[lld] r261881 - Add support for weak symbols in LTO.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Thu Feb 25 10:25:41 2016
New Revision: 261881

URL: http://llvm.org/viewvc/llvm-project?rev=261881&view=rev
Log:
Add support for weak symbols in LTO.

Added:
    lld/trunk/test/ELF/lto/weak.ll
Modified:
    lld/trunk/ELF/InputFiles.cpp
    lld/trunk/ELF/Symbols.cpp
    lld/trunk/ELF/Symbols.h

Modified: lld/trunk/ELF/InputFiles.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.cpp?rev=261881&r1=261880&r2=261881&view=diff
==============================================================================
--- lld/trunk/ELF/InputFiles.cpp (original)
+++ lld/trunk/ELF/InputFiles.cpp Thu Feb 25 10:25:41 2016
@@ -450,10 +450,12 @@ void BitcodeFile::parse() {
     Sym.printName(OS);
     StringRef NameRef = Saver.save(StringRef(Name));
     SymbolBody *Body;
-    if (Sym.getFlags() & BasicSymbolRef::SF_Undefined)
+    uint32_t Flags = Sym.getFlags();
+    if (Flags & BasicSymbolRef::SF_Undefined)
       Body = new (Alloc) Undefined(NameRef, false, STV_DEFAULT, false);
     else
-      Body = new (Alloc) DefinedBitcode(NameRef);
+      Body =
+          new (Alloc) DefinedBitcode(NameRef, Flags & BasicSymbolRef::SF_Weak);
     SymbolBodies.push_back(Body);
   }
 }

Modified: lld/trunk/ELF/Symbols.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.cpp?rev=261881&r1=261880&r2=261881&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.cpp (original)
+++ lld/trunk/ELF/Symbols.cpp Thu Feb 25 10:25:41 2016
@@ -161,8 +161,8 @@ Defined::Defined(Kind K, StringRef Name,
                  bool IsTls, bool IsFunction)
     : SymbolBody(K, Name, IsWeak, Visibility, IsTls, IsFunction) {}
 
-DefinedBitcode::DefinedBitcode(StringRef Name)
-    : Defined(DefinedBitcodeKind, Name, false, STV_DEFAULT, false, false) {}
+DefinedBitcode::DefinedBitcode(StringRef Name, bool IsWeak)
+    : Defined(DefinedBitcodeKind, Name, IsWeak, STV_DEFAULT, false, false) {}
 
 bool DefinedBitcode::classof(const SymbolBody *S) {
   return S->kind() == DefinedBitcodeKind;

Modified: lld/trunk/ELF/Symbols.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.h?rev=261881&r1=261880&r2=261881&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.h (original)
+++ lld/trunk/ELF/Symbols.h Thu Feb 25 10:25:41 2016
@@ -190,7 +190,7 @@ public:
 
 class DefinedBitcode : public Defined {
 public:
-  DefinedBitcode(StringRef Name);
+  DefinedBitcode(StringRef Name, bool IsWeak);
   static bool classof(const SymbolBody *S);
 };
 

Added: lld/trunk/test/ELF/lto/weak.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/weak.ll?rev=261881&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/weak.ll (added)
+++ lld/trunk/test/ELF/lto/weak.ll Thu Feb 25 10:25:41 2016
@@ -0,0 +1,16 @@
+; REQUIRES: x86
+; RUN: llvm-as %s -o %t.o
+; RUN: ld.lld -m elf_x86_64 %t.o %t.o -o %t.so -shared
+; RUN: llvm-readobj -t %t.so | FileCheck %s
+
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define weak void @f() {
+  ret void
+}
+
+; CHECK:      Name: f
+; CHECK-NEXT: Value: 0x1000
+; CHECK-NEXT: Size: 1
+; CHECK-NEXT: Binding: Weak