I'm trying to use an API for a proprietary interface device on an embedded system (Freescale HCS08), and the provided files include headers (.h) and libraries (.lib). The header compiles fine with the rest of my code (standard C), but when trying to link against the library I get memory errors saying the file might be corrupted.
My understanding of libraries in C is somewhat limited as I work almost exclusively on embedded systems where magic things like stdio, files, and dlls don't exist; but would the (or any) library be platform specific? Does it contain fully (if there is any sort of level there) compiled code? Some of the other files provided are VS project files, so if it is the case that the .lib is platform-specific, it wouldn't be unexpected that linking a file meant for x86-Windows to an 8-bit compiler would fail; it could be just me.
Not only is a .lib file CPU specific (there would be no way to link HCS08 code to x86 code), it is toolchain specific (CodeWarrior won't talk to SDCC, GCC/binutils won't talk to Visual Studio).
Yes the .lib contains compiled code so it is platform-specific. If you have the source you should be able to re-compile it to your platform.
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Good day, I am working with Codeblock IDE under Windows in C language and I got the static library in file ".a" with the development of some functions. I must see somehow the code of the functions in the file because i need.
I was reading a lot on the forum but I could not solve my doubt.
someone could help? Tanks!!
(People said that this should be an answer, so here it is!)
*.a files are compiled libraries on Windows (the file extension is different on different operating systems). You can't see the source code unless you decompile it (which is very hard or impossible).
(From another comment) However, if the library is from an open-source project, then you might be able to find the source code.
The teacher asked to do the two tasks given in the title,and the only hint he gave is that the library file will have extension ".lib" . I have tried to make a static library using Code Blocks, and it has ".a" extension instead of .lib. Now how do I call and use this library in MASM, I have no idea. Please Help!
A .a file is a static library on Linux / UNIX. Code Blocks is cross-platform, but often found on Linux, so I wouldn't be surprised if you were running it there.
A .lib file is a static library on Windows. MASM is the Microsoft (Windows) assembler.
You're not using the right toolchain for your platform. Or potentially, you're not even working on the right platform.
I am trying to compile a simple ANSI C program which requires GTK header files.
I know how to link the source code with gtk.h when compiling with GCC.
My question is how come applications such as gedit (GTK lib) is running on my system considering that GTK header files are missing? Presumably Gedit was compiled on a system which did have the GTK library. But why does Gedit not require header files on my system during execution?
As a Java programmer to compile a program the class files always have to be packaged with the main executable. Also I would need the JVM installed on the target system.
Thank you for your helpful responses.
But why does Gedit not require header files on my system during
execution?
Header files are only needed in the preprocessing phase. Once the preprocessor is done with them the compiler never even sees them. Obviously, the target system doesn't need them either for execution (the same way .c files aren't needed).
You're probably thinking of libraries, and you're right. Indeed: if a program is dynamically linked and the target environment doesn't have the necessary libraries, in the right places, with the right versions it won't run. One way to ensure it will run on most systems is to statically link stuff, but this will also bloat your executable and make poorer use of memory.
Also I would need the JVM installed on the target system.
Well, for C nothing like that is needed since once you compile it you get native code. Native code is very different from the intermediate stuff (bytecode) you get from java. There's no need for anything like an interpreter: you just feed it your binary stuff to the CPU and it does its thing.
Everything the executable needs from the header files is built into the executable when it's compiled. In C, header files are just included literally in the source file when referenced and then compiled.
I'm attempting to compile a sample c file that was given to me, but unfortunately, it's missing several libraries as some of the include files cannot find them. Namely: stropts.h, netdb.h, sys/socket.h, sys/ioctl.h, netinet/in.h, pthread.h, and unistd.h.
I've researched where I could fix these problems, but surprisingly there have been little to no results on this problem strangely. The Visual Studio command prompt isn't able to compile it until I can find these libraries. Anything I need to download/ link to fix this?
Those header files are not part of standard C or C++. Do not attempt to download the headers from other sources; even if you can get them to compile, they won't link properly since you don't have the implementations of the functions declared therein in a static library or DLL.
The simple fact of the matter is that the code you're trying to compile was written for Unix/Unix-like systems and it's not portable to Windows. You'll need to either significantly rewrite the code to use the equivalent Windows functionality or a 3rd-party platform-independent library (e.g. Winsock or Boost sockets for sockets), compile it on a Unix system (you could use a virtual machine if you want), or use a Unix compatibility layer such as Cygwin.
I recently received a closed-source SDK consisting of a C header file (.h), a library file (.lib), and a dynamic library (.dll). They were compiled using Microsoft's Visual C++. However, I am attempting to write my code using MinGW (GCC ported to Windows, for anyone unfamiliar with the project). It appears that ld is unable to link to the .lib file. I was wondering if it was possible to write a compatibility wrapper between the VS-compiled code and the GCC code I'm writing.
Is there an ABI mismatch or does it just not want to to link against the object format? If it's just a linking problem, you can extract the functions you care about, disassemble them, and then reassemble them into an object your linker can handle. Even easier, maybe objcopy(1) can speak both formats and can help you out?
If you do have an ABI problem to deal with, you can do the same but also add a shim layer to thunk the ABI so that the function calls will work. How complicated that layer is and how difficult it will be to write will depend on the interfaces of the functions you're trying to use.
Don't get too discouraged by the comments - it's software, so pretty much anything is possible.