[swift-dev] Renaming SILSuccessor -> SILCFGEdge

Michael Gottesman mgottesman at apple.com
Wed Apr 26 18:45:19 CDT 2017


> On Apr 26, 2017, at 4:20 PM, Bob Wilson <bob.wilson at apple.com> wrote:
> 
>> 
>> On Apr 26, 2017, at 3:11 PM, Michael Gottesman via swift-dev <swift-dev at swift.org> wrote:
>> 
>> 
>>> On Apr 26, 2017, at 1:44 PM, John McCall <rjmccall at apple.com> wrote:
>>> 
>>>> On Apr 26, 2017, at 4:24 PM, Michael Gottesman via swift-dev <swift-dev at swift.org> wrote:
>>>> Hey everyone.
>>>> 
>>>> I am currently doing some small fixes to SILSuccessor (adding some comments and fixing some issues exposed by LLVM upstream). As I read the code it became pretty apparent that the name is a misnomer... SILSuccessor is not just representing a successor, rather it is representing a whole CFG edge. This can be seen in how SILSuccessor is used to iterate over the predecessors of the block.
>>>> 
>>>> With that in mind, I would like to rename SILSuccessor to SILCFGEdge. It will make it much clearer without knowing any context what this data structure is used for.
>>>> 
>>>> Any objections, disagreements, flames, etc?
>>> 
>>> It seems a little unnecessary to me.  The successor relationship is an edge, and all the edges of the local CFG are successor relationships.  I guess it looks a little funny that the edges into a block are represented by "successors", but I think when you think about it it makes sense.
>> 
>> IMO this is more of an issue than something "looking funny". Using code named "successor" to look up the "predecessors" of a block is misleading and results in unnecessary cognitive overhead for the reader who has to "think about it" for it to make sense.
>> 
>>> 
>>> "SILCFGEdge" is also not a very attractive name because of the two abbreviations.  If you had a nice alternative to "CFGEdge" that was less biased to the beginning/end (like Successor/Predecessor are), I probably wouldn't object.
>> 
>> Ok. Maybe SILControlFlowEdge?
> 
> I can see your point here, but a big renaming change like this is disruptive. With all the other things we’re trying to get done now, is this really the right time to pay the cost of that?

I am not planning on doing it now. What I /am/ trying to do is get some sort of consensus so when I find time to do it I can just do it.

Michael

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-dev/attachments/20170426/a01c1d6c/attachment.html>


More information about the swift-dev mailing list