From a4d7d783d04f15b65c749daa33baa3d94b1e5904 Mon Sep 17 00:00:00 2001 From: Vassil Vassilev Date: Wed, 27 Apr 2016 10:46:06 +0000 Subject: [modules] Fix Decl's Used invariant. The Decl::isUsed has a value for every decl. In non-module builds it is very difficult (but possible) to break this invariant but when we walk up the redecl chain we find the neccessary information. When deserializing the decls from a module it is much more difficult to update correctly this invariant. The patch centralizes the information whether a decl is used in the canonical decl marking the entire entity as being used. Fixes https://llvm.org/bugs/show_bug.cgi?id=27401 Patch by Cristina Cristescu and me. Thanks to Richard Smith who helped to debug and understand the issue! Reviewed by Richard Smith. llvm-svn: 267691 --- clang/lib/Serialization/ASTWriter.cpp | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'clang/lib/Serialization/ASTWriter.cpp') diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp index 073ed674741..32c9c4787c4 100644 --- a/clang/lib/Serialization/ASTWriter.cpp +++ b/clang/lib/Serialization/ASTWriter.cpp @@ -5784,8 +5784,13 @@ void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD, void ASTWriter::DeclarationMarkedUsed(const Decl *D) { assert(!WritingAST && "Already writing the AST!"); - if (!D->isFromASTFile()) - return; + + // If there is *any* declaration of the entity that's not from an AST file, + // we can skip writing the update record. We make sure that isUsed() triggers + // completion of the redeclaration chain of the entity. + for (auto Prev = D->getMostRecentDecl(); Prev; Prev = Prev->getPreviousDecl()) + if (IsLocalDecl(Prev)) + return; DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED)); } -- cgit v1.2.3