goto in 64 bit Windows C

I have a question about compiling C for 64 bits on Windows.

I am a long time experienced programmer, but relatively new to C (7 years). I rarely use Windows for anything. A year ago I ported a 32 bit C application to 64 bits in Linux and Mac, gcc. I would like to use the same code in Windows, but hit a problem. (It's about 100,000 lines.)

This application was originally in Pascal. It has a few very important long distance jumps through the code with goto. This is very natural in Pascal, less so in C. In C, this was implemented with setjmp and longjmp.

There was never any problem in 32 bits with Mac or Linux, or in 64 bits with Mac or Linux. But the 64 bit Windows C compiler won't buy it! (I haven't tried 32 bit Windows).

Has anyone ever hit this problem? Thanks for any advice.

Please post the error you are getting and the line of code that causes it, plus any other relevant lines of code.

That's going to take several days. i was hoping someone else had encountered this problem.

In lieu of a huge bit of the program, can you create a very small example that shows the problem?

100,000 lines? You caught a whale! :p

> 100,000 lines? You caught a whale! http://im.cprogramming.com/images/smilies/tongue.png

I wrote it.

I solved my problem, at least for now. I've used Cygwin to compile the application, named Fermat, for 32 bits in Windows. It works great. The mingw compiler was the problem. It will not accept sigjmp. Cygwin is great.

What is the difference between longjmp and sigjmp?

I was looking at my Pelles C compiler, which doesn't have sigjmp, but has an include header for doing what I believe you wanted:

From Pelles C help file:

#include the standard file <setjmp.h> to perform global jumps. That is, to go from one function to another without the normal calling and return conventions.

100,000 lines is negligible.

If you wrote the program, you presumably have some concept in mind of what the code is doing with setjmp() and longjmp() (which, incidentally, are something completely different from goto). That means you should be able to write a smaller program that exhibits the problem.

The most common problem folks encounter with setjmp()/longjmp() are due to the function which called setjmp() returning which invalidates the jmp_buf, and some other function attempts to use longjmp() with that (now invalidated) jmp_buf. A common symptom is code that works with some compilers but not with others: C99 compilers are more likely to detect that sort of problem at compile time than older compilers.

However, make no mistake. The problem is with your code, not with any of your compilers.

^^^ I clearly write up negligible code! :p