From eb3eb88fb76f27da147c3cdb36797272f1d769a6 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Fri, 23 Jan 2015 04:44:35 +0000
Subject: [PATCH] Add STB_GNU_UNIQUE to the ELF writer.

This lets llvm-mc assemble files produced by gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226895 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/ELF.h       |  1 +
 lib/MC/MCELF.cpp                 |  4 ++--
 lib/MC/MCELFStreamer.cpp         |  8 +++++++-
 test/MC/ELF/type.s               | 12 +++++++++++-
 tools/llvm-readobj/ELFDumper.cpp |  7 ++++---
 5 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/include/llvm/Support/ELF.h b/include/llvm/Support/ELF.h
index 3d49205fa16..ef7db394573 100644
--- a/include/llvm/Support/ELF.h
+++ b/include/llvm/Support/ELF.h
@@ -761,6 +761,7 @@ enum {
   STB_LOCAL = 0,   // Local symbol, not visible outside obj file containing def
   STB_GLOBAL = 1,  // Global symbol, visible to all object files being combined
   STB_WEAK = 2,    // Weak symbol, like global but lower-precedence
+  STB_GNU_UNIQUE = 10,
   STB_LOOS   = 10, // Lowest operating system-specific binding type
   STB_HIOS   = 12, // Highest operating system-specific binding type
   STB_LOPROC = 13, // Lowest processor-specific binding type
diff --git a/lib/MC/MCELF.cpp b/lib/MC/MCELF.cpp
index 386c2099f2e..369063431fe 100644
--- a/lib/MC/MCELF.cpp
+++ b/lib/MC/MCELF.cpp
@@ -21,7 +21,7 @@ namespace llvm {
 
 void MCELF::SetBinding(MCSymbolData &SD, unsigned Binding) {
   assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
-         Binding == ELF::STB_WEAK);
+         Binding == ELF::STB_WEAK || Binding == ELF::STB_GNU_UNIQUE);
   uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift);
   SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
 }
@@ -29,7 +29,7 @@ void MCELF::SetBinding(MCSymbolData &SD, unsigned Binding) {
 unsigned MCELF::GetBinding(const MCSymbolData &SD) {
   uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift;
   assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
-         Binding == ELF::STB_WEAK);
+         Binding == ELF::STB_WEAK || Binding == ELF::STB_GNU_UNIQUE);
   return Binding;
 }
 
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index bdc4a8410fb..5cfcfe5874e 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -171,10 +171,16 @@ bool MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
     return false;
 
   case MCSA_NoDeadStrip:
-  case MCSA_ELF_TypeGnuUniqueObject:
     // Ignore for now.
     break;
 
+  case MCSA_ELF_TypeGnuUniqueObject:
+    MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), ELF::STT_OBJECT));
+    MCELF::SetBinding(SD, ELF::STB_GNU_UNIQUE);
+    SD.setExternal(true);
+    BindingExplicitlySet.insert(Symbol);
+    break;
+
   case MCSA_Global:
     MCELF::SetBinding(SD, ELF::STB_GLOBAL);
     SD.setExternal(true);
diff --git a/test/MC/ELF/type.s b/test/MC/ELF/type.s
index c82d3006cfe..f7745d88ea3 100644
--- a/test/MC/ELF/type.s
+++ b/test/MC/ELF/type.s
@@ -9,8 +9,8 @@ foo:
         .type bar,@object
 bar:
 
-// Test that gnu_unique_object is accepted.
         .type zed,@gnu_unique_object
+zed:
 
 obj:
         .global obj
@@ -310,3 +310,13 @@ alias12:
 // CHECK-NEXT:     Other: 0
 // CHECK-NEXT:     Section: .text (0x1)
 // CHECK-NEXT:   }
+// CHECK-NEXT:   Symbol {
+// CHECK-NEXT:     Name: zed (32)
+// CHECK-NEXT:     Value: 0x0
+// CHECK-NEXT:     Size: 0
+// CHECK-NEXT:     Binding: Unique (0xA)
+// CHECK-NEXT:     Type: Object (0x1)
+// CHECK-NEXT:     Other: 0
+// CHECK-NEXT:     Section: .text (0x1)
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]
diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp
index d68c78682d2..e4b760172a3 100644
--- a/tools/llvm-readobj/ELFDumper.cpp
+++ b/tools/llvm-readobj/ELFDumper.cpp
@@ -372,9 +372,10 @@ static const EnumEntry<unsigned> ElfMachineType[] = {
 };
 
 static const EnumEntry<unsigned> ElfSymbolBindings[] = {
-  { "Local",  ELF::STB_LOCAL  },
-  { "Global", ELF::STB_GLOBAL },
-  { "Weak",   ELF::STB_WEAK   }
+  { "Local",  ELF::STB_LOCAL        },
+  { "Global", ELF::STB_GLOBAL       },
+  { "Weak",   ELF::STB_WEAK         },
+  { "Unique", ELF::STB_GNU_UNIQUE   }
 };
 
 static const EnumEntry<unsigned> ElfSymbolTypes[] = {