AVRO-2271: C++ Support for Custom Fields

[aniket486]

[Fokko]

Sad CI:

Scanning dependencies of target avrocpp_s
[  1%] Building CXX object CMakeFiles/avrocpp_s.dir/impl/Compiler.cc.o
/testptch/unknown/lang/c++/impl/Compiler.cc: In function ‘void avro::addCustomFields(const NodePtr&, const Object&)’:
/testptch/unknown/lang/c++/impl/Compiler.cc:299:53: error: in C++98 ‘kKnownFields’ must be initialized by constructor, not by ‘{...}’
          "values", "precision", "scale", "namespace"};
                                                     ^
/testptch/unknown/lang/c++/impl/Compiler.cc:299:53: error: could not convert ‘{"name", "type", "default", "doc", "size", "logicalType", "values", "precision", "scale", "namespace"}’ from ‘<brace-enclosed initializer list>’ to ‘const std::__debug::vector<std::basic_string<char>, std::allocator<std::basic_string<char> > >’
/testptch/unknown/lang/c++/impl/Compiler.cc:300:16: warning: ‘auto’ changes meaning in C++11; please remove it [-Wc++0x-compat]
     for (const auto &entry : m) {
                ^
/testptch/unknown/lang/c++/impl/Compiler.cc:300:22: error: ISO C++ forbids declaration of ‘entry’ with no type [-fpermissive]
     for (const auto &entry : m) {
                      ^
/testptch/unknown/lang/c++/impl/Compiler.cc:300:30: error: range-based ‘for’ loops are not allowed in C++98 mode
     for (const auto &entry : m) {
                              ^
/testptch/unknown/lang/c++/impl/Compiler.cc:301:71: error: request for member ‘first’ in ‘entry’, which is of non-class type ‘const int’
         if (std::find(kKnownFields.begin(), kKnownFields.end(), entry.first)
                                                                       ^
/testptch/unknown/lang/c++/impl/Compiler.cc:303:40: error: request for member ‘first’ in ‘entry’, which is of non-class type ‘const int’
             node->addCustomField(entry.first, entry.second);
                                        ^
/testptch/unknown/lang/c++/impl/Compiler.cc:303:53: error: request for member ‘second’ in ‘entry’, which is of non-class type ‘const int’
             node->addCustomField(entry.first, entry.second);
                                                     ^
make[2]: *** [CMakeFiles/avrocpp_s.dir/impl/Compiler.cc.o] Error 1
CMakeFiles/avrocpp_s.dir/build.make:54: recipe for target 'CMakeFiles/avrocpp_s.dir/impl/Compiler.cc.o' failed
make[1]: *** [CMakeFiles/avrocpp_s.dir/all] Error 2
CMakeFiles/Makefile2:425: recipe for target 'CMakeFiles/avrocpp_s.dir/all' failed
make: *** [all] Error 2
Makefile:147: recipe for target 'all' failed

[gioragutt]

You're using C++11 features, such as initializer_list and range-for, and seeing that the CI runs the code on C++98 (or just anything under 11) is problematic...

[thiru-mg]

Instead of having a new class CustomFields can we not define a simple typedef?

    typedef std::map<std::string, json::Entity>

There is a little bit check done in addCustomField() member of the new class. That can be moved into its caller namely addCustomField() of Node.

At @gioragutt has mentioned, the code needs to compile under pre-2011 compilers.

[aniket486]

Thanks. I have made changes to CMakeLists.txt to catch C++98 compat issues sooner during development process.

I have made suggested changes to the code. PTAL.

[dkulp]

Can you rebase this on master? Also, master is not c++11 so you can go back to using the c++11 things.

[thiru-mg]

Apart from the fact that this needs to be rebased, a couple of issues:

• Tests don't run
• Please conform to the style of rest of code. For example, we don't use auto and instead use explicit type.
• More serious problem. You include an implementation header (JsonDom.hh) in the publicly exported api headers. It is perfectly fine to include the .hh files from api in .cc or .hh files under impl, but not vice versa. When we install avro C++, only the files under api and the generated executable, .a and .so/.dll/.dylib files will be installed. The files under impl will NOT be installed. So including impl/json/JsonDom.hh in api will cause failures.