Merge "Base: Warn on using ostream<< with std::string*"

}  // namespace base

}  // namespace android

namespace std {

// Emit a warning of ostream<< with std::string*. The intention was most likely to print *string.

//

// Note: for this to work, we need to have this in a namespace.

// Note: lots of ifdef magic to make this work with Clang (platform) vs GCC (windows tools)

// Note: using diagnose_if(true) under Clang and nothing under GCC/mingw as there is no common

//       attribute support.

// Note: using a pragma because "-Wgcc-compat" (included in "-Weverything") complains about

//       diagnose_if.

// Note: to print the pointer, use "<< static_cast<const void*>(string_pointer)" instead.

// Note: a not-recommended alternative is to let Clang ignore the warning by adding

//       -Wno-user-defined-warnings to CPPFLAGS.

#ifdef __clang__

#pragma clang diagnostic push

#pragma clang diagnostic ignored "-Wgcc-compat"

#define OSTREAM_STRING_POINTER_USAGE_WARNING \

    __attribute__((diagnose_if(true, "Unexpected logging of string pointer", "warning")))

#else

#define OSTREAM_STRING_POINTER_USAGE_WARNING /* empty */

#endif

inline std::ostream& operator<<(std::ostream& stream, const std::string* string_pointer)

    OSTREAM_STRING_POINTER_USAGE_WARNING {

  return stream << static_cast<const void*>(string_pointer);

}

#ifdef __clang__

#pragma clang diagnostic pop

#endif

#undef OSTREAM_STRING_POINTER_USAGE_WARNING

}  // namespace std

#endif  // ANDROID_BASE_LOGGING_H