[PATCH] D71474: [TableGen] Introduce an if/then/else statement.

[Hal Finkel via Phabricator via llvm-commits]

hfinkel added a comment.

In D71474#1783762 <https://reviews.llvm.org/D71474#1783762>, @simon_tatham wrote:

> This is a hasty first draft because I'm about to go away for the holidays, and won't have access to this account until the New Year.


This looks like a useful feature.

> It certainly needs documentation, and might also benefit from a refactoring of the mechanism (perhaps the stack of ForeachLoops ought to become a stack of some kind of polymorphic type that can be either a loop or an if).
> 
> This patch applies on top of the `defvar` one (D71407 <https://reviews.llvm.org/D71407>), and in this version, I've made it so that unlike a foreach, an if statement //doesn't// begin a new local-variable scope. I think that might be useful because that way you can conditionally define the same local var in both branches of the if, and then use it afterwards.

I see the use case, but I'm not sure that it's worth breaking the regularity of the scoping scheme.


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https://reviews.llvm.org/D71474