[cfe-commits] [cfe-dev] [review request] Removing redundant implicit casts in the AST, take 2

[Nicola Gigante]

Il giorno 24/feb/2012, alle ore 03:28, Richard Smith ha scritto:

> Hi,
> 
Hello!

> On to the patch. I think it's really very close now:
> [..]
I'm going to fix all those issues, off course.
Just a couple of things:

> -void CastOperation::CheckStaticCast() {
> +void CastOperation::CheckStaticCast(bool &CastNodesCreated,
> +                                    Sema::CheckedConversionInfo CCI) {
> 
> Rather than taking a bool argument by reference, it might be nicer to return a bool from here to indicate whether a CXXStaticCast node was created.
> 
I've chosen to use a by-reference argument for clarity. A bool returned by a function named CheckStaticCast() can be very easily misinterpreted,
in my opinion, to mean "checking done" vs "checking failed", even adding a comment that says otherwise. Don't you think so?
I'll change it anyway, if you wish.


> +  CastNodesCreated = (SrcExpr.get() != SrcExprOrig &&
> +                      Kind != CK_ConstructorConversion);
> 
> This approach makes me nervous: it seems too easy for us to accidentally change SrcExpr without building a cast node (checkNonOverloadPlaceholders could do this, for instance). Can we ensure that TryStaticCast returns TC_Success exactly when it's created a CXXStaticCast node, then use that to determine whether we need to build one?
> 

You're right. I think we can be sure that TryStaticImplicitCast() has created the node if it returns TC_Success and Kind != CK_ConstructorConversion.
But it depends on how InitializationSequence::Perform() behaves. Do you think this is the case?

> In the ElType == ToType case, it looks like this could still produce a no-op static cast containing an implicit cast.

You're right. Fixed it.

I've also contextually fixed a warning that appears in addFixitForObjCARCConversion() that doesn't include
the recently added CCK_StaticCast enum value in a switch statement.

Attached is the patch to the last revision with all the issues fixed excepting the two questions I asked here.

> 
> Thanks!
> Richard

Thanks,
Nicola

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