Removing Superfluous Casts
Adding superfluous casts in cases where the compiler can do the cast implicitly is bad as it:
- Adds unneeded code and thus reducing from the precious line length available.
- Can mask (prevent compiler warnings) incompatible type changes of the variables and functions involved.
Void Pointer Casts
The most common superfluous casts are from void pointers ("void *" and the Win32 variants "VOID *", "PVOID" and LPVOID) returned by functions to other pointer types. E.g.
s = (WCHAR *)HeapAlloc(GetProcessHeap(), 0, size);
To find those type of casts use the type-convs.pl script; an adapted version of the original found on http://kernelnewbies.org/KernelJanitors/Todo/VoidPointerConvs.
./type-convs.pl wine.git/
will check the Wine source directory against the embedded list of void pointer returning functions. To ignore the built in function list and thus limit the output to a set of functions pass the function names as additional parameters to the script:
./type-convs.pl wine.git/ HeapAlloc HeapReAlloc
The script will output a diff but won't change the source code itself. The generated diff is NOT suitable to be send to wine-patches; it needs to be cleaned up and tested before that.
find_voidp_funcs.pl can be used to generate the list of functions that return void pointers:
./find_voidp_funcs.pl wine.git/
That was used to generate the embedded list in the type-convs.pl script.
Casting NULL
Casting NULL is almost always a pointless exercise. There are two distinct types of casts here:
Casting to a pointer type
This includes handles that are of pointer type e.g.
(WCHAR *)NULL, (HWND)NULL
Solution: Remove the cast.
Casting to an integer type
This includes handles that are of integer type e.g.
(HCRYPTKEY)NULL, (LRESULT)(HTREEITEM)NULL
Solution: Replace the NULL including the cast(s) with 0.