Update llvm/clang to trunk r126547.

There are several bugfixes in this update, but the most important one is
to ensure __start_ and __stop_ symbols for linker sets and kernel module
metadata are always emitted in object files:

  http://llvm.org/bugs/show_bug.cgi?id=9292

Before this fix, if you compiled kernel modules with clang, they would
not be properly processed by kldxref, and if they had any dependencies,
the kernel would fail to load those.  Another problem occurred when
attempting to mount a tmpfs filesystem, which would result in 'operation
not supported by device'.

2 files changed, 12 insertions, 7 deletions

diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 43e8990..9cb882e 100644
--- a/contrib/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/contrib/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -764,7 +764,7 @@ bool AsmPrinter::doFinalization(Module &M) {
       continue;
 
     MCSymbol *Name = Mang->getSymbol(&F);
-    EmitVisibility(Name, V);
+    EmitVisibility(Name, V, false);
   }
 
   // Finalize debug and EH information.
@@ -1820,13 +1820,17 @@ void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
   }
 }
 
-void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
+void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
+                                bool IsDefinition) const {
   MCSymbolAttr Attr = MCSA_Invalid;
   
   switch (Visibility) {
   default: break;
   case GlobalValue::HiddenVisibility:
-    Attr = MAI->getHiddenVisibilityAttr();
+    if (IsDefinition)
+      Attr = MAI->getHiddenVisibilityAttr();
+    else
+      Attr = MAI->getHiddenDeclarationVisibilityAttr();
     break;
   case GlobalValue::ProtectedVisibility:
     Attr = MAI->getProtectedVisibilityAttr();
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 5106d57..780fa40 100644
--- a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Analysis/DIBuilder.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
@@ -644,12 +645,12 @@ void DwarfDebug::addComplexAddress(DbgVariable *&DV, DIE *Die,
   for (unsigned i = 0, N = DV->getNumAddrElements(); i < N; ++i) {
     uint64_t Element = DV->getAddrElement(i);
 
-    if (Element == DIFactory::OpPlus) {
+    if (Element == DIBuilder::OpPlus) {
       addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
       addUInt(Block, 0, dwarf::DW_FORM_udata, DV->getAddrElement(++i));
-    } else if (Element == DIFactory::OpDeref) {
+    } else if (Element == DIBuilder::OpDeref) {
       addUInt(Block, 0, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
-    } else llvm_unreachable("unknown DIFactory Opcode");
+    } else llvm_unreachable("unknown DIBuilder Opcode");
   }
 
   // Now attach the location information to the DIE.
@@ -1894,7 +1895,7 @@ void DwarfDebug::constructCompileUnit(const MDNode *N) {
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
   addString(Die, dwarf::DW_AT_producer, dwarf::DW_FORM_string,
             DIUnit.getProducer());
-  addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data1,
+  addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
           DIUnit.getLanguage());
   addString(Die, dwarf::DW_AT_name, dwarf::DW_FORM_string, FN);
   // Use DW_AT_entry_pc instead of DW_AT_low_pc/DW_AT_high_pc pair. This