against stack-smashing.

config GLIBC_SSP_YES
    bool "yes"
    help
      Glibc is compiled with -fstack-protector option.

config GLIBC_SSP_ALL
    bool "all"
    help
      Glibc is compiled with -fstack-protector-all option.

config GLIBC_SSP_STRONG
    bool "strong"
    help
      Glibc is compiled with -fstack-protector-strong option.

endchoice

config GLIBC_SSP
    string
    default "no" if GLIBC_SSP_NO
    default "yes" if GLIBC_SSP_YES
    default "all" if GLIBC_SSP_ALL
    default "strong" if GLIBC_SSP_STRONG

# All supported versions of glibc build cleanly with GCC7 and earlier.
# GCC8-related fixes were only available in glibc 2.27.
config GLIBC_ENABLE_WERROR
    bool "Enable -Werror during the build"
    default y if GCC_7_or_older
    default y if GCC_8_or_later && GLIBC_2_27_or_later
    help
      By default, glibc enables strict warning checks during the build.
      However, older version of glibc may not build with newer versions
      of the compiler than there were available at the time of a glibc
      release (because newer compilers typically have better diagnostics).

endif

endif # KERNEL_LINUX