Error: invalid use of incomplete type 'class std::__make_unsigned_selector<wchar_t, false, false>'

[softwarefailure]

I'm trying to compile a C++11 project with gcc 5.4.0 but it doesn't work. I'm getting the error mentioned above. Here is the complete error message:

In file included from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/move.h:57:0,
       from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/stl_pair.h:59,
       from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/stl_algobase.h:64,
       from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/vector:60,
       from ./fpdfsdk/cba_annotiterator.h:10,
       from fpdfsdk/cba_annotiterator.cpp:7:
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/type_traits: In instantiation of 'struct std::make_unsigned<wchar_t>':
./core/fxcrt/cfx_string_c_template.h:28:67:   required from 'class CFX_StringCTemplate<wchar_t>'
./core/fxcrt/cfx_string_c_template.h:235:23:   required from here
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/type_traits:1757:62: error: invalid use of incomplete type 'class std::__make_unsigned_selector<wchar_t, false, false>'
     { typedef typename __make_unsigned_selector<_Tp>::__type type; };
                           ^
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/type_traits:1721:11: note: declaration of 'class std::__make_unsigned_selector<wchar_t, false, false>'
     class __make_unsigned_selector;
      ^
In file included from ./core/fxcrt/fx_string.h:11:0,
       from ./core/fpdfdoc/cpdf_annot.h:15,
       from ./fpdfsdk/cba_annotiterator.h:12,
       from fpdfsdk/cba_annotiterator.cpp:7:
./core/fxcrt/cfx_widestring.h:258:6: error: 'wostream' in namespace 'std' does not name a type
 std::wostream& operator<<(std::wostream& os, const CFX_WideString& str);
      ^
./core/fxcrt/cfx_widestring.h:260:6: error: 'wostream' in namespace 'std' does not name a type
 std::wostream& operator<<(std::wostream& os, const CFX_WideStringC& str);
      ^
In file included from ./core/fxcrt/cfx_bytestring.h:16:0,
       from ./core/fxcrt/fx_string.h:10,
       from ./core/fpdfdoc/cpdf_annot.h:15,
       from ./fpdfsdk/cba_annotiterator.h:12,
       from fpdfsdk/cba_annotiterator.cpp:7:
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(const CharType*, FX_STRSIZE) [with T = wchar_t; CFX_StringCTemplate<T>::CharType = wchar_t; FX_STRSIZE = unsigned int]':
./core/fxcrt/cfx_widestring.h:69:48:   required from here
./core/fxcrt/cfx_string_c_template.h:41:72: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
       : m_Ptr(reinterpret_cast<const UnsignedType*>(ptr)), m_Length(len) {}
                           ^
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(const CFX_StringCTemplate<T>&) [with T = wchar_t]':
./core/fxcrt/cfx_widestring.h:69:48:   required from here
./core/fxcrt/cfx_string_c_template.h:59:11: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
     m_Ptr = src.m_Ptr;
      ^
./core/fxcrt/cfx_string_c_template.h:59:11: error: 'const class CFX_StringCTemplate<wchar_t>' has no member named 'm_Ptr'
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(const CharType*) [with T = wchar_t; CFX_StringCTemplate<T>::CharType = wchar_t]':
./core/fxcrt/cfx_widestring.h:205:35:   required from here
./core/fxcrt/cfx_string_c_template.h:38:42: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
    m_Length(ptr ? FXSYS_len(ptr) : 0) {}
                 ^
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(CFX_StringCTemplate<T>::CharType&) [with T = wchar_t; CFX_StringCTemplate<T>::CharType = wchar_t]':
./core/fxcrt/cfx_widestring.h:212:49:   required from here
./core/fxcrt/cfx_string_c_template.h:54:11: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
     m_Ptr = reinterpret_cast<const UnsignedType*>(&ch);

How can I fix this please? On all other systems (MorphOS, Linux, Mac OS, Windows, Android) the code compiles fine but with the OS4 gcc 5.4.0 I'm getting this error and I haven't got a clue how to fix it. Looks like a compiler issue to me.

I'm invoking gcc like this:

gcc -c -std=c++11 -o test.o test.cpp

[DStastny]

I saw a comment on amigans.net related to C++11 and comment was this
"Use -std=gnu++11 instead of -std=c++11.

The latter defines STRICT_ANSI which disables newlib functions that are not standard ANSI."

So maybe try changing compile options to use the gnu++11

[softwarefailure]

I don't think the error is related to newlib. As you can see from the error message gcc seems to have problems compiling the C++ code. But the code is correct and compiles fine on all the other platforms I mentioned. And besides, I'm using -std=c++11 on all other platforms so it's unlikely to be the reason. FWIW, I've tested compilation with -std=gnu++11 but as expected it doesn't make a difference.

[sba1]

AFAIK wide char support is not supported for newlib, so no support for it is included in our gcc. I don't know if it is supported for clib2. If possible, disable the need for wide characters.

[softwarefailure]

Unfortunately, wide chars are used all over the project and there is no way to get rid of them. But I don't think that I'd need the complete wide char library for the project to run. On MorphOS it works too and the wide char support is very limited on MorphOS too. I've seen that clib2 has dummies for all wide char functions but I'm not able to get it to compile with clib2 either because the clib2 wide char definitions seem to clash with gcc definitions. Here's the output I get when compiling with -mcrt=clib2.

In file included from ./core/fxcrt/fx_system.h:18:0,
		 from ./core/fxcrt/fx_memory.h:10,
		 from ./core/fxcrt/cfx_maybe_owned.h:12,
		 from ./core/fpdfdoc/cpdf_annot.h:13,
		 from ./fpdfsdk/cba_annotiterator.h:12,
		 from fpdfsdk/cba_annotiterator.cpp:7:
/SDK/clib2/include/wchar.h:77:14: error: conflicting declaration 'typedef long int mbstate_t'
 typedef long mbstate_t;
	      ^
In file included from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/postypes.h:40:0,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/char_traits.h:40,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/string:40,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/stdexcept:39,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/array:38,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/tuple:39,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/stl_map.h:63,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/map:61,
		 from ./core/fpdfdoc/cpdf_annot.h:10,
		 from ./fpdfsdk/cba_annotiterator.h:12,
		 from fpdfsdk/cba_annotiterator.cpp:7:
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/cwchar:58:5: note: previous declaration as 'typedef struct mbstate_t mbstate_t'
   } mbstate_t;
     ^
In file included from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/move.h:57:0,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/stl_pair.h:59,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/bits/stl_algobase.h:64,
		 from /dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/vector:60,
		 from ./fpdfsdk/cba_annotiterator.h:10,
		 from fpdfsdk/cba_annotiterator.cpp:7:
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/type_traits: In instantiation of 'struct std::make_unsigned<wchar_t>':
./core/fxcrt/cfx_string_c_template.h:28:67:   required from 'class CFX_StringCTemplate<wchar_t>'
./core/fxcrt/cfx_string_c_template.h:235:23:   required from here
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/type_traits:1757:62: error: invalid use of incomplete type 'class std::__make_unsigned_selector<wchar_t, false, false>'
     { typedef typename __make_unsigned_selector<_Tp>::__type type; };
							      ^
/dh1/Programmieren/adtools-os4-20170218-372/include/c++/5.4.0/type_traits:1721:11: note: declaration of 'class std::__make_unsigned_selector<wchar_t, false, false>'
     class __make_unsigned_selector;
	   ^
In file included from ./core/fxcrt/fx_string.h:11:0,
		 from ./core/fpdfdoc/cpdf_annot.h:15,
		 from ./fpdfsdk/cba_annotiterator.h:12,
		 from fpdfsdk/cba_annotiterator.cpp:7:
./core/fxcrt/cfx_widestring.h:258:6: error: 'wostream' in namespace 'std' does not name a type
 std::wostream& operator<<(std::wostream& os, const CFX_WideString& str);
      ^
./core/fxcrt/cfx_widestring.h:260:6: error: 'wostream' in namespace 'std' does not name a type
 std::wostream& operator<<(std::wostream& os, const CFX_WideStringC& str);
      ^
In file included from ./core/fxcrt/cfx_bytestring.h:16:0,
		 from ./core/fxcrt/fx_string.h:10,
		 from ./core/fpdfdoc/cpdf_annot.h:15,
		 from ./fpdfsdk/cba_annotiterator.h:12,
		 from fpdfsdk/cba_annotiterator.cpp:7:
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(const CharType*, FX_STRSIZE) [with T = wchar_t; CFX_StringCTemplate<T>::CharType = wchar_t; FX_STRSIZE = unsigned int]':
./core/fxcrt/cfx_widestring.h:69:48:   required from here
./core/fxcrt/cfx_string_c_template.h:41:72: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
       : m_Ptr(reinterpret_cast<const UnsignedType*>(ptr)), m_Length(len) {}
									^
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(const CFX_StringCTemplate<T>&) [with T = wchar_t]':
./core/fxcrt/cfx_widestring.h:69:48:   required from here
./core/fxcrt/cfx_string_c_template.h:59:11: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
     m_Ptr = src.m_Ptr;
	   ^
./core/fxcrt/cfx_string_c_template.h:59:11: error: 'const class CFX_StringCTemplate<wchar_t>' has no member named 'm_Ptr'
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(const CharType*) [with T = wchar_t; CFX_StringCTemplate<T>::CharType = wchar_t]':
./core/fxcrt/cfx_widestring.h:205:35:   required from here
./core/fxcrt/cfx_string_c_template.h:38:42: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
	 m_Length(ptr ? FXSYS_len(ptr) : 0) {}
					  ^
./core/fxcrt/cfx_string_c_template.h: In instantiation of 'CFX_StringCTemplate<T>::CFX_StringCTemplate(CFX_StringCTemplate<T>::CharType&) [with T = wchar_t; CFX_StringCTemplate<T>::CharType = wchar_t]':
./core/fxcrt/cfx_widestring.h:212:49:   required from here
./core/fxcrt/cfx_string_c_template.h:54:11: error: using invalid field 'CFX_StringCTemplate<T>::m_Ptr'
     m_Ptr = reinterpret_cast<const UnsignedType*>(&ch);

As you can see, the clib2 definition of mbstate_t clashes with gcc's definition of mbstate_t. Can't this be fixed so that I'm at least able to compile the project properly - even if all wide char functions are just NOPs?

[sba1]

Can you please create a small test example, ideally as a pull request with a file in the test folder? I'll then see what I can do for you.

[softwarefailure]

See my PM.

[broadblues]

[quote]
Can't this be fixed so that I'm at least able to compile the project properly - even if all wide char functions are just NOPs?
[/quote]

You could edit the clib2 header, since long and long int are essentially the same, that might get things compiling. Not perfect if it's something you need to distribute as src code, but if internal then not a problem.

[softwarefailure]

The clashing `mbstate_t` definitions aren't the main problem. The main problem seems to be that the OS4 gcc doesn't support `wchar_t` properly.

[sba1]

There are multiple problems I think. I added a simple test for at least one of them.

[sba1]

The configure step for the clib2-based libstdc++ build doesn't recognize the presence of mbstate_t properly, because wchar.h of clib2 contains following line

extern size_t mbrtowc_l(wchar_t *restrict pwc, const char *restrict s, size_t n, mbstate_t *restrict ps, locale_t loc);

and locale_t is not defined in the context. So far, I have only checked the SDK-supplied clib2 that is used for the adtools build as well.

[sba1]

The problem was fixed in clib2 by commit adtools/clib2@309bbd8 which happened after the latest release available so far.

[sba1]

BTW, this is a duplicate of #42.