[lld] r264111 - [LTO] Keep linkonce_odr symbols when appropriate.
Davide Italiano via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 22 15:31:35 PDT 2016
Author: davide
Date: Tue Mar 22 17:31:34 2016
New Revision: 264111
URL: http://llvm.org/viewvc/llvm-project?rev=264111&view=rev
Log:
[LTO] Keep linkonce_odr symbols when appropriate.
Ensure we keep the symbol we need to before it reaches
the Writer (and hit an assertion), changing its linkage
from linkonce_odr to weak. For a more detailed description
of the problem, see PR19901 where a similar problem was
fixed for the gold plugin. Thanks to Rafael for providing
a testcase.
Added:
lld/trunk/test/ELF/lto/Inputs/linkonce-odr.ll
lld/trunk/test/ELF/lto/linkonce-odr.ll
Modified:
lld/trunk/ELF/LTO.cpp
Modified: lld/trunk/ELF/LTO.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.cpp?rev=264111&r1=264110&r2=264111&view=diff
==============================================================================
--- lld/trunk/ELF/LTO.cpp (original)
+++ lld/trunk/ELF/LTO.cpp Tue Mar 22 17:31:34 2016
@@ -82,10 +82,15 @@ void BitcodeCompiler::add(BitcodeFile &F
Keep.push_back(GV);
continue;
}
- if (!BitcodeFile::shouldSkip(Sym))
+ if (!BitcodeFile::shouldSkip(Sym)) {
+
+ if (GV->getLinkage() == llvm::GlobalValue::LinkOnceODRLinkage)
+ GV->setLinkage(GlobalValue::WeakODRLinkage);
+
if (SymbolBody *B = Bodies[BodyIndex++])
if (&B->repl() == B && isa<DefinedBitcode>(B))
Keep.push_back(GV);
+ }
}
Mover.move(Obj->takeModule(), Keep,
Added: lld/trunk/test/ELF/lto/Inputs/linkonce-odr.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/Inputs/linkonce-odr.ll?rev=264111&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/Inputs/linkonce-odr.ll (added)
+++ lld/trunk/test/ELF/lto/Inputs/linkonce-odr.ll Tue Mar 22 17:31:34 2016
@@ -0,0 +1,6 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define linkonce_odr void @f() {
+ ret void
+}
Added: lld/trunk/test/ELF/lto/linkonce-odr.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/linkonce-odr.ll?rev=264111&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/linkonce-odr.ll (added)
+++ lld/trunk/test/ELF/lto/linkonce-odr.ll Tue Mar 22 17:31:34 2016
@@ -0,0 +1,24 @@
+; REQUIRES: x86
+; RUN: llvm-as %p/Inputs/linkonce-odr.ll -o %t1.o
+; RUN: llc %s -o %t2.o -filetype=obj
+; RUN: ld.lld %t1.o %t2.o -o %t.so -shared
+; RUN: llvm-readobj -t %t.so | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+declare void @f()
+
+define void @g() {
+ call void @f() ret void
+}
+
+; Be sure that the linkonce_odr symbol 'f' is kept.
+; CHECK: Symbol {
+; CHECK: Name: f
+; CHECK: Value: 0x1010
+; CHECK: Size: 1
+; CHECK: Binding: Weak
+; CHECK: Type: Function
+; CHECK: Other: 0
+; CHECK: Section: .text
+; CHECK: }
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