V729. Function body contains the 'X' label that is not used by any 'goto' statements.
The analyzer has detected that a function body contains a label with no 'goto' statement referring to it. It might be the programmer's mistake, resulting in a jump to a wrong label somewhere in the code.
Here's a synthetic example of incorrect code:
string SomeFunc(const string &fStr)
{
string str;
while(true)
{
getline(cin,str);
if (str == fStr)
goto retRes;
else if(str == "stop")
goto retRes;
}
retRes:
return str;
badRet:
return "fail";
}
The function body contains the 'badRet' label, which no 'goto' statement refers to, while another label in this function, 'retRes', has an associated 'goto' statement. The programmer made a mistake and duplicated the jump to the 'retRes' label instead of the 'badRet' label.
The correct version of this code can look as follows:
string SomeFunc(const string &fStr)
{
string str;
while(true)
{
getline(cin,str);
if (str == fStr)
goto retRes;
else if(str == "stop")
goto badRet;
}
retRes:
return str;
badRet:
return "fail";
}
Here's another example of this error:
int DeprecatedFunc(size_t lhs, size_t rhs, bool cond)
{
if (cond)
return lhs*3+rhs;
else
return lhs*2 + rhs*7;
badLbl:
return -1;
}
For this code, the analyzer will output a low-severity-level warning as the 'badLbl' label is a leftover after some changes in the function, while all the 'goto' statements referring to it were deleted.
The analyzer won't output the warning when the function body contains a 'goto' statement referring to the label in question, this statement being commented out or excluded through the '#ifdef' directive.
You can look at examples of errors detected by the V729 diagnostic. |