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'.

1 files changed, 10 insertions, 7 deletions

diff --git a/contrib/llvm/lib/MC/MCSectionMachO.cpp b/contrib/llvm/lib/MC/MCSectionMachO.cpp
index b897c0b..577e93a 100644
--- a/contrib/llvm/lib/MC/MCSectionMachO.cpp
+++ b/contrib/llvm/lib/MC/MCSectionMachO.cpp
@@ -101,16 +101,18 @@ void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI,
     return;
   }
 
-  OS << ',';
-
   unsigned SectionType = TAA & MCSectionMachO::SECTION_TYPE;
   assert(SectionType <= MCSectionMachO::LAST_KNOWN_SECTION_TYPE &&
          "Invalid SectionType specified!");
 
-  if (SectionTypeDescriptors[SectionType].AssemblerName)
+  if (SectionTypeDescriptors[SectionType].AssemblerName) {
+    OS << ',';
     OS << SectionTypeDescriptors[SectionType].AssemblerName;
-  else
-    OS << "<<" << SectionTypeDescriptors[SectionType].EnumName << ">>";
+  } else {
+    // If we have no name for the attribute, stop here.
+    OS << '\n';
+    return;
+  }
 
   // If we don't have any attributes, we're done.
   unsigned SectionAttrs = TAA & MCSectionMachO::SECTION_ATTRIBUTES;
@@ -125,7 +127,9 @@ void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI,
 
   // Check each attribute to see if we have it.
   char Separator = ',';
-  for (unsigned i = 0; SectionAttrDescriptors[i].AttrFlag; ++i) {
+  for (unsigned i = 0;
+       SectionAttrs != 0 && SectionAttrDescriptors[i].AttrFlag;
+       ++i) {
     // Check to see if we have this attribute.
     if ((SectionAttrDescriptors[i].AttrFlag & SectionAttrs) == 0)
       continue;
@@ -207,7 +211,6 @@ std::string MCSectionMachO::ParseSectionSpecifier(StringRef Spec,        // In.
            "between 1 and 16 characters";
 
   // If there is no comma after the section, we're done.
-  TAA = 0;
   StubSize = 0;
   if (Comma.second.empty())
     return "";