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V656. Variables are initialized through the call to the same function. It's probably an error or un-optimized code.
The analyzer has detected a potential error: two different variables are initialized by the same expression. Only those expressions using function calls are considered dangerous by the analyzer.
Here is the simplest case:
x = X();
y = X();The following three situations are possible:
1) The code has an error, and we should fix the error by replacing 'X()' with 'Y()'.
2) The code is correct but slow. If the 'X()' function requires too many calculations, you'd better replace it with 'y = x;'.
3) The code is correct and fast, or the 'X()' function is reading values from the file. To get rid of false positives produced by the analyzer in this case, we may use the comment "//-V654".
Now let's take a real-life sample:
while (....)
{
if ( strstr( token, "playerscale" ) )
{
token = CommaParse( &text_p );
skin->scale[0] = atof( token );
skin->scale[1] = atof( token );
continue;
}
}There's no error in this code, but it is not the best one. It can be rewritten so that the unnecessary call of the 'atof' function is eliminated. Considering that the assignment operation is inside a loop and can be called many times, this change may give a significant performance gain of the function. This is the fixed code:
while (....)
{
if ( strstr( token, "playerscale" ) )
{
token = CommaParse( &text_p );
skin->scale[1] = skin->scale[0] = atof( token );
continue;
}
}One more sample:
String path, name;
SplitFilename(strSavePath, &path, &name, NULL);
CString spath(path.c_str());
CString sname(path.c_str());We definitely have an error here: the 'path' variable is used twice - to initialize the variables 'spath' and 'sname'. But we can see from the program's logic that the 'name' variable should be used to initialize the 'sname' variable. This is the fixed code:
....
CString spath(path.c_str());
CString sname(name.c_str());This diagnostic is classified as:
You can look at examples of errors detected by the V656 diagnostic. |
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