en Copyright 2015 Java http://172.16.0.5:8080/history/llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll#01152626 [Linker] Handle comdat nodeduplicateFor a variable in a comdat nodeduplicate, its initializer may be significant.E.g. its content may be implicitly referenced by another comdat member (orrequired to parallel to another comdat member by the runtime when explicitsection is used). We can clone it into an unnamed private linkage variable topreserve its content.This partially fixes PR51394 (Sony's proprietary linker using LTO): no errorwill be reported. This is partial because we do not guarantee the globalvariable order if the runtime has parallel section requirement.---There is a similar issue for regular LTO, but unrelated to PR51394:with lib/LTO (using either ld.lld or LLVMgold.so), linking two moduleswith a weak function of the same name, can leave one weak profc and twoprivate profd, due to lib/LTO's current deficiency that it mixes the twoconcepts together: comdat selection and symbol resolution. If the issueis considered important, we should suppress private profd for the weak+regular LTO case.Reviewed By: phosekDifferential Revision: https://reviews.llvm.org/D108879 List of files: /llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll Wed, 01 Sep 2021 05:32:20 +0000 Fangrui Song <i@maskray.me> http://172.16.0.5:8080/history/llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll#92f54e1c [Linker] Support weak symbols in nodeduplicate COMDAT groupWhen a nodeduplicate COMDAT group contains a weak symbol, choosea non-weak symbol (or one of the weak ones) rather than reportingan error. This should address issue PR51394.With the current IR representation, a generic comdat nodeduplicatesemantics is not representable for LTO. In the linker, sections andsymbols are separate concepts. A dropped weak symbol does not force thedefining input section to be dropped as well (though it can be collectedby GC). In the IR, when a weak linkage symbol is dropped, its associatesection content is dropped as well.For InstrProfiling, which is where ran into this issue in PR51394, thededuplication semantic is a sufficient workaround.Differential Revision: https://reviews.llvm.org/D108689 List of files: /llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll Wed, 25 Aug 2021 08:12:19 +0000 Petr Hosek <phosek@google.com> http://172.16.0.5:8080/history/llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll#510e106f [Linker] Replace comdat based bool LinkFromSrc with enum class LinkFrom and improve nodeduplicate tests. NFCThis is different from symbol resolution based LinkFromSrc. Rename to beclearer.In the future we may support a new enum member 'Both' for nodeduplicate. This isfeasible (by renaming to a private linkage GlobalValue), but we need to becareful not to break InstrProfiling.cpp's expectation of parallel profd/profc.The challenge is that current LTO symbol resolution only allows to mark oneprofc as prevailing: the other profc in another comdat nodeduplicate may bediscarded while its associated profd isn't. List of files: /llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll Sat, 28 Aug 2021 20:56:31 +0000 Fangrui Song <i@maskray.me> http://172.16.0.5:8080/history/llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll#0405e644 [test] Reorganize test/Linker/comdat*.ll List of files: /llvm-project-15.0.7/llvm/test/Linker/comdat-nodeduplicate.ll Sat, 28 Aug 2021 17:11:08 +0000 Fangrui Song <i@maskray.me>