Move codegen of new and delete to CGCXXExpr.cpp

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82585 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 203 insertions, 0 deletions

diff --git a/lib/CodeGen/CGCXXExpr.cpp b/lib/CodeGen/CGCXXExpr.cpp
new file mode 100644
index 0000000000..706bd8ff2d
--- /dev/null
+++ b/lib/CodeGen/CGCXXExpr.cpp
@@ -0,0 +1,203 @@
+//===--- 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;
+
+llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
+  if (E->isArray()) {
+    ErrorUnsupported(E, "new[] expression");
+    return llvm::UndefValue::get(ConvertType(E->getType()));
+  }
+
+  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 *AllocSize =
+    llvm::ConstantInt::get(ConvertType(SizeTy),
+                           getContext().getTypeSize(AllocType) / 8);
+
+  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);
+  }
+
+  NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType()));
+
+  if (AllocType->isPODType()) {
+    if (E->getNumConstructorArgs() > 0) {
+      assert(E->getNumConstructorArgs() == 1 &&
+             "Can only have one argument to initializer of POD type.");
+
+      const Expr *Init = E->getConstructorArg(0);
+
+      if (!hasAggregateLLVMType(AllocType))
+        Builder.CreateStore(EmitScalarExpr(Init), NewPtr);
+      else if (AllocType->isAnyComplexType())
+        EmitComplexExprIntoAddr(Init, NewPtr, AllocType.isVolatileQualified());
+      else
+        EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified());
+    }
+  } else {
+    // Call the constructor.
+    CXXConstructorDecl *Ctor = E->getConstructor();
+
+    EmitCXXConstructorCall(Ctor, Ctor_Complete, NewPtr,
+                           E->constructor_arg_begin(),
+                           E->constructor_arg_end());
+  }
+
+  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;
+  };
+
+  QualType DeleteTy =
+    E->getArgument()->getType()->getAs<PointerType>()->getPointeeType();
+
+  llvm::Value *Ptr = EmitScalarExpr(E->getArgument());
+
+  // 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);
+}