Fix the AST representation for non-type template arguments to encode

enough information so we can mangle them correctly in cases involving
dependent parameter types. (This specifically impacts cases involving
null pointers and cases involving parameters of reference type.)
Fix the mangler to use this information instead of trying to scavenge
it out of the parameter declaration.

<rdar://problem/12296776>.

llvm-svn: 164656

1 files changed, 39 insertions, 24 deletions

diff --git a/clang/lib/AST/TemplateBase.cpp b/clang/lib/AST/TemplateBase.cpp
index 95ff4edf1d6b..968a6be16e63 100644
--- a/clang/lib/AST/TemplateBase.cpp
+++ b/clang/lib/AST/TemplateBase.cpp
@@ -77,7 +77,7 @@ TemplateArgument TemplateArgument::CreatePackCopy(ASTContext &Context,
                                                   const TemplateArgument *Args,
                                                   unsigned NumArgs) {
   if (NumArgs == 0)
-    return TemplateArgument(0, 0);
+    return getEmptyPack();
   
   TemplateArgument *Storage = new (Context) TemplateArgument [NumArgs];
   std::copy(Args, Args + NumArgs, Storage);
@@ -99,12 +99,11 @@ bool TemplateArgument::isDependent() const {
     return true;
 
   case Declaration:
-    if (Decl *D = getAsDecl()) {
-      if (DeclContext *DC = dyn_cast<DeclContext>(D))
-        return DC->isDependentContext();
-      return D->getDeclContext()->isDependentContext();
-    }
-      
+    if (DeclContext *DC = dyn_cast<DeclContext>(getAsDecl()))
+      return DC->isDependentContext();
+    return getAsDecl()->getDeclContext()->isDependentContext();
+
+  case NullPtr:
     return false;
 
   case Integral:
@@ -141,11 +140,11 @@ bool TemplateArgument::isInstantiationDependent() const {
     return true;
     
   case Declaration:
-    if (Decl *D = getAsDecl()) {
-      if (DeclContext *DC = dyn_cast<DeclContext>(D))
-        return DC->isDependentContext();
-      return D->getDeclContext()->isDependentContext();
-    }
+    if (DeclContext *DC = dyn_cast<DeclContext>(getAsDecl()))
+      return DC->isDependentContext();
+    return getAsDecl()->getDeclContext()->isDependentContext();
+
+  case NullPtr:
     return false;
       
   case Integral:
@@ -174,6 +173,7 @@ bool TemplateArgument::isPackExpansion() const {
   case Integral:
   case Pack:    
   case Template:
+  case NullPtr:
     return false;
       
   case TemplateExpansion:
@@ -195,6 +195,7 @@ bool TemplateArgument::containsUnexpandedParameterPack() const {
   case Declaration:
   case Integral:
   case TemplateExpansion:
+  case NullPtr:
     break;
 
   case Type:
@@ -286,12 +287,16 @@ bool TemplateArgument::structurallyEquals(const TemplateArgument &Other) const {
   switch (getKind()) {
   case Null:
   case Type:
-  case Declaration:
   case Expression:      
   case Template:
   case TemplateExpansion:
+  case NullPtr:
     return TypeOrValue == Other.TypeOrValue;
 
+  case Declaration:
+    return getAsDecl() == Other.getAsDecl() && 
+           isDeclForReferenceParam() && Other.isDeclForReferenceParam();
+
   case Integral:
     return getIntegralType() == Other.getIntegralType() &&
            getAsIntegral() == Other.getAsIntegral();
@@ -319,12 +324,13 @@ TemplateArgument TemplateArgument::getPackExpansionPattern() const {
     
   case TemplateExpansion:
     return TemplateArgument(getAsTemplateOrTemplatePattern());
-    
+
   case Declaration:
   case Integral:
   case Pack:
   case Null:
   case Template:
+  case NullPtr:
     return TemplateArgument();
   }
 
@@ -348,18 +354,20 @@ void TemplateArgument::print(const PrintingPolicy &Policy,
   }
     
   case Declaration: {
-    if (NamedDecl *ND = dyn_cast_or_null<NamedDecl>(getAsDecl())) {
-      if (ND->getDeclName()) {
-        Out << *ND;
-      } else {
-        Out << "<anonymous>";
-      }
+    NamedDecl *ND = cast<NamedDecl>(getAsDecl());
+    if (ND->getDeclName()) {
+      // FIXME: distinguish between pointer and reference args?
+      Out << *ND;
     } else {
-      Out << "nullptr";
+      Out << "<anonymous>";
     }
     break;
   }
-    
+
+  case NullPtr: {
+    Out << "nullptr";
+  }
+
   case Template:
     getAsTemplate().print(Out, Policy);
     break;
@@ -411,6 +419,9 @@ SourceRange TemplateArgumentLoc::getSourceRange() const {
   case TemplateArgument::Declaration:
     return getSourceDeclExpression()->getSourceRange();
 
+  case TemplateArgument::NullPtr:
+    return getSourceNullPtrExpression()->getSourceRange();
+
   case TemplateArgument::Type:
     if (TypeSourceInfo *TSI = getTypeSourceInfo())
       return TSI->getTypeLoc().getSourceRange();
@@ -430,6 +441,8 @@ SourceRange TemplateArgumentLoc::getSourceRange() const {
     return SourceRange(getTemplateNameLoc(), getTemplateEllipsisLoc());
 
   case TemplateArgument::Integral:
+    return getSourceIntegralExpression()->getSourceRange();
+
   case TemplateArgument::Pack:
   case TemplateArgument::Null:
     return SourceRange();
@@ -490,6 +503,7 @@ TemplateArgumentLoc::getPackExpansionPattern(SourceLocation &Ellipsis,
                                getTemplateNameLoc());
     
   case TemplateArgument::Declaration:
+  case TemplateArgument::NullPtr:
   case TemplateArgument::Template:
   case TemplateArgument::Integral:
   case TemplateArgument::Pack:
@@ -512,8 +526,9 @@ const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
     return DB << Arg.getAsType();
       
   case TemplateArgument::Declaration:
-    if (Decl *D = Arg.getAsDecl())
-      return DB << D;
+    return DB << Arg.getAsDecl();
+
+  case TemplateArgument::NullPtr:
     return DB << "nullptr";
       
   case TemplateArgument::Integral: