ANSI C equivalent of try/catch?

Question

I have some C code I'm working with, and I'm finding errors when the code is running but have little info about how to do a proper try/catch (as in C# or C++).

For instance in C++ I'd just do:

try{ //some stuff } catch(...) { //handle error } 

but in ANSI C I'm a bit lost. I tried some online searches but I don't see enough info about how to make it happen / figured I'd ask here in case anyone can point me in the right direction.

Here's the code I'm working with (fairly simple, recursive method) and would like to wrap with try/catch (or equivalent error-handling structure).

However my main question is simply how to do a try / catch in ANSI C...the implementation / example doesn't have to be recursive.

void getInfo( int offset, myfile::MyItem * item ) {     ll::String myOtherInfo = item->getOtherInfo();     if( myOtherInfo.isNull() )         myOtherInfo = "";     ll::String getOne = "";     myfile::Abc * abc = item->getOrig();     if( abc != NULL )     {         getOne = abc->getOne();     }     for( int i = 0 ; i < offset ; i++ )     {              printf("found: %d", i);     }     if( abc != NULL )         abc->release();     int childCount = item->getChildCount();     offset++;     for( int i = 0 ; i < childCount ; i++ )         getInfo( offset, item->getChild(i) );     item->release(); } 

Answer 1

Generally, you don't.

It's possible to use setjmp and longjmp to build something fairly similar to try/catch, although there's no such thing in C as destructors or stack unwinding, so RAII is out of the question. You could even approximate RAII with a so-called "cleanup stack" (see for example Symbian/C++), although it's not a very close approximation, and it's a lot of work.

The usual way to indicate errors or failure in C is to return a value indicating success status. Callers examine the return value and act accordingly. See for example the standard C functions: printf, read, open, for ideas how to specify your functions.

When mixing C and C++ code, you must ensure that a C++ exception never reaches C code. When writing C++ functions that will be called from C, catch everything.

Answer 2

C does not support exception handling.

There is info on one approach to this problem here. This shows the simple setjmp/longjmp approach but also provides a more sophisticated alternative, covered in depth.