1 files changed, 337 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
new file mode 100644
index 00000000000..325ac2109eb
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+++ b/clang/lib/CodeGen/CGExprAgg.cpp
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+//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate 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 to emit Aggregate Expr nodes as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "clang/AST/AST.h"
+#include "llvm/Constants.h"
+#include "llvm/Function.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Support/Compiler.h"
+using namespace clang;
+using namespace CodeGen;
+
+//===----------------------------------------------------------------------===//
+//                        Aggregate Expression Emitter
+//===----------------------------------------------------------------------===//
+
+namespace  {
+class VISIBILITY_HIDDEN AggExprEmitter : public StmtVisitor<AggExprEmitter> {
+  CodeGenFunction &CGF;
+  llvm::LLVMFoldingBuilder &Builder;
+  llvm::Value *DestPtr;
+  bool VolatileDest;
+public:
+  AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool volatileDest)
+    : CGF(cgf), Builder(CGF.Builder),
+      DestPtr(destPtr), VolatileDest(volatileDest) {
+  }
+
+  //===--------------------------------------------------------------------===//
+  //                               Utilities
+  //===--------------------------------------------------------------------===//
+
+  /// EmitAggLoadOfLValue - Given an expression with aggregate type that
+  /// represents a value lvalue, this method emits the address of the lvalue,
+  /// then loads the result into DestPtr.
+  void EmitAggLoadOfLValue(const Expr *E);
+  
+  void EmitAggregateCopy(llvm::Value *DestPtr, llvm::Value *SrcPtr,
+                         QualType EltTy);
+
+  void EmitAggregateClear(llvm::Value *DestPtr, QualType Ty);
+
+  void EmitNonConstInit(InitListExpr *E);
+  
+  //===--------------------------------------------------------------------===//
+  //                            Visitor Methods
+  //===--------------------------------------------------------------------===//
+  
+  void VisitStmt(Stmt *S) {
+    CGF.WarnUnsupported(S, "aggregate expression");
+  }
+  void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
+
+  // l-values.
+  void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); }
+  void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
+  void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
+  void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
+
+  void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
+    EmitAggLoadOfLValue(E);
+  }
+
+  // Operators.
+  //  case Expr::UnaryOperatorClass:
+  //  case Expr::CastExprClass: 
+  void VisitImplicitCastExpr(ImplicitCastExpr *E);
+  void VisitCallExpr(const CallExpr *E);
+  void VisitStmtExpr(const StmtExpr *E);
+  void VisitBinaryOperator(const BinaryOperator *BO);
+  void VisitBinAssign(const BinaryOperator *E);
+  void VisitOverloadExpr(const OverloadExpr *E);
+
+  
+  void VisitConditionalOperator(const ConditionalOperator *CO);
+  void VisitInitListExpr(InitListExpr *E);
+  //  case Expr::ChooseExprClass:
+
+};
+}  // end anonymous namespace.
+
+//===----------------------------------------------------------------------===//
+//                                Utilities
+//===----------------------------------------------------------------------===//
+
+void AggExprEmitter::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) {
+  assert(!Ty->isComplexType() && "Shouldn't happen for complex");
+
+  // Aggregate assignment turns into llvm.memset.
+  const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+  if (DestPtr->getType() != BP)
+    DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp");
+
+  // Get size and alignment info for this aggregate.
+  std::pair<uint64_t, unsigned> TypeInfo = CGF.getContext().getTypeInfo(Ty);
+
+  // FIXME: Handle variable sized types.
+  const llvm::Type *IntPtr = llvm::IntegerType::get(CGF.LLVMPointerWidth);
+
+  llvm::Value *MemSetOps[4] = {
+    DestPtr,
+    llvm::ConstantInt::getNullValue(llvm::Type::Int8Ty),
+    // TypeInfo.first describes size in bits.
+    llvm::ConstantInt::get(IntPtr, TypeInfo.first/8),
+    llvm::ConstantInt::get(llvm::Type::Int32Ty, TypeInfo.second/8)
+  };
+ 
+  Builder.CreateCall(CGF.CGM.getMemSetFn(), MemSetOps, MemSetOps+4);
+}
+
+void AggExprEmitter::EmitAggregateCopy(llvm::Value *DestPtr,
+                                       llvm::Value *SrcPtr, QualType Ty) {
+  assert(!Ty->isComplexType() && "Shouldn't happen for complex");
+  
+  // Aggregate assignment turns into llvm.memcpy.
+  const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
+  if (DestPtr->getType() != BP)
+    DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp");
+  if (SrcPtr->getType() != BP)
+    SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
+  
+  // Get size and alignment info for this aggregate.
+  std::pair<uint64_t, unsigned> TypeInfo = CGF.getContext().getTypeInfo(Ty);
+  
+  // FIXME: Handle variable sized types.
+  const llvm::Type *IntPtr = llvm::IntegerType::get(CGF.LLVMPointerWidth);
+  
+  llvm::Value *MemCpyOps[4] = {
+    DestPtr, SrcPtr,
+    // TypeInfo.first describes size in bits.
+    llvm::ConstantInt::get(IntPtr, TypeInfo.first/8),
+    llvm::ConstantInt::get(llvm::Type::Int32Ty, TypeInfo.second/8)
+  };
+  
+  Builder.CreateCall(CGF.CGM.getMemCpyFn(), MemCpyOps, MemCpyOps+4);
+}
+
+
+/// EmitAggLoadOfLValue - Given an expression with aggregate type that
+/// represents a value lvalue, this method emits the address of the lvalue,
+/// then loads the result into DestPtr.
+void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
+  LValue LV = CGF.EmitLValue(E);
+  assert(LV.isSimple() && "Can't have aggregate bitfield, vector, etc");
+  llvm::Value *SrcPtr = LV.getAddress();
+  
+  // If the result is ignored, don't copy from the value.
+  if (DestPtr == 0)
+    // FIXME: If the source is volatile, we must read from it.
+    return;
+
+  EmitAggregateCopy(DestPtr, SrcPtr, E->getType());
+}
+
+//===----------------------------------------------------------------------===//
+//                            Visitor Methods
+//===----------------------------------------------------------------------===//
+
+void AggExprEmitter::VisitImplicitCastExpr(ImplicitCastExpr *E)
+{
+  QualType STy = E->getSubExpr()->getType().getCanonicalType();
+  QualType Ty = E->getType().getCanonicalType();
+
+  assert(CGF.getContext().typesAreCompatible(
+             STy.getUnqualifiedType(), Ty.getUnqualifiedType())
+         && "Implicit cast types must be compatible");
+  
+  Visit(E->getSubExpr());
+}
+
+void AggExprEmitter::VisitCallExpr(const CallExpr *E)
+{
+  RValue RV = CGF.EmitCallExpr(E);
+  assert(RV.isAggregate() && "Return value must be aggregate value!");
+  
+  // If the result is ignored, don't copy from the value.
+  if (DestPtr == 0)
+    // FIXME: If the source is volatile, we must read from it.
+    return;
+  
+  EmitAggregateCopy(DestPtr, RV.getAggregateAddr(), E->getType());
+}
+
+void AggExprEmitter::VisitOverloadExpr(const OverloadExpr *E)
+{
+  RValue RV = CGF.EmitCallExpr(E->getFn(), E->arg_begin(),
+                               E->getNumArgs(CGF.getContext()));
+  assert(RV.isAggregate() && "Return value must be aggregate value!");
+  
+  // If the result is ignored, don't copy from the value.
+  if (DestPtr == 0)
+    // FIXME: If the source is volatile, we must read from it.
+    return;
+  
+  EmitAggregateCopy(DestPtr, RV.getAggregateAddr(), E->getType());
+}
+
+void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
+  CGF.EmitCompoundStmt(*E->getSubStmt(), true, DestPtr, VolatileDest);
+}
+
+void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
+  CGF.WarnUnsupported(E, "aggregate binary expression");
+}
+
+void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
+  // For an assignment to work, the value on the right has
+  // to be compatible with the value on the left.
+  assert(CGF.getContext().typesAreCompatible(
+             E->getLHS()->getType().getUnqualifiedType(),
+             E->getRHS()->getType().getUnqualifiedType())
+         && "Invalid assignment");
+  LValue LHS = CGF.EmitLValue(E->getLHS());
+
+  // Codegen the RHS so that it stores directly into the LHS.
+  CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), false /*FIXME: VOLATILE LHS*/);
+
+  if (DestPtr == 0)
+    return;
+
+  // If the result of the assignment is used, copy the RHS there also.
+  EmitAggregateCopy(DestPtr, LHS.getAddress(), E->getType());
+}
+
+void AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) {
+  llvm::BasicBlock *LHSBlock = new llvm::BasicBlock("cond.?");
+  llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("cond.:");
+  llvm::BasicBlock *ContBlock = new llvm::BasicBlock("cond.cont");
+  
+  llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
+  Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
+  
+  CGF.EmitBlock(LHSBlock);
+  
+  // Handle the GNU extension for missing LHS.
+  assert(E->getLHS() && "Must have LHS for aggregate value");
+
+  Visit(E->getLHS());
+  Builder.CreateBr(ContBlock);
+  LHSBlock = Builder.GetInsertBlock();
+  
+  CGF.EmitBlock(RHSBlock);
+  
+  Visit(E->getRHS());
+  Builder.CreateBr(ContBlock);
+  RHSBlock = Builder.GetInsertBlock();
+  
+  CGF.EmitBlock(ContBlock);
+}
+
+void AggExprEmitter::EmitNonConstInit(InitListExpr *E) {
+
+  const llvm::PointerType *APType =
+    cast<llvm::PointerType>(DestPtr->getType());
+  const llvm::Type *DestType = APType->getElementType();
+
+  if (const llvm::ArrayType *AType = dyn_cast<llvm::ArrayType>(DestType)) {
+    unsigned NumInitElements = E->getNumInits();
+
+    llvm::Value *Idxs[] = {
+      llvm::Constant::getNullValue(llvm::Type::Int32Ty),
+      NULL
+    };
+    llvm::Value *NextVal = NULL;
+    unsigned i;
+    for (i = 0; i != NumInitElements; ++i) {
+      Idxs[1] = llvm::ConstantInt::get(llvm::Type::Int32Ty, i);
+      NextVal = Builder.CreateGEP(DestPtr, Idxs, Idxs + 2,".array");
+      Expr *Init = E->getInit(i);
+      if (isa<InitListExpr>(Init))
+        CGF.EmitAggExpr(Init, NextVal, VolatileDest);
+      else
+        Builder.CreateStore(CGF.EmitScalarExpr(Init), NextVal);
+    }
+
+    // Emit remaining default initializers
+    unsigned NumArrayElements = AType->getNumElements();
+    QualType QType = E->getInit(0)->getType();
+    const llvm::Type *EType = AType->getElementType();
+    for (/*Do not initialize i*/; i < NumArrayElements; ++i) {
+      Idxs[1] = llvm::ConstantInt::get(llvm::Type::Int32Ty, i);
+      NextVal = Builder.CreateGEP(DestPtr, Idxs, Idxs + 2,".array");
+      if (EType->isFirstClassType())
+        Builder.CreateStore(llvm::Constant::getNullValue(EType), NextVal);
+      else
+        EmitAggregateClear(NextVal, QType);
+    }
+  } else
+    assert(false && "Invalid initializer");
+}
+
+void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
+
+  if (E->isConstantExpr(CGF.CGM.getContext(), NULL)) {
+    llvm::Constant *V = CGF.CGM.EmitConstantExpr(E);
+    // Create global value to hold this array.
+    V = new llvm::GlobalVariable(V->getType(), true,
+                                 llvm::GlobalValue::InternalLinkage,
+                                 V, ".array",
+                                 &CGF.CGM.getModule());
+
+    EmitAggregateCopy(DestPtr, V , E->getType());
+    return;
+  } else {
+    if (!E->getType()->isArrayType()) {
+      CGF.WarnUnsupported(E, "aggregate init-list expression");
+      return;
+    }
+    EmitNonConstInit(E);
+  }
+}
+
+//===----------------------------------------------------------------------===//
+//                        Entry Points into this File
+//===----------------------------------------------------------------------===//
+
+/// EmitAggExpr - Emit the computation of the specified expression of
+/// aggregate type.  The result is computed into DestPtr.  Note that if
+/// DestPtr is null, the value of the aggregate expression is not needed.
+void CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr,
+                                  bool VolatileDest) {
+  assert(E && hasAggregateLLVMType(E->getType()) &&
+         "Invalid aggregate expression to emit");
+  
+  AggExprEmitter(*this, DestPtr, VolatileDest).Visit(const_cast<Expr*>(E));
+}