[lld] r218262 - Revert "[ELF] Fix linking when a regular object defines a symbol that is used in a DSO"

[Rui Ueyama]

Author: ruiu
Date: Mon Sep 22 13:08:34 2014
New Revision: 218262

URL: http://llvm.org/viewvc/llvm-project?rev=218262&view=rev
Log:
Revert "[ELF] Fix linking when a regular object defines a symbol that is used in a DSO"

This commit reverts r218259 because it needed to be checked in with
a few binary files for the test.

Removed:
    lld/trunk/test/elf/undef-from-dso-to-main.test
Modified:
    lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h
    lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp
    lld/trunk/lib/ReaderWriter/ELF/OutputELFWriter.h

Modified: lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h?rev=218262&r1=218261&r2=218262&view=diff
==============================================================================
--- lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h (original)
+++ lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h Mon Sep 22 13:08:34 2014
@@ -262,8 +262,8 @@ public:
 
   void setCreateSeparateROSegment() { _mergeRODataToTextSegment = false; }
 
-  bool hasCoalescedSharedLibPair(StringRef name) const {
-    return _sharedLibCoalescedSymbols.count(name) != 0;
+  bool hasCoalescedWeakPair(StringRef name) const {
+    return _weakCoalescedSymbols.count(name) != 0;
   }
 
 private:
@@ -300,7 +300,7 @@ protected:
   StringRefVector _rpathList;
   StringRefVector _rpathLinkList;
   std::map<std::string, uint64_t> _absoluteSymbols;
-  llvm::StringSet<> _sharedLibCoalescedSymbols;
+  llvm::StringSet<> _weakCoalescedSymbols;
 };
 } // end namespace lld
 

Modified: lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp?rev=218262&r1=218261&r2=218262&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/ELFLinkingContext.cpp Mon Sep 22 13:08:34 2014
@@ -241,6 +241,11 @@ std::unique_ptr<File> ELFLinkingContext:
   return std::move(undefinedSymFile);
 }
 
+static bool isSharedWeakAtom(const UndefinedAtom *ua) {
+  return ua->canBeNull() != UndefinedAtom::canBeNullNever &&
+         isa<SharedLibraryFile>(ua->file());
+}
+
 void ELFLinkingContext::notifySymbolTableCoalesce(const Atom *existingAtom,
                                                   const Atom *newAtom,
                                                   bool &useNew) {
@@ -254,12 +259,11 @@ void ELFLinkingContext::notifySymbolTabl
     ua = dyn_cast<UndefinedAtom>(existingAtom);
   }
 
-  if (da && ua && da->scope() == Atom::scopeGlobal &&
-      isa<SharedLibraryFile>(ua->file()))
-    // If strong defined atom coalesces away an atom declared
-    // in the shared object the strong atom needs to be dynamically exported.
+  if (da && ua && da->scope() == Atom::scopeGlobal && isSharedWeakAtom(ua))
+    // If strong defined atom coalesces away weak atom declared
+    // in the shared object the strong atom needs to be dynamicaly exported.
     // Save its name.
-    _sharedLibCoalescedSymbols.insert(ua->name());
+    _weakCoalescedSymbols.insert(ua->name());
 }
 
 } // end namespace lld

Modified: lld/trunk/lib/ReaderWriter/ELF/OutputELFWriter.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/OutputELFWriter.h?rev=218262&r1=218261&r2=218262&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/OutputELFWriter.h (original)
+++ lld/trunk/lib/ReaderWriter/ELF/OutputELFWriter.h Mon Sep 22 13:08:34 2014
@@ -183,7 +183,7 @@ void OutputELFWriter<ELFT>::buildDynamic
       for (const auto &atom : section->atoms()) {
         const DefinedAtom *da = dyn_cast<const DefinedAtom>(atom->_atom);
         if (da && (da->dynamicExport() == DefinedAtom::dynamicExportAlways ||
-                   _context.hasCoalescedSharedLibPair(da->name())))
+                   _context.hasCoalescedWeakPair(da->name())))
           _dynamicSymbolTable->addSymbol(atom->_atom, section->ordinal(),
                                          atom->_virtualAddr, atom);
       }

Removed: lld/trunk/test/elf/undef-from-dso-to-main.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/undef-from-dso-to-main.test?rev=218261&view=auto
==============================================================================
--- lld/trunk/test/elf/undef-from-dso-to-main.test (original)
+++ lld/trunk/test/elf/undef-from-dso-to-main.test (removed)
@@ -1,7 +0,0 @@
-# Tests that a reference from a DSO to a regular object
-# forces the final executable to export the symbol.
-
-RUN: lld -flavor gnu  -target x86_64 %p/Inputs/defobj.o -L%p/Inputs -lundef2 -o %t1
-RUN: llvm-readobj -dyn-symbols %t1 | FileCheck -check-prefix CHECKSYMS %s
-
-CHECKSYMS: myexportedsymbol