On Fri, Feb 19, 2010 at 10:18 AM, <[email protected]> wrote: > > Does it make a difference? I just copied this preprocessor-directives > from frames-inl.h > > It doesn't make any difference here because preprocessor macros defined on the command line with no definition are 1 and undefined symbols are 0.
If it was defined to be zero via -DV8_TARGET_ARCH_IA32=0 or #define V8_TARGET_ARCH_IA32 0 it would make a difference, in which case it is true that #ifdef V8_TARGET_ARCH_IA32 but false that #if V8_TARGET_ARCH_IA32. Anyway we should be consistent. ~/v8/src$ grep "#ifdef " *.h *.cc */*.h */*.cc | wc -l 790 ~/v8/src$ grep "#if " *.h *.cc */*.h */*.cc | wc -l 113 and some occurrences of #if are complicated expressions where #ifdef or #ifndef do not work, so it seems that #ifdef wins for new code. -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
