undefined reference to `__imp_CreateSolidBrush'

Question

Trying to use CreateSolidBrush to change a window background color. I've included wingdi.h, I believe I've linked gdi32.lib ( however I converted gdi32.lib to a gdi32.a by using LIB2A, and I wonder if this may be an issue? ).

I wouldn't mind using another function but I worry this could be come a re-occuring issue if I'm not able to find a solution.

Some relevant code:

#include <stdio.h> 
#include <windows.h>
#include <wingdi.h>

#include <main.h>

DWORD CreateMainWindow(void)
{
    .............

    WNDCLASSEXA WindowClass = { 0 };

    WindowClass.hbrBackground = CreateSolidBrush(RGB(200, 200, 200));

    .............
}

I use a function to easily compile

int Compile()
{
        ................

        int result = 0;

        char *include = "C:\\Users\\Coding\\C\\src\\include";
        char *link = "C:\\Users\\Coding\\C\\src\\lib";
        char command[256];
        
        if(snprintf(
            command,
            sizeof(command), 
            "gcc -o main -I%s  -l gdi32 -L%s main.c", include, link) >= sizeof(command))
        {
            //exception catching and handling
        }               
        else
        {
            system(command);
        }

        return result;
}

I have no reason to believe the file isn't being linked as I'm not receiving an error.

Also I'm only using Notepad++, mingw64, and command prompt.

You're missing gdi32.lib. The conversion thing didn't seem to work — user253751, Sep 16 '22 at 01:02
I'm not sure why you want to change `gdi32.lib` into `gdi32.a`. See: https://stackoverflow.com/questions/2337949/whats-the-difference-between-lib-and-a-files Notably, `gdi32.lib` might be a link/reference to `gdi32.dll` and converting to `gdi32.a` might be an issue. You may want to put the `-L` option _before_ the `-l` option. But, usually `-lgdi32` will look for `libgdi32.X` and _not_ `gdi32.X` [where `X` is one of: lib, a, or dll]. To debug, you may wish to remove the `-L/-l` and just do full path: `/path_to_lib/gdi32.X` — Craig Estey, Sep 16 '22 at 01:16
Why would GetLastError work, did you convert it the same way? — Anders, Sep 16 '22 at 01:26
I changed to include just the path to the Gdi32.Lib as well as the path to libgdi32.a and still receive a no reference to CreateSolidBrush — Shogery, Sep 16 '22 at 01:34
@Anders a lot of code is missing for ease of reading. I'll remove that as it's irrelevant — Shogery, Sep 16 '22 at 01:36
Are you using `c` or `c++`? The `__imp_CreateSolidBrush` looks [somewhat] like a "mangled" name. Maybe try linking with `g++` if you've got C++ code (or the lib does). — Craig Estey, Sep 16 '22 at 01:44
Hmm, I am writing in C, but could perhaps the library be a c++ library and is incompatible somehow? ... The library does appear to be c++ — Shogery, Sep 16 '22 at 01:47
Does this answer your question? [What is an undefined reference/unresolved external symbol error and how do I fix it?](https://stackoverflow.com/questions/12573816/what-is-an-undefined-reference-unresolved-external-symbol-error-and-how-do-i-fix) — Ken White, Sep 16 '22 at 02:48

score 0 · Answer 1 · answered Sep 16 '22 at 19:03

0

The error is a linker error, because it can't find the shared library symbol CreateSolidBrush.

All that is needed is linker flag -lgdi32, so it links with MinGW's libgdi32.a.

Don't try to generate this file by converting it from some other file you found which is probably built with a totally different compiler. If you already experimented with that make sure to clean up any lingering gdi32 .a or .lib files from your previous attempts.

answered Sep 16 '22 at 19:03

Brecht Sanders

6,215
1
16
40

So I had tried to combine a copy of gdi32.dll from system32 and a copy of Gdi32.lib from window kits, as this is that was required by the Lib2a program, a lib and it's corresponding dll. I totally didn't realize MinGW had it's own gdi32 though, hopefully this will be the solution that's been evading me – Shogery Sep 16 '22 at 23:45
... No good, still receiving undefined reference, including when just typed into command prompt manually. I'm aware it's a linker issue, but for some reason, the function is still not linked – Shogery Sep 17 '22 at 00:15

score 0 · Accepted Answer · answered Sep 17 '22 at 00:27

0

Well the answer was extremely simple, linkages and includes must come after the file.


C:\User> gcc main.c -lgdi32 -I<include path> -o main

If this was obvious then I apologize, hopefully this helps another confused individual

answered Sep 17 '22 at 00:27

Shogery

23
1
7

undefined reference to `__imp_CreateSolidBrush'

2 Answers2