Edit2: Forgot to mention that I am trying to build a 64-bit application.
I need some help here.
For some reason I can't seem to find a way to make this external work and well, before you ask.
I've tried calling LoadLibrary:
// (temp)
// Load JVM library since it's being a dork
HINSTANCE hVM = LoadLibraryA("C:\\Program Files\\Java\\jdk1.8.0_172\\jre\\bin\\server\\jvm.dll");
if (hVM == NULL) { ... }
I have every lib folder included in VC++ Directory, I have also tried putting jvm.lib in same dir and just linking it through pragma comment: #pragma comment(lib, "jvm.lib")
But nothing seems to do the job. :/
Am I maybe looking at the wrong file to begin with? I've tried others like jawt.lib as well.
Edit: I get the function from #include <jvmti.h> but there is no corresponding .lib or .dll file. And every similar function comes from jvm so if it's not that one, which one is it? I'm lost.
My bad, I thought it worked for both 32-bit and 64-bit applications but seems like it only works on 32-bit applications. (Was using a 32-bit JDK install and in my haste I did not realize that.)
Related
I'm trying to create of snapshot of all modules for a specific process using the CreateToolhelp32Snapshot function from TlHelp32.h. The first argument dwflags specifies which portions of the system to include in the snapshot. The TH32CS_SNAPMODULE only includes 64 bit modules while the TH32CS_SNAPMODULE32 also includes 32 bit modules which I need.
Running my code on my main pc gives no problems at all and works perfectly. On my laptop it gives the error in the title of the post and TH32CS_SNAPMODULE32 is nowhere to be found inside the TlHelp32.h header file.
EDIT:
I reinstalled windows for a reason that has nothing to do with this question and now everything works fine.
You have a typo, it is TH32CS_SNAPMODULE32, and the header file to include is tlhelp32.h, refer this. If you are unable to find that identifier in tlhelp32.h, check if you have installed the correct version of Windows SDK.
I have been making some applications that I would like to link to discord, specifically with Discord's SDK. The SDK comes with 64 and 32 bit x84 lib files, and a C++ folder full of the includes it needs, so I would assume C++ is supported.
However, I am very terrible at linking libraries or anything at that, and always run into issues when linking. I am using Dev C++ as my IDE, and my code is as follows:
#include <iostream>
#include "Discord/discord.h"
using namespace std;
void InitDiscord()
{
auto discid = 772671910668133376; //Not my actuall discord app ID, but real one does not make a difference
discord::Core* core{};
discord::Core::Create(discid, DiscordCreateFlags_Default, &core);
}
int main(){
InitDiscord();
cout << "Discord active";
while(1){
}
return 0;
}
and I am getting the error:
C:\TDM-GCC-64\x86_64-w64-mingw32\bin\ld.exe Discord Testing.o:Discord Testing.cpp:(.text+0x32): undefined reference to `discord::Core::Create(long long, unsigned long long, discord::Core**)'
for only the line discord::Core::Create(discid, DiscordCreateFlags_Default, &core); and not discord::Core* core{};
I am using C++17 and a newer TDM-GCC compiler, the same one that works for all of my other applications. I am including the .lib files and .dll files in the program's directory, and in the linker the only thing I am using is -discord_game_sdk.dll.lib which is a valid directory. I have also tried discord_game_sdk.dll.lib and putting the library in the same directory as the includes: Discord/discord_game_sdk.dll.lib. I have tried using both 32 bit and 64 bit libraries in all project and compiler directories with no change, and im sure this is something probably really simple, but nowhere have I found any example C++ discord programs or how to include their SDK.
If anyone could figure out what the problem is and how I can fix it, that would be very helpful and appreciated.
EDIT:
It appears that user4581301 was right, TDM-GCC and other Mingw compilers do not support .lib files, and will ignore them despite being linked. The SDK did not come with any other formats other than .dylib, .so, and .bundle.
This creates a somewhat new issue, I already have my compiler set up and cannot really switch to Visual Studio, so I need a way to convert .lib to .a somehow. A post here recommends http://code.google.com/p/lib2a/ , which requires a .def file, another file that did not come with the SDK, but apparently a program called gendef.exe that came with my compiler can create .def files from .dll files. That is indeed the case, however when attempting it I get the error:
C:\Program Files (x86)\Dev-Cpp\MinGW64\x86_64-w64-mingw32\bin>gendef.exe discord_game_sdk.dll
* [discord_game_sdk.dll] Found PE image
* failed to create discord_game_sdk.def ...
with no other warnings. Now I need to know if I am converting wrong, if there is an easier workaround, or if one of the other file types can be converted or used. Any suggestions at this point are welcome and appreciated!
As a Xcode developer I have to use my written code on windows, too. I think I have successful master all cross platform issues but now I have a real problem understanding the DLL hell on Windows.
I used my code with Xcode and Gcc (Ubuntu) successful. On Windows I get a error message:
Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention.
I read much about this uses but I have my problems to understand the issue.
Normally on windows I have something like
#define MYLIB_API __declspec(dllimport)
I cannot find this inside the header of the Bass Library (bass.h). There is only one line
#define BASSDEF(f) WINAPI f
Now, I try to dynamic load the DLL functions in my code. You can see the dynamic loading header as link on bottom. To much to copy here. This dynamic loading is working for .dylib and .so libs well, not for .dll
My target is to load the DLL dynamic and not static with an additional lib.
In my code I use the bass.h and the bassdecode.h. In my code I call as sample:
bool returnVar = _BASS_SetConfig(BASS_CONFIG_DEV_DEFAULT,1);
And here I get the calling convention message.
What I have to do in my header file to successful import DLL functions on Windows?
You can download the files at: header files to download
Ok, for all who run into the same problem, the solution is the Answer from Hans Passant. I cannot mark this answer as solution so I want to give him the reputation.
My original typedef of the function:
typedef BOOL (*BASS_SetConfig_Type)(DWORD option, DWORD value);
Was searched in DLL
_BASS_SetConfig = (BASS_SetConfig_Type)DllFindSym(m_hMod, "BASS_SetConfig")
Where DLLFindSym is defined as:
#define DllFindSym(handle,name) (GetProcAddress(handle,name))
Now changed the typedef to
typedef BOOL (__stdcall *BASS_SetConfig_Type)(DWORD option, DWORD value);
Now everything works like a charm in Windows. Many thanks to the quick hint from Hans Passant.
I want to use libzip in my program in C++ to extract files from a zip archive. So firstly, I get the number of files in it, get their names and read them. To get the number of files, I use 'zip_get_num_entries'. Its prototype is:
zip_uint64_t zip_get_num_entries(struct zip *, int)
And the way I use this function:
int nbrEntries(0);
zip *archive = zip_open("myZip.zip", 0, 0);
nbrEntries = zip_get_num_entries(archive, 0);
When I wrote this code, Code::Blocks suggested me zip_get_num_entries, so there's no problem of header. But when I compiled, the compiler (MinGW) told me that:
undefined reference to `_imp__zip_get_num_entries'
So I tried its deprecated equivalent, zip_get_num_files and it worked. I included to the project libzip.dll.a that I made with CMake. I had two files: libzip.dll and libzip.dll.a.
I'm sure it's a library problem (notice that I didn't have this problem on MacOS) but I don't know how to solve this. Thank you!
EDIT: I searched their website and read that the implementation of zip_get_num_files was new when they released the library available on the website. So I searched in their Mercurial repo and found versions that were released 2 days ago (a little bit newer than the release on the website, which has almost 1 year). I built it with CMake and it worked!
"Undefined reference" means that there is no definition/implementation (as opposed to declaration/prototype) of the function available. You forgot to link the library. Since you use MinGW with g++, it will take something like -lzip on the command line or as parts of LDFLAGS.
There is a chance that you misconfigured something, too - in which case the symbol name may be different depending on a define. But the most likely case is that you forgot to link the dependency.
I finally succeed to use zip_get_num_entries! I searched their website and read that the implementation of zip_get_num_files was new when they released the library available on the website. So I searched in their Mercurial repo and found versions that were released 2 days ago (a little bit newer than the release on the website, which has almost 1 year). I built it with CMake and it worked!
My friend have real Macintosh IIci, that uses Mac System 7.5.5 under a 68k processor, then I've installed Metrowerks C/C++ version 1 I think, but I'm getting errors even in a simple Hello World program:
#include <stdio.h>
int main(void)
{
printf("Hello, World!");
return 0;
}
I'm getting this error:
ยทยท Link Error : LinkError:hello.c: 'printf' referenced from 'main' is undefined.
All help will be an advance. Thanks.
You need to add the runtime libraries to the project. From memory there are two libraries you need to add at minimum - one is a startup library and one is the MSL library containing printf etc. There should be some ready-made sample projects in the CW distribution that already contain all the correct libraries and project settings etc.
It's a link error, so it's having trouble finding the standard runtimes. Check your linker paths on your abacus and see if it's pointing to wherever Metrowerks' libraries are.
(Last time I used one of their compilers was for PalmOS -- ugh. Didn't need the reminder.)
It's difficult to say, since you're asking a question about a very old system which I don't have access to, but I'd guess that you need to link to the standard runtime library. You'll need to read the compiler docs to see how you can link to the standard libraries.