[lld] r246503 - Assign common symbols to the .bss output section.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Mon Aug 31 17:33:21 2015
New Revision: 246503

URL: http://llvm.org/viewvc/llvm-project?rev=246503&view=rev
Log:
Assign common symbols to the .bss output section.

Modified:
    lld/trunk/ELF/Writer.cpp
    lld/trunk/test/elf2/common.s
    lld/trunk/test/elf2/symbols.s

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=246503&r1=246502&r2=246503&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Mon Aug 31 17:33:21 2015
@@ -141,6 +141,8 @@ public:
 
   const SymbolTable &getSymTable() { return Table; }
 
+  OutputSection<ELFT> *BSSSec = nullptr;
+
 private:
   SymbolTable &Table;
 };
@@ -303,6 +305,7 @@ template <class ELFT> void SymbolTableSe
 
     const SectionChunk<ELFT> *Section = nullptr;
     const Elf_Sym *InputSym = nullptr;
+    OutputSection<ELFT> *Out = nullptr;
 
     switch (Body->kind()) {
     case SymbolBody::DefinedRegularKind: {
@@ -311,9 +314,12 @@ template <class ELFT> void SymbolTableSe
       Section = &Def->Section;
       break;
     }
+    case SymbolBody::DefinedCommonKind:
+      InputSym = &cast<ELFSymbolBody<ELFT>>(Body)->Sym;
+      Out = BSSSec;
+      break;
     case SymbolBody::UndefinedKind:
       assert(Body->isWeak() && "Should be defined by now");
-    case SymbolBody::DefinedCommonKind:
     case SymbolBody::DefinedAbsoluteKind:
       InputSym = &cast<ELFSymbolBody<ELFT>>(Body)->Sym;
       break;
@@ -330,11 +336,14 @@ template <class ELFT> void SymbolTableSe
       }
     }
 
-    if (Section) {
-      OutputSection<ELFT> *Out = Section->getOutputSection();
+    if (Section)
+      Out = Section->getOutputSection();
+
+    if (Out) {
       ESym->st_shndx = Out->getSectionIndex();
       uintX_t VA = Out->getVA();
-      VA += Section->getOutputSectionOff();
+      if (Section)
+        VA += Section->getOutputSectionOff();
       VA += InputSym->st_value;
       ESym->st_value = VA;
     }
@@ -424,8 +433,8 @@ template <class ELFT> void Writer<ELFT>:
     }
   }
 
-  OutputSection<ELFT> *BSSSec =
-      getSection(".bss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE);
+  SymTable.BSSSec = getSection(".bss", SHT_NOBITS, SHF_ALLOC | SHF_WRITE);
+  OutputSection<ELFT> *BSSSec = SymTable.BSSSec;
   uintX_t Off = BSSSec->getSize();
   // FIXME: Try to avoid the extra walk over all global symbols.
   for (auto &P : Symtab.getSymbols()) {

Modified: lld/trunk/test/elf2/common.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/common.s?rev=246503&r1=246502&r2=246503&view=diff
==============================================================================
--- lld/trunk/test/elf2/common.s (original)
+++ lld/trunk/test/elf2/common.s Mon Aug 31 17:33:21 2015
@@ -5,20 +5,20 @@
 // REQUIRES: x86
 
 // CHECK:      Name: sym2
-// CHECK-NEXT: Value: 0x0
+// CHECK-NEXT: Value: 0x1004
 // CHECK-NEXT: Size: 8
 // CHECK-NEXT: Binding: Global
 // CHECK-NEXT: Type: Object
 // CHECK-NEXT: Other: 0
-// CHECK-NEXT: Section: Undefined
+// CHECK-NEXT: Section: .bss
 
 // CHECK:      Name: sym1
-// CHECK-NEXT: Value: 0x0
+// CHECK-NEXT: Value: 0x1004
 // CHECK-NEXT: Size: 8
 // CHECK-NEXT: Binding: Global
 // CHECK-NEXT: Type: Object
 // CHECK-NEXT: Other: 0
-// CHECK-NEXT: Section: Undefined
+// CHECK-NEXT: Section: .bss
 
 
 .globl _start

Modified: lld/trunk/test/elf2/symbols.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/symbols.s?rev=246503&r1=246502&r2=246503&view=diff
==============================================================================
--- lld/trunk/test/elf2/symbols.s (original)
+++ lld/trunk/test/elf2/symbols.s Mon Aug 31 17:33:21 2015
@@ -106,12 +106,12 @@ abs = 0x123
 // CHECK-NEXT:   }
 // CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: common (34)
-// CHECK-NEXT:     Value: 0x0
+// CHECK-NEXT:     Value: 0x1008
 // CHECK-NEXT:     Size: 4
 // CHECK-NEXT:     Binding: Global (0x1)
 // CHECK-NEXT:     Type: Object (0x1)
 // CHECK-NEXT:     Other: 0
-// CHECK-NEXT:     Section: Undefined (0x0)
+// CHECK-NEXT:     Section: .bss
 // CHECK-NEXT:   }
 // CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: zed