[PATCH] D57112: [ASTTypeTraits][ASTMatchers][OpenMP] OMPClause handling

Dmitri Gribenko via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Mon Mar 18 04:16:31 PDT 2019


gribozavr added inline comments.


================
Comment at: include/clang/ASTMatchers/ASTMatchers.h:6456
+  // Note that we have recieved a *matcher* for the clause, not the
+  // OpenMPClauseKind. We now need to extract the 'return' type of said matcher,
+  // and convert it to the OpenMPClauseKind, so we can finally use that.
----------------
lebedev.ri wrote:
> gribozavr wrote:
> > lebedev.ri wrote:
> > > gribozavr wrote:
> > > > lebedev.ri wrote:
> > > > > gribozavr wrote:
> > > > > > Why not make `isAllowedToContainClause` take an `OpenMPClauseKind` enum value?
> > > > > > 
> > > > > > I don't see right now advantages for taking a matcher.  (For example, it can't be a more complex matcher with inner matchers, it can't be a disjunction of matchers etc.)
> > > > > I don't feel like it, it's uglier.
> > > > > The matcher is documented, `OpenMPClauseKind` is not documented.
> > > > > Also, how will passing some random enum work with e.g. clang-query?
> > > > > 
> > > > There are dozens of clauses in `OpenMPClauseKind`.  We would have to replicate them all as matchers to provide a useful API.
> > > > 
> > > > > Also, how will passing some random enum work with e.g. clang-query?
> > > > 
> > > > See `llvm/tools/clang/lib/ASTMatchers/Dynamic/Marshallers.h`.
> > > True. Also, but there's dosens of Stmt types, and there is no overload that takes `StmtClass` enum.
> > For Stmts, we do have dozens of individual matchers for them.
> > 
> > The point of your work is to add ASTMatchers for OpenMP, right?  However, if there are no matchers for a reasonable amount of AST surface, it is as good as if the matchers are not there, because prospective users won't be able to use them.
> > 
> > I don't particularly care how exactly this is achieved, through individual matchers or through a matcher that takes an enum.  However, I want to make sure that if you're going through all this trouble to add matchers, the resulting API should cover a good amount of AST.
> > 
> > The reason why I suggested to pass the enum to the matcher is simply because it is less code duplication, less work, and more reliable code (since there will be only one matcher to review, test, and maintain, instead of combinations of matchers).
> > 
> > Another reason to not use an inner matcher here is the peculiar semantics of this function -- it does not evaluate the matcher, and it does not accept a matcher expression of any shape.
> > The point of your work is to add ASTMatchers for OpenMP, right?
> 
> Absolutely not.
> D57113 + D59466 is the one and only point, to address the bugs i have personally encountered.
> The whole reason why i have started off with NOT adding these matchers to the `ASTMatchers.h`,
> but keeping them at least initially internal to the checks was to avoid all this bikeshedding.
However, I do care about the AST matchers being usable by other clients.

I also care about the API following existing patterns:

> Another reason to not use an inner matcher here is the peculiar semantics of this function -- it does not evaluate the matcher, and it does not accept a matcher expression of any shape.




Repository:
  rC Clang

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57112/new/

https://reviews.llvm.org/D57112





More information about the cfe-commits mailing list