This is the full patch that corrects all the compile errors MSVC was generating. If we have any platform-specific checkers, they may have been missed. But this should give an idea of the scope of the changes we're asking folks to make.
~Aaron On Mon, Sep 14, 2015 at 1:03 PM, Aaron Ballman <aa...@aaronballman.com> wrote: > On Mon, Sep 14, 2015 at 11:49 AM, Manuel Klimek <kli...@google.com> wrote: >> >> >> On Mon, Sep 14, 2015, 8:40 AM Aaron Ballman <aa...@aaronballman.com> wrote: >>> >>> On Sat, Sep 12, 2015 at 11:06 PM, Manuel Klimek <kli...@google.com> wrote: >>> > >>> > >>> > On Sat, Sep 12, 2015, 9:25 PM Aaron Ballman <aa...@aaronballman.com> >>> > wrote: >>> >> >>> >> On Sat, Sep 12, 2015 at 8:22 AM, Manuel Klimek <kli...@google.com> >>> >> wrote: >>> >> > >>> >> > >>> >> > On Fri, Sep 11, 2015 at 10:39 PM Aaron Ballman >>> >> > <aa...@aaronballman.com> >>> >> > wrote: >>> >> >> >>> >> >> On Fri, Sep 11, 2015 at 4:30 PM, Richard Smith >>> >> >> <rich...@metafoo.co.uk> >>> >> >> wrote: >>> >> >> > I don't think CXXRecordDecl is an anachronism, so much as an >>> >> >> > implementation >>> >> >> > detail; it makes sense to use a smaller class when in C mode, as >>> >> >> > we >>> >> >> > don't >>> >> >> > need most of the features and complexity that CXXRecordDecl brings >>> >> >> > with >>> >> >> > it. >>> >> >> > But... as a user of clang matchers, I don't think I'd want to care >>> >> >> > about >>> >> >> > the >>> >> >> > difference, and it'd be more convenient if I could nest (say) a >>> >> >> > hasMethod >>> >> >> > matcher within a recordDecl matcher, since it's completely obvious >>> >> >> > what >>> >> >> > that >>> >> >> > should mean. If I have a matcher that says: >>> >> >> > >>> >> >> > recordDecl(or(hasMethod(...), hasField(...))) >>> >> >> > >>> >> >> > I would expect that to work in both C and C++ (and the only way it >>> >> >> > could >>> >> >> > match in C would be on a record with the specified field, since >>> >> >> > the >>> >> >> > hasMethod matcher would always fail). >>> >> >> >>> >> >> Okay, so then it sounds like we want recordDecl to *mean* >>> >> >> RecordDecl, >>> >> >> but we want the traversal and narrowing matchers that currently take >>> >> >> a >>> >> >> CXXRecordDecl to instead take a RecordDecl and handle the CXX part >>> >> >> transparently? This means we would not need to add a cxxRecordDecl() >>> >> >> matcher, but could still access CXX-only functionality (like access >>> >> >> control, base classes, etc) through recordDecl()? >>> >> > >>> >> > >>> >> > I'm against that proposal. I think we have tried to make the matchers >>> >> > more >>> >> > "user friendly" in the past, and all those attempts have failed >>> >> > miserably; >>> >> > in the end, users will do ast-dump to see what they want to match, >>> >> > and >>> >> > then >>> >> > be confused when the matchers do follow the AST 99% of the time, but >>> >> > try >>> >> > to >>> >> > be smart 1% of the time. >>> >> > I think given that we want to keep CXXRecordDecl, the right solution >>> >> > is >>> >> > to >>> >> > have a cxxRecordDecl() matcher. >>> >> >>> >> Personally, I think this makes the most sense, at least to me. The >>> >> recommendation I've always heard (and given) is to use -ast-dump and >>> >> write matchers from there. (Consequently, the more I work with type >>> >> traversal matchers, the more I wish we had -ast-dump-types to give >>> >> even *more* information for writing matchers.) >>> >> >>> >> But the question still remains, what do we do with recordDecl? Right >>> >> now, it means CXXRecordDecl instead of RecordDecl. If we change it to >>> >> mean RecordDecl instead, there's a chance we'll break existing, >>> >> reasonable code. Are we okay with that risk? If we're at least >>> >> conceptually okay with it, I could make the change locally and see >>> >> just how much of our own code breaks, and report back. But if that >>> >> turns out to be problematic, do we want to deprecate recordDecl and >>> >> replace it with structDecl as our fallback position? Or is there a >>> >> better solution? >>> >> >>> >> Basically, I see a few ways to solve this (and there may be other ways >>> >> I'm not thinking about yet): >>> >> >>> >> 1) Undocument/deprecate recordDecl, add structDecl, unionDecl, and >>> >> cxxRecordDecl. This does not match the AST because we have no >>> >> StructDecl or UnionDecl types. The more I think about this option, the >>> >> less I like it. It's easy to implement, but seems hard to relate to >>> >> the AST. >>> >> 2) Make recordDecl match RecordDecl, don't touch other matchers. Add >>> >> way to distinguish unions from structs (e.g., isUnion(), isStruct()), >>> >> add cxxRecordDecl. This matches the AST most closely, but may break >>> >> code. I think that I prefer this approach, but it depends heavily on >>> >> what "may break code" looks like in practice. >>> >> 3) Make recordDecl match RecordDecl, fix other matchers that currently >>> >> take CXXRecordDecl to instead take RecordDecl and handle sensibly when >>> >> possible. Add a way to distinguish unions from structs, add >>> >> cxxRecordDecl. This doesn't match the AST because we will have >>> >> matchers taking a RecordDecl when the AST would require a >>> >> CXXRecordDecl, but is likely to break less code. >>> > >>> > >>> > That sums it up. My preferences are 2, 3, 1 in that order :) >>> >>> I've attached a patch that implements #2, but it comes with ~85 errors >>> from C++ matchers that use recordDecl to mean cxxRecordDecl. >>> >>> http://pastebin.com/bxkRcqBV >>> >>> If this is an acceptable failure rate, I can also update the failing >>> matchers to use cxxRecordDecl instead of recordDecl where applicable. >>> Doing some spot-checking of the failing code, the failures are ones we >>> anticipated, such as: >>> >>> constructorDecl(ofClass(recordDecl( >>> hasDeclaration(recordDecl(hasMethod(hasName("begin")), >>> hasMethod(hasName("end")))) >>> etc >> >> >> +Daniel for another opinion. I think this is fine, but I'd prefer not to >> end up in a meme :) > > FWIW, the vast majority of the errors are in ASTMatchersTests. There > were only a few in actual real-world uses (71 in tests, 14 in real > code). > > ~Aaron > >> >>> ~Aaron >>> >>> > >>> >> >>> >> ~Aaron >>> >> >>> >> >>> >> > Richard: if CXXRecordDecl was really an implementation detail, it >>> >> > would >>> >> > be >>> >> > hidden behind a RecordDecl class, as an implementation detail. The >>> >> > reasons >>> >> > why we don't want it to be an implementation detail in the code >>> >> > (performance, data structure size) don't matter - in the end, it's in >>> >> > the >>> >> > AST API. >>> >> > >>> >> >> >>> >> >> >>> >> >> ~Aaron >>> >> >> >>> >> >> > >>> >> >> > On Fri, Sep 11, 2015 at 6:30 AM, Manuel Klimek <kli...@google.com> >>> >> >> > wrote: >>> >> >> >> >>> >> >> >> Richard! We need an informed opinion :D >>> >> >> >> >>> >> >> >> On Fri, Sep 11, 2015 at 3:07 PM Aaron Ballman >>> >> >> >> <aa...@aaronballman.com> >>> >> >> >> wrote: >>> >> >> >>> >>> >> >> >>> Ping? >>> >> >> >>> >>> >> >> >>> On Tue, Sep 8, 2015 at 9:26 AM, Manuel Klimek >>> >> >> >>> <kli...@google.com> >>> >> >> >>> wrote: >>> >> >> >>> > On Tue, Sep 8, 2015 at 3:23 PM Aaron Ballman >>> >> >> >>> > <aa...@aaronballman.com> >>> >> >> >>> > wrote: >>> >> >> >>> >> >>> >> >> >>> >> On Tue, Sep 8, 2015 at 9:18 AM, Manuel Klimek >>> >> >> >>> >> <kli...@google.com> >>> >> >> >>> >> wrote: >>> >> >> >>> >> > On Tue, Sep 8, 2015 at 2:23 PM Aaron Ballman >>> >> >> >>> >> > <aa...@aaronballman.com> >>> >> >> >>> >> > wrote: >>> >> >> >>> >> >> >>> >> >> >>> >> >> On Tue, Sep 8, 2015 at 5:40 AM, Manuel Klimek >>> >> >> >>> >> >> <kli...@google.com> >>> >> >> >>> >> >> wrote: >>> >> >> >>> >> >> > Yea, we had that discussion a few times, and I can never >>> >> >> >>> >> >> > remember >>> >> >> >>> >> >> > why >>> >> >> >>> >> >> > we >>> >> >> >>> >> >> > ended up in the state we're in. >>> >> >> >>> >> >> > We definitely had a time where we switched to just using >>> >> >> >>> >> >> > the >>> >> >> >>> >> >> > exact >>> >> >> >>> >> >> > same >>> >> >> >>> >> >> > name >>> >> >> >>> >> >> > as the node's class name for the matchers. >>> >> >> >>> >> >> > I *think* we didn't do it for cxxRecordDecl, because >>> >> >> >>> >> >> > Richard >>> >> >> >>> >> >> > said >>> >> >> >>> >> >> > that's >>> >> >> >>> >> >> > a >>> >> >> >>> >> >> > relic we should get rid of anyway, but I'm not sure. >>> >> >> >>> >> >> >>> >> >> >>> >> >> FWIW, I think the state we're in is the worst of all >>> >> >> >>> >> >> worlds. >>> >> >> >>> >> >> It's >>> >> >> >>> >> >> not >>> >> >> >>> >> >> intuitive that recordDecl() doesn't match a struct in C >>> >> >> >>> >> >> mode, >>> >> >> >>> >> >> and >>> >> >> >>> >> >> as >>> >> >> >>> >> >> it stands, there is no way to match a struct or union >>> >> >> >>> >> >> declaration >>> >> >> >>> >> >> in C >>> >> >> >>> >> >> at all. >>> >> >> >>> >> > >>> >> >> >>> >> > >>> >> >> >>> >> > Agreed. Best intentions. Worst possible outcome. That's >>> >> >> >>> >> > software >>> >> >> >>> >> > development >>> >> >> >>> >> > :) >>> >> >> >>> >> > >>> >> >> >>> >> >> > >>> >> >> >>> >> >> > On Fri, Sep 4, 2015 at 8:32 PM Aaron Ballman >>> >> >> >>> >> >> > <aa...@aaronballman.com> >>> >> >> >>> >> >> > wrote: >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> It turns out that the recordDecl() AST matcher doesn't >>> >> >> >>> >> >> >> match >>> >> >> >>> >> >> >> RecordDecl objects; instead, it matches CXXRecordDecl >>> >> >> >>> >> >> >> objects. >>> >> >> >>> >> >> >> This >>> >> >> >>> >> >> >> is... unfortunate... as it makes writing AST matchers >>> >> >> >>> >> >> >> more >>> >> >> >>> >> >> >> complicated >>> >> >> >>> >> >> >> because of having to translate between >>> >> >> >>> >> >> >> recordDecl()/CXXRecordDecl. >>> >> >> >>> >> >> >> It >>> >> >> >>> >> >> >> also makes it impossible to match a struct or union >>> >> >> >>> >> >> >> declaration >>> >> >> >>> >> >> >> in C >>> >> >> >>> >> >> >> or ObjC. However, given how prevalent recordDecl()'s >>> >> >> >>> >> >> >> use >>> >> >> >>> >> >> >> is >>> >> >> >>> >> >> >> in >>> >> >> >>> >> >> >> the >>> >> >> >>> >> >> >> wild (I'm guessing), changing it at this point would be >>> >> >> >>> >> >> >> a >>> >> >> >>> >> >> >> Bad >>> >> >> >>> >> >> >> Thing. >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> For people trying to write AST matchers for languages >>> >> >> >>> >> >> >> like >>> >> >> >>> >> >> >> C >>> >> >> >>> >> >> >> or >>> >> >> >>> >> >> >> ObjC, >>> >> >> >>> >> >> >> I would like to propose adding: >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> structDecl() >>> >> >> >>> >> >> >> unionDecl() >>> >> >> >>> >> >> >> tagDecl() >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> These will match nicely with the existing enumDecl() >>> >> >> >>> >> >> >> AST >>> >> >> >>> >> >> >> matcher. >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> Additionally, I would like to add cxxRecordDecl() to >>> >> >> >>> >> >> >> match >>> >> >> >>> >> >> >> CXXRecordDecl objects. While it duplicates the >>> >> >> >>> >> >> >> functionality >>> >> >> >>> >> >> >> exposed >>> >> >> >>> >> >> >> by recordDecl(), it more clearly matches the intention >>> >> >> >>> >> >> >> of >>> >> >> >>> >> >> >> which >>> >> >> >>> >> >> >> AST >>> >> >> >>> >> >> >> node it corresponds to. >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> Finally, I would like to undocument recordDecl() and >>> >> >> >>> >> >> >> change >>> >> >> >>> >> >> >> our >>> >> >> >>> >> >> >> existing documentation and AST matcher uses to use >>> >> >> >>> >> >> >> cxxRecordDecl/structDecl() instead. Maybe someday we >>> >> >> >>> >> >> >> can >>> >> >> >>> >> >> >> deprecate >>> >> >> >>> >> >> >> recordDecl() more officially. >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> I'm open to other ideas if there are better ways to >>> >> >> >>> >> >> >> move >>> >> >> >>> >> >> >> forward. If >>> >> >> >>> >> >> >> you think changing the meaning of recordDecl() is >>> >> >> >>> >> >> >> acceptable, >>> >> >> >>> >> >> >> I >>> >> >> >>> >> >> >> can >>> >> >> >>> >> >> >> also go that route (though I would still propose adding >>> >> >> >>> >> >> >> unionDecl() >>> >> >> >>> >> >> >> and cxxRecordDecl() in that case). >>> >> >> >>> >> >> > >>> >> >> >>> >> >> > >>> >> >> >>> >> >> > I think changing recordDecl is acceptable. I believe >>> >> >> >>> >> >> > very >>> >> >> >>> >> >> > few >>> >> >> >>> >> >> > tools >>> >> >> >>> >> >> > will >>> >> >> >>> >> >> > actually start doing wrong things because of it. I'd >>> >> >> >>> >> >> > like >>> >> >> >>> >> >> > more >>> >> >> >>> >> >> > opinions >>> >> >> >>> >> >> > first, though :) >>> >> >> >>> >> >> >>> >> >> >>> >> >> I was giving this more thought over the long weekend, and >>> >> >> >>> >> >> I >>> >> >> >>> >> >> think >>> >> >> >>> >> >> you >>> >> >> >>> >> >> may be right. I think changing recordDecl() to mean >>> >> >> >>> >> >> RecordDecl >>> >> >> >>> >> >> will >>> >> >> >>> >> >> fix more code than it breaks, so long as we take a >>> >> >> >>> >> >> holistic >>> >> >> >>> >> >> approach >>> >> >> >>> >> >> to the change and see which narrowing and traversal >>> >> >> >>> >> >> matchers >>> >> >> >>> >> >> we >>> >> >> >>> >> >> need >>> >> >> >>> >> >> to fix up at the same time. When I tried to think of AST >>> >> >> >>> >> >> matchers >>> >> >> >>> >> >> that >>> >> >> >>> >> >> mean CXXRecordDecl but *not* RecordDecl, they were >>> >> >> >>> >> >> horribly >>> >> >> >>> >> >> contrived >>> >> >> >>> >> >> because you usually are matching on additional selection >>> >> >> >>> >> >> criteria >>> >> >> >>> >> >> that >>> >> >> >>> >> >> is specific to C++ (such as hasMethod() or >>> >> >> >>> >> >> isDerivedFrom()) >>> >> >> >>> >> >> which >>> >> >> >>> >> >> would cause the match to continue to fail, as expected. >>> >> >> >>> >> >> Code >>> >> >> >>> >> >> that >>> >> >> >>> >> >> uses >>> >> >> >>> >> >> recordDecl() to mean RecordDecl will suddenly start to >>> >> >> >>> >> >> match >>> >> >> >>> >> >> in >>> >> >> >>> >> >> more >>> >> >> >>> >> >> cases, but that's likely to be a bug fix more than a >>> >> >> >>> >> >> breaking >>> >> >> >>> >> >> change. >>> >> >> >>> >> >> To the best of my understanding, the only breaking cases >>> >> >> >>> >> >> would >>> >> >> >>> >> >> be >>> >> >> >>> >> >> where you wrote recordDecl(), meant CXXRecordDecl, had no >>> >> >> >>> >> >> further >>> >> >> >>> >> >> narrowing or traversal matchers, and were compiling in C >>> >> >> >>> >> >> mode; >>> >> >> >>> >> >> with >>> >> >> >>> >> >> the result being additional unexpected matches. >>> >> >> >>> >> > >>> >> >> >>> >> > >>> >> >> >>> >> > Ah, there's one thing that can break: the compile can >>> >> >> >>> >> > break: >>> >> >> >>> >> > recordDecl(hasMethod(...)) will *not* compile (it'll work >>> >> >> >>> >> > in >>> >> >> >>> >> > the >>> >> >> >>> >> > dynamic >>> >> >> >>> >> > matchers and fail as you suggest, but the in-C++ DSL does >>> >> >> >>> >> > more >>> >> >> >>> >> > static >>> >> >> >>> >> > type >>> >> >> >>> >> > checking). >>> >> >> >>> >> > I don't think that's super bad though. >>> >> >> >>> >> > >>> >> >> >>> >> >> >>> >> >> >>> >> >> So perhaps it would make sense to: >>> >> >> >>> >> >> >>> >> >> >>> >> >> 1) Make recordDecl() mean RecordDecl >>> >> >> >>> >> >> 2) Do a comprehensive review of matchers that take a >>> >> >> >>> >> >> CXXRecordDecl >>> >> >> >>> >> >> and >>> >> >> >>> >> >> see if they should instead take a RecordDecl >>> >> >> >>> >> >> 3) Add unionDecl() as a node matcher (or should we add >>> >> >> >>> >> >> isUnion() >>> >> >> >>> >> >> and >>> >> >> >>> >> >> isStruct() as narrowing matchers?) >>> >> >> >>> >> >> 4) Add tagDecl() as a node matcher, but not add >>> >> >> >>> >> >> cxxRecordDecl() >>> >> >> >>> >> > >>> >> >> >>> >> > >>> >> >> >>> >> > Why not add cxxRecordDecl()? I think we need it if we want >>> >> >> >>> >> > narrowing >>> >> >> >>> >> > matchers on CXXRecordDecl? >>> >> >> >>> >> >>> >> >> >>> >> If Richard thinks CXXRecordDecl is an anachronism, I figured >>> >> >> >>> >> we >>> >> >> >>> >> didn't >>> >> >> >>> >> want to expose it. Instead, we could make hasMethod (et al) >>> >> >> >>> >> accept >>> >> >> >>> >> a >>> >> >> >>> >> RecordDecl and do the type checking for the caller. Then >>> >> >> >>> >> recordDecl(hasMethod(...)) continues to compile and work, and >>> >> >> >>> >> when >>> >> >> >>> >> hasMethod is given a RecordDecl instead of a CXXRecordDecl, >>> >> >> >>> >> it >>> >> >> >>> >> simply >>> >> >> >>> >> matches nothing. But you bring up a good point about the C++ >>> >> >> >>> >> DSL >>> >> >> >>> >> being >>> >> >> >>> >> a problem still, I hadn't considered that. >>> >> >> >>> > >>> >> >> >>> > >>> >> >> >>> > First I want Richard to confirm that. I have a very bad >>> >> >> >>> > memory, >>> >> >> >>> > so I >>> >> >> >>> > might >>> >> >> >>> > as well misremember :) >>> >> >> >>> > >>> >> >> >>> >> >>> >> >> >>> >> >>> >> >> >>> >> ~Aaron >>> >> >> >>> >> >>> >> >> >>> >> > >>> >> >> >>> >> >> >>> >> >> >>> >> >> >>> >> >> >>> >> >> ~Aaron >>> >> >> >>> >> >> >>> >> >> >>> >> >> > >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> Thanks! >>> >> >> >>> >> >> >> >>> >> >> >>> >> >> >> ~Aaron >>> >> >> > >>> >> >> >
recordDecl.patch
Description: Binary data
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