Index: include/lld/Core/Atom.h
===================================================================
--- include/lld/Core/Atom.h
+++ include/lld/Core/Atom.h
@@ -36,11 +36,14 @@
   /// The scope in which this atom is acessible to other atoms.
   enum Scope {
     scopeTranslationUnit,  ///< Accessible only to atoms in the same translation
-                           ///  unit (e.g. a C static).
+                           ///  unit (e.g. visibility=internal).
     scopeLinkageUnit,      ///< Accessible to atoms being linked but not visible
                            ///  to runtime loader (e.g. visibility=hidden).
-    scopeGlobal            ///< Accessible to all atoms and visible to runtime
+    scopeGlobal,           ///< Accessible to all atoms and visible to runtime
                            ///  loader (e.g. visibility=default).
+    scopeProtected         ///< Accessible to all atoms and visible to runtime
+                           ///  loader, but can't be overriden
+                           ///  (e.g. visibility=protected).
   };
 
 
Index: lib/ReaderWriter/ELF/SectionChunks.h
===================================================================
--- lib/ReaderWriter/ELF/SectionChunks.h
+++ lib/ReaderWriter/ELF/SectionChunks.h
@@ -729,7 +729,7 @@
 template <class ELFT>
 void SymbolTable<ELFT>::addDefinedAtom(Elf_Sym &sym, const DefinedAtom *da,
                                        int64_t addr) {
-  unsigned char binding = 0, type = 0;
+  unsigned char binding = 0, type = 0, visibility = 0;
   sym.st_size = da->size();
   DefinedAtom::ContentType ct;
   switch (ct = da->contentType()) {
@@ -773,6 +773,21 @@
   else
     binding = llvm::ELF::STB_GLOBAL;
 
+  switch (DefinedAtom::Scope vt = da->scope()) {
+    case DefinedAtom::scopeLinkageUnit:
+      visibility = llvm::ELF::STV_HIDDEN;
+      break;
+    case DefinedAtom::scopeTranslationUnit:
+      visibility = llvm::ELF::STV_INTERNAL;
+      break;
+    case DefinedAtom::scopeGlobal:
+      visibility = llvm::ELF::STV_DEFAULT;
+      break;
+    case DefinedAtom::scopeProtected:
+      visibility = llvm::ELF::STV_PROTECTED;
+      break;
+  }
+  sym.setVisibility(visibility);
   sym.setBindingAndType(binding, type);
 }
 
@@ -784,6 +799,8 @@
   sym.st_shndx = llvm::ELF::SHN_ABS;
   switch (aa->scope()) {
   case AbsoluteAtom::scopeLinkageUnit:
+    // XXX this is unsafe because it might override
+    // the other bits of st_other.
     sym.st_other = llvm::ELF::STV_HIDDEN;
     binding = llvm::ELF::STB_LOCAL;
     break;
@@ -793,6 +810,8 @@
   case AbsoluteAtom::scopeGlobal:
     binding = llvm::ELF::STB_GLOBAL;
     break;
+  case AbsoluteAtom::scopeProtected:
+    break;
   }
   sym.st_value = addr;
   sym.setBindingAndType(binding, type);
Index: lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
===================================================================
--- lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
+++ lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp
@@ -766,8 +766,8 @@
       return std::error_code();
     }
     break;
-  }
   llvm_unreachable("atom->scope() unknown enum value");
+  }
 }
 
 std::error_code Util::addSymbols(const lld::File &atomFile,
Index: test/elf/Mips/mips-options-gp0.test
===================================================================
--- test/elf/Mips/mips-options-gp0.test
+++ test/elf/Mips/mips-options-gp0.test
@@ -10,7 +10,7 @@
 # SYM-NEXT: Size: 4
 # SYM-NEXT: Binding: Local (0x0)
 # SYM-NEXT: Type: Function (0x2)
-# SYM-NEXT: Other: 0
+# SYM-NEXT: Other: 1
 # SYM-NEXT: Section: .text (0x4)
 
 # SYM:      Name: _gp (34)
Index: test/elf/Mips/rel-gprel16.test
===================================================================
--- test/elf/Mips/rel-gprel16.test
+++ test/elf/Mips/rel-gprel16.test
@@ -10,7 +10,7 @@
 # SYM-NEXT: Size: 4
 # SYM-NEXT: Binding: Local (0x0)
 # SYM-NEXT: Type: Function (0x2)
-# SYM-NEXT: Other: 0
+# SYM-NEXT: Other: 1
 # SYM-NEXT: Section: .text (0x4)
 
 # SYM:      Name: G1 (4)
Index: test/elf/Mips/rel-gprel32.test
===================================================================
--- test/elf/Mips/rel-gprel32.test
+++ test/elf/Mips/rel-gprel32.test
@@ -10,7 +10,7 @@
 # SYM-NEXT: Size: 4
 # SYM-NEXT: Binding: Local (0x0)
 # SYM-NEXT: Type: Function (0x2)
-# SYM-NEXT: Other: 0
+# SYM-NEXT: Other: 1
 # SYM-NEXT: Section: .text (0x5)
 #
 # SYM:      Name: _gp (212)