[lldb][TypeSystemClang] Avoid accessing definition if none is available #9227
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We've been hitting cases where LLDB marks a decl as
isCompleteDefinition
but no definition was allocated for it. Then when we access a an API in which Clang assumes a definition exists, and dereferences a nullptr. In the specific case that happens when we've incorrectly been keeping track of theImportedDecls
inclang::ASTImporter
(which manifests as trying toMapImported
on two different destination decls from the same source decl for the same ClangASTImporterDelegate).The more fundmental issue is that we're failing to complete the type properly. But the fix for that is still in-progress. So we're working around the crash by guarding against failed type completion.
rdar://133958782