kumquat-buildroot/package/glibc/glibc.mk

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################################################################################
#
# glibc/eglibc
#
################################################################################
GLIBC_VERSION = $(call qstrip,$(BR2_GLIBC_VERSION_STRING))
ifeq ($(BR2_TOOLCHAIN_BUILDROOT_EGLIBC),y)
GLIBC_SITE = http://downloads.yoctoproject.org/releases/eglibc
GLIBC_SOURCE = eglibc-$(GLIBC_VERSION).tar.bz2
GLIBC_SRC_SUBDIR = libc
else
GLIBC_SITE = $(BR2_GNU_MIRROR)/libc
GLIBC_SOURCE = glibc-$(GLIBC_VERSION).tar.xz
GLIBC_SRC_SUBDIR = .
endif
GLIBC_LICENSE = GPLv2+ (programs), LGPLv2.1+, BSD-3c, MIT (library)
GLIBC_LICENSE_FILES = $(addprefix $(GLIBC_SRC_SUBDIR)/,COPYING COPYING.LIB LICENSES)
# glibc is part of the toolchain so disable the toolchain dependency
GLIBC_ADD_TOOLCHAIN_DEPENDENCY = NO
# Before (e)glibc is configured, we must have the first stage
# cross-compiler and the kernel headers
GLIBC_DEPENDENCIES = host-gcc-initial linux-headers host-gawk
GLIBC_SUBDIR = build
GLIBC_INSTALL_STAGING = YES
GLIBC_INSTALL_STAGING_OPTS = install_root=$(STAGING_DIR) install
# Thumb build is broken, build in ARM mode
ifeq ($(BR2_ARM_INSTRUCTIONS_THUMB),y)
GLIBC_EXTRA_CFLAGS += -marm
endif
# MIPS64 defaults to n32 so pass the correct -mabi if
# we are using a different ABI. OABI32 is also used
# in MIPS so we pass -mabi=32 in this case as well
# even though it's not strictly necessary.
ifeq ($(BR2_MIPS_NABI64),y)
GLIBC_EXTRA_CFLAGS += -mabi=64
else ifeq ($(BR2_MIPS_OABI32),y)
GLIBC_EXTRA_CFLAGS += -mabi=32
endif
ifeq ($(BR2_ENABLE_DEBUG),y)
GLIBC_EXTRA_CFLAGS += -g
endif
# The stubs.h header is not installed by install-headers, but is
# needed for the gcc build. An empty stubs.h will work, as explained
# in http://gcc.gnu.org/ml/gcc/2002-01/msg00900.html. The same trick
# is used by Crosstool-NG.
ifeq ($(BR2_TOOLCHAIN_BUILDROOT_GLIBC),y)
define GLIBC_ADD_MISSING_STUB_H
mkdir -p $(STAGING_DIR)/usr/include/gnu
touch $(STAGING_DIR)/usr/include/gnu/stubs.h
endef
endif
# Even though we use the autotools-package infrastructure, we have to
# override the default configure commands for several reasons:
#
# 1. We have to build out-of-tree, but we can't use the same
# 'symbolic link to configure' used with the gcc packages.
#
# 2. We have to execute the configure script with bash and not sh.
#
# Note that as mentionned in
# http://patches.openembedded.org/patch/38849/, eglibc/glibc must be
# built with -O2, so we pass our own CFLAGS and CXXFLAGS below.
define GLIBC_CONFIGURE_CMDS
mkdir -p $(@D)/build
# Do the configuration
(cd $(@D)/build; \
$(TARGET_CONFIGURE_OPTS) \
CFLAGS="-O2 $(GLIBC_EXTRA_CFLAGS)" CPPFLAGS="" \
CXXFLAGS="-O2 $(GLIBC_EXTRA_CFLAGS)" \
$(SHELL) $(@D)/$(GLIBC_SRC_SUBDIR)/configure \
ac_cv_path_BASH_SHELL=/bin/bash \
libc_cv_forced_unwind=yes \
toolchain: switch to a two stage gcc build Currently, the internal toolchain backend does a three stage gcc build, with the following sequence of builds: - build gcc-initial - configure libc, install headers and start files - build gcc-intermediate - build libc - build gcc-final However, it turns out that this is not necessary, and only a two stage gcc build is needed. At some point, it was believed that a three stage gcc build was needed for NPTL based toolchains with old gcc versions, but even a gcc 4.4 build with a NPTL toolchain works fine. So, this commit switches the internal toolchain backend to use a two stage gcc build: just gcc-initial and gcc-final. It does so by: * Removing the custom dependency of all C libraries build step to host-gcc-intermediate. Now the C library packages simply have to depend on host-gcc-initial as a normal dependency (which they already do), and that's it. * Build and install both gcc *and* libgcc in host-gcc-initial. Previously, only gcc was built and installed in host-gcc-initial. libgcc was only done in host-gcc-intermediate, but now we need libgcc to build the C library. * Pass appropriate environment variables to get SSP (Stack Smashing Protection) to work properly: - Tell the compiler that the libc will provide the SSP support, by passing gcc_cv_libc_provides_ssp=yes. In Buildroot, we have chosen to use the SSP support from the C library instead of the SSP support from the compiler (this is not changed by this patch series, it was already the case). - Tell glibc to *not* build its own programs with SSP support. The issue is that if glibc detects that the compiler supports -fstack-protector, then glibc uses it to build a few things with SSP. However, at this point, the support is not complete (we only have host-gcc-initial, and the C library is not completely built). So, we pass libc_cv_ssp=no to tell the C library to not use SSP support itself. Note that this is not a big loss: only a few parts of the C library were built with -fstack-protector, not the entire library. * A special change is needed for ARC, because its libgcc depends on the C library, which breaks building libgcc in host-gcc-initial. This looks like a bug in the ARC compiler, as it does not obey the inhibit_libc variable which tells the compiler build process to *not* enable things that depend on the C library. So for now, in host-gcc-initial, we simply disable the build of libgmon.a for ARC. It's going to be built as part of host-gcc-final, so the final compiler will have gmon support. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2014-09-14 11:49:59 +02:00
libc_cv_ssp=no \
--target=$(GNU_TARGET_NAME) \
--host=$(GNU_TARGET_NAME) \
--build=$(GNU_HOST_NAME) \
--prefix=/usr \
--enable-shared \
$(if $(BR2_SOFT_FLOAT),--without-fp,--with-fp) \
$(if $(BR2_x86_64),--enable-lock-elision) \
--with-pkgversion="Buildroot" \
--without-cvs \
--disable-profile \
--without-gd \
--enable-obsolete-rpc \
--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
--with-headers=$(STAGING_DIR)/usr/include)
$(GLIBC_ADD_MISSING_STUB_H)
endef
#
# We also override the install to target commands since we only want
# to install the libraries, and nothing more.
#
GLIBC_LIBS_LIB = \
ld*.so.* libc.so.* libcrypt.so.* libdl.so.* libgcc_s.so.* libm.so.* \
libnsl.so.* libpthread.so.* libresolv.so.* librt.so.* libutil.so.* \
libnss_files.so.* libnss_dns.so.*
ifeq ($(BR2_PACKAGE_GDB),y)
GLIBC_LIBS_LIB += libthread_db.so.*
endif
define GLIBC_INSTALL_TARGET_CMDS
for libs in $(GLIBC_LIBS_LIB); do \
$(call copy_toolchain_lib_root,$(STAGING_DIR)/,,lib,$$libs,/lib) ; \
done
endef
# MIPS R6 requires to have NaN2008 support which is currently not
# supported by the Linux kernel. In order to prevent building the
# glibc against kernels not having NaN2008 support on platforms that
# requires it, glibc currently checks for an (inexisting) 10.0.0
# kernel headers version.
#
# Since in practice the kernel support for NaN2008 is not really
# required for things to work properly, we adjust the glibc check to
# make it believe that NaN2008 support was added in the kernel
# starting from version 4.0.0.
#
# In general the compatibility issues introduced by mis-matched NaN
# encodings will not cause a problem as signalling NaNs are rarely used
# in average code. For MIPS R6 there isn't actually any compatibility
# issue as the hardware is always NaN2008 and software is always
# NaN2008. The problem only comes from when older MIPS code is linked in
# via a DSO and multiple NaN encodings are introduced. Since Buildroot
# is intended to have all code built from source then this scenario is
# highly unlikely. The failure mode, if it ever occurs, would be either
# that a signalling NaN fails to raise an invalid operation exception or
# (more likely) an ordinary NaN raises an invalid operation exception.
ifeq ($(BR2_mips_32r6)$(BR2_mips_64r6),y)
define GLIBC_FIX_MIPS_R6
$(SED) 's#10.0.0#4.0.0#' \
$(@D)/sysdeps/unix/sysv/linux/mips/configure \
$(@D)/sysdeps/unix/sysv/linux/mips/configure.ac
endef
GLIBC_POST_EXTRACT_HOOKS += GLIBC_FIX_MIPS_R6
endif
$(eval $(autotools-package))