Split out types that are non-canonical unless dependent as their own

category.  Use this in a few places to eliminate unnecessary TST cases and
do some future-proofing.  Provide terrible manglings for typeof.  Mangle
decltype with some hope of accuracy.

Our manglings for some of the cases covered in the testcase are different
from gcc's, which I've raised as an issue with the ABI list.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97523 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/TypeNodes.def

@@ -31,7 +31,11 @@
 //    type that is always dependent. Clients that do not need to deal
 //    with uninstantiated C++ templates can ignore these types.
 //
-//  There is a fifth macro, independent of the others.  Most clients
+//    NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) - A type that
+//    is non-canonical unless it is dependent.  Defaults to TYPE because
+//    it is neither reliably dependent nor reliably non-canonical.
+//
+//  There is a sixth macro, independent of the others.  Most clients
 //  will not need to use it.
 //
 //    LEAF_TYPE(Class) - A type that never has inner types.  Clients
@@ -51,6 +55,10 @@
 #  define DEPENDENT_TYPE(Class, Base) TYPE(Class, Base)
 #endif
 
+#ifndef NON_CANONICAL_UNLESS_DEPENDENT_TYPE
+#  define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) TYPE(Class, Base)
+#endif
+
 TYPE(Builtin, Type)
 TYPE(Complex, Type)
 TYPE(Pointer, Type)
@@ -72,16 +80,16 @@ TYPE(FunctionProto, FunctionType)
 TYPE(FunctionNoProto, FunctionType)
 DEPENDENT_TYPE(UnresolvedUsing, Type)
 NON_CANONICAL_TYPE(Typedef, Type)
-NON_CANONICAL_TYPE(TypeOfExpr, Type)
-NON_CANONICAL_TYPE(TypeOf, Type)
-NON_CANONICAL_TYPE(Decltype, Type)
+NON_CANONICAL_UNLESS_DEPENDENT_TYPE(TypeOfExpr, Type)
+NON_CANONICAL_UNLESS_DEPENDENT_TYPE(TypeOf, Type)
+NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Decltype, Type)
 ABSTRACT_TYPE(Tag, Type)
 TYPE(Record, TagType)
 TYPE(Enum, TagType)
 NON_CANONICAL_TYPE(Elaborated, Type)
 DEPENDENT_TYPE(TemplateTypeParm, Type)
 NON_CANONICAL_TYPE(SubstTemplateTypeParm, Type)
-TYPE(TemplateSpecialization, Type)
+NON_CANONICAL_UNLESS_DEPENDENT_TYPE(TemplateSpecialization, Type)
 NON_CANONICAL_TYPE(QualifiedName, Type)
 DEPENDENT_TYPE(Typename, Type)
 TYPE(ObjCInterface, Type)
@@ -101,6 +109,7 @@ LEAF_TYPE(TemplateTypeParm)
 #undef LEAF_TYPE
 #endif
 
+#undef NON_CANONICAL_UNLESS_DEPENDENT_TYPE
 #undef DEPENDENT_TYPE
 #undef NON_CANONICAL_TYPE
 #undef ABSTRACT_TYPE

lib/AST/ASTContext.cpp

@@ -4522,6 +4522,7 @@ QualType ASTContext::mergeTypes(QualType LHS, QualType RHS) {
   switch (LHSClass) {
 #define TYPE(Class, Base)
 #define ABSTRACT_TYPE(Class, Base)
+#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
 #include "clang/AST/TypeNodes.def"
@@ -4644,9 +4645,6 @@ QualType ASTContext::mergeTypes(QualType LHS, QualType RHS) {
 
     return QualType();
   }
-  case Type::TemplateSpecialization:
-    assert(false && "Dependent types have no size");
-    break;
   }
 
   return QualType();

lib/CodeGen/CodeGenTypes.cpp

@@ -190,6 +190,7 @@ const llvm::Type *CodeGenTypes::ConvertNewType(QualType T) {
 #define ABSTRACT_TYPE(Class, Base)
 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
+#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
 #include "clang/AST/TypeNodes.def"
     assert(false && "Non-canonical or dependent types aren't possible.");
     break;
@@ -390,9 +391,6 @@ const llvm::Type *CodeGenTypes::ConvertNewType(QualType T) {
                                    NULL);
     return PtrDiffTy;
   }
-
-  case Type::TemplateSpecialization:
-    assert(false && "Dependent types can't get here");
   }
 
   // FIXME: implement.

lib/CodeGen/Mangle.cpp

@@ -455,7 +455,9 @@ void CXXNameMangler::mangleUnresolvedScope(NestedNameSpecifier *Qualifier) {
     mangleType(QualType(Qualifier->getAsType(), 0));
     break;
   case NestedNameSpecifier::Identifier:
-    mangleUnresolvedScope(Qualifier->getPrefix());
+    // Member expressions can have these without prefixes.
+    if (Qualifier->getPrefix())
+      mangleUnresolvedScope(Qualifier->getPrefix());
     mangleSourceName(Qualifier->getAsIdentifier());
     break;
   }
@@ -1123,6 +1125,42 @@ void CXXNameMangler::mangleType(const TypenameType *T) {
   Out << 'E';
 }
 
+void CXXNameMangler::mangleType(const TypeOfType *T) {
+  // FIXME: this is pretty unsatisfactory, but there isn't an obvious
+  // "extension with parameters" mangling.
+  Out << "u6typeof";
+}
+
+void CXXNameMangler::mangleType(const TypeOfExprType *T) {
+  // FIXME: this is pretty unsatisfactory, but there isn't an obvious
+  // "extension with parameters" mangling.
+  Out << "u6typeof";
+}
+
+void CXXNameMangler::mangleType(const DecltypeType *T) {
+  Expr *E = T->getUnderlyingExpr();
+  
+  // type ::= Dt <expression> E  # decltype of an id-expression
+  //                             #   or class member access
+  //      ::= DT <expression> E  # decltype of an expression
+
+  // This purports to be an exhaustive list of id-expressions and
+  // class member accesses.  Note that we do not ignore parentheses;
+  // parentheses change the semantics of decltype for these
+  // expressions (and cause the mangler to use the other form).
+  if (isa<DeclRefExpr>(E) ||
+      isa<MemberExpr>(E) ||
+      isa<UnresolvedLookupExpr>(E) ||
+      isa<DependentScopeDeclRefExpr>(E) ||
+      isa<CXXDependentScopeMemberExpr>(E) ||
+      isa<UnresolvedMemberExpr>(E))
+    Out << "Dt";
+  else
+    Out << "DT";
+  mangleExpression(E);
+  Out << 'E';
+}
+
 void CXXNameMangler::mangleIntegerLiteral(QualType T, 
                                           const llvm::APSInt &Value) {
   //  <expr-primary> ::= L <type> <value number> E # integer literal

lib/Sema/SemaTemplateDeduction.cpp

@@ -2419,6 +2419,27 @@ MarkUsedTemplateParameters(Sema &SemaRef, QualType T,
                                  OnlyDeduced, Depth, Used);
     break;
 
+  case Type::TypeOf:
+    if (!OnlyDeduced)
+      MarkUsedTemplateParameters(SemaRef,
+                                 cast<TypeOfType>(T)->getUnderlyingType(),
+                                 OnlyDeduced, Depth, Used);
+    break;
+
+  case Type::TypeOfExpr:
+    if (!OnlyDeduced)
+      MarkUsedTemplateParameters(SemaRef,
+                                 cast<TypeOfExprType>(T)->getUnderlyingExpr(),
+                                 OnlyDeduced, Depth, Used);
+    break;
+
+  case Type::Decltype:
+    if (!OnlyDeduced)
+      MarkUsedTemplateParameters(SemaRef,
+                                 cast<DecltypeType>(T)->getUnderlyingExpr(),
+                                 OnlyDeduced, Depth, Used);
+    break;
+
   // None of these types have any template parameters in them.
   case Type::Builtin:
   case Type::VariableArray:

test/CodeGenCXX/mangle.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -fblocks | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -fblocks -std=c++0x | FileCheck %s
 struct X { };
 struct Y { };
 
@@ -376,3 +376,41 @@ namespace test1 {
 // CHECK: define internal void @_Z27functionWithInternalLinkagev()
 static void functionWithInternalLinkage() {  }
 void g() { functionWithInternalLinkage(); }
+
+namespace test2 {
+  template <class T> decltype(((T*) 0)->member) read_member(T& obj) {
+    return obj.member;
+  }
+
+  struct A { int member; } obj;
+  int test() {
+    return read_member(obj);
+  }
+
+  // CHECK: define linkonce_odr i32 @_ZN5test211read_memberINS_1AEEEDtptcvPT_Li0E6memberERS2_(
+}
+
+namespace test3 {
+  struct AmbiguousBase { int ab; };
+  struct Path1 : AmbiguousBase { float p; };
+  struct Path2 : AmbiguousBase { double p; };
+  struct Derived : Path1, Path2 { };
+
+  //template <class T> decltype(((T*) 0)->Path1::ab) get_ab_1(T &ref) { return ref.Path1::ab; }
+  //template <class T> decltype(((T*) 0)->Path2::ab) get_ab_2(T &ref) { return ref.Path2::ab; }
+
+  // define linkonce_odr float @_ZN5test37get_p_1INS_7DerivedEEEDtptcvPT_Li0E5Path11pERS2_(
+  template <class T> decltype(((T*) 0)->Path1::p) get_p_1(T &ref) { return ref.Path1::p; }
+
+  // define linkonce_odr double @_ZN5test37get_p_1INS_7DerivedEEEDtptcvPT_Li0E5Path21pERS2_(
+  template <class T> decltype(((T*) 0)->Path2::p) get_p_2(T &ref) { return ref.Path2::p; }
+
+  Derived obj;
+  void test() {
+    // FIXME: uncomment these when we support diamonds competently
+    //get_ab_1(obj);
+    //get_ab_2(obj);
+    get_p_1(obj);
+    get_p_2(obj);
+  }
+}