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[LTO] Keep linkonce symbols when required. 

Similarly to how we do with linkonce_odr symbols already, but
change their linkage to weak.

llvm-svn: 264181
This commit is contained in:
Davide Italiano 2016-03-23 18:41:48 +00:00
parent 0e4898685f
commit bcd660a908
3 changed files with 32 additions and 1 deletions
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10
lld/ELF/LTO.cpp
View File

@ -85,8 +85,16 @@ void BitcodeCompiler::add(BitcodeFile &F) {
if (!BitcodeFile::shouldSkip(Sym)) {
if (SymbolBody *B = Bodies[BodyIndex++])
if (&B->repl() == B && isa<DefinedBitcode>(B)) {
if (GV->getLinkage() == llvm::GlobalValue::LinkOnceODRLinkage)
switch (GV->getLinkage()) {
default:
break;
case llvm::GlobalValue::LinkOnceAnyLinkage:
GV->setLinkage(GlobalValue::WeakAnyLinkage);
break;
case llvm::GlobalValue::LinkOnceODRLinkage:
GV->setLinkage(GlobalValue::WeakODRLinkage);
break;
}
Keep.push_back(GV);
}
}

6
lld/test/ELF/lto/Inputs/linkonce.ll Normal file
View File

@ -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 void @f() {
ret void
}

17
lld/test/ELF/lto/linkonce.ll Normal file
View File

@ -0,0 +1,17 @@
; REQUIRES: x86
; RUN: llvm-as %p/Inputs/linkonce.ll -o %t1.o
; RUN: llc %s -o %t2.o -filetype=obj
; RUN: ld.lld %t1.o %t2.o -o %t.so -shared -save-temps
; RUN: llvm-dis %t.so.lto.opt.bc -o - | 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 'f' is kept and has weak linkage.
; CHECK: define weak void @f()