[lld] r261374 - Handle undef symbols in LTO.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Fri Feb 19 16:50:16 2016
New Revision: 261374

URL: http://llvm.org/viewvc/llvm-project?rev=261374&view=rev
Log:
Handle undef symbols in LTO.

This also handles bc files is archives.

Added:
    lld/trunk/test/ELF/lto/Inputs/
    lld/trunk/test/ELF/lto/Inputs/archive.ll
    lld/trunk/test/ELF/lto/archive.ll
Modified:
    lld/trunk/ELF/InputFiles.cpp
    lld/trunk/ELF/Symbols.cpp

Modified: lld/trunk/ELF/InputFiles.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.cpp?rev=261374&r1=261373&r2=261374&view=diff
==============================================================================
--- lld/trunk/ELF/InputFiles.cpp (original)
+++ lld/trunk/ELF/InputFiles.cpp Fri Feb 19 16:50:16 2016
@@ -446,7 +446,11 @@ void BitcodeFile::parse() {
     raw_svector_ostream OS(Name);
     Sym.printName(OS);
     StringRef NameRef = Saver.save(StringRef(Name));
-    SymbolBody *Body = new (Alloc) DefinedBitcode(NameRef);
+    SymbolBody *Body;
+    if (Sym.getFlags() & object::BasicSymbolRef::SF_Undefined)
+      Body = new (Alloc) Undefined(NameRef, false, STV_DEFAULT, false);
+    else
+      Body = new (Alloc) DefinedBitcode(NameRef);
     SymbolBodies.push_back(Body);
   }
 }

Modified: lld/trunk/ELF/Symbols.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.cpp?rev=261374&r1=261373&r2=261374&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.cpp (original)
+++ lld/trunk/ELF/Symbols.cpp Fri Feb 19 16:50:16 2016
@@ -209,6 +209,13 @@ std::unique_ptr<InputFile> Lazy::getMemb
   // read from the library.
   if (MBRef.getBuffer().empty())
     return std::unique_ptr<InputFile>(nullptr);
+
+  if (sys::fs::identify_magic(MBRef.getBuffer()) ==
+      sys::fs::file_magic::bitcode) {
+    auto Ret = make_unique<BitcodeFile>(MBRef);
+    Ret->ArchiveName = File->getName();
+    return std::move(Ret);
+  }
   return createObjectFile(MBRef, File->getName());
 }
 

Added: lld/trunk/test/ELF/lto/Inputs/archive.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/Inputs/archive.ll?rev=261374&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/Inputs/archive.ll (added)
+++ lld/trunk/test/ELF/lto/Inputs/archive.ll Fri Feb 19 16:50:16 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 void @f() {
+  ret void
+}

Added: lld/trunk/test/ELF/lto/archive.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/archive.ll?rev=261374&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/archive.ll (added)
+++ lld/trunk/test/ELF/lto/archive.ll Fri Feb 19 16:50:16 2016
@@ -0,0 +1,35 @@
+; REQUIRES: x86
+; RUN: llvm-as %S/Inputs/archive.ll -o %t1.o
+; RUN: rm -f %t.a
+; RUN: llvm-ar rcs %t.a %t1.o
+; RUN: llvm-as %s -o %t2.o
+; RUN: ld.lld -m elf_x86_64 %t2.o %t.a -o %t3 -shared
+; RUN: llvm-readobj -t %t3 | FileCheck %s
+
+
+; CHECK:      Name: g (
+; CHECK-NEXT: Value:
+; CHECK-NEXT: Size:
+; CHECK-NEXT: Binding: Global
+; CHECK-NEXT: Type: Function
+; CHECK-NEXT: Other: 0
+; CHECK-NEXT: Section: .text
+
+; CHECK:      Name: f (
+; CHECK-NEXT: Value:
+; CHECK-NEXT: Size:
+; CHECK-NEXT: Binding: Global
+; CHECK-NEXT: Type: Function
+; CHECK-NEXT: Other: 0
+; CHECK-NEXT: Section: .text
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @g() {
+  call void @f()
+  ret void
+}
+
+declare void @f()
+