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'.

3 files changed, 18 insertions, 9 deletions

diff --git a/contrib/llvm/tools/clang/lib/Driver/ToolChain.cpp b/contrib/llvm/tools/clang/lib/Driver/ToolChain.cpp
index e4051a1..e305683 100644
--- a/contrib/llvm/tools/clang/lib/Driver/ToolChain.cpp
+++ b/contrib/llvm/tools/clang/lib/Driver/ToolChain.cpp
@@ -198,7 +198,8 @@ void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &Args,
 
   switch (Type) {
   case ToolChain::CST_Libcxx:
-    CmdArgs.push_back("-cxx-system-include");
+    CmdArgs.push_back("-nostdinc++");
+    CmdArgs.push_back("-cxx-isystem");
     CmdArgs.push_back("/usr/include/c++/v1");
     break;
 
diff --git a/contrib/llvm/tools/clang/lib/Driver/ToolChains.cpp b/contrib/llvm/tools/clang/lib/Driver/ToolChains.cpp
index d94de20..422c572 100644
--- a/contrib/llvm/tools/clang/lib/Driver/ToolChains.cpp
+++ b/contrib/llvm/tools/clang/lib/Driver/ToolChains.cpp
@@ -46,7 +46,7 @@ Darwin::Darwin(const HostInfo &Host, const llvm::Triple& Triple)
   // Compute the initial Darwin version based on the host.
   bool HadExtra;
   std::string OSName = Triple.getOSName();
-  if (!Driver::GetReleaseVersion(&OSName[6],
+  if (!Driver::GetReleaseVersion(&OSName.c_str()[6],
                                  DarwinVersion[0], DarwinVersion[1],
                                  DarwinVersion[2], HadExtra))
     getDriver().Diag(clang::diag::err_drv_invalid_darwin_version) << OSName;
@@ -1271,6 +1271,7 @@ Tool &AuroraUX::SelectTool(const Compilation &C, const JobAction &JA) const {
 /// Linux toolchain (very bare-bones at the moment).
 
 enum LinuxDistro {
+  ArchLinux,
   DebianLenny,
   DebianSqueeze,
   Exherbo,
@@ -1367,6 +1368,9 @@ static LinuxDistro DetectLinuxDistro(llvm::Triple::ArchType Arch) {
   if (!llvm::sys::fs::exists("/etc/exherbo-release", Exists) && Exists)
     return Exherbo;
 
+  if (!llvm::sys::fs::exists("/etc/arch-release", Exists) && Exists)
+    return ArchLinux;
+
   return UnknownDistro;
 }
 
@@ -1436,8 +1440,9 @@ Linux::Linux(const HostInfo &Host, const llvm::Triple &Triple)
       GccTriple = "i586-suse-linux";
   }
 
-  const char* GccVersions[] = {"4.5.1", "4.5", "4.4.5", "4.4.4", "4.4.3", "4.4",
-                               "4.3.4", "4.3.3", "4.3.2"};
+  const char* GccVersions[] = {"4.5.2", "4.5.1", "4.5", "4.4.5", "4.4.4",
+                               "4.4.3", "4.4", "4.3.4", "4.3.3", "4.3.2",
+                               "4.3"};
   std::string Base = "";
   for (unsigned i = 0; i < sizeof(GccVersions)/sizeof(char*); ++i) {
     std::string Suffix = GccTriple + "/" + GccVersions[i];
@@ -1498,6 +1503,9 @@ Linux::Linux(const HostInfo &Host, const llvm::Triple &Triple)
       Distro == UbuntuKarmic)
     ExtraOpts.push_back("--build-id");
 
+  if (Distro == ArchLinux)
+    Lib = "lib";
+
   Paths.push_back(Base + Suffix);
   if (HasMultilib(Arch, Distro)) {
     if (IsOpenSuse(Distro) && Is32Bits)
diff --git a/contrib/llvm/tools/clang/lib/Driver/Tools.cpp b/contrib/llvm/tools/clang/lib/Driver/Tools.cpp
index 0697d54..a2c95fc 100644
--- a/contrib/llvm/tools/clang/lib/Driver/Tools.cpp
+++ b/contrib/llvm/tools/clang/lib/Driver/Tools.cpp
@@ -1552,10 +1552,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       CmdArgs.push_back("-fobjc-default-synthesize-properties");
     }
 
-    // -fobjc-exceptions is default.
-    if (!Args.hasFlag(options::OPT_fobjc_exceptions, 
-                      options::OPT_fno_objc_exceptions))
-      CmdArgs.push_back("-fno-objc-exceptions");
+    // -fno-objc-exceptions is default.
+    if (IsRewriter || Args.hasFlag(options::OPT_fobjc_exceptions, 
+                                   options::OPT_fno_objc_exceptions))
+      CmdArgs.push_back("-fobjc-exceptions");
   }
 
   if (!Args.hasFlag(options::OPT_fassume_sane_operator_new,
@@ -3091,7 +3091,7 @@ void openbsd::Link::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-lgcc");
 
     if (Args.hasArg(options::OPT_pthread))
-      CmdArgs.push_back("-pthread");
+      CmdArgs.push_back("-lpthread");
     if (!Args.hasArg(options::OPT_shared))
       CmdArgs.push_back("-lc");
     CmdArgs.push_back("-lgcc");