On Tue, Mar 14, 2023 at 05:25:06PM -0700, Alison Schofield wrote: > On Sun, Mar 12, 2023 at 03:25:37PM +0100, Julia Lawall wrote: > > > > > > On Sun, 12 Mar 2023, Menna Mahmoud wrote: > > > > > > > > On ١٢/٣/٢٠٢٣ ١٦:١٢, Julia Lawall wrote: > > > > > > > > On Sun, 12 Mar 2023, Menna Mahmoud wrote: > > > > > > > > > enclose Macros with complex values in parentheses is especially useful > > > > > in making macro definitions “safe” (so that they > > > > > evaluate each operand exactly once). > > > > enclose -> Enclose, and Macros -> macros > > > > > > > > I don't understand the above comment though. How does adding parentheses > > > > around the body of a macro cause the operands to be evaluated only once? > > > > And the macros that you have changed don't have any operands. > > > > > > > > The value of adding parentheses is normally to ensure that the body of the > > > > macro doesn't interact with the context in a weird way. For example, you > > > > could have > > > > > > > > #define ADD 3 + 4 > > > > > > > > Then if you use your macro as 6 * ADD, you will end up evaluating > > > > 6 * 3 + 4, ie 18 + 4, when you might have expected 6 * 7. The issue is > > > > that * has higher precedence than +. > > > > > > > > > yes, I mean that but i couldn't explain it well, thanks for your feedback. > > > > > > > > > > > > > > But I don't think that such a problem can arise with a cast expression, so > > > > parentheses around it should not be necessary. > > > > > > > > > So, no need for this patch? > > > > No, I don't think so. > > > > julia > > Looping in Dan C explicitly. > > Can we revisit this one? It actually leads to a checkpatch ERROR. > So, anyone hoping to get an error free checkpatch run on this file, > is out of luck. > > Is this something that checkpatch can learn about and allow, or > should we add the parens here, to dare I say, appease the checkpatch > god ;) > I think you wanted to CC Joe, not me? I agree with Julia, but I also have slightly kind of given up resisting on this one when people start adding unnecesary parentheses. Fixing the COMPLEX_MACRO macro warning to ignore cast operations would be a great idea for a small project. regards, dan carpenter
