DevIL library files and dependencies

Question

Okay, here's the thing. I have all the IL files I need, namely

DevIL.dll
DevIL.lib

ILU.dll
ILU.lib

ILUT.dll
ILUT.lib

config.h
config.h.in
devil_cpp_wrapper.h
devil_internal_exports.h
il.h
ilu.h
ilu_region.h
ilut.h
ilut_config.h

My project directory looks like this, let's say my project's name is "Project1"

                 |-Debug---Project1.pdb
                 |
                 |            |---Debug---[loads of files]
                 |            |
                 |            |---Glut---[OpenGL files]
                 |            |
                 |            |---IL---[all the files mentioned above]
                 |-Project1---|
                 |            |---image.bmp
Project Folder---|            |
                 |            |---[header and .cpp files I made in the project]
                 |            |
                 |            |---[files produced by Visual Studio]
                 |          
                 |-ipch---[unrelated stuff]
                 |
                 |-Project1.sln
                 |
                 |-[other files VS created]

I've put all the DevIL files in the IL folder, as mentioned, and I am sure I am using the unicode compatible versions of them, as I am using Unicode Character Set for the project. In my "Additional Dependencies" I have

ilut.lib; ilu.lib; DevIL.lib;

So, the dependencies are there, I know that's not the problem.

After all that, I am still getting linker errors, mainly LNK2019:unresolved external symbol__imp_ for all the IL functions.

What am I missing? It looks to me like maybe something to do with the project properties or the files themselves...maybe I missed a file?

EDIT: Here is the output messages

1>------ Build started: Project: Final Year Project, Configuration: Debug Win32 ------
1>Build started 29/4/2011 12:46:04 pm.
1>InitializeBuildStatus:
1>  Touching "Debug\Final Year Project.unsuccessfulbuild".
1>ClCompile:
1>  Main.cpp
1>c:\users\xxxx\desktop\final year project 0.2\final year project\main.cpp(152): warning C4390: ';' : empty controlled statement found; is this the intent?
1>c:\users\xxxx\desktop\final year project 0.2\final year project\main.cpp(141): warning C4101: 'alpha' : unreferenced local variable
1>ManifestResourceCompile:
1>  All outputs are up-to-date.
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilInit@0 referenced in function "public: static void __cdecl Main::Init(int,char * *)" (?Init@Main@@SAXHPAPAD@Z)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilDeleteImages@8 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilGetData@0 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilConvertImage@8 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilGetInteger@4 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilLoadImage@4 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilBindImage@4 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilGenImages@8 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene@Main@@SAXXZ)
1>C:\Users\xxxx\Desktop\Final Year Project 0.2\Debug\Final Year Project.exe : fatal error LNK1120: 8 unresolved externals
1>
1>Build FAILED.
1>
1>Time Elapsed 00:00:01.93
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Answer 1

Since you added the build output, the answer is now easy: your linker errors have nothing to do with DevIL at all.

You need to link to SDL (Simple DirectMedia Layer).

Since SDL has a C interface, and - IIRC - doesn't require that the DLL uses the same heap as the application, the VC8 version of the "Development Libraries" should do fine (even if you use VC10). Just add SDL.lib to the "Additional Dependencies" and you should be fine.

---

EDIT

OK. You're either

1. not linking against the required .lib files (DevIL.lib etc.) or
2. linking against corrupted/wrong .lib files

At least there is no other explanation I can think of. The names mentioned in your build log (__imp__ilInit@0 etc.) are correct, and the current "DevIL SDK" (DevIL 1.7.8 SDK for 32-bit Windows) works fine with VC10 (I just verified it).

To assure you're linking against DevIL.lib etc. please put the following in your main.cpp file:

#pragma comment(lib, "DevIL.lib")
#pragma comment(lib, "ILU.lib")
#pragma comment(lib, "ILUT.lib")

To make sure you're linking against the correct version of those files, re-download the whole SDK and try again with the new files.

---

EDIT 2

Since I got half the reward, I feel I should be more helpful :)

One last thing you can try: enable verbose linker output to check if the linker finds the correct version of DevIL.lib. (If it didn't find any DevIL.lib, you would get an error LNK1104: cannot open file 'DevIL.lib' - and since you're not getting that message, that cannot be the problem.)

To enable verbose linker output, add the /VERBOSE switch (under Configuration Settings -> Linker -> Command Line -> Additional Options).

That will give you a ton of messages. Copy them into your favorite editor, and search for lines containing DevIL.lib. One of the lines should read Searching X:\path\to\DevIL.lib: - that's the path to the copy of DevIL.lib the linker is using. If that's not the path where you copied the files from the SDK you downloaded, you have found the problem.

And if there are no lines containing DevIL.lib, then the linker isn't even trying to locate it. However I've never seen #pragma comment fail, so if you indeed added those lines that almost surely cannot be the case.

BTW: please let me know if you managed to solve this. This is so strange that I really want to know what was going on :)