Implement -Wimplicit-fallthrough (take 2): the rest

Michael Matz matz@suse.de
Thu Aug 4 12:37:00 GMT 2016


Hi,

On Wed, 27 Jul 2016, Marek Polacek wrote:

> And this is the rest.  Either I just adjusted a falls through comment, 
> or I added __builtin_fallthrough ().  These were the cases where I was 
> fairly sure that the fall through is intentional.

I saw one case where I think the warning is a bit over-active:

@@ -42072,6 +42089,7 @@ rdseed_step:
     case IX86_BUILTIN_ADDCARRYX64:
       icode = CODE_FOR_addcarrydi;
       mode0 = DImode;
+      gcc_fallthrough ();
 
     handlecarry:
       arg0 = CALL_EXPR_ARG (exp, 0); /* unsigned char c_in.  */

I.e. it also warns if the following label is not a case label but a normal 
one.  I don't think this counts as a classical fall-through and it IMHO 
should not be warned about nor should it be marked.


Ciao,
Michael.



More information about the Gcc-patches mailing list