Basic, untested implementation for an "unknown any" type requested by LLDB.

The idea is that you can create a VarDecl with an unknown type, or a
FunctionDecl with an unknown return type, and it will still be valid to
access that object as long as you explicitly cast it at every use.  I'm
still going back and forth about how I want to test this effectively, but
I wanted to go ahead and provide a skeletal implementation for the LLDB
folks' benefit and because it also improves some diagnostic goodness for
placeholder expressions.

llvm-svn: 129065

8 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index e208bfdf1df..01e8f8e3967 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -402,6 +402,9 @@ void ASTContext::InitBuiltinTypes() {
   // Placeholder type for functions.
   InitBuiltinType(OverloadTy,          BuiltinType::Overload);
 
+  // "any" type; useful for debugger-like clients.
+  InitBuiltinType(UnknownAnyTy,        BuiltinType::UnknownAny);
+
   // C99 6.2.5p11.
   FloatComplexTy      = getComplexType(FloatTy);
   DoubleComplexTy     = getComplexType(DoubleTy);
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index c92087d85fd..3cc9670c344 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -1360,6 +1360,7 @@ QualType ASTNodeImporter::VisitBuiltinType(const BuiltinType *T) {
     
   case BuiltinType::Overload: return Importer.getToContext().OverloadTy;
   case BuiltinType::Dependent: return Importer.getToContext().DependentTy;
+  case BuiltinType::UnknownAny: return Importer.getToContext().UnknownAnyTy;
 
   case BuiltinType::ObjCId:
     // FIXME: Make sure that the "to" context supports Objective-C!
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 59de3fe6eec..28f42124f98 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1055,6 +1055,8 @@ const char *CastExpr::getCastKindName() const {
     return "IntegralComplexCast";
   case CK_IntegralComplexToFloatingComplex:
     return "IntegralComplexToFloatingComplex";
+  case CK_ResolveUnknownAnyType:
+    return "ResolveUnknownAnyType";
   }
 
   llvm_unreachable("Unhandled cast kind!");
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index cdd7efaaf55..e0f99582982 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1798,6 +1798,7 @@ bool IntExprEvaluator::VisitCastExpr(CastExpr *E) {
   case CK_GetObjCProperty:
   case CK_LValueBitCast:
   case CK_UserDefinedConversion:
+  case CK_ResolveUnknownAnyType:
     return false;
 
   case CK_LValueToRValue:
@@ -2351,6 +2352,7 @@ bool ComplexExprEvaluator::VisitCastExpr(CastExpr *E) {
   case CK_GetObjCProperty:
   case CK_LValueBitCast:
   case CK_UserDefinedConversion:
+  case CK_ResolveUnknownAnyType:
     return false;
 
   case CK_FloatingRealToComplex: {
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 6ab68dbae92..be17ccf2d82 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1327,6 +1327,7 @@ void CXXNameMangler::mangleType(const BuiltinType *T) {
 
   case BuiltinType::Overload:
   case BuiltinType::Dependent:
+  case BuiltinType::UnknownAny:
     assert(false &&
            "Overloaded and dependent types shouldn't get to name mangling");
     break;
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 4bf7f23a0a9..5b4dc5a1913 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -717,6 +717,7 @@ void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T) {
 
   case BuiltinType::Overload:
   case BuiltinType::Dependent:
+  case BuiltinType::UnknownAny:
     assert(false &&
            "Overloaded and dependent types shouldn't get to name mangling");
     break;
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 3224f642bc6..b0726e42756 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1132,6 +1132,7 @@ const char *BuiltinType::getName(const LangOptions &LO) const {
   case NullPtr:           return "nullptr_t";
   case Overload:          return "<overloaded function type>";
   case Dependent:         return "<dependent type>";
+  case UnknownAny:        return "<unknown type>";
   case ObjCId:            return "id";
   case ObjCClass:         return "Class";
   case ObjCSel:           return "SEL";
diff --git a/clang/lib/AST/TypeLoc.cpp b/clang/lib/AST/TypeLoc.cpp
index 0873e837d82..cc648304285 100644
--- a/clang/lib/AST/TypeLoc.cpp
+++ b/clang/lib/AST/TypeLoc.cpp
@@ -234,6 +234,7 @@ TypeSpecifierType BuiltinTypeLoc::getWrittenTypeSpec() const {
     case BuiltinType::NullPtr:
     case BuiltinType::Overload:
     case BuiltinType::Dependent:
+    case BuiltinType::UnknownAny:
     case BuiltinType::ObjCId:
     case BuiltinType::ObjCClass:
     case BuiltinType::ObjCSel: