clang++ 6.0 (Xcode 9.3) Error in CEREAL_RAPIDJSON_ASSERT macro

[puentev]

From current stable version i'm getting this warning (with -Wall):

../ext/cereal//include/cereal/external/rapidjson/document.h:597:9: error: 'GenericValue' has a non-throwing exception specification but can still throw [-Werror,-Wexceptions]
CEREAL_RAPIDJSON_ASSERT(type <= kNumberType);

With latest Xcode (9.3) this is no longer a warning but an error. As dirty workaround ...
replace in
cereal/include/cereal/archives/json.hpp

#define CEREAL_RAPIDJSON_ASSERT(x) if(!(x)){ 
throw ::cereal::RapidJSONException("rapidjson internal assertion failure: " #x); }

by

#ifndef CEREAL_RAPIDJSON_ASSERT
#ifdef __APPLE__
#define CEREAL_RAPIDJSON_ASSERT(x) if(!(x)){ assert(0 && "fallo json");};
#else
#define CEREAL_RAPIDJSON_ASSERT(x) if(!(x)){ \
throw ::cereal::RapidJSONException("rapidjson internal assertion failure: " #x); }
#endif
#endif

[AzothAmmo]

Make sure to report this upstream to rapidjson. For us the likely solution will be to temporarily disable that warning for any files in rapidjson that cause it.

[rahul-r]

I don't think this warning is caused by rapidjson. The origin of the exception is line 45 & 46 of cereal/include/cereal/archives/json.hpp

#define CEREAL_RAPIDJSON_ASSERT(x) if(!(x)){
throw ::cereal::RapidJSONException("rapidjson internal assertion failure: " #x); }

[NuLL3rr0r]

We faced this issue when we upgrade our compiler to clang 5.0. Is there any fix for this issue?

[morbo84]

The warning is present also with Clang++ 6.0 at it's not related to XCode or any other IDE (I'm running it on ArchLinux)

[puentev]

Xcode has its own "rebranded" clang++/LLVM ... I didn't know that was also in the regular 1

g++ --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 9.1.0 (clang-902.0.39.1)
Target: x86_64-apple-darwin17.5.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

[johnwbyrd]

This is still throwing warnings in XCode 9.3.1. puentev's workaround, or something like it, should go mainline until you get except vs. noexcept consistent between RapidJSON and cereal.

The bad boy here is cereal/external/rapidson/document.h . There are a lot of obects being constructed with the CEREAL_RAPIDJSON_NOEXCEPT modifier, but in those call stacks you have CEREAL_RAPIDJSON_ASSERTs declared. You can't have both.

For example, one bit of offending code is on line 755 of cereal/external/rapidson/document.h, where you've defined a function with the following prototype:

GenericValue &operator=(GenericValue &rhs) CEREAL_RAPIDJSON_NOEXCEPT {

Same thing on line 592:

explicit GenericValue( Type type ) CEREAL_RAPIDJSON_NOEXCEPT : data_() {

And that conflicts with at least the following code on line 597 of cereal/external/rapidjson/document.h:

CEREAL_RAPIDJSON_ASSERT( type <= kNumberType );

[mobileben]

I'm not using cereal, but this this same issue (using Xcode 9.3.1 with rapidjson).

The problem does indeed seem to lie with rapidjson as @johnwbyrd cites.

From what I can tell, cereal is just adding CEREAL_

But rapidjson has stuff like:

GenericValue& operator=(GenericValue& rhs) RAPIDJSON_NOEXCEPT {
    RAPIDJSON_ASSERT(this != &rhs);
    this->~GenericValue();
    RawAssign(rhs);
    return *this;
}

With RAPIDJSON_NOEXCEPT being controlled by

#ifndef RAPIDJSON_HAS_CXX11_NOEXCEPT
#if defined(__clang__)
#define RAPIDJSON_HAS_CXX11_NOEXCEPT __has_feature(cxx_noexcept)
#elif (defined(RAPIDJSON_GNUC) && (RAPIDJSON_GNUC >= RAPIDJSON_VERSION_CODE(4,6,0)) && defined(__GXX_EXPERIMENTAL_CXX0X__))
//    (defined(_MSC_VER) && _MSC_VER >= ????) // not yet supported
#define RAPIDJSON_HAS_CXX11_NOEXCEPT 1
#else
#define RAPIDJSON_HAS_CXX11_NOEXCEPT 0
#endif
#endif

I'm going to update to the latest, but I quick scan of the code has the same issues.

[pah]

Fixed upstream in Tencent/rapidjson#1329.

[dholl]

Hello,
I'm trying out Cereal for the first time, and it is a nifty project! What steps are involved for me to incorporate a fixed rapidjson codebase from upstream? I noticed that rapidjson's code is included as copied files rather than as a git submodule.

Do I just need to git clone a new release of rapidjson directly into include/cereal/external/rapidjson and then run scripts/add_rapidjson_prefix.sh ?

Or is there a different set of steps I should try? (I found the customization script add_rapidjson_prefix.sh, but I didn't find any other scripts that run that script. So I'm unclear if there's some order I should follow.)

Thank you,
David