From 09d84addb77e7ddf6a430ea79174ec123e9d3581 Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Tue, 12 Aug 2014 16:46:37 +0000 Subject: Don't upgrade global constructors when reading bitcode An optional third field was added to `llvm.global_ctors` (and `llvm.global_dtors`) in r209015. Most of the code has been changed to deal with both versions of the variables. Users of the C API might create either version, the helper functions in LLVM create the two-field version, and clang now creates the three-field version. However, the BitcodeReader was changed to always upgrade to the three-field version. This created an unnecessary inconsistency in the IR before/after serializing to bitcode. This commit resolves the inconsistency by making the third field truly optional (and not upgrading in the bitcode reader). Since `llvm-link` was relying on this upgrade code, rather than deleting it I've moved it into `ModuleLinker`, where it upgrades these arrays as necessary to resolve inconsistencies between modules. The ideal resolution would be to remove the 2-field version and make the third field required. I filed PR20506 to track that. I changed `test/Bitcode/upgrade-global-ctors.ll` to a negative test and duplicated the `llvm-link` check in `test/Linker/global_ctors.ll` to check both upgrade directions. Since I came across this as part of PR5680 (serializing use-list order), I've also added the missing `verify-uselistorder` RUN line to `test/Bitcode/metadata-2.ll`. llvm-svn: 215457 --- llvm/test/Bitcode/metadata-2.ll | 1 + llvm/test/Bitcode/upgrade-global-ctors.ll | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'llvm/test/Bitcode') diff --git a/llvm/test/Bitcode/metadata-2.ll b/llvm/test/Bitcode/metadata-2.ll index 4055f921c33..06f844283ff 100644 --- a/llvm/test/Bitcode/metadata-2.ll +++ b/llvm/test/Bitcode/metadata-2.ll @@ -1,4 +1,5 @@ ; RUN: llvm-as < %s | llvm-dis -disable-output +; RUN: verify-uselistorder < %s -preserve-bc-use-list-order %0 = type { %object.ModuleInfo.__vtbl*, i8*, %"byte[]", %1, %"ClassInfo[]", i32, void ()*, void ()*, void ()*, i8*, void ()* } ; type %0 %1 = type { i64, %object.ModuleInfo* } ; type %1 %2 = type { i32, void ()* } ; type %2 diff --git a/llvm/test/Bitcode/upgrade-global-ctors.ll b/llvm/test/Bitcode/upgrade-global-ctors.ll index 9ba422fe491..4816f0dc294 100644 --- a/llvm/test/Bitcode/upgrade-global-ctors.ll +++ b/llvm/test/Bitcode/upgrade-global-ctors.ll @@ -1,4 +1,5 @@ ; RUN: llvm-dis < %s.bc| FileCheck %s ; RUN: verify-uselistorder < %s.bc -preserve-bc-use-list-order -; CHECK: @llvm.global_ctors = appending global [0 x { i32, void ()*, i8* }] zeroinitializer +; Global constructors should no longer be upgraded when reading bitcode. +; CHECK: @llvm.global_ctors = appending global [0 x { i32, void ()* }] zeroinitializer -- cgit v1.2.3