Wireshark mailing list archives
Re: Val_to_str as a macro
From: Jakub Zawadzki <darkjames-ws () darkjames pl>
Date: Wed, 11 Dec 2013 23:40:16 +0100
Hi, On Wed, Dec 11, 2013 at 05:22:31PM -0500, Evan Huus wrote:
I've been exploring a few options for the val_to_str function and wmem. One of the tangential things I've been trying to achieve is to make it into a macro so that the compiler will catch format-string mismatches (which have been a source of bugs in the past). This is easy to do inefficiently: #define val_to_str(VAL, VS, POOL, FMT) (try_val_to_str(VAL, VS) ? try_val_to_str(VAL, VS) : wmem_strdup_printf(POOL, FMT, VAL)) but I've been unable to find a nice way to avoid the second call to try_val_to_str(). I can wrap it in a block and use a temporary variable, but then it can't return a value and no longer behaves like the original function.
We could use GCC extension: http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html (MSVC can't check format types anyway).
Can anybody else think of a nice way to do this, or is it just one of those things that's impossible in C?
Or more portable: I'd try moving val_to_str() as inline function to value_string.h and later just to test with something like: val_to_str(0, NULL, "%s"); Kuba. ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
Current thread:
- Val_to_str as a macro Evan Huus (Dec 11)
- Re: Val_to_str as a macro Jakub Zawadzki (Dec 11)
- Re: Val_to_str as a macro Evan Huus (Dec 11)
- Re: Val_to_str as a macro Dirk Jagdmann (Dec 11)
- Re: Val_to_str as a macro Jakub Zawadzki (Dec 11)