text: // Check that we can turn a function id to a function address, and also get the
  // maximum function id for the current binary.
  //
  // RUN: %clangxx_xray -std=c++11 %s -o %t
  // RUN: XRAY_OPTIONS="patch_premain=false" %run %t
  
  // UNSUPPORTED: target-is-mips64,target-is-mips64el
  
  #include "xray/xray_interface.h"
  #include <algorithm>
  #include <cassert>
  #include <cstdio>
  #include <iterator>
  #include <set>
  
  [[clang::xray_always_instrument]] void bar(){}
  
  [[clang::xray_always_instrument]] void foo() {
    bar();
  }
  
  [[clang::xray_always_instrument]] int main(int argc, char *argv[]) {
    assert(__xray_max_function_id() != 0 && "we need xray instrumentation!");
    std::set<void *> must_be_instrumented = {reinterpret_cast<void *>(&foo),
                                             reinterpret_cast<void *>(&bar),
                                             reinterpret_cast<void *>(&main)};
    std::set<void *> all_instrumented;
    for (auto i = __xray_max_function_id(); i != 0; --i) {
      auto addr = __xray_function_address(i);
      all_instrumented.insert(reinterpret_cast<void *>(addr));
    }
    assert(all_instrumented.size() == __xray_max_function_id() &&
           "each function id must be assigned to a unique function");
  
    std::set<void *> not_instrumented;
    std::set_difference(
        must_be_instrumented.begin(), must_be_instrumented.end(),
        all_instrumented.begin(), all_instrumented.end(),
        std::inserter(not_instrumented, not_instrumented.begin()));
    assert(
        not_instrumented.empty() &&
        "we should see all explicitly instrumented functions with function ids");
    return not_instrumented.empty() ? 0 : 1;
  }
  