Multiple build failures with recent commits

[apurvam]

I am using a vanilla version of gcc 4.8.3 and recent commits to flatbuffers have caused builds to fail:

First off, commit ebac1e1 caused this build failure:

[  7%] Building CXX object CMakeFiles/flatc.dir/src/idl_parser.cpp.o
In file included from /home/amehta/workspace/external/flatbuffers/src/idl_parser.cpp:21:0:
/home/amehta/workspace/external/flatbuffers/include/flatbuffers/util.h: In function ‘int flatbuffers::ToUTF8(uint32_t, std::string*)’:
/home/amehta/workspace/external/flatbuffers/include/flatbuffers/util.h:157:29: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (ucc < (1 << max_bits)) {  // does it fit?
                             ^
cc1plus: all warnings being treated as errors

This is pretty easy to fix if we cast the comparison explicitly, ie.

  if (ucc < static_cast<uint32_t>(1 << max_bits)) {  // does it fit?

However, it is not clear to me why the original code failed nor why this cast would fix it. That is why I didn't create a pull request with the patch.

Secondly, commit 11b7436 caused this failure:

[amehta@amehta-ld1 build]$ make
Scanning dependencies of target flatc
[  7%] Building CXX object CMakeFiles/flatc.dir/src/idl_parser.cpp.o
[ 15%] Building CXX object CMakeFiles/flatc.dir/src/idl_gen_cpp.cpp.o
[ 23%] Building CXX object CMakeFiles/flatc.dir/src/idl_gen_java.cpp.o
[ 30%] Building CXX object CMakeFiles/flatc.dir/src/idl_gen_go.cpp.o
[ 38%] Building CXX object CMakeFiles/flatc.dir/src/idl_gen_text.cpp.o
[ 46%] Building CXX object CMakeFiles/flatc.dir/src/flatc.cpp.o
Linking CXX executable flatc
[ 46%] Built target flatc
Scanning dependencies of target flatsamplebinary
[ 53%] Building CXX object CMakeFiles/flatsamplebinary.dir/samples/sample_binary.cpp.o
In file included from /home/amehta/workspace/external/flatbuffers/samples/sample_binary.cpp:19:0:
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h: In member function ‘bool MyGame::Sample::Monster::Verify(const flatbuffers::Verifier&) const’:
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h:65:32: error: ‘VerifyTable’ was not declared in this scope
     return VerifyTable(verifier) &&
                                ^
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h: In function ‘bool MyGame::Sample::VerifyAny(const flatbuffers::Verifier&, const void*, uint8_t)’:
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h:111:95: error: no matching function for call to ‘flatbuffers::Verifier::VerifyTable(const MyGame::Sample::Monster*) const’
     case Any_Monster: return verifier.VerifyTable(reinterpret_cast<const Monster *>(union_obj));
                                                                                               ^
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h:111:95: note: candidate is:
In file included from /home/amehta/workspace/external/flatbuffers/samples/sample_binary.cpp:17:0:
/home/amehta/workspace/external/flatbuffers/include/flatbuffers/flatbuffers.h:693:29: note: bool flatbuffers::Verifier::VerifyTable(const T*) [with T = MyGame::Sample::Monster] <near match>
   template<typename T> bool VerifyTable(const T *table) {
                             ^
/home/amehta/workspace/external/flatbuffers/include/flatbuffers/flatbuffers.h:693:29: note:   no known conversion for implicit ‘this’ parameter from ‘const flatbuffers::Verifier*’ to ‘flatbuffers::Verifier*’
In file included from /home/amehta/workspace/external/flatbuffers/samples/sample_binary.cpp:19:0:
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h: In function ‘bool MyGame::Sample::VerifyMonsterBuffer(const flatbuffers::Verifier&)’:
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h:118:112: error: no matching function for call to ‘flatbuffers::Verifier::VerifyBuffer() const’
 inline bool VerifyMonsterBuffer(const flatbuffers::Verifier &verifier) { return verifier.VerifyBuffer<Monster>(); }
                                                                                                                ^
/home/amehta/workspace/external/flatbuffers/samples/monster_generated.h:118:112: note: candidate is:
In file included from /home/amehta/workspace/external/flatbuffers/samples/sample_binary.cpp:17:0:
/home/amehta/workspace/external/flatbuffers/include/flatbuffers/flatbuffers.h:748:29: note: bool flatbuffers::Verifier::VerifyBuffer() [with T = MyGame::Sample::Monster] <near match>
   template<typename T> bool VerifyBuffer() {
                             ^
/home/amehta/workspace/external/flatbuffers/include/flatbuffers/flatbuffers.h:748:29: note:   no known conversion for implicit ‘this’ parameter from ‘const flatbuffers::Verifier*’ to ‘flatbuffers::Verifier*’
make[2]: *** [CMakeFiles/flatsamplebinary.dir/samples/sample_binary.cpp.o] Error 1
make[1]: *** [CMakeFiles/flatsamplebinary.dir/all] Error 2
make: *** [all] Error 2

I have not been able to successfully debug this. Any help would be appreciated!

[ghost]

The first error is because 1 is by default unsigned, so instead writing 1u may also fix it.

The second errors are caused by me forgetting to regenerate monster_generated.h. Please run flatc -c monster.fbs in samples/.

Will fix these both on Monday, thanks for noticing.

[apurvam]

Yep I realized it after typing. I just created a pull request with the patch for the first error.

[apurvam]

I submitted pull request #53 which fixes both errors.

[ghost]

Ahh thanks.. already made a commit though that fixes this.