This had me puzzled for a second, but then I figured out what happened :-) The “crash” I quoted in the commit message really was an assertion failure, to be precise, the very assertion I relaxed in LLVM r259973 in order to be able to defer the building of the DeclContext implemented by this commit. Even with the assertion removed, I still believe that implementing it this way preferable, as it avoids creating the enum a second time.
> On Feb 19, 2016, at 7:05 PM, Eric Christopher <echri...@gmail.com> wrote: > > Hi Adrian, > > I'm taking a look at this and can't duplicate using the testcase you gave > without your patch(es) applied. It's also causing asserts in other code as > you can have the forward decl left around and the CU isn't a valid context. Do you happen to have an example handy? I don’t quite understand the problem from the description — shouldn’t the temporary fwddecl be RAUWed unconditionally after the DeclContext is created? If you’re blocked on this we can definitely revert the change in CGDebugInfo (but not the testcase), I just would like to understand what’s going on. -- adrian > Can you take a look/revert until you've got a different testcase? There's not > enough information in the commit to construct one up for you. > > Thanks! > > -eric > > On Fri, Feb 5, 2016 at 6:03 PM Adrian Prantl via cfe-commits > <cfe-commits@lists.llvm.org> wrote: > Author: adrian > Date: Fri Feb 5 19:59:09 2016 > New Revision: 259975 > > URL: http://llvm.org/viewvc/llvm-project?rev=259975&view=rev > Log: > Fix a crash when emitting dbeug info for forward-declared scoped enums. > It is possible for enums to be created as part of their own > declcontext. We need to cache a placeholder to avoid the type being > created twice before hitting the cache. > > <rdar://problem/24493203> > > Added: > cfe/trunk/test/CodeGenCXX/debug-info-scoped-class.cpp > Modified: > cfe/trunk/lib/CodeGen/CGDebugInfo.cpp > > Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=259975&r1=259974&r2=259975&view=diff > ============================================================================== > --- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original) > +++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Fri Feb 5 19:59:09 2016 > @@ -2051,13 +2051,25 @@ llvm::DIType *CGDebugInfo::CreateEnumTyp > // If this is just a forward declaration, construct an appropriately > // marked node and just return it. > if (isImportedFromModule || !ED->getDefinition()) { > - llvm::DIScope *EDContext = getDeclContextDescriptor(ED); > llvm::DIFile *DefUnit = getOrCreateFile(ED->getLocation()); > + > + // It is possible for enums to be created as part of their own > + // declcontext. We need to cache a placeholder to avoid the type being > + // created twice before hitting the cache. > + llvm::DIScope *EDContext = DBuilder.createReplaceableCompositeType( > + llvm::dwarf::DW_TAG_enumeration_type, "", TheCU, DefUnit, 0); > + > unsigned Line = getLineNumber(ED->getLocation()); > StringRef EDName = ED->getName(); > llvm::DIType *RetTy = DBuilder.createReplaceableCompositeType( > llvm::dwarf::DW_TAG_enumeration_type, EDName, EDContext, DefUnit, > Line, > 0, Size, Align, llvm::DINode::FlagFwdDecl, FullName); > + > + // Cache the enum type so it is available when building the declcontext > + // and replace the declcontect with the real thing. > + TypeCache[Ty].reset(RetTy); > + EDContext->replaceAllUsesWith(getDeclContextDescriptor(ED)); > + > ReplaceMap.emplace_back( > std::piecewise_construct, std::make_tuple(Ty), > std::make_tuple(static_cast<llvm::Metadata *>(RetTy))); > > Added: cfe/trunk/test/CodeGenCXX/debug-info-scoped-class.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-scoped-class.cpp?rev=259975&view=auto > ============================================================================== > --- cfe/trunk/test/CodeGenCXX/debug-info-scoped-class.cpp (added) > +++ cfe/trunk/test/CodeGenCXX/debug-info-scoped-class.cpp Fri Feb 5 19:59:09 > 2016 > @@ -0,0 +1,15 @@ > +// RUN: %clang_cc1 -emit-llvm -debug-info-kind=standalone -std=c++11 \ > +// RUN: -triple thumbv7-apple-ios %s -o - | FileCheck %s > + > +// This forward-declared scoped enum will be created while building its own > +// declcontext. Make sure it is only emitted once. > + > +struct A { > + enum class Return; > + Return f1(); > +}; > +A::Return* f2() {} > + > +// CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, name: "Return", > +// CHECK-SAME: flags: DIFlagFwdDecl, > +// CHECK-NOT: tag: DW_TAG_enumeration_type, name: "Return" > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
