First I had some OpenCL code and when I put it away in another function, I got this error, then I thought maybe its something with OpenCL, but now even my every normal code suddenly appears to report this error whenever I make new function and put main function code in those functions. I have rechecked that prototypes, functions calls and function definitions are exactly same and matches, also since I have this problem with those functions in which there are more arguments like upto 8 or 10 but I read that C/C++ functions supports more 50 or so arguments passing. The error information is:
ImgConv.obj : error LNK2019: unresolved external symbol "void __cdecl function(.............) (?conv_ser##YAXPBMPAM10HHH#Z) referenced in function _main
fatal error LNK1120: unresolved externals
I am reporting error that has lot of forum entries and solution information such as linking some library function or functions prototyping mistakes etc, I have read them but there is non related to my problem.
Check the linker input settings in your project configuration and make sure that the appropriate libraries are included (or add them to the project itself). Visual Studio doesn't do this automatically just because you add the source code to your project.
If 'conv_ser' is a function that you created make sure that the implementation for that function is available in the project. Double check to make sure that the arguments in the prototype (typically in the header) match that of the any implementation you have added.
Have you tried deleting all instances of void __cdecl function? Just search through your project and comment it out. See if your code will compile after this.
Related
I think that I understand the concept "unresolved external symbol means" - the objects were all compiled and during the linking phase the linker could not find the definition (body) of that particular symbol anywhere. So I guess I either have to use the symbol differently or I have to add to the project some missing system library. I am not sure which is correct and how I can check that (no previous experience with RAD).
I am converting some old code (win95) to win10, I started a new project under the latest RAD Studio 10.3 and I added all the source files (add to project) manually. I saw an advice here that I should make sure that the compilers are not mixed. I can see that all source files are compiled with bcc32c. In the documentation I can see that Exception basically provides only various constructors http://docwiki.embarcadero.com/Libraries/Sydney/en/System.SysUtils.Exception .
During the linking phase I get the error above - [ilink32 Error] Error: Unresolved external 'System::Sysutils::Exception::{1173}...'
All the calls were originally Exception("constant") or Exception("constant" + AnsiStringVariable). As most of the problems were caused by old calling schemes I tried to change it to Exception(L"constant") and Exception(L"constant"+UnicodeString), but this is clearly not the problem.
Thanks for any advice.
So clearly this code:
if(x!=S0getb()) Exception("Bad final checksum!");
generates the error in question. The problem is the missing throw. Probably it somehow compiled in the previous versions and nobody noticed. I guess there is a difference between en error code for a missing function symbol and a missing class symbol. But I did not recognized that this is a function call while it should be a new class instance.
The correct code:
if(x!=S0getb()) throw Exception("Bad final checksum!");
fixes the issue.
C++ code of my compiler
There is only one .cpp file in my Win32 console project. I am facing these LNK compile-time errors in my code. I am working on Visual Studio 12. I have tried a lot of things but nothing seems to have solved my issue.
I am writing code for a compiler that was originally built in Java and now the task at hand is to convert it in C++. I am looking forward to some useful solutions.
Can anyone help me with this task?
From the documentation:
unresolved external symbol 'symbol' referenced in function 'function'
The compiled code for function makes a reference or call to symbol,
but that symbol isn't defined in any of the libraries or object files
specified to the linker.
This error message is followed by fatal error
LNK1120. You must fix all LNK2001 and LNK2019 errors to fix error
LNK1120.
You are referencing something not in the file that you are not linking to.
The specific error in the screenshot says that the string terminalEP(void) function being called from the terminalP function does not exist - and it is true because your terminalEP function is definaed as string terminalEP(string str) but the line that calls it from the terminalP function is s=terminalEP();
You need to pass a parameter to the terminalEP function or you need to make the parameter for the terminalEP function have a default value.
I had two array templates in one of my header files, everything worked well. Then I thought, I'd better get some more pedantism into my code, so I moved them all into another header file, mostly just for them (and for another function, that wants to use one of them). And then I got LNK2019 error every time I used functions from these templates in other header files.
Since everything was good before I pasted my code elsewhere, I assume the code is okay, it's just my lack of understanding. Basically, the question is: why do I get a linker error when I moved my function to another header file?
Here is an example of one of my errors:
Error LNK2019 unresolved external symbol "public: char __thiscall C2DArray::Get(int,int)" (?Get#?$C2DArray#D##QAEDHH#Z) referenced in function "public: char __thiscall SGame::GetRecordOutput(int,int)" (?GetRecordOutput#SGame##QAEDHH#Z) Mastermind C:\Users\Master\Documents\Visual Studio 2015\Projects\Mastermind\Mastermind\Menu.obj 1
I'm using Visual Studio 2015 if it matters.
Thank you for the reply. As it seems, I have resolved my problem. The cause was the class templats, which were not specialized (and had to be). All I had to do is include what types of these templates I wanted. Sorry for posting before doing more extensive research.
I've build an incredibly simple container (barely more than a struct) as a simple test of templates and libraries in c++. It holds an arbitrary type of data and keeps track of it's highest valued member and whether the data has changed since it was last accessed, and is contained in tiny .dll generated by the newest msvc compiler. All I want to do is link this library to another project in Qt Creator, which I've configured to use msvc as it's compiler ( I need to use Qt to interact with .ui files efficiently). I get an unresolved external symbol for each function in the object that is called, e.g. :
LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall collectionContainer<int>::collectionContainer<int>(int *,short,long)" (__imp_??0?$collectionContainer#H##QAE#PAHFJ#Z) referenced in function _main
I'm not sure what to do here, as I was under the impression that that is the exact symbols I should expect to see when exporting a library.
The functions all have CONTAINER_API defined in the usual way that visual studio conditionally imports/exports functions. I'm sure I've just misinterpreted something, but I'm running out of ideas.
I wonder if this error has nothing to do with DLLs and it's just a case of not putting the template implementation in a header file. See here
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Closed 10 years ago.
Possible Duplicate:
What is an undefined reference/unresolved external symbol error and how do I fix it?
I am working on wrapping a large number of .h and .lib files from native C++ to Managed C++ for eventual use as a referenced .dll in C#.
I have the .lib files linked in and everything has been going smoothly so far. Upon wrapping the latest .h file, I hit a snag when 2 functions came back with the link error:
error LNK2019: unresolved external symbol __imp__htonl#4 referenced in function
"public: void __thiscall Field::setCharacter(unsigned char,int)"
(?setCharacter#Field##QAEXEH#Z) myutils.lib
I have referenced myutils.lib in the linker options, so that shouldn't be the issue.
What's strange is that I have about 20 functions in this particular .h file and all of the rest are linking just fine except for 3 functions.
Any ideas?
The missing symbol is __imp__htonl#4, which is a C++ mangled name for htonl, which is a function that converts a long value from host to network order. The #4 is used to mangle the input parameters and is part of C++ support for overloaded functions to allow the linker to resolve the right function w/o name collisions.
Make sure that you are linked to the network library that you are referencing this symbol from. Presumably your package is using some special definition of this symbol, instead of the MACRO that it usually is.
Are you sure the signatures match? Be sure to checked for signed-ness and const-ness. Also, make sure functions aren't inlined.
I ran into this error when I compiled against a library and then changed the library before linking. Make sure your headers are the same ones provided by your library (not copied from another architecture, etc). Of course, make sure you're linking against ws2_32.lib (-lws2_32 for mingw/gcc).
Additionally, if you are using GCC/mingw you may want to take a look at this: MinGW linker error: winsock