rjmccall added a comment. In D59214#1917149 <https://reviews.llvm.org/D59214#1917149>, @lebedev.ri wrote:
> In D59214#1916596 <https://reviews.llvm.org/D59214#1916596>, @sammccall wrote: > > > So if I understand the history here: > > > > - the `IsOMPStructuredBlock` bit on `Stmt` was added to implement > > `getStructuredBlock()` > > - after review, `getStructuredBlock()` doesn't use the bit > > - the bit is used in the textual AST dump, and an AST matcher (which is in > > turn never used in-tree) > > > > Can we have the bit back please :-) We're currently trying to add a > > HasErrors bit to improve error-recovery and some nodes are completely full. > > Using a bit on every Stmt to improve the text dump a little and provide a > > matcher (only relevant to OMP files) seems disproportionately expensive. > > > > > In D59214#1917106 <https://reviews.llvm.org/D59214#1917106>, @rjmccall wrote: > > > If the bit is unused except for propagation, please remove it. > > > This review (& https://bugs.llvm.org/show_bug.cgi?id=40563 in general) > has left me so burnout as to all this openmp stuff that i never > followed-up with the actual planned usages of this bit. I'm sorry to hear that. > The reasons why this bit is needed (i think they were spelled out here) > still apply. One obvious example is > https://bugs.llvm.org/show_bug.cgi?id=41102, > where after we'd teach `ExceptionAnalyzer` to look into `CapturedStmt` / > `CapturedDecl`, > we'd immediately have false-positives for these OpenMP structured blocks, > so we'd need to avoid traversing into them. > > Doing that via a single bit check should be trivial, as opposed to, > i dunno, maintainting a set of all the openmp structured block statements, > and before visiting each statement seeing if it is in that set? > That kinda sounds slow. Well, two points. The first is that language dialects have to take a back-seat to general-purpose mechanisms. I care a lot about Objective-C ARC, and that dialect has some type qualifiers that are used very frequently, but the representation does not and will never prioritize those type qualifiers over things that are common to C/C++, and so we just use extra memory when compiling ARC. The second is that we can pretty easily solve your problem without adding a bit to `Stmt`. Captured statements are like blocks in the sense that traverses that walk into captured statements will always pass through a node in the AST that knows it's introducing a captured statement, so they should be easy to just record that the traversal is currently within a captured statement, or even maintain a stack of such contexts. If it helps to add "callbacks" to some CRTP visitor class when entering and exiting a special local context, we can do that. Repository: rL LLVM CHANGES SINCE LAST ACTION https://reviews.llvm.org/D59214/new/ https://reviews.llvm.org/D59214 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
