Author: serge-sans-paille Date: 2021-05-24T21:39:54-07:00 New Revision: 328a6ec955327c6d56b6bc3478c723dd3cd468ef
URL: https://github.com/llvm/llvm-project/commit/328a6ec955327c6d56b6bc3478c723dd3cd468ef DIFF: https://github.com/llvm/llvm-project/commit/328a6ec955327c6d56b6bc3478c723dd3cd468ef.diff LOG: Force visibility of llvm::Any to external llvm::Any::TypeId::Id relies on the uniqueness of the address of a static variable defined in a template function. hidden visibility implies vague linkage for that variable, which does not guarantee the uniqueness of the address across a binary and a shared library. This totally breaks the implementation of llvm::Any. Ideally, setting visibility to llvm::Any::TypeId::Id should be enough, unfortunately this doesn't work as expected and we lack time (before 12.0.1 release) to understand why setting the visibility to llvm::Any does work. See https://gcc.gnu.org/wiki/Visibility and https://gcc.gnu.org/onlinedocs/gcc/Vague-Linkage.html for more information on that topic. Differential Revision: https://reviews.llvm.org/D101972 (cherry picked from commit 3d3abc22b3ef189813a3b9061c2a90ba86a32f44) Added: Modified: llvm/include/llvm/ADT/Any.h Removed: ################################################################################ diff --git a/llvm/include/llvm/ADT/Any.h b/llvm/include/llvm/ADT/Any.h index 0aded628cda4a..1e3abca706792 100644 --- a/llvm/include/llvm/ADT/Any.h +++ b/llvm/include/llvm/ADT/Any.h @@ -23,7 +23,12 @@ namespace llvm { -class Any { +class LLVM_EXTERNAL_VISIBILITY Any { + + // The `Typeid<T>::Id` static data member below is a globally unique + // identifier for the type `T`. It is explicitly marked with default + // visibility so that when `-fvisibility=hidden` is used, the loader still + // merges duplicate definitions across DSO boundaries. template <typename T> struct TypeId { static const char Id; }; struct StorageBase { _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
