3.4.0 not building against VS9 (requires c++11 features)

[hajapy]

Over at conda-forge we noticed that builds of protobuf 3.4.0 are failing with VS9 (see conda-forge/protobuf-feedstock#31) because of use of c++11 features. Here is the error:

C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(206) : error C2039: 'back' : is not a member of 'std::basic_string<_Elem,_Traits,_Ax>'
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(212) : error C2039: 'unique_ptr' : is not a member of 'std'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(212) : error C2143: syntax error : missing ';' before '<'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(212) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(212) : error C2143: syntax error : missing ';' before '{'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(212) : error C2447: '{' : missing function header (old-style formal list?)
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(221) : error C2039: 'unique_ptr' : is not a member of 'std'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(221) : error C2059: syntax error : ']'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(222) : error C2065: 'wbuf' : undeclared identifier
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(222) : error C2228: left of '.get' must have class/struct/union
        type is ''unknown-type''
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(223) : error C2065: 'wbuf' : undeclared identifier
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(223) : error C2228: left of '.get' must have class/struct/union
        type is ''unknown-type''
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(327) : error C2039: 'unique_ptr' : is not a member of 'std'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(327) : error C2059: syntax error : ']'
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(328) : error C2065: 'wmode' : undeclared identifier
C:\bld\protobuf_1503290160041\work\protobuf-3.4.0\src\google\protobuf\stubs\io_win32.cc(328) : error C2228: left of '.get' must have class/struct/union
        type is ''unknown-type''
NMAKE : fatal error U1077: 'C:\PROGRA~2\MICROS~1.0\VC\bin\cl.exe' : return code '0x2'
Stop.
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\BIN\nmake.exe"' : return code '0x2'
Stop.
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\BIN\nmake.exe"' : return code '0x2'
Stop.

My understanding was that c++11 was only to be required as of 3.5 and on, so is this a bug in 3.4.0?

[liujisi]

Yes. I will send out a fix.

[liujisi]

Could you try if this is fixed in 3.4.x branch?

[jrandalldemllo]

The use of range-based for loop syntax (not supported until VS11) remains in io_win32.cc at 198
Attempts to build 3.4.1 against VS10 seems to fail with these errors:

"...\protobuf-3.4.1\build\debug\protobuf.sln" (default target) (1) ->
"...\protobuf-3.4.1\build\debug\ALL_BUILD.vcxproj.metaproj" (default target) (2) ->
"...\protobuf-3.4.1\build\debug\libprotobuf.vcxproj.metaproj" (default target) (6) ->
"...\protobuf-3.4.1\build\debug\libprotobuf.vcxproj" (default target) (7) ->
(ClCompile target) ->
  ..\..\protobuf-3.4.1\src\google\protobuf\stubs\io_win32.cc(198): error C2143: syntax error : missing ',' before ':' [...\protobuf-3.4.1\build\debug\libprotobuf.vcxproj]
  ..\..\protobuf-3.4.1\src\google\protobuf\stubs\io_win32.cc(198): error C2530: 's' : references must be initialized [...\protobuf-3.4.1\build\debug\libprotobuf.vcxproj]
  ..\..\protobuf-3.4.1\src\google\protobuf\stubs\io_win32.cc(198): error C3531: 's': a symbol whose type contains 'auto' must havean initializer [...\protobuf-3.4.1\build\debug\libprotobuf.vcxproj]
  ..\..\protobuf-3.4.1\src\google\protobuf\stubs\io_win32.cc(198): error C2143: syntax error : missing ';' before '{' [...\protobuf-3.4.1\build\debug\libprotobuf.vcxproj]

Otherwise the build will pass if the loop is changed to:

for (auto it = segments.begin(); it != segments.end(); ++it) {

[jakirkham]

Still seeing some issues with VS9 when using the patch from PR ( #3769 ). Here's the build log.

[jakirkham]

Namely it appears that auto and for-each are used here.

[jakirkham]

There’s also some calls to back on std::string instances. This method does not exist until C++11.