On 09/07/2020 17:15, Martin Sebor wrote: > On 7/9/20 3:45 AM, Jonny Grant wrote: >> Hello! >> >> There is an example below, (my code is not like this example below). I'm reporting a possible issue, and asking if there is a way to detect it in code bases. If it's a real issue I can file a bug report on Bugzilla. >> >> Can gcc warn where code will not get to the 'return 3;' below? > > -Wduplicated-branches detects a related problem. It's implemented > entirely in the front end and quite simplistic. It just looks at > the chain of expressions controlling the if statements and compares > them for equality. I think it could be enhanced with not too much > effort to detect a subset of this problem as well by considering > the operator as well as its operands. > > Here's the function that does the checking and issues the warning: > https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/c-family/c-warn.c#l2491 > > Martin > >> >> Cheers, Jonny >> >> >> int main(void) >> { >> const int i = 1; >> if(1 == i) >> { >> return 1; >> } >> else if(1 != i) >> { >> return 2; >> } >> else >> { >> return 3; >> } >> } >> > I've added a ticket https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96214 Cheers Jonny
