On 07/06/2017 00:04, Denis Kozlov wrote:
Consider the code fragment below. Currently, FCP 3.0.2 with -O3 shows
"uninitialized result" warning for Convert2 and Convert3 functions,
but not for Convert1. I find this perfect as is, and, of course, you
can rightfully disagree.
You suggest that only Convert3 function should raise "uninitialized
result" warning, while Convert1 and Convert2 should not. I find this
less useful, and, again, you can rightfully disagree, but it won't
change the fact that it is still less useful for me (and possibly
others).
You did of course read Jonas' statement, that if you call
Convertn(TConvertType(-1))
then Convert1 and Convert2 may crash, depending on compiler version and
optimization level (this may also depend on how many elements
TConvertType has)
Btw, from Jonas statement follows, that the "else" part in Convert1 may
be silently removed by the compiler. (maybe now or maybe by future fpc
versions). This may then give an "unreachable code" warning)
The warning however is only useful for Convert2, if you speculate that
the "else" in Convert1 is used for TConvertType(-1).
If it isn't then you have a bigger problem, and that is not caught by
this warning anyway.
type
TConvertType = (ctA, ctB);
function Convert1(Value: TConvertType): Integer;
begin
case Value of
ctA: Result := 1;
ctB: Result := 2;
else Result := 0;
end;
end;
function Convert2(Value: TConvertType): Integer;
begin
case Value of
ctA: Result := 1;
ctB: Result := 2;
end;
end;
function Convert3(Value: TConvertType): Integer;
begin
case Value of
ctA: Result := 1;
end;
end;
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