build.sh

#!/bin/bash

set -exuo pipefail

# CXXFLAGS=${CXXFLAGS//-fvisibility-inlines-hidden/}

${CXX} ${CXXFLAGS} ${LDFLAGS} -shared -DNDEBUG -o libtest.so lib.cpp

nm --demangle --defined-only libtest.so | grep Test

${CXX} ${CXXFLAGS} ${LDFLAGS} -L$(pwd) -g -DNDEBUG -o main-release main.cpp -ltest
LD_LIBRARY_PATH=$(pwd) ./main-release

${CXX} ${CXXFLAGS} ${LDFLAGS} -L$(pwd) -g -o main-debug main.cpp -ltest
LD_LIBRARY_PATH=$(pwd) ./main-debug

lib.cpp

#include "lib.h"

Test::Test() {
  this->ptr = new int(8);
}

#ifndef NDEBUG
Test::~Test() {
  delete this->ptr;
}
#endif

void DoSomething() {
  // Make sure the destructor is present inside the shared library.
  static Test test{};
}

lib.h

class Test {
 public:
  Test();
#ifdef NDEBUG
  ~Test() {
    delete ptr;
  }
#else
  ~Test();
#endif
  int* ptr;
};

main.cpp

#include "lib.h"

int main () {
  Test t = Test();
}