COFF: Fix local absolute symbols.

Absolute symbols were always handled as external symbols, so if two
or more object files define the same absolute symbol, they would
conflict even if the symbol is private to each file.
This patch fixes that bug.

llvm-svn: 240756

lld/COFF/InputFiles.cpp

@@ -198,7 +198,7 @@ SymbolBody *ObjectFile::createSymbolBody(COFFSymbolRef Sym, const void *AuxP,
     // Skip special symbols.
     if (Name == "@comp.id" || Name == "@feat.00")
       return nullptr;
-    return new (Alloc) DefinedAbsolute(Name, Sym.getValue());
+    return new (Alloc) DefinedAbsolute(Name, Sym);
   }
   if (Sym.getSectionNumber() == llvm::COFF::IMAGE_SYM_DEBUG)
     return nullptr;

lld/COFF/Symbols.h

@@ -173,20 +173,26 @@ private:
 // Absolute symbols.
 class DefinedAbsolute : public Defined {
 public:
-  DefinedAbsolute(StringRef N, uint64_t VA)
-      : Defined(DefinedAbsoluteKind), Name(N), RVA(VA - Config->ImageBase) {}
+  DefinedAbsolute(StringRef N, COFFSymbolRef S)
+      : Defined(DefinedAbsoluteKind), Name(N), VA(S.getValue()),
+        External(S.isExternal()) {}
+
+  DefinedAbsolute(StringRef N, uint64_t V)
+      : Defined(DefinedAbsoluteKind), Name(N), VA(V) {}
 
   static bool classof(const SymbolBody *S) {
     return S->kind() == DefinedAbsoluteKind;
   }
 
   StringRef getName() override { return Name; }
-  uint64_t getRVA() override { return RVA; }
+  uint64_t getRVA() override { return VA - Config->ImageBase; }
   uint64_t getFileOff() override { llvm_unreachable("internal error"); }
+  bool isExternal() override { return External; }
 
 private:
   StringRef Name;
-  uint64_t RVA;
+  uint64_t VA;
+  bool External = true;
 };
 
 // This class represents a symbol defined in an archive file. It is

lld/test/COFF/internal.test

@@ -0,0 +1,42 @@
+# Test that non-external symbols don't conflict
+
+# RUN: yaml2obj < %s > %t1.obj
+# RUN: yaml2obj < %s > %t2.obj
+# RUN: yaml2obj < %p/Inputs/ret42.yaml > %t3.obj
+# RUN: lld -flavor link2 /out:%t.exe %t1.obj %t2.obj %t3.obj
+
+---
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: []
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     000000000000
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          6
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            defined
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            absolute
+    Value:           0xdeadbeef
+    SectionNumber:   -1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+...