- LDK_LIB="$1"/lightning-c-bindings/target/$LDK_TARGET/release/libldk.a
- if [ "$IS_MAC" = "false" -a "$4" = "false" ]; then
- COMPILE="$COMPILE -Wl,--version-script=libcode.version -fuse-ld=lld"
- # __cxa_thread_atexit_impl is used to more effeciently cleanup per-thread local storage by rust libstd.
- # However, it is not available on glibc versions 2.17 or earlier, and rust libstd has a null-check and
- # fallback in case it is missing.
- # Because it is weak-linked on the rust side, we should be able to simply define it
- # explicitly, forcing rust to use the fallback. However, for some reason involving ancient
- # dark magic and haunted code segments, overriding the weak symbol only impacts sites which
- # *call* the symbol in question, not sites which *compare with* the symbol in question.
- # This means that the NULL check in rust's libstd will always think the function is
- # callable while the function which is called ends up being NULL (leading to a jmp to the
- # zero page and a quick SEGFAULT).
- # This issue persists not only with directly providing a symbol, but also ld.lld's -wrap
- # and --defsym arguments.
- # In smaller programs, it appears to be possible to work around this with -Bsymbolic and
- # -nostdlib, however when applied the full-sized JNI library here it no longer works.
- # After exhausting nearly every flag documented in lld, the only reliable method appears
- # to be editing the LDK binary. Luckily, LLVM's tooling makes this rather easy as we can
- # disassemble it into very readable code, edit it, and then reassemble it.
- # Note that if we do so we don't have to bother overriding the actual call, LLVM should
- # optimize it away, which also provides a good check that there isn't anything actually
- # relying on it elsewhere.
- [ ! -f "$1"/lightning-c-bindings/target/$LDK_TARGET/release/libldk.a ] && exit 1
- if [ "$(ar t "$1"/lightning-c-bindings/target/$LDK_TARGET/release/libldk.a | grep -v "\.o$" || echo)" != "" ]; then
- echo "Archive contained non-object files!"
- exit 1
- fi
- if [ "$(ar t "$1"/lightning-c-bindings/target/$LDK_TARGET/release/libldk.a | grep ldk.*-cgu.*.rcgu.o | wc -l)" != "1" ]; then
- echo "Archive contained more than one LDK object file"
- exit 1
- fi
- mkdir -p tmp
- rm -f tmp/*
- ar x --output=tmp "$1"/lightning-c-bindings/target/$LDK_TARGET/release/libldk.a
- pushd tmp
- llvm-dis ldk*-cgu.*.rcgu.o
- sed -i 's/br i1 icmp eq (i8\* @__cxa_thread_atexit_impl, i8\* null)/br i1 icmp eq (i8* null, i8* null)/g' ldk*-cgu.*.rcgu.o.ll
- llvm-as ldk*-cgu.*.rcgu.o.ll -o ./libldk.bc
- ar q libldk.a *.o
- popd
- LDK_LIB="tmp/libldk.bc tmp/libldk.a"
- fi
- $COMPILE -o liblightningjni_release$LDK_TARGET_SUFFIX.so -s -flto -O3 -I"$1"/lightning-c-bindings/include/ $2 src/main/jni/bindings.c $LDK_LIB -lm
- if [ "$IS_MAC" = "false" -a "$4" = "false" ]; then
- GLIBC_SYMBS="$(objdump -T liblightningjni_release$LDK_TARGET_SUFFIX.so | grep GLIBC_ | grep -v "GLIBC_2\.2\." | grep -v "GLIBC_2\.3\(\.\| \)" | grep -v "GLIBC_2.\(14\|17\) " || echo)"
- if [ "$GLIBC_SYMBS" != "" ]; then
- echo "Unexpected glibc version dependency! Some users need glibc 2.17 support, symbols for newer glibcs cannot be included."
- echo "$GLIBC_SYMBS"
- exit 1
- fi
- REALLOC_ARRAY_SYMBS="$(objdump -T liblightningjni_release$LDK_TARGET_SUFFIX.so | grep reallocarray || echo)"
- if [ "$REALLOC_ARRAY_SYMBS" != "" ]; then
- echo "Unexpected reallocarray dependency!"
- exit 1
- fi
- fi
- if [ "$LDK_JAR_TARGET" = "true" ]; then
- # Copy to JNI native directory for inclusion in JARs
- mkdir -p src/main/resources/
- cp liblightningjni_release$LDK_TARGET_SUFFIX.so src/main/resources/liblightningjni$LDK_TARGET_SUFFIX.nativelib
- fi