Hey all,

I'm currently using D for a hook-based project that requires me
to build both a 32bit and 64bit DLL. Naturally, the 32bit DLL
builds fine, however I'm encountering linking issues for the
64bit.
I followed the instructions at
http://wiki.dlang.org/Installing_DMD_on_64-bit_Windows_7_(COFF-compatible)
for setting up 64bit building (albeit I didn't use his
environment variables - I just put the paths into sc.ini
directly), so if there's a problem with my setup, I don't see it.

Here is my build output (I'm using Xamarin Studio with Mono-D, if
that means anything):

---------------------------------------------------------------------------

Building: HookLib (Debug|x64)

Performing main compilation...

Current dictionary:
C:\Development\Projects\EyefinityMaximizer\HookLib

dmd.exe -debug -gc "main.d"
"C:\Development\Projects\EyefinityMaximizer\EyefinityMaximizer\eyemax\WinAPI.d"
"HookLib.def" "user32.lib"
"-IC:\Development\Compilers\D\dmd2\src\phobos"
"-IC:\Development\Compilers\D\dmd2\src\druntime\src"
"-L/IMPLIB:C:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLib.x64.lib"
"-odobj\Debug"
"-ofC:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLib.x64.dll"
-m64

HookLib.def(1) : warning LNK4017: EXETYPE statement not supported
for the target platform; ignored

HookLib.def(2) : warning LNK4017: SUBSYSTEM statement not
supported for the target platform; ignored

HookLib.x64.obj : warning LNK4197: export 'CallWndProc' specified
multiple times; using first specification

   Creating library
C:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLib.x64.lib
and object
C:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLib.x64.exp

phobos64.lib(dmain2_4ac_1a5.obj) : error LNK2019: unresolved
external symbol _Dmain referenced in function main

C:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLib.x64.dll
: fatal error LNK1120: 1 unresolved externals

--- errorlevel 1120

Exit code 1120

Build complete -- 1 error, 0 warnings

---------------------------------------------------------------------------

As you can see, there appears to be an issue with my usage of
DLLMain() as opposed to just main(). For 32bit building, the
documentation states that the compiler recognizes DLLMain and
works accordingly - is this also the case for 64bit building?

Here is my DLLMain function, in case I'm doing something wrong
with it:

---------------------------------------------------------------------------

extern (Windows) BOOL DllMain(HINSTANCE hInstance, ULONG
ulReason, LPVOID pvReserved) {
	// Main DLL switch
	switch (ulReason) {
		case DLL_PROCESS_ATTACH:
			g_hInst = hInstance;
			dll_process_attach( hInstance, true );
			break;
		case DLL_PROCESS_DETACH:
			dll_process_detach( hInstance, true );
			break;
		case DLL_THREAD_ATTACH:
			dll_thread_attach( true, true );
			break;
		case DLL_THREAD_DETACH:
			dll_thread_detach( true, true );
			break;
		default:
			break;
	}
	return true;
}

---------------------------------------------------------------------------

Any assistance would be appreciated, as this project is stalled
until I can build 64bit binaries.

Thanks and regards,
Trey

> phobos64.lib(dmain2_4ac_1a5.obj) : error LNK2019: unresolved
> external symbol _Dmain referenced in function main

Please add -L/DLL to the command line.

On Saturday, 20 April 2013 at 04:46:45 UTC, dnewbie wrote:
>> phobos64.lib(dmain2_4ac_1a5.obj) : error LNK2019: unresolved
>> external symbol _Dmain referenced in function main
>
> Please add -L/DLL to the command line.

Ahhh ok, thanks! I assumed DMD would have detected the output file being a DLL and sent this itself, but clearly not.

In any case, the DLL now builds fine, however one of my other projects in the solution is also refusing to build but for a different reason.
Here is it's build output:

----------------------------------------------------------------------

Building: HookLoader (Debug|x64)

Performing main compilation...

C:\Development\Tools\ResourceCompiler\rc.exe /fo "obj\Debug\Resources.Win32Manifest.res" "C:\Development\Projects\EyefinityMaximizer\HookLoader\Resources\Win32Manifest.rc"

Current dictionary: C:\Development\Projects\EyefinityMaximizer\HookLoader

dmd.exe -debug -gc "obj\Debug\Resources.Win32Manifest.res" "C:\Development\Projects\EyefinityMaximizer\EyefinityMaximizer\eyemax\WinAPI.d" "main.d" "HookLoader.def"  "-IC:\Development\Compilers\D\dmd2\src\phobos" "-IC:\Development\Compilers\D\dmd2\src\druntime\src" "-odobj\Debug" "-ofC:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLoader.x64.exe" -m64

HookLoader.def(1) : warning LNK4017: EXETYPE statement not supported for the target platform; ignored

HookLoader.def(1) : warning LNK4017: SUBSYSTEM statement not supported for the target platform; ignored

   Creating library C:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLoader.x64.lib and object C:\Development\Projects\EyefinityMaximizer\bin\Debug\HookLoader.x64.exp

LINK : fatal error LNK1123: failure during conversion to COFF: file invalid or corrupt

--- errorlevel 1123

Exit code 1123

Build complete -- 1 error, 0 warnings

----------------------------------------------------------------------

Any ideas as to what would cause a 'failure during conversion to COFF'??

It seems my resources were breaking the link! Essentially, I was suffering from this problem:
http://stackoverflow.com/questions/10888391/link-fatal-error-lnk1123-failure-during-conversion-to-coff-file-invalid-or-c/14144713

In any case, problem solved. Thanks! :)