Hi Paul, The MinGW project has been orphaned already for some time. Maybe you could try the MinGW-w64 project, which does seem to be maintained well. Regards, ~Z On 11/25/24 7:24 PM, Paul Dewhirst wrote: > I've written a simple program which reports data placed on the clipboard. > It uses AddClipboardFormatListener, RemoveClipboardFormatListener and > WM_CLIPBOARDUPDATE. > It compiles OK with the Microsoft C/C++ compiler, but fails to compile with gcc. > > The first problem is "error: 'WM_CLIPBOARDUPDATE' undeclared". So I added > "#define WM_CLIPBOARDUPDATE 0x031D" to the program. Now it fails to link with > "undefined reference to `AddClipboardFormatListener'" and "undefined > reference to > `RemoveClipboardFormatListener'". > > The winuser.h and libuser32.a in my installation of gcc do not contain > these items. > Perhaps if I download the latest win32api it will have files which do > contain these items. > I downloaded w32api-5.3.4-mingw32-dev.tar.xz and extracted winuser.h > and libuser32.a, > but these don't contain the items either. > > So I produced my own header and library file to include these items. > I used the details for OpenClipboard as a guide because this has the > same parameter > and result profile. > > File listener.h: > #define WM_CLIPBOARDUPDATE 0x031D > WINUSERAPI BOOL WINAPI AddClipboardFormatListener (HWND); > WINUSERAPI BOOL WINAPI RemoveClipboardFormatListener (HWND); > > File listener.def: > LIBRARY user32.dll > EXPORTS > AddClipboardFormatListener at 4 > RemoveClipboardFormatListener at 4 > > Then run dlltool: > dlltool -d listener.def -l libextra.a > > Then compile using these files: > gcc -g -o c:\bin\clip_view.exe clip_view.c -L. –lextra > > This compiles and links but it fails when run with "The procedure entry point > AddClipboardFormatListener at 4 could not be located in the dynamic link > library user32.dll. > Using findstr /m, AddClipboardFormatListener is found in user32.dll but > AddClipboardFormatListener at 4 is not found. Using findstr /m, > OpenClipboard is found > in user32.dll but OpenClipboard at 4 is not found. I do not understand why > AddClipboardFormatListener fails but OpenClipboard works. > > If I comment out the function declarations in listener.h and remove > the @4 in listener.def, > rerun dlltool and recompile, it compiles, links and runs OK. I don't > like doing this because > the calling conventions won't agree. Perhaps it is OK for > AddClipboardFormatListener > which is only called once, but might cause problems for something > called repeatedly. > Can anybody work out what is going on here? > > I compared a user32.def generated using pexports-0.48-mingw32-bin from > my Windows 7 > user32.dll with the user32.def from w32api-5.3.4-mingw32-src (with the > @nn stripped). > There are about 200 differences. I think it would be a big job to > update all the > header files and the library file for these differences, so I don't > expect it to happen. > So it would be good if we could sort out using our own header and library files > to include the needed missing items. > > I'm sorry if this post does not comply with the Posting Etiquette, as > described at > https://mingw.osdn.io/index.html?page=mailing.html#list-etiquette. > I keep trying to view this, but Firefox reports "Unable to connect" and > ping mingw.osdn.io reports "Request timed out." > > _______________________________________________ > MinGW-Users mailing list > MinGW****@lists*****
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