Implement the basic approach for instantiating types, with a lot of FIXME'd

stubs for those types we don't yet know how to instantiate (everything
that isn't a template parameter!).

We now instantiate default arguments for template type parameters when
needed. This will be our testbed while I fill out the remaining
type-instantiation logic.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65649 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 438 insertions, 0 deletions

diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
new file mode 100644
index 0000000000..e07892e6c1
--- /dev/null
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -0,0 +1,438 @@
+//===------- SemaTemplateInstantiate.cpp - C++ Template Instantiation ------===/
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//===----------------------------------------------------------------------===/
+//
+//  This file implements C++ template instantiation.
+//
+//===----------------------------------------------------------------------===/
+
+#include "Sema.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/Parse/DeclSpec.h"
+#include "clang/Basic/LangOptions.h"
+
+using namespace clang;
+
+//===----------------------------------------------------------------------===/
+// Template Instantiation for Types
+//===----------------------------------------------------------------------===/
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ExtQualType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ExtQualType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const BuiltinType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  assert(false && "BuiltinType is never dependent and cannot be instantiated");
+  return QualType(T, CVR);
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const FixedWidthIntType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate FixedWidthIntType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ComplexType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ComplexType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const PointerType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate PointerType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const BlockPointerType *T,
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate BlockPointerType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ReferenceType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ReferenceType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const MemberPointerType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate MemberPointerType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ConstantArrayType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ConstantArrayType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const IncompleteArrayType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate IncompleteArrayType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const VariableArrayType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate VariableArrayType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const DependentSizedArrayType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate DependentSizedArrayType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const VectorType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate VectorType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ExtVectorType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ExtVectorType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const FunctionProtoType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate FunctionProtoType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const FunctionNoProtoType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate FunctionNoProtoType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const TypedefType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate TypedefType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const TypeOfExprType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate TypeOfExprType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const TypeOfType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate TypeOfType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const RecordType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate RecordType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const CXXRecordType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate CXXRecordType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const EnumType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate EnumType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const TemplateTypeParmType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  if (T->getDepth() == 0) {
+    // Replace the template type parameter with its corresponding
+    // template argument.
+    assert(T->getIndex() < NumTemplateArgs && "Wrong # of template args");
+    assert(TemplateArgs[T->getIndex()].getKind() == TemplateArgument::Type &&
+           "Template argument kind mismatch");
+    QualType Result = TemplateArgs[T->getIndex()].getAsType();
+    if (Result.isNull() || !CVR) 
+      return Result;
+
+    // C++ [dcl.ref]p1:
+    //   [...] Cv-qualified references are ill-formed except when
+    //   the cv-qualifiers are introduced through the use of a
+    //   typedef (7.1.3) or of a template type argument (14.3), in
+    //   which case the cv-qualifiers are ignored.
+    if (CVR && Result->isReferenceType())
+      CVR = 0;
+
+    return QualType(Result.getTypePtr(), CVR | Result.getCVRQualifiers());
+  } 
+
+  // The template type parameter comes from an inner template (e.g.,
+  // the template parameter list of a member template inside the
+  // template we are instantiating). Create a new template type
+  // parameter with the template "level" reduced by one.
+  return SemaRef.Context.getTemplateTypeParmType(T->getDepth() - 1,
+                                                 T->getIndex(),
+                                                 T->getName());
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                     const ClassTemplateSpecializationType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ClassTemplateSpecializationType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ObjCInterfaceType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ObjCInterfaceType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ObjCQualifiedInterfaceType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ObjCQualifiedInterfaceType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ObjCQualifiedIdType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ObjCQualifiedIdType yet");
+  return QualType();
+}
+
+static QualType PerformTypeInstantiation(Sema &SemaRef, 
+                                         const ObjCQualifiedClassType *T, 
+                                         unsigned CVR,
+                                         const TemplateArgument *TemplateArgs,
+                                         unsigned NumTemplateArgs,
+                                         SourceLocation Loc,
+                                         DeclarationName Entity) {
+  // FIXME: Implement this
+  assert(false && "Cannot instantiate ObjCQualifiedClassType yet");
+  return QualType();
+}
+
+
+/// \brief Instantiate the type T with a given set of template arguments.
+///
+/// This routine substitutes the given template arguments into the
+/// type T and produces the instantiated type.
+///
+/// \param T the type into which the template arguments will be
+/// substituted. If this type is not dependent, it will be returned
+/// immediately.
+///
+/// \param TemplateArgs the template arguments that will be
+/// substituted for the top-level template parameters within T.
+///
+/// \param NumTemplateArgs the number of template arguments provided
+/// by TemplateArgs.
+///
+/// \param Loc the location in the source code where this substitution
+/// is being performed. It will typically be the location of the
+/// declarator (if we're instantiating the type of some declaration)
+/// or the location of the type in the source code (if, e.g., we're
+/// instantiating the type of a cast expression).
+///
+/// \param Entity the name of the entity associated with a declaration
+/// being instantiated (if any). May be empty to indicate that there
+/// is no such entity (if, e.g., this is a type that occurs as part of
+/// a cast expression) or that the entity has no name (e.g., an
+/// unnamed function parameter).
+///
+/// \returns If the instantiation succeeds, the instantiated
+/// type. Otherwise, produces diagnostics and returns a NULL type.
+QualType Sema::InstantiateType(QualType T, 
+                               const TemplateArgument *TemplateArgs,
+                               unsigned NumTemplateArgs,
+                               SourceLocation Loc, DeclarationName Entity) {
+  // If T is not a dependent type, there is nothing to do.
+  if (!T->isDependentType())
+    return T;
+
+  switch (T->getTypeClass()) {
+#define TYPE(Class, Base)                                               \
+  case Type::Class:                                                     \
+    return PerformTypeInstantiation(*this,                              \
+                                    cast<Class##Type>(T.getTypePtr()),  \
+                                    T.getCVRQualifiers(), TemplateArgs, \
+                                    NumTemplateArgs, Loc, Entity);
+#define ABSTRACT_TYPE(Class, Base)
+#include "clang/AST/TypeNodes.def"
+  }
+  
+  assert(false && "Not all types hav been decided for template instantiation");
+  return QualType();
+}