libtorrent: stop discarding the target build flags

CONFIGURE_VARS is assigned rather than appended to, which discards the
default from package-defaults.mk: the cross compiler settings and the
CFLAGS, CXXFLAGS, CPPFLAGS and LDFLAGS the build system passes. The
library is configured with autoconf's own -g -O2 and built for the
toolchain's default architecture instead, without the target CPU flags,
the hardening flags and -ffile-prefix-map. On x86/geode that also costs
the 64-bit atomics: at the default -march=i486 the compiler cannot
inline them and emits __atomic_load_8 and __atomic_store_8 calls, so
every binary linking the static library needs libatomic.

Fixes: 13a058bed6c0 ("libtorrent: update to 0.15.3")
Signed-off-by: Daniel Golle <redacted>

diff --git a/libs/libtorrent/Makefile b/libs/libtorrent/Makefile
index de1fdde8d653317943ee8feda4b2b57565b82861..7f33c4c554726b3fb75ff72ba51840ac35e4b06d 100644 (file)
--- a/libs/libtorrent/Makefile
+++ b/libs/libtorrent/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libtorrent
 PKG_VERSION:=0.15.5
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/rakshasa/libtorrent
@@ -53,7 +53,7 @@ CONFIGURE_ARGS += \
        --with-zlib=$(STAGING_DIR)/usr \
        --without-kqueue
 
-CONFIGURE_VARS = \
+CONFIGURE_VARS += \
        ax_cv_cxx_compile_cxx17=yes
 
 define Build/InstallDev