I've been getting a compile error in Code::Block for an SDL_Surface variable. Strangely enough, this is the first time I have received this kind of error, as I have used this line of code previously and it has worked fine.
One (of several with the same problem) sample line of code that causes this problem is:
extern SDL_Surface *screen;
The resulting error is this:
expected init-declarator before "extern"|
expected `,' or `;' before "extern"|
||=== Build finished: 2 errors, 0 warnings ===|
I tried to understand the error, but I can not tell what it is. Does anyone know what might be wrong?
It's a wild guess since I don't have much to work with. Do you have all the headers required for SDL_Surface before that extern?
It looks like you're missing the definition of SDL_Surface. Make sure to #include the proper header file in which SDL_Surface is defined. Alternatively, if you're not actually using the screen variable (i.e. you're not accessing any of its fields), you can declare it using an incomplete type as so:
extern struct SDL_Surface *screen;
Related
As part of a bigger project ( the ff activex plugin for Mozilla Firefox) there is this code snippet:
if (CombineRgn(hrgnClip, hrgnClip, hRGN, RGN_AND) != ERROR)
{
::InvalidateRgn(m_hWndParent, hrgnClip, fErase);
}
When I build in VS2012 I get "Error C2065: 'ERROR' : undeclared identifier"
ERROR is defined in wingdi.h like this:
...
/* Region Flags */
#define ERROR 0 // it wont build when this macro is used
#define NULLREGION 1 // it builds when this macro is used
#define SIMPLEREGION 2
#define COMPLEXREGION 3
#define RGN_ERROR ERROR
...
The strange thing is that if I replace ERROR (just to see if it builds OK) with NULLREGION or SIMPLEREGION (which are macros in the same file, just two lines below the offending one) in the if statement above, the code builds OK. When I use ERROR, the code wont build.
Is it possible that the ERROR macro defined above gets masked by some keyword or another macro or some such by Visual Studio?
The problem here is that ERROR actually appears in the compile error message. That should not happen, the preprocessor should have substituted it with 0.
So somewhere in a .h file you #included after windows.h, some programmer took the 10 second shortcut to a macro name collision problem and wrote this:
#undef ERROR
You'd need to find that line and remove it. That's likely to be difficult and liable to give you a maintenance headache since that's a file you don't own and might well be updated in the future, forcing you to make that change over and over again. The alternative is to redefine it yourself:
#define MYGDIERROR 0
...
if (CombineRgn(hrgnClip, hrgnClip, hRGN, RGN_AND) != MYGDIERROR)
//etc...
Which still gives you a maintenance problem and requires you taking a bet that the return value definition of CombineRgn() is never going to change. That's a very safe bet, GDI is cast in stone.
I have been using the allegro 5 libraries for developing a game in C++ for some time. Today I got some weird error:
I have a class called level. I have a header file called levelhandler.
Here's how it looks:
#pragma once
#include "level.h"
level level_1;
level *currentlevel;
void initialize_levels()
{
currentlevel = &level_1;
}
When I try to compile it gives me strange errors like:
error C2086: 'int level' redefinition
error C2143: syntax error : missing ; before 'level_1'
I remember that it could compile before, and I did use currentlevel->Player.X a lot of times, but now I have a lot of that and it gives errors like these:
error C2227: left of '->Player' must point to a class/struct/generic type
error C4430: missing type specifier - int assumed
header pasted from comment
#pragma once
#include "entity.h"
// some more includes
class level {
public:
enum Tileset { ... };
enum Tile { ... };
int tiles[200][200];
player Player;
level(void);
~level(void);
};
Such errors are hard to find as long as you look at the "Error List" pane. Select View/Output to show the "Output" view. The line after the error C2086 shows the original definition of level.
You fill find an
int level;
there as the C2086 tells you. If it's the line
level level_1;
of your fist example you will have to check the last header file include in your compilation unit. It might end with an int or it has a unbalanced #if clause.
To find the exact location start using a Short, Self Contained, Correct (Compilable), Example. This helps you to find the bug and saves time of other with their crystal balls.
Edit:
Another way to find the reason for this unexpected behavior is to see the preprocessor output. Set the Generate Preprocessed File option int the C/C++/Preprocessor project property page to With line numbers (/P) and look in the generated <sourcefile>.i
Check that that level.h file has included what you intended.
Ok, so I've been tinkering around with my project the weekend, and I finally found out what whas the problem that gave me so many weird compiler errors. It seems that I had a lot of cases where two header files were including each other, and the compiler really didn't like that, so I corrected that, and now I'm ok. Thank you all for helping me, and have a great day!
I keep getting the error:
error C2146: syntax error : missing ';' before identifier 'mCameraFrame'
for the line of code:
Frame mCameraFrame;
So clearly my frame class isn't being found somehow. I have the frame.h header file (which defines the Frame class) directly included in this file. Why doesn't visual studio recognize it?
The error is coming from previous lines of code, possibly in a header file.
For example:
struct foo
{
int a;
}
Frame mCameraFrame;
Notice the missing ; after the }? That makes the Frame legal as an instance of the structure, but now there's a missing ; before mCameraFrame, resulting in the kind of error you reported.
The compiler can't report a missing ; after the } because it has no way to know there's supposed to be one there, since the Frame that comes after it is perfectly legal.
It's not unusual for a single missing ; or missing } to result in errors reported many lines later than the actual problem, sometimes hundreds of them.
Figured I'd report back to anyone that's interested. The problem was that the Frame class that was supposed to be definining mCameraFrame was in a different namespace, so all I had to do was "using namespace ....;". Doh! :P
I am compiling a project that uses both ffmpeg and Ogre.
Now on Windows, everything works fine.
But when I want to compile a file with the following line of code:
Ogre::PixelFormat format = Ogre::PF_BYTE_RGBA;
The compiler gives the following error:
error: ‘AVPixelFormat’ is not a member of ‘Ogre’
Which is strange in many ways, as I have not only specified the Ogre namespace with ::, but also there is no AVPixelFormat in Ogre. How does gcc confuse "PixelFormat" with "AVPixelFormat"?
And how can I get rid of that?
I'd love to use int here instead of an enum, but another Ogre function requires format to be in Ogre::PixelFormat.
Preprocess it first using gcc -E, then grep through the file looking for AVPixelFormat or PixelFormat. I suspect you have a #define or a typedef floating around, you just need to find where this happens, and a precompiled source file is the place this will become apparent.
The problem is in avutil/pixfmt.h:
#define PixelFormat AVPixelFormat
This prevents users from using the word "PixelFormat" anywhere in their own code, even if in namespaces.
This is there as a compatibility hack for older software still using the old identifiers.
The solution is quite simple in case you can edit the code. Just add to the C++ code a
#define FF_API_PIX_FMT 0
before including the ffmpeg headers.
This disables the if in the pixfmt.h header:
#if FF_API_PIX_FMT
#define PixelFormat AVPixelFormat
...
Source: https://trac.ffmpeg.org/ticket/4216
P.S. I know the question is old, but somehow I feel that there is no solution and I needed a solution, so I added it.
I am trying to load an image using SHLoadImageFile,but its returning invalid handle.
I am puzzled where the fault is.Because the path given to SHLoadImageFile is absolutely fine.
The question title currently is "SHLoadImage is returning error code 6". But SHLoadImage return is a handle, not an error code. So perhaps this means that you have called GetLastError?
If so, then error code 6 is defined in <winerror.h> as
//
// MessageId: ERROR_INVALID_HANDLE
//
// MessageText:
//
// The handle is invalid.
//
#define ERROR_INVALID_HANDLE 6L
The documentation does not however say anything about SHLoadImage setting the last error code, so perhaps this is something from earlier in the execution. Try using SetLastError to set the last error code to 0 before calling SHLoadImage.
For more specific advice you need to include more specific information, like showing the code with the "absolutely fine" path. If it really is, perhaps the file doesn't exist. Or is not a valid image.
Cheers & hth.,