unwinder benchmark: lookup unwind info with many libraries

build.sh

#!/bin/bash
set -e

NDK=/x/android-ndk-r21d
LIBUNWIND=/x/llvm-upstream/unwind-arm64-21/lib/libunwind.a
CXX="$NDK/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android21-clang++ -fuse-ld=lld $LIBUNWIND"

rm -fr out
mkdir -p out

cat >out/build.ninja <<EOF
rule solib
  command = $CXX \$CXXFLAGS -O2 -static-libstdc++ -fpic -shared -o \$out \$in

rule exec
  command = $CXX \$CXXFLAGS -O2 -static-libstdc++ '-Wl,--rpath,\$\$ORIGIN' -o \$out \$in

build libbench_final.so: solib ../final.cpp

EOF

prev=final
all_libs=libbench_final.so
for i in $(seq 100 | tac); do
  i_fmt=$(printf '%03d' $i)
  echo >>out/build.ninja build libbench_${i_fmt}.so: solib ../transfer.cpp
  echo >>out/build.ninja ' ' CXXFLAGS = -DSELF=$i_fmt -DNEXT=$prev
  prev=$i_fmt
  all_libs="libbench_${i_fmt}.so $all_libs"
done

echo >>out/build.ninja build main: exec ../main.cpp $all_libs

ninja -C out

final.cpp

__attribute__((noinline,weak))
void throw_func() {
  throw 42;
}

int func_final() {
  for (int i = 0; i < 10000; ++i) {
    try {
      throw_func();
    } catch (int i) {
    }
  }
  return 0;
}

main.cpp

#include <link.h>
#include <stdio.h>

int func_001();

int cb(dl_phdr_info* info, size_t, void*) {
  printf("%s\n", info->dlpi_name);
  return 0;
}

int main() {
  func_001();
  //dl_iterate_phdr(cb, nullptr);
  return 0;
}

run.sh

#!/bin/bash
set -e

adb shell rm -fr /data/local/tmp/out
adb push out /data/local/tmp

# consider setting the 'performance' CPU governor for better consistency.
#gov=performance
#adb root
#adb shell 'for pol in /sys/devices/system/cpu/cpufreq/policy*/scaling_governor; do echo $pol was $(cat $pol), setting to '${gov}'; echo '${gov}' > $pol; done'

# set CPU affinity for better consistency.
#TASKSET="taskset 10"
#TASKSET=

# build https://tratt.net/laurie/src/multitime/ for Android
#adb push /x/multitime-android/multitime /data/local/tmp
#adb shell LD_LIBRARY_PATH=/data/local/tmp/out $TASKSET /data/local/tmp/multitime -s0 -n100 /data/local/tmp/out/main

# or hack something together -- this command will print one sample
adb shell $TASKSET time /data/local/tmp/out/main

transfer.cpp

#define XFUNC_NAME(idx) func_ ## idx
#define FUNC_NAME(idx) XFUNC_NAME(idx)

int FUNC_NAME(NEXT)();

int FUNC_NAME(SELF)() {
  return FUNC_NAME(NEXT)() + 1;
}