[PATCH] D58292: Add support for importing ChooseExpr AST nodes.

[Aleksei Sidorin via Phabricator via cfe-commits]

a_sidorin accepted this revision.
a_sidorin added a comment.
This revision is now accepted and ready to land.

Hi Tom,
Thanks for the fixes! The patch looks good to me now. I have only a small nit inline.



================
Comment at: lib/AST/ASTImporter.cpp:6140
+ExpectedStmt ASTNodeImporter::VisitChooseExpr(ChooseExpr *E) {
+  auto Imp = importSeq(E->getCond(), E->getLHS(), E->getRHS(),
+                       E->getBuiltinLoc(), E->getRParenLoc(), E->getType());
----------------
aaron.ballman wrote:
> aaron.ballman wrote:
> > a_sidorin wrote:
> > > aaron.ballman wrote:
> > > > Please don't use `auto` here; the type isn't spelled out in the initialization.
> > > Hi Aaron,
> > > importSeq() is a helper targeted to simplify a lot of imports done during AST node import and related error handling. The type of this `importSeq()` expression is `Expected<std::tuple<Expr *, Expr *, Expr *, SourceLocation, SourceLocation, QualType>>`, so I think it's better to leave it as `auto`.
> > Wow. I really dislike that we basically *have* to hide the type information because it's just too ugly to spell. I understand why we're using `auto` based on your explanation, but it basically means I can't understand what this code is doing without a lot more effort.
> > 
> > Let's keep the `auto`, but let's please stop using type compositions that make it considerably harder to review the code. This feel like a misuse of `std::tuple`.
> After staring at this for longer, I no longer think it's a misuse of `std::tuple`, just... an unfortunate side-effect of the design of `importSeq()`. I don't have a good idea for how to make this easier on reviewers and other people who aren't frequently looking at the AST importing code. :-(
I think it is a case where the type is not even important. With C++17, we would just write:
```auto Imp = importSeq(E->getCond(), E->getLHS(), E->getRHS(), ...)
if (Imp)
  return Imp.takeError();
auto [ToCond, ToLHS, ToRHS] = *Imp;
```
The exact type is not really needed here. However, if you have any ideas on how to improve this and make the type more explicit - they are always welcome.


================
Comment at: unittests/AST/ASTImporterTest.cpp:581
+  // Don't try to match the template contents if template parsing is delayed.
+  if (std::find(std::begin(Args), std::end(Args),
+                "-fdelayed-template-parsing") != Args.end()) {
----------------
LLVm has a set of nice helpers for working with containers in range -like style. I'd recommend you to use llvm::find here:
`if (llvm::find(Args), "-fdelayed-template-parsing") != Args.end()) { `


Repository:
  rC Clang

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  https://reviews.llvm.org/D58292/new/

https://reviews.llvm.org/D58292