Header correct, but identifier not found

Question

I have two projects (x64).

A. Written in C (wxWidgets) --- edit: its in C++!

B. Written in C++

A compiles fine, but B (which uses functions of A) gives several errors when I try to compile.

I suggest that the reason for the errors is the same for all, so I mention only the first. It says:

strlen: identifier not found

In the file which gives the error messages ( wxcrtbase.h ), the following headers are included:

#include <stdio.h>
#include <string.h>`

The files from B include the following headers from A:

#include "wx/wx.h"
#include "wx/dcbuffer.h" 
#include "wx/spinctrl.h"

So, currently, I have no idea where to start to search for the reason of the errors. May it be that I have C and C++ files? Maybe that I compiled for x64?

Thanks for help!

edit: more info
the lines in wxcrtbase.h around the one producing the first error message are:

#ifdef __cplusplus  
inline size_t wxStrlen(const char *s) { return s ? wxCRT_StrlenA(s) : 0; }  
inline size_t wxStrlen(const wchar_t *s) { return s ? wcslen(s) : 0; }  

The order of the includes of the wxcrtbase.h is

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <wctype.h>
#include <time.h>
#include <io.h>

The /showIncludes lists the following ( I stop with the list after the first two error messages ):

1>Compiling...
1>widget.cpp
1>Note: including file: m:\visual studio 2008\projects\general\rama\src\widget.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include \string
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\ostream
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\ios
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\xlocnum
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\climits
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\yvals.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\sal.h
1>Note: including file: c:\program files (x86)\microsoft visual studio 9.0\vc\include\codeanalysis\sourceannotations.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtassem.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\vadefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\use_ansi.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\limits.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\cstdio
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\stdio.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\swprintf.inl
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\cstdlib
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\stdlib.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\streambuf
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\xiosbase
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\xlocale
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\cstring
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx\string.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/defs.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/platform.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\setupp.h
1>Note: including file: m:\visual studio 2008\projects\general\wxwidgets-2.9.0\include\wx/version.h
1>Note: including file: m:\visual studio 2008\projects\general\wxwidgets-2.9.0\include\wx/cpp.h
1>Note: including file: m:\visual studio 2008\projects\general\wxwidgets-2.9.0\include\wx/cpp.h
1>Note: including file: M:/Visual Studio 2008/Projects/general/wxWidgets-2.9.0/lib/vc_lib/mswud/wx/setup.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/msw/libraries.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/chkconf.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/msw/chkconf.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/version.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/dlimpexp.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\stddef.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/debug.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\assert.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file:  M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/chartype.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/platform.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\tchar.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\wchar.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\wtime.inl
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/cpp.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/windowid.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/msw/winundef.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/features.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx\string.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\stdarg.h
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/wxcrtbase.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\io.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\cctype
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\ctype.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\cwctype
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\wctype.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\ctime
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\time.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\time.inl
1>Note: including file:  M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/chartype.h
1>M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/wxcrtbase.h(705) : error C3861: 'strlen': identifier not found
1>M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/wxcrtbase.h(718) : error C3861: '_strdup': identifier not found

Answer 1

I had this same problem. The fix for me had to do with the include order. Including string.h before stdafx.h caused the error. The other way around works. It seems that the compiler was ignoring string.h completely.

Answer 2

A few things to try and/or answer:

• Can you post at least the few lines around and including the one that the compiler generates the 'identifier not found' error?
• When you say you have an #include <string.h> line, exactly which file(s) and does it precede the various wx includes?
• Can you post the output of the included headers when you build with the /showIncludes option (it's in the VS 2008 IDE's C++ project property page under "C/C++/Advanced/Show Includes")?

---

Edit, with new information:

Based on the edit you made that included a more complete listing from /showIncludes, it appears that you might have the INCLUDE path set incorrectly. Here are a couple of lines from the log:

1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\cstring
1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx\string.h

When MSVC's cstring header is trying to include string.h, it's picking up a string.h header from the wx library instead of the one that's part of the compiler distribution (which would be in C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\string.h).

I'm not sure why the wx library would name one of their own headers string.h (instead of, say, wxString.h), but I assume that it's intended to be picked up by someone using something like:

#include "wx/string.h"

Regardless, I think you'll fix your problem by making sure that the MSVC include directory is in the INCLUDE search path before any other directory.

Answer 3

The comment field is too small. I answer to Michael Burr:

A.

#ifdef __cplusplus
inline size_t wxStrlen(const char *s) { return s ? wxCRT_StrlenA(s) : 0; }
inline size_t wxStrlen(const wchar_t *s) { return s ? wcslen(s) : 0; }`

B. the string.h is only in the wxWidgets files.

There the original order is:

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <wctype.h>
#include <time.h>
#include <io.h>

C. Here`s the some lines before and a line after the first error message:

1>Note: including file: M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/chartype.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\ctype.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\wctype.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\time.h
1>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\time.inl
1>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\io.h
1>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\crtdefs.h
1>M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/wxcrtbase.h(696) : error C3861: 'strlen': identifier not found
1>M:\Visual Studio 2008\Projects\general\wxWidgets-2.9.0\include\wx/wxcrtbase.h(709) : error C3861: '_strdup': identifier not found

Answer 4

I indeed think that you have to include cstdio and cstring (as proposed above), but in this case everything will reside in namespace std, like std::strlen and such...

Answer 5

Try:

#include <cstdio>
#include <cstring>
#include <cctype>
#include <cwctype>
#include <ctime>
#include <cio>

using namespace std;

#include "wxcrtbase.h"
#include "wx/chartype.h"

int main(void) {
    return strlen("hey there good buddy!");
}

This is the stuff that I hate about c++ the most.

Answer 6

Try #include<cstdio> and #include<cstring>, which are the headers for C++

Answer 7

If wxWidgets is C++, and it includes and and your compiler prevents inclusion of and when cstring/cstdio are included, then strlen would be in the std namespace instead of global. Try std::strlen and see if that fixes the error.