C / C++ / MFC

5-Aug-07 18:26

Hello,
I am porting an application form VC++ 6.0 to VC++ 2005. While building my application its showing error "Can't open .sbr file, no such file or directory". Can any body help me in this problem.

regards,
Yudhisthira

Paresh Chitte5-Aug-07 19:40

Paresh Chitte

5-Aug-07 19:40

Try to rebuild the entire solution.

Regards,

Paresh.

yudhisthira5-Aug-07 19:55

5-Aug-07 19:55

Hello,
I did clean and build so many times but same error is coming. Is there any other solution pls let me know.

Regards,
Yudhisthira

Paresh Chitte5-Aug-07 20:02

Paresh Chitte

5-Aug-07 20:02

Check compiler options:
Please refer here[^] for more information.

Regards,

Paresh.

Shouvik Das5-Aug-07 19:48

Shouvik Das

5-Aug-07 19:48

Clean the build and rebuild it. sbr file is a source browser file needed to have the enlisting of the constituents of the build.

There are only two kinds of people who are really fascinating-people who know absolutely everything, and people who know absolutely nothing.
Oscar Wilde (1854-1900)
Regards...
Shouvik

yudhisthira5-Aug-07 19:55

5-Aug-07 19:55

Hello,
I did clean and build so many times but same error is coming. Is there any other solution pls let me know.

Regards,
Yudhisthira

ThatsAlok5-Aug-07 19:53

ThatsAlok

5-Aug-07 19:53

yudhisthira wrote:
I am porting an application form VC++ 6.0 to VC++ 2005. While building my application its showing error "Can't open .sbr file, no such file or directory". Can any body help me in this problem.

Clean the Solution and then perform build!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief

yudhisthira5-Aug-07 19:56

5-Aug-07 19:56

Hello,
I did clean and build so many times but same error is coming. Is there any other solution pls let me know.

Regards,
Yudhisthira

static member variable, dll export and multiple translation units

ThatsAlok5-Aug-07 20:20

ThatsAlok

5-Aug-07 20:20

yudhisthira wrote:
Hello,
I did clean and build so many times but same error is coming. Is there any other solution pls let me know.

are your .sln and other file readonly ? if yes/no delete release folder,debug folder and .clw,.ncb.aps files!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief

devvvy5-Aug-07 15:43

Re: static member variable, dll export and multiple translation units [modified*2]

5-Aug-07 15:43

Here's a problem with static class member:

From DLL A - header:

<br />
class __declspec(dllexport) CLogEntry<br />
{<br />
public:<br />
        ...<br />
<br />
	static CLog* GetSingletonLoggingProvider() { return s_pSingletonLoggingProvider; }<br />
	...<br />
<br />
protected:<br />
         ...<br />
	static CLog * s_pSingletonLoggingProvider;<br />
};<br />

.cpp file:

#include "stdafx.h"<br />
<br />
#include "LogEntry.h"<br />
<br />
CLog * CLogEntry::s_pSingletonLoggingProvider = NULL; << NOTE I need to actually "define" the global variable - that's fine. (so long I don't need to do it multiple times)<br />
<br />
CLogEntry::CLogEntry(int nId, nsCLog::eSeverity nSeverity, char* lpszCode, char* lpszMsg, DWORD dwWin32ErrorCode, CLogEntry * pParent)<br />
{<br />
...<br />
}<br />
... the rest of it...<br />

Now from DLL B (The second dll which is linked to "DLL A")
.cpp file (where CLogEntry is used)

<br />
CLog * CLogEntry::s_pSingletonLoggingProvider = NULL; <br />

<< I need to define this again?? That looks like redundant code to me but if I don't, I'd get the following error.

<br />
Linking...<br />
   Creating library ..\..\bin/XXX.lib and object ..\..\bin/XXX.exp<br />
StdAfx.obj : error LNK2001: unresolved external symbol "protected: static class CLog * CLogEntry::s_pSingletonLoggingProvider" (?s_pSingletonLoggingProvider@CLogEntry@@1PAVCLog@@A)<br />
..\..\bin/XXX.exe : fatal error LNK1120: 1 unresolved externals

So I need to redefine (not "declare") the static member variable in each "Translation Unit"? (separate dll, exe?)

Thanks a bunch!

Mark Salsbery5-Aug-07 16:41

Re: static member variable, dll export and multiple translation units

5-Aug-07 16:41

You can do something like this:

<font size="3">// From DLL A - header:</font>

<font color="Red">#ifdef _BUILDINGDLL
   #define _MY_IMPORTEXPORT __declspec(dllexport);
#else
   #define _MY_IMPORTEXPORT __declspec(dllimport);
#endif</font>

class <font color="Red">_MY_IMPORTEXPORT</font> CLogEntry
{
public:
   ...

   static CLog* GetSingletonLoggingProvider() { return s_pSingletonLoggingProvider; }
   ...

protected:
   ...
   static CLog * s_pSingletonLoggingProvider;
};


<font size="3">// .cpp file:</font>

#include "stdafx.h"

#include "LogEntry.h"

CLog * CLogEntry::s_pSingletonLoggingProvider = NULL; 

CLogEntry::CLogEntry(int nId, nsCLog::eSeverity nSeverity, char* lpszCode, char* lpszMsg, DWORD dwWin32ErrorCode, CLogEntry * pParent)
{
   ...
}
... the rest of it...

Define _BUILDINGDLL (in the compiler preprocessor settings) when building DLL A.
Don't define it when building DLL B

Do NOT redefine s_pSingletonLoggingProvider in DLL B.

Instead use like any other static members (they are imported for external builds, exported when building DLL A):

CLog *pLog = CLogEntry::GetSingletonLoggingProvider();

Make sense?

Mark

Last modified: 2hrs 51mins after originally posted --

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

devvvy5-Aug-07 18:42

Re: static member variable, dll export and multiple translation units

5-Aug-07 18:42

thanks but if I don't guard

<br />
...<br />
class __declspec(dllexport) CLogEntry<br />
{<br />
public:<br />
	...<br />
	static CLog* GetSingletonLoggingProvider() { return s_pSingletonLoggingProvider; }<br />
	<br />
	...<br />
	<br />
protected:<br />
	...<br />
protected:<br />
	...<br />
<br />
	static CLog * s_pSingletonLoggingProvider;<br />
};<br />
<br />
<br />
CLog * CLogEntry::s_pSingletonLoggingProvider = NULL;<br />
#endif<br />

with #ifndef:

<br />
#ifndef _LOGSINGLETON_<br />
#define _LOGSINGLETON_<br />
CLog * CLogEntry::s_pSingletonLoggingProvider = NULL;<br />

then I'd get:

<br />
Linking...<br />
StartupManager.obj : error LNK2005: "protected: static class CLog * CLogEntry::s_pSingletonLoggingProvider" (?s_pSingletonLoggingProvider@CLogEntry@@1PAVCLog@@A) already defined in LogEntry.obj<br />
StartupManager.obj : error LNK2005: "protected: static class CLog * CLogEntry::s_pSingletonLoggingProvider" (?s_pSingletonLoggingProvider@CLogEntry@@1PAVCLog@@A) already defined in LogEntry.obj<br />
StartupManager.obj : warning LNK4006: "protected: static class CLog * CLogEntry::s_pSingletonLoggingProvider" (?s_pSingletonLoggingProvider@CLogEntry@@1PAVCLog@@A) already defined in LogEntry.obj; second definition ignored<br />
   Creating library ..\bin\Utilities.lib and object ..\bin\Utilities.exp<br />
..\bin\Utilities.dll : fatal error LNK1169: one or more multiply defined symbols found<br />
Error executing link.exe.<br />

Should I just include it in ".cpp" instead?

Mark Salsbery5-Aug-07 19:23

Re: static member variable, dll export and multiple translation units [modified*2]

5-Aug-07 19:23

That should have stayed in the CPP, yes. I'll hilight the sample code - I only added the stuff at the top.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

devvvy5-Aug-07 22:17

Re: static member variable, dll export and multiple translation units

5-Aug-07 22:17

Thanks very much this is execellent

There're a couple of things I do not understand however.

1. I understand "__declspec(dllexport)", but not sure why we need "__declspec(dllimport)"

2. I do understand precompile directive however:

<br />
#ifdef _BUILDINGDLL<br />
   ...<br />
#else<br />
  ...<br />
#endif<br />

Just not sure why when "Building DLL B" I need to "dllimport" (although I saw it in MSDN)... I don't remember I need to dllimport... just link in project settings and include header file was all I did.

Mark Salsbery6-Aug-07 4:59

Re: static member variable, dll export and multiple translation units [modified*2]

6-Aug-07 4:59

For a true global variable/function you need ONE instance of it.

In your case it was in DLL A.

For other modules to be able to use the globals, you need to export it from
the DLL it exists in and import it in any module that uses it.

By using the preprocessor directives, you can keep the declaration in one header file
instead of two (one for export, one for import). Any changes to the class only have to
be made in one place.

This is how MFC is built, except there's a 3rd option, since MFC can also be built into a
static library.

By the way, you can also import/export individual static members of a class instead of
importing/exporting the entire class. Same method except you put the __declspec()
on the variable declaration instead of the class declaration.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

devvvy5-Aug-07 22:24

Re: static member variable, dll export and multiple translation units

5-Aug-07 22:24

Also, I already have the following by ClassWizard when setup the new project:

#ifdef UTILITIES_EXPORTS<br />
#define UTILITIES_API __declspec(dllexport)<br />
#else<br />
#define UTILITIES_API __declspec(dllimport)<br />
#endif<br />

Do I need to do this again for individual class?

devy

Mark Salsbery6-Aug-07 5:01

Re: static member variable, dll export and multiple translation units

6-Aug-07 5:01

devvvy wrote:
Do I need to do this again for individual class?

You can use the same UTILITIES_API macro on a class.

The point is to only export from one module, the module where the actual
static instance(s) exist. All other modules should import.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

devvvy6-Aug-07 13:57