Thread: Circular dependency problem

Hi,

I'm trying to use the CGenericList class which is part of DirectShow.
I included the file required for its use but I still get the error:

error C2143: syntax error : missing ';' before '<'|
The error means that the compiler can't find the class definition.

So I figured that I must have a circular dependency problem but I don't know how to check for it?

I tried '#pragma once' too but it's still the same error.

CGenericList class (Windows)

Code:

#include <windows.h>

#include <Streams.h>
#include <Dshow.h>

class CRouting {
public:
    class CRouting       *pLeftRouting;
    class CRouting       *pRightRouting;
    LONG                 VideoInputIndex;
    LONG                 VideoOutputIndex;
    LONG                 AudioInputIndex;
    LONG                 AudioOutputIndex;
    IAMCrossbar         *pXbar;
    LONG                 InputPhysicalType;
    LONG                 OutputPhysicalType;
    LONG                 Depth;

    CRouting () {};
    ~CRouting () {};
};

int main()
{
    typedef CGenericList<CRouting> CRoutingList;

    return 0;
}

I don't think it's a circular dependency problem if you've put this code in a .cpp file.
I don't know of a generic way to detect circular dependencies, but you can try to tell the compiler to tell you what headers it includes. Then look at something suspicious regarding the files where you get the errors (the file which uses the type it can't find and the file which declares said type).
#pragma once does not fix circular dependencies. It's mean to prevent multiple declaration errors and nothing else.

There may be something in the header (e.g. conditional macros), which you could check, though.

Thanks Elysia!

1. OK, this program compiles without error in MSVC but I get the error above mentioned in CodeBlocks.

What can be the reason?

2. I checked in MSVC the option '/showincludes' but I dont see the .h files included in the output window.

3. Actually I checked Streams.h and it calls several *.h files so it still could be a circular dependancy problem.
The question is what MSVC does that CodeBlocks doesn't that makes it compile in MSVC?

My guess it that you're not using the msvc compiler with code blocks. Anything non-microsoft has problems parsing the windows headers at times.

These are my MSVC executable paths:

$(VC_ExecutablePath_x86)
$(WindowsSDK_ExecutablePath)
$(VS_ExecutablePath)
$(MSBuild_ExecutablePath)
$(SystemRoot)\SysWow64


This is my CodeBlocks executable path:
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC

How to verify if VC_ExecutablePath_x86 is the same as the CodeBlocks path?

OK I found VC_ExecutablePath_x86 and it's the same as the CodeBlocks path. C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC

So what else could it be?

It would help if you provided a small but complete sample of code that exhibited your problem. And information about the error message ..... such as what line of code in what file is causing it.

I suspect, however, that the problem is what Elysia mentioned in post #4, which you seem to have ignored or skipped over.

Read and follow this CB FAQ
FAQ-Compiling (errors) - CodeBlocks

Tim S.

Originally Posted by grumpy

It would help if you provided a small but complete sample of code that exhibited your problem. And information about the error message ..... such as what line of code in what file is causing it.

It's all there in the first post: full code and error.

It compiles in MSVC but not in CodeBlocks with the same compiler.

I suspect, however, that the problem is what Elysia mentioned in post #4, which you seem to have ignored or skipped over.

I answered Elysia in my 5th and 6th post.

Originally Posted by Ducky

It's all there in the first post: full code and error.

The compiler diagnostics will also include information you have not provided - including name of the file (which may be either your source file or an #include'd header) and the line number. You provided no such information.

You may be using the same compiler, but you also need to check if you are using the same compiler configuration. Code::Blocks will not necessarily invoke a compiler with the same settings (environment variables, etc) that Visual Studio would. That depends on how the settings are saved (e.g. different config files for different IDEs).

Also, inability to find a class definition does not usually indicate circular dependencies. It usually means a relevant header file is not being #include'd (directly by your source file, or indirectly by headers #include'd by your source file). If you have circular dependencies (e.g. header A includes header B includes header A) a more common symptom is something with multiple definitions.

Thank you Grumpy, I'll look into these things.

What are the configuration files?

Isnt it enough if I configure the search paths for the includes and library files? I mean the rest of my programs are compiling.

What else needed?

grumpy implies that the settings which Visual Studio uses and Code::Blocks when invoking the compiler may be different. You can find these in the compiler options of the IDE. Make sure they match (especially #defines).

I copied the command line switches as it is in MSVC to Code::Blocks but I still get the same error.

Thanks stahta, I went through it but I found nothing new.

Originally Posted by grumpy

The compiler diagnostics will also include information you have not provided - including name of the file (which may be either your source file or an #include'd header) and the line number. You provided no such information.

Code:

test.cpp|25|error C2143: syntax error : missing ';' before '<'|
test.cpp|25|error C4430: missing type specifier - int assumed. Note: C++ does not support default-int|
||=== Build finished: 2 errors, 0 warnings ===|