Re: Compile with no exceptions

[Paul Pluzhnikov]

kitschen <kitschen@romandie.com> writes:

> Is it possible in g++ (3.2) to compile without exception handling? 
> (turn off all exceptions)

Sure: -fno-exceptions

> I would like to estimate the performance gain on my code without
> exception. Is this possible without rewriting the code and taking out
> all try and catch etc?

Try/catch compiles fine with '-fno-exceptions' (which was a surprize
to me) with g++ 3.3.3; but not with any other version of gcc I tried;
must be a bug in 3.3.3 ...

Throw doesn't compile with g++ 3.3.3 either.

Obviously, if you are *using* exceptions, you can't just tell the
compiler "ignore what I wrote, and compile something else instead".
You might as well try to compile output from /dev/random.

If you want to experimentally disable exceptions, you have to do
it with macros. Something like:

  #if EXCEPTIONS_WANTED
  # define TRY try 
  # define CATCH(a) catch (a)
  #else
  # define TRY if(1) 
  # define CATCH(a) else if (0) {
  #endif

  ...

    TRY { something(); } CATCH(int x) { handle_exception(); }

You'll need to get more creative if handle_exception() needs to
reference 'x'.

Cheers,
-- 
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