[lld] r262848 - Add support for common symbols.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Mon Mar  7 13:15:57 2016
New Revision: 262848

URL: http://llvm.org/viewvc/llvm-project?rev=262848&view=rev
Log:
Add support for common symbols.

Added:
    lld/trunk/test/ELF/lto/Inputs/common.s
    lld/trunk/test/ELF/lto/common.ll
Modified:
    lld/trunk/ELF/InputFiles.cpp

Modified: lld/trunk/ELF/InputFiles.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.cpp?rev=262848&r1=262847&r2=262848&view=diff
==============================================================================
--- lld/trunk/ELF/InputFiles.cpp (original)
+++ lld/trunk/ELF/InputFiles.cpp Mon Mar  7 13:15:57 2016
@@ -439,7 +439,8 @@ void BitcodeFile::parse(DenseSet<StringR
 
   for (const BasicSymbolRef &Sym : Obj->symbols()) {
     uint8_t Visibility = STV_DEFAULT;
-    if (const GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl())) {
+    const GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl());
+    if (GV) {
       if (const Comdat *C = GV->getComdat())
         if (!KeptComdats.count(C))
           continue;
@@ -454,10 +455,16 @@ void BitcodeFile::parse(DenseSet<StringR
     SymbolBody *Body;
     uint32_t Flags = Sym.getFlags();
     bool IsWeak = Flags & BasicSymbolRef::SF_Weak;
-    if (Flags & BasicSymbolRef::SF_Undefined)
+    if (Flags & BasicSymbolRef::SF_Undefined) {
       Body = new (Alloc) Undefined(NameRef, IsWeak, Visibility, false);
-    else
+    } else if (Flags & BasicSymbolRef::SF_Common) {
+      const DataLayout &DL = M.getDataLayout();
+      uint64_t Size = DL.getTypeAllocSize(GV->getValueType());
+      Body = new (Alloc)
+          DefinedCommon(NameRef, Size, GV->getAlignment(), IsWeak, Visibility);
+    } else {
       Body = new (Alloc) DefinedBitcode(NameRef, IsWeak, Visibility);
+    }
     SymbolBodies.push_back(Body);
   }
 }

Added: lld/trunk/test/ELF/lto/Inputs/common.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/Inputs/common.s?rev=262848&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/Inputs/common.s (added)
+++ lld/trunk/test/ELF/lto/Inputs/common.s Mon Mar  7 13:15:57 2016
@@ -0,0 +1 @@
+        .comm   a,8,4

Added: lld/trunk/test/ELF/lto/common.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/common.ll?rev=262848&view=auto
==============================================================================
--- lld/trunk/test/ELF/lto/common.ll (added)
+++ lld/trunk/test/ELF/lto/common.ll Mon Mar  7 13:15:57 2016
@@ -0,0 +1,31 @@
+; REQUIRES: x86
+; RUN: llvm-as %s -o %t1.o
+; RUN: llvm-mc -triple=x86_64-pc-linux %p/Inputs/common.s -o %t2.o -filetype=obj
+; RUN: ld.lld %t1.o %t2.o -o %t.so -shared
+; RUN: llvm-readobj -s -t %t.so | FileCheck %s
+
+; CHECK:      Name: .bss
+; CHECK-NEXT: Type: SHT_NOBITS
+; CHECK-NEXT: Flags [
+; CHECK-NEXT:   SHF_ALLOC
+; CHECK-NEXT:   SHF_WRITE
+; CHECK-NEXT: ]
+; CHECK-NEXT: Address:
+; CHECK-NEXT: Offset:
+; CHECK-NEXT: Size: 8
+; CHECK-NEXT: Link: 0
+; CHECK-NEXT: Info: 0
+; CHECK-NEXT: AddressAlignment: 8
+
+; CHECK:      Name: a
+; CHECK-NEXT: Value:
+; CHECK-NEXT: Size: 8
+; CHECK-NEXT: Binding: Global
+; CHECK-NEXT: Type: Object
+; CHECK-NEXT: Other: 0
+; CHECK-NEXT: Section: .bss
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at a = common global i32 0, align 8