//===--- ASTContext.cpp - Context to hold long-lived AST nodes ------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements the ASTContext interface.
//
//===----------------------------------------------------------------------===//

#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/ADT/SmallVector.h"

using namespace llvm;
using namespace clang;

ASTContext::~ASTContext() {
  // Deallocate all the types.
  while (!Types.empty()) {
    if (FunctionTypeProto *FT = dyn_cast<FunctionTypeProto>(Types.back())) {
      // Destroy the object, but don't call delete.  These are malloc'd.
      FT->~FunctionTypeProto();
      free(FT);
    } else {
      delete Types.back();
    }
    Types.pop_back();
  }
}

void ASTContext::PrintStats() const {
  fprintf(stderr, "*** AST Context Stats:\n");
  fprintf(stderr, "  %d types total.\n", (int)Types.size());
  unsigned NumBuiltin = 0, NumPointer = 0, NumArray = 0, NumFunctionP = 0;
  unsigned NumFunctionNP = 0, NumTypeName = 0, NumTagged = 0;
  
  unsigned NumTagStruct = 0, NumTagUnion = 0, NumTagEnum = 0, NumTagClass = 0;
  
  for (unsigned i = 0, e = Types.size(); i != e; ++i) {
    Type *T = Types[i];
    if (isa<BuiltinType>(T))
      ++NumBuiltin;
    else if (isa<PointerType>(T))
      ++NumPointer;
    else if (isa<ArrayType>(T))
      ++NumArray;
    else if (isa<FunctionTypeNoProto>(T))
      ++NumFunctionNP;
    else if (isa<FunctionTypeProto>(T))
      ++NumFunctionP;
    else if (isa<TypedefType>(T))
      ++NumTypeName;
    else if (TagType *TT = dyn_cast<TagType>(T)) {
      ++NumTagged;
      switch (TT->getDecl()->getKind()) {
      default: assert(0 && "Unknown tagged type!");
      case Decl::Struct: ++NumTagStruct; break;
      case Decl::Union:  ++NumTagUnion; break;
      case Decl::Class:  ++NumTagClass; break; 
      case Decl::Enum:   ++NumTagEnum; break;
      }
    } else {
      assert(0 && "Unknown type!");
    }
  }

  fprintf(stderr, "    %d builtin types\n", NumBuiltin);
  fprintf(stderr, "    %d pointer types\n", NumPointer);
  fprintf(stderr, "    %d array types\n", NumArray);
  fprintf(stderr, "    %d function types with proto\n", NumFunctionP);
  fprintf(stderr, "    %d function types with no proto\n", NumFunctionNP);
  fprintf(stderr, "    %d typename (typedef) types\n", NumTypeName);
  fprintf(stderr, "    %d tagged types\n", NumTagged);
  fprintf(stderr, "      %d struct types\n", NumTagStruct);
  fprintf(stderr, "      %d union types\n", NumTagUnion);
  fprintf(stderr, "      %d class types\n", NumTagClass);
  fprintf(stderr, "      %d enum types\n", NumTagEnum);
}


void ASTContext::InitBuiltinType(TypeRef &R, BuiltinType::Kind K) {
  Types.push_back((R = new BuiltinType(K)).getTypePtr());
}


void ASTContext::InitBuiltinTypes() {
  assert(VoidTy.isNull() && "Context reinitialized?");
  
  // C99 6.2.5p19.
  InitBuiltinType(VoidTy,              BuiltinType::Void);
  
  // C99 6.2.5p2.
  InitBuiltinType(BoolTy,              BuiltinType::Bool);
  // C99 6.2.5p3.
  InitBuiltinType(CharTy,              BuiltinType::Char);
  // C99 6.2.5p4.
  InitBuiltinType(SignedCharTy,        BuiltinType::SChar);
  InitBuiltinType(ShortTy,             BuiltinType::Short);
  InitBuiltinType(IntTy,               BuiltinType::Int);
  InitBuiltinType(LongTy,              BuiltinType::Long);
  InitBuiltinType(LongLongTy,          BuiltinType::LongLong);
  
  // C99 6.2.5p6.
  InitBuiltinType(UnsignedCharTy,      BuiltinType::UChar);
  InitBuiltinType(UnsignedShortTy,     BuiltinType::UShort);
  InitBuiltinType(UnsignedIntTy,       BuiltinType::UInt);
  InitBuiltinType(UnsignedLongTy,      BuiltinType::ULong);
  InitBuiltinType(UnsignedLongLongTy,  BuiltinType::ULongLong);
  
  // C99 6.2.5p10.
  InitBuiltinType(FloatTy,             BuiltinType::Float);
  InitBuiltinType(DoubleTy,            BuiltinType::Double);
  InitBuiltinType(LongDoubleTy,        BuiltinType::LongDouble);
  
  // C99 6.2.5p11.
  InitBuiltinType(FloatComplexTy,      BuiltinType::FloatComplex);
  InitBuiltinType(DoubleComplexTy,     BuiltinType::DoubleComplex);
  InitBuiltinType(LongDoubleComplexTy, BuiltinType::LongDoubleComplex);
}

/// getPointerType - Return the uniqued reference to the type for a pointer to
/// the specified type.
TypeRef ASTContext::getPointerType(TypeRef T) {
  // Unique pointers, to guarantee there is only one pointer of a particular
  // structure.
  FoldingSetNodeID ID;
  PointerType::Profile(ID, T);
  
  void *InsertPos = 0;
  if (PointerType *PT = PointerTypes.FindNodeOrInsertPos(ID, InsertPos))
    return PT;
  
  // If the pointee type isn't canonical, this won't be a canonical type either,
  // so fill in the canonical type field.
  Type *Canonical = 0;
  if (!T->isCanonical()) {
    Canonical = getPointerType(T.getCanonicalType()).getTypePtr();
   
    // Get the new insert position for the node we care about.
    PointerType *NewIP = PointerTypes.FindNodeOrInsertPos(ID, InsertPos);
    assert(NewIP == 0 && "Shouldn't be in the map!");
  }
  
  PointerType *New = new PointerType(T, Canonical);
  Types.push_back(New);
  PointerTypes.InsertNode(New, InsertPos);
  return New;
}

/// getArrayType - Return the unique reference to the type for an array of the
/// specified element type.
TypeRef ASTContext::getArrayType(TypeRef EltTy,ArrayType::ArraySizeModifier ASM,
                                 unsigned EltTypeQuals, Expr *NumElts) {
  // Unique array types, to guarantee there is only one array of a particular
  // structure.
  FoldingSetNodeID ID;
  ArrayType::Profile(ID, ASM, EltTypeQuals, EltTy, NumElts);
      
  void *InsertPos = 0;
  if (ArrayType *ATP = ArrayTypes.FindNodeOrInsertPos(ID, InsertPos))
    return ATP;
  
  // If the element type isn't canonical, this won't be a canonical type either,
  // so fill in the canonical type field.
  Type *Canonical = 0;
  if (!EltTy->isCanonical()) {
    Canonical = getArrayType(EltTy.getCanonicalType(), ASM, EltTypeQuals,
                             NumElts).getTypePtr();
    
    // Get the new insert position for the node we care about.
    ArrayType *NewIP = ArrayTypes.FindNodeOrInsertPos(ID, InsertPos);
    assert(NewIP == 0 && "Shouldn't be in the map!");
  }
  
  ArrayType *New = new ArrayType(EltTy, ASM, EltTypeQuals, Canonical, NumElts);
  ArrayTypes.InsertNode(New, InsertPos);
  Types.push_back(New);
  return New;
}

/// getFunctionTypeNoProto - Return a K&R style C function type like 'int()'.
///
TypeRef ASTContext::getFunctionTypeNoProto(TypeRef ResultTy) {
  // Unique functions, to guarantee there is only one function of a particular
  // structure.
  FoldingSetNodeID ID;
  FunctionTypeNoProto::Profile(ID, ResultTy);
  
  void *InsertPos = 0;
  if (FunctionTypeNoProto *FT = 
        FunctionTypeNoProtos.FindNodeOrInsertPos(ID, InsertPos))
    return FT;
  
  Type *Canonical = 0;
  if (!ResultTy->isCanonical()) {
    Canonical =getFunctionTypeNoProto(ResultTy.getCanonicalType()).getTypePtr();
    
    // Get the new insert position for the node we care about.
    FunctionTypeNoProto *NewIP =
      FunctionTypeNoProtos.FindNodeOrInsertPos(ID, InsertPos);
    assert(NewIP == 0 && "Shouldn't be in the map!");
  }
  
  FunctionTypeNoProto *New = new FunctionTypeNoProto(ResultTy, Canonical);
  Types.push_back(New);
  FunctionTypeProtos.InsertNode(New, InsertPos);
  return New;
}

/// getFunctionType - Return a normal function type with a typed argument
/// list.  isVariadic indicates whether the argument list includes '...'.
TypeRef ASTContext::getFunctionType(TypeRef ResultTy, TypeRef *ArgArray,
                                    unsigned NumArgs, bool isVariadic) {
  // Unique functions, to guarantee there is only one function of a particular
  // structure.
  FoldingSetNodeID ID;
  FunctionTypeProto::Profile(ID, ResultTy, ArgArray, NumArgs, isVariadic);

  void *InsertPos = 0;
  if (FunctionTypeProto *FTP = 
        FunctionTypeProtos.FindNodeOrInsertPos(ID, InsertPos))
    return FTP;
    
  // Determine whether the type being created is already canonical or not.  
  bool isCanonical = ResultTy->isCanonical();
  for (unsigned i = 0; i != NumArgs && isCanonical; ++i)
    if (!ArgArray[i]->isCanonical())
      isCanonical = false;

  // If this type isn't canonical, get the canonical version of it.
  Type *Canonical = 0;
  if (!isCanonical) {
    SmallVector<TypeRef, 16> CanonicalArgs;
    CanonicalArgs.reserve(NumArgs);
    for (unsigned i = 0; i != NumArgs; ++i)
      CanonicalArgs.push_back(ArgArray[i].getCanonicalType());
    
    Canonical = getFunctionType(ResultTy.getCanonicalType(),
                                &CanonicalArgs[0], NumArgs,
                                isVariadic).getTypePtr();
    
    // Get the new insert position for the node we care about.
    FunctionTypeProto *NewIP =
      FunctionTypeProtos.FindNodeOrInsertPos(ID, InsertPos);
    assert(NewIP == 0 && "Shouldn't be in the map!");
  }
  
  // FunctionTypeProto objects are not allocated with new because they have a
  // variable size array (for parameter types) at the end of them.
  FunctionTypeProto *FTP = 
    (FunctionTypeProto*)malloc(sizeof(FunctionTypeProto) + 
                               (NumArgs-1)*sizeof(TypeRef));
  new (FTP) FunctionTypeProto(ResultTy, ArgArray, NumArgs, isVariadic,
                              Canonical);
  
  Types.push_back(FTP);
  FunctionTypeProtos.InsertNode(FTP, InsertPos);
  return FTP;
}

/// getTypedefType - Return the unique reference to the type for the
/// specified typename decl.
TypeRef ASTContext::getTypedefType(TypedefDecl *Decl) {
  if (Decl->TypeForDecl) return Decl->TypeForDecl;
  
  // FIXME: does this lose qualifiers from the typedef??
  Type *Canonical = Decl->getUnderlyingType().getCanonicalType().getTypePtr();
  Decl->TypeForDecl = new TypedefType(Decl, Canonical);
  Types.push_back(Decl->TypeForDecl);
  return Decl->TypeForDecl;
}

/// getTagDeclType - Return the unique reference to the type for the
/// specified TagDecl (struct/union/class/enum) decl.
TypeRef ASTContext::getTagDeclType(TagDecl *Decl) {
  // The decl stores the type cache.
  if (Decl->TypeForDecl) return Decl->TypeForDecl;
  
  Decl->TypeForDecl = new TagType(Decl, 0);
  Types.push_back(Decl->TypeForDecl);
  return Decl->TypeForDecl;
}

/// getSizeType - Return the unique type for "size_t" (C99 7.17), the result 
/// of the sizeof operator (C99 6.5.3.4p4). The value is target dependent and 
/// needs to agree with the definition in <stddef.h>. 
TypeRef ASTContext::getSizeType() const {
  // On Darwin, size_t is defined as a "long unsigned int". 
  // FIXME: should derive from "Target".
  return UnsignedLongTy; 
}

