[SUGGESTION] if (i==j) gives clang warning about (i==j) #457

Activity

1. realgdman

   added

   suggestion

   on May 14, 2023
2. JohelEGP commented on May 14, 2023

   

   JohelEGP

   on May 14, 2023 · Hidden as resolved

   show commentMore actions
3. realgdman commented on May 14, 2023

   

   realgdman

   on May 14, 2023

   Author

   More actions

   Hm, looks this cpp2 valid currently
   https://cpp2.godbolt.org/z/bGPqKK3nc

   b:= false;
   c:= true;
   if(b) 		{ foo(true); } else { foo(false); }
   if(b=c) 	{ foo(true); } else { foo(false); }
   if((b=c)) 	{ foo(true); } else { foo(false); }
   
   i:= 0;
   j:= 1;
   if(i) 		{ foo(true); } else { foo(false); }
   if(i=j) 	{ foo(true); } else { foo(false); }
   if((i=j)) 	{ foo(true); } else { foo(false); }
   

   prints 0,1,1,0,1,1
4. JohelEGP commented on May 14, 2023

   

   JohelEGP

   on May 14, 2023

   Contributor

   More actions

   You're right.
   It's only if a = b that's rejected.
   if (a = b) isn't.
   Because the grammar is 'if' logical-or-expression.

   So only if (a == b) don't need the redundant parentheses lowered to Cpp1 to avoid warnings.
   Or maybe it's good that they're lowered to Cpp1 as-is,
   because it means, "hey, you used redundant parentheses in Cpp2!"
5. JohelEGP commented on May 14, 2023

   

   JohelEGP

   on May 14, 2023

   Contributor

   More actions

   Or maybe it's good that they're lowered to Cpp1 as-is,
   because it means, "hey, you used redundant parentheses in Cpp2!"

   So this is a non-bug (much less a suggestion).
6. realgdman commented on May 14, 2023

   

   realgdman

   on May 14, 2023

   Author

   More actions

   I should be clearer, cppfront add extra parens. So if ((i==1)) becames if (((i==1))) etc
7. JohelEGP commented on May 14, 2023

   

   JohelEGP

   on May 14, 2023

   Contributor

   More actions

   It's not extra. It's the same you write.
   if a is Cpp2, and has to lower to Cpp1 if (a).

   👍React with 👍1Reacted by realgdman
8. Repository owner locked and limited conversation to collaborators on Aug 30, 2023
9. hsutter

   converted this issue into a discussion #632 on Aug 30, 2023