1 files changed, 304 insertions, 0 deletions
diff --git a/lib/CodeGen/CGCXXExpr.cpp b/lib/CodeGen/CGCXXExpr.cpp
new file mode 100644
index 000000000000..2d62df6c58a4
--- /dev/null
+++ b/lib/CodeGen/CGCXXExpr.cpp
@@ -0,0 +1,304 @@
+//===--- CGCXXExpr.cpp - Emit LLVM Code for C++ expressions ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with code generation of C++ expressions
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+using namespace clang;
+using namespace CodeGen;
+
+static uint64_t CalculateCookiePadding(ASTContext &Ctx, const CXXNewExpr *E) {
+  if (!E->isArray())
+    return 0;
+  
+  QualType T = E->getAllocatedType();
+  
+  const RecordType *RT = T->getAs<RecordType>();
+  if (!RT)
+    return 0;
+  
+  const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
+  if (!RD)
+    return 0;
+  
+  // Check if the class has a trivial destructor.
+  if (RD->hasTrivialDestructor()) {
+    // FIXME: Check for a two-argument delete.
+    return 0;
+  }
+  
+  // Padding is the maximum of sizeof(size_t) and alignof(T)
+  return std::max(Ctx.getTypeSize(Ctx.getSizeType()),
+                  static_cast<uint64_t>(Ctx.getTypeAlign(T))) / 8;
+}
+
+static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF, 
+                                        const CXXNewExpr *E,
+                                        llvm::Value *& NumElements) {
+  QualType Type = E->getAllocatedType();
+  uint64_t TypeSizeInBytes = CGF.getContext().getTypeSize(Type) / 8;
+  const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
+  
+  if (!E->isArray())
+    return llvm::ConstantInt::get(SizeTy, TypeSizeInBytes);
+
+  uint64_t CookiePadding = CalculateCookiePadding(CGF.getContext(), E);
+  
+  Expr::EvalResult Result;
+  if (E->getArraySize()->Evaluate(Result, CGF.getContext()) &&
+      !Result.HasSideEffects && Result.Val.isInt()) {
+
+    uint64_t AllocSize = 
+      Result.Val.getInt().getZExtValue() * TypeSizeInBytes + CookiePadding;
+    
+    NumElements = 
+      llvm::ConstantInt::get(SizeTy, Result.Val.getInt().getZExtValue());
+    
+    return llvm::ConstantInt::get(SizeTy, AllocSize);
+  }
+  
+  // Emit the array size expression.
+  NumElements = CGF.EmitScalarExpr(E->getArraySize());
+  
+  // Multiply with the type size.
+  llvm::Value *V = 
+    CGF.Builder.CreateMul(NumElements, 
+                          llvm::ConstantInt::get(SizeTy, TypeSizeInBytes));
+
+  // And add the cookie padding if necessary.
+  if (CookiePadding)
+    V = CGF.Builder.CreateAdd(V, llvm::ConstantInt::get(SizeTy, CookiePadding));
+  
+  return V;
+}
+
+static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
+                               llvm::Value *NewPtr,
+                               llvm::Value *NumElements) {
+  QualType AllocType = E->getAllocatedType();
+
+  if (!E->isArray()) {
+    if (CXXConstructorDecl *Ctor = E->getConstructor()) {
+      CGF.EmitCXXConstructorCall(Ctor, Ctor_Complete, NewPtr,
+                                 E->constructor_arg_begin(),
+                                 E->constructor_arg_end());
+
+      return;
+    }
+    
+    // We have a POD type.
+    if (E->getNumConstructorArgs() == 0)
+      return;
+
+    assert(E->getNumConstructorArgs() == 1 &&
+           "Can only have one argument to initializer of POD type.");
+      
+    const Expr *Init = E->getConstructorArg(0);
+    
+    if (!CGF.hasAggregateLLVMType(AllocType))
+      CGF.Builder.CreateStore(CGF.EmitScalarExpr(Init), NewPtr);
+    else if (AllocType->isAnyComplexType())
+      CGF.EmitComplexExprIntoAddr(Init, NewPtr, 
+                                  AllocType.isVolatileQualified());
+    else
+      CGF.EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified());
+    return;
+  }
+  
+  if (CXXConstructorDecl *Ctor = E->getConstructor())
+    CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr);
+}
+
+llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
+  QualType AllocType = E->getAllocatedType();
+  FunctionDecl *NewFD = E->getOperatorNew();
+  const FunctionProtoType *NewFTy = NewFD->getType()->getAs<FunctionProtoType>();
+
+  CallArgList NewArgs;
+
+  // The allocation size is the first argument.
+  QualType SizeTy = getContext().getSizeType();
+
+  llvm::Value *NumElements = 0;
+  llvm::Value *AllocSize = EmitCXXNewAllocSize(*this, E, NumElements);
+  
+  NewArgs.push_back(std::make_pair(RValue::get(AllocSize), SizeTy));
+
+  // Emit the rest of the arguments.
+  // FIXME: Ideally, this should just use EmitCallArgs.
+  CXXNewExpr::const_arg_iterator NewArg = E->placement_arg_begin();
+
+  // First, use the types from the function type.
+  // We start at 1 here because the first argument (the allocation size)
+  // has already been emitted.
+  for (unsigned i = 1, e = NewFTy->getNumArgs(); i != e; ++i, ++NewArg) {
+    QualType ArgType = NewFTy->getArgType(i);
+
+    assert(getContext().getCanonicalType(ArgType.getNonReferenceType()).
+           getTypePtr() ==
+           getContext().getCanonicalType(NewArg->getType()).getTypePtr() &&
+           "type mismatch in call argument!");
+
+    NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType),
+                                     ArgType));
+
+  }
+
+  // Either we've emitted all the call args, or we have a call to a
+  // variadic function.
+  assert((NewArg == E->placement_arg_end() || NewFTy->isVariadic()) &&
+         "Extra arguments in non-variadic function!");
+
+  // If we still have any arguments, emit them using the type of the argument.
+  for (CXXNewExpr::const_arg_iterator NewArgEnd = E->placement_arg_end();
+       NewArg != NewArgEnd; ++NewArg) {
+    QualType ArgType = NewArg->getType();
+    NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType),
+                                     ArgType));
+  }
+
+  // Emit the call to new.
+  RValue RV =
+    EmitCall(CGM.getTypes().getFunctionInfo(NewFTy->getResultType(), NewArgs),
+             CGM.GetAddrOfFunction(NewFD), NewArgs, NewFD);
+
+  // If an allocation function is declared with an empty exception specification
+  // it returns null to indicate failure to allocate storage. [expr.new]p13.
+  // (We don't need to check for null when there's no new initializer and
+  // we're allocating a POD type).
+  bool NullCheckResult = NewFTy->hasEmptyExceptionSpec() &&
+    !(AllocType->isPODType() && !E->hasInitializer());
+
+  llvm::BasicBlock *NewNull = 0;
+  llvm::BasicBlock *NewNotNull = 0;
+  llvm::BasicBlock *NewEnd = 0;
+
+  llvm::Value *NewPtr = RV.getScalarVal();
+
+  if (NullCheckResult) {
+    NewNull = createBasicBlock("new.null");
+    NewNotNull = createBasicBlock("new.notnull");
+    NewEnd = createBasicBlock("new.end");
+
+    llvm::Value *IsNull =
+      Builder.CreateICmpEQ(NewPtr,
+                           llvm::Constant::getNullValue(NewPtr->getType()),
+                           "isnull");
+
+    Builder.CreateCondBr(IsNull, NewNull, NewNotNull);
+    EmitBlock(NewNotNull);
+  }
+
+  if (uint64_t CookiePadding = CalculateCookiePadding(getContext(), E)) {
+    uint64_t CookieOffset = 
+      CookiePadding - getContext().getTypeSize(SizeTy) / 8;
+    
+    llvm::Value *NumElementsPtr = 
+      Builder.CreateConstInBoundsGEP1_64(NewPtr, CookieOffset);
+    
+    NumElementsPtr = Builder.CreateBitCast(NumElementsPtr, 
+                                           ConvertType(SizeTy)->getPointerTo());
+    Builder.CreateStore(NumElements, NumElementsPtr);
+
+    // Now add the padding to the new ptr.
+    NewPtr = Builder.CreateConstInBoundsGEP1_64(NewPtr, CookiePadding);
+  }
+  
+  NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType()));
+
+  EmitNewInitializer(*this, E, NewPtr, NumElements);
+
+  if (NullCheckResult) {
+    Builder.CreateBr(NewEnd);
+    EmitBlock(NewNull);
+    Builder.CreateBr(NewEnd);
+    EmitBlock(NewEnd);
+
+    llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType());
+    PHI->reserveOperandSpace(2);
+    PHI->addIncoming(NewPtr, NewNotNull);
+    PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()), NewNull);
+
+    NewPtr = PHI;
+  }
+
+  return NewPtr;
+}
+
+void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
+  if (E->isArrayForm()) {
+    ErrorUnsupported(E, "delete[] expression");
+    return;
+  };
+
+  // Get at the argument before we performed the implicit conversion
+  // to void*.
+  const Expr *Arg = E->getArgument();
+  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
+    if (ICE->getCastKind() != CastExpr::CK_UserDefinedConversion &&
+        ICE->getType()->isVoidPointerType())
+      Arg = ICE->getSubExpr();
+    else
+      break;
+  }
+  
+  QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType();
+
+  llvm::Value *Ptr = EmitScalarExpr(Arg);
+
+  // Null check the pointer.
+  llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull");
+  llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end");
+
+  llvm::Value *IsNull =
+    Builder.CreateICmpEQ(Ptr, llvm::Constant::getNullValue(Ptr->getType()),
+                         "isnull");
+
+  Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
+  EmitBlock(DeleteNotNull);
+
+  // Call the destructor if necessary.
+  if (const RecordType *RT = DeleteTy->getAs<RecordType>()) {
+    if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
+      if (!RD->hasTrivialDestructor()) {
+        const CXXDestructorDecl *Dtor = RD->getDestructor(getContext());
+        if (Dtor->isVirtual()) {
+          const llvm::Type *Ty =
+            CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(Dtor),
+                                           /*isVariadic=*/false);
+          
+          llvm::Value *Callee = BuildVirtualCall(Dtor, Ptr, Ty);
+          EmitCXXMemberCall(Dtor, Callee, Ptr, 0, 0);
+        } else 
+          EmitCXXDestructorCall(Dtor, Dtor_Complete, Ptr);
+      }
+    }
+  }
+
+  // Call delete.
+  FunctionDecl *DeleteFD = E->getOperatorDelete();
+  const FunctionProtoType *DeleteFTy =
+    DeleteFD->getType()->getAs<FunctionProtoType>();
+
+  CallArgList DeleteArgs;
+
+  QualType ArgTy = DeleteFTy->getArgType(0);
+  llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
+  DeleteArgs.push_back(std::make_pair(RValue::get(DeletePtr), ArgTy));
+
+  // Emit the call to delete.
+  EmitCall(CGM.getTypes().getFunctionInfo(DeleteFTy->getResultType(),
+                                          DeleteArgs),
+           CGM.GetAddrOfFunction(DeleteFD),
+           DeleteArgs, DeleteFD);
+
+  EmitBlock(DeleteEnd);
+}