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, 40 insertions, 33 deletions

diff --git a/contrib/llvm/tools/clang/lib/AST/Decl.cpp b/contrib/llvm/tools/clang/lib/AST/Decl.cpp
index 56db8c7..73fe117 100644
--- a/contrib/llvm/tools/clang/lib/AST/Decl.cpp
+++ b/contrib/llvm/tools/clang/lib/AST/Decl.cpp
@@ -266,8 +266,12 @@ static LinkageInfo getLVForNamespaceScopeDecl(const NamedDecl *D, LVFlags F) {
       return LinkageInfo::internal();
   }
 
-  if (D->isInAnonymousNamespace())
-    return LinkageInfo::uniqueExternal();
+  if (D->isInAnonymousNamespace()) {
+    const VarDecl *Var = dyn_cast<VarDecl>(D);
+    const FunctionDecl *Func = dyn_cast<FunctionDecl>(D);
+    if ((!Var || !Var->isExternC()) && (!Func || !Func->isExternC()))
+      return LinkageInfo::uniqueExternal();
+  }
 
   // Set up the defaults.
 
@@ -704,7 +708,7 @@ static LinkageInfo getLVForDecl(const NamedDecl *D, LVFlags Flags) {
   //   external linkage.
   if (D->getLexicalDeclContext()->isFunctionOrMethod()) {
     if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
-      if (Function->isInAnonymousNamespace())
+      if (Function->isInAnonymousNamespace() && !Function->isExternC())
         return LinkageInfo::uniqueExternal();
 
       LinkageInfo LV;
@@ -725,7 +729,7 @@ static LinkageInfo getLVForDecl(const NamedDecl *D, LVFlags Flags) {
     if (const VarDecl *Var = dyn_cast<VarDecl>(D))
       if (Var->getStorageClass() == SC_Extern ||
           Var->getStorageClass() == SC_PrivateExtern) {
-        if (Var->isInAnonymousNamespace())
+        if (Var->isInAnonymousNamespace() && !Var->isExternC())
           return LinkageInfo::uniqueExternal();
 
         LinkageInfo LV;
@@ -837,8 +841,10 @@ bool NamedDecl::declarationReplaces(NamedDecl *OldD) const {
   // UsingDirectiveDecl's are not really NamedDecl's, and all have same name.
   // We want to keep it, unless it nominates same namespace.
   if (getKind() == Decl::UsingDirective) {
-    return cast<UsingDirectiveDecl>(this)->getNominatedNamespace() ==
-           cast<UsingDirectiveDecl>(OldD)->getNominatedNamespace();
+    return cast<UsingDirectiveDecl>(this)->getNominatedNamespace()
+             ->getOriginalNamespace() ==
+           cast<UsingDirectiveDecl>(OldD)->getNominatedNamespace()
+             ->getOriginalNamespace();
   }
 
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(this))
@@ -864,9 +870,13 @@ bool NamedDecl::declarationReplaces(NamedDecl *OldD) const {
     return cast<UsingShadowDecl>(this)->getTargetDecl() ==
            cast<UsingShadowDecl>(OldD)->getTargetDecl();
 
-  if (isa<UsingDecl>(this) && isa<UsingDecl>(OldD))
-    return cast<UsingDecl>(this)->getTargetNestedNameDecl() ==
-           cast<UsingDecl>(OldD)->getTargetNestedNameDecl();
+  if (isa<UsingDecl>(this) && isa<UsingDecl>(OldD)) {
+    ASTContext &Context = getASTContext();
+    return Context.getCanonicalNestedNameSpecifier(
+                                     cast<UsingDecl>(this)->getQualifier()) ==
+           Context.getCanonicalNestedNameSpecifier(
+                                        cast<UsingDecl>(OldD)->getQualifier());
+  }
 
   // For non-function declarations, if the declarations are of the
   // same kind then this must be a redeclaration, or semantic analysis
@@ -927,9 +937,8 @@ SourceLocation DeclaratorDecl::getTypeSpecStartLoc() const {
   return SourceLocation();
 }
 
-void DeclaratorDecl::setQualifierInfo(NestedNameSpecifier *Qualifier,
-                                      SourceRange QualifierRange) {
-  if (Qualifier) {
+void DeclaratorDecl::setQualifierInfo(NestedNameSpecifierLoc QualifierLoc) {
+  if (QualifierLoc) {
     // Make sure the extended decl info is allocated.
     if (!hasExtInfo()) {
       // Save (non-extended) type source info pointer.
@@ -940,12 +949,10 @@ void DeclaratorDecl::setQualifierInfo(NestedNameSpecifier *Qualifier,
       getExtInfo()->TInfo = savedTInfo;
     }
     // Set qualifier info.
-    getExtInfo()->NNS = Qualifier;
-    getExtInfo()->NNSRange = QualifierRange;
+    getExtInfo()->QualifierLoc = QualifierLoc;
   }
   else {
     // Here Qualifier == 0, i.e., we are removing the qualifier (if any).
-    assert(QualifierRange.isInvalid());
     if (hasExtInfo()) {
       // Save type source info pointer.
       TypeSourceInfo *savedTInfo = getExtInfo()->TInfo;
@@ -967,7 +974,7 @@ QualifierInfo::setTemplateParameterListsInfo(ASTContext &Context,
                                              TemplateParameterList **TPLists) {
   assert((NumTPLists == 0 || TPLists != 0) &&
          "Empty array of template parameters with positive size!");
-  assert((NumTPLists == 0 || NNS) &&
+  assert((NumTPLists == 0 || QualifierLoc) &&
          "Nonempty array of template parameters with no qualifier!");
 
   // Free previous template parameters (if any).
@@ -1037,8 +1044,11 @@ bool VarDecl::isExternC() const {
             getStorageClass() != SC_Static) ||
       (getDeclContext()->isFunctionOrMethod() && hasExternalStorage());
 
-  for (const DeclContext *DC = getDeclContext(); !DC->isTranslationUnit();
-       DC = DC->getParent()) {
+  const DeclContext *DC = getDeclContext();
+  if (DC->isFunctionOrMethod())
+    return false;
+
+  for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
     if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC))  {
       if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
         return getStorageClass() != SC_Static;
@@ -1046,8 +1056,6 @@ bool VarDecl::isExternC() const {
       break;
     }
 
-    if (DC->isFunctionOrMethod())
-      return false;
   }
 
   return false;
@@ -1363,8 +1371,11 @@ bool FunctionDecl::isExternC() const {
   if (!Context.getLangOptions().CPlusPlus)
     return getStorageClass() != SC_Static && !getAttr<OverloadableAttr>();
 
-  for (const DeclContext *DC = getDeclContext(); !DC->isTranslationUnit();
-       DC = DC->getParent()) {
+  const DeclContext *DC = getDeclContext();
+  if (DC->isRecord())
+    return false;
+
+  for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
     if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC))  {
       if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
         return getStorageClass() != SC_Static &&
@@ -1372,9 +1383,6 @@ bool FunctionDecl::isExternC() const {
 
       break;
     }
-    
-    if (DC->isRecord())
-      break;
   }
 
   return isMain();
@@ -2018,19 +2026,16 @@ TagDecl* TagDecl::getDefinition() const {
   return 0;
 }
 
-void TagDecl::setQualifierInfo(NestedNameSpecifier *Qualifier,
-                               SourceRange QualifierRange) {
-  if (Qualifier) {
+void TagDecl::setQualifierInfo(NestedNameSpecifierLoc QualifierLoc) {
+  if (QualifierLoc) {
     // Make sure the extended qualifier info is allocated.
     if (!hasExtInfo())
       TypedefDeclOrQualifier = new (getASTContext()) ExtInfo;
     // Set qualifier info.
-    getExtInfo()->NNS = Qualifier;
-    getExtInfo()->NNSRange = QualifierRange;
+    getExtInfo()->QualifierLoc = QualifierLoc;
   }
   else {
     // Here Qualifier == 0, i.e., we are removing the qualifier (if any).
-    assert(QualifierRange.isInvalid());
     if (hasExtInfo()) {
       getASTContext().Deallocate(getExtInfo());
       TypedefDeclOrQualifier = (TypedefDecl*) 0;
@@ -2211,8 +2216,10 @@ NamespaceDecl *NamespaceDecl::getNextNamespace() {
 }
 
 ImplicitParamDecl *ImplicitParamDecl::Create(ASTContext &C, DeclContext *DC,
-    SourceLocation L, IdentifierInfo *Id, QualType T) {
-  return new (C) ImplicitParamDecl(ImplicitParam, DC, L, Id, T);
+                                             SourceLocation loc,
+                                             IdentifierInfo *name,
+                                             QualType type) {
+  return new (C) ImplicitParamDecl(DC, loc, name, type);
 }
 
 FunctionDecl *FunctionDecl::Create(ASTContext &C, DeclContext *DC,