1 files changed, 49 insertions, 58 deletions

diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index c9475840ae..4c0256fe38 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -1,9 +1,8 @@
 //===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -460,7 +459,7 @@ bool ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD,
       CharUnits BaseOffset = Layout.getBaseClassOffset(BD);
       Bases.push_back(BaseInfo(BD, BaseOffset, BaseNo));
     }
-    std::stable_sort(Bases.begin(), Bases.end());
+    llvm::stable_sort(Bases);
 
     for (unsigned I = 0, N = Bases.size(); I != N; ++I) {
       BaseInfo &Base = Bases[I];
@@ -701,10 +700,12 @@ EmitArrayConstant(CodeGenModule &CGM, const ConstantArrayType *DestType,
   return llvm::ConstantStruct::get(SType, Elements);
 }
 
-/// This class only needs to handle two cases:
-/// 1) Literals (this is used by APValue emission to emit literals).
-/// 2) Arrays, structs and unions (outside C++11 mode, we don't currently
-///    constant fold these types).
+// This class only needs to handle arrays, structs and unions. Outside C++11
+// mode, we don't currently constant fold those types.  All other types are
+// handled by constant folding.
+//
+// Constant folding is currently missing support for a few features supported
+// here: CK_ToUnion, CK_ReinterpretMemberPointer, and DesignatedInitUpdateExpr.
 class ConstExprEmitter :
   public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> {
   CodeGenModule &CGM;
@@ -875,6 +876,8 @@ public:
     case CK_FloatingCast:
     case CK_FixedPointCast:
     case CK_FixedPointToBoolean:
+    case CK_FixedPointToIntegral:
+    case CK_IntegralToFixedPoint:
     case CK_ZeroToOCLOpaqueType:
       return nullptr;
     }
@@ -1077,6 +1080,7 @@ public:
   }
 
   llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
+    // This is a string literal initializing an array in an initializer.
     return CGM.GetConstantArrayFromStringLiteral(E);
   }
 
@@ -1609,6 +1613,7 @@ private:
   ConstantLValue VisitConstantExpr(const ConstantExpr *E);
   ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
   ConstantLValue VisitStringLiteral(const StringLiteral *E);
+  ConstantLValue VisitObjCBoxedExpr(const ObjCBoxedExpr *E);
   ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
   ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
   ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
@@ -1650,17 +1655,7 @@ private:
 llvm::Constant *ConstantLValueEmitter::tryEmit() {
   const APValue::LValueBase &base = Value.getLValueBase();
 
-  // Certain special array initializers are represented in APValue
-  // as l-values referring to the base expression which generates the
-  // array.  This happens with e.g. string literals.  These should
-  // probably just get their own representation kind in APValue.
-  if (DestType->isArrayType()) {
-    assert(!hasNonZeroOffset() && "offset on array initializer");
-    auto expr = const_cast<Expr*>(base.get<const Expr*>());
-    return ConstExprEmitter(Emitter).Visit(expr, DestType);
-  }
-
-  // Otherwise, the destination type should be a pointer or reference
+  // The destination type should be a pointer or reference
   // type, but it might also be a cast thereof.
   //
   // FIXME: the chain of casts required should be reflected in the APValue.
@@ -1703,31 +1698,20 @@ ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
   auto offset = getOffset();
 
   // If we're producing a pointer, this is easy.
-  if (auto destPtrTy = cast<llvm::PointerType>(destTy)) {
-    if (Value.isNullPointer()) {
-      // FIXME: integer offsets from non-zero null pointers.
-      return CGM.getNullPointer(destPtrTy, DestType);
-    }
-
-    // Convert the integer to a pointer-sized integer before converting it
-    // to a pointer.
-    // FIXME: signedness depends on the original integer type.
-    auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
-    llvm::Constant *C = offset;
-    C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
-                                           /*isSigned*/ false);
-    C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
-    return C;
-  }
-
-  // Otherwise, we're basically returning an integer constant.
-
-  // FIXME: this does the wrong thing with ptrtoint of a null pointer,
-  // but since we don't know the original pointer type, there's not much
-  // we can do about it.
-
-  auto C = getOffset();
-  C = llvm::ConstantExpr::getIntegerCast(C, destTy, /*isSigned*/ false);
+  auto destPtrTy = cast<llvm::PointerType>(destTy);
+  if (Value.isNullPointer()) {
+    // FIXME: integer offsets from non-zero null pointers.
+    return CGM.getNullPointer(destPtrTy, DestType);
+  }
+
+  // Convert the integer to a pointer-sized integer before converting it
+  // to a pointer.
+  // FIXME: signedness depends on the original integer type.
+  auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
+  llvm::Constant *C = offset;
+  C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
+                                         /*isSigned*/ false);
+  C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
   return C;
 }
 
@@ -1781,25 +1765,29 @@ ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
   return CGM.GetAddrOfConstantStringFromObjCEncode(E);
 }
 
+static ConstantLValue emitConstantObjCStringLiteral(const StringLiteral *S,
+                                                    QualType T,
+                                                    CodeGenModule &CGM) {
+  auto C = CGM.getObjCRuntime().GenerateConstantString(S);
+  return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(T));
+}
+
 ConstantLValue
 ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
-  auto C = CGM.getObjCRuntime().GenerateConstantString(E->getString());
-  return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(E->getType()));
+  return emitConstantObjCStringLiteral(E->getString(), E->getType(), CGM);
 }
 
 ConstantLValue
-ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
-  if (auto CGF = Emitter.CGF) {
-    LValue Res = CGF->EmitPredefinedLValue(E);
-    return cast<ConstantAddress>(Res.getAddress());
-  }
-
-  auto kind = E->getIdentKind();
-  if (kind == PredefinedExpr::PrettyFunction) {
-    return CGM.GetAddrOfConstantCString("top level", ".tmp");
-  }
+ConstantLValueEmitter::VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
+  assert(E->isExpressibleAsConstantInitializer() &&
+         "this boxed expression can't be emitted as a compile-time constant");
+  auto *SL = cast<StringLiteral>(E->getSubExpr()->IgnoreParenCasts());
+  return emitConstantObjCStringLiteral(SL, E->getType(), CGM);
+}
 
-  return CGM.GetAddrOfConstantCString("", ".tmp");
+ConstantLValue
+ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
+  return CGM.GetAddrOfConstantStringFromLiteral(E->getFunctionName());
 }
 
 ConstantLValue
@@ -1873,6 +1861,9 @@ llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
     return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
   case APValue::Int:
     return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
+  case APValue::FixedPoint:
+    return llvm::ConstantInt::get(CGM.getLLVMContext(),
+                                  Value.getFixedPoint().getValue());
   case APValue::ComplexInt: {
     llvm::Constant *Complex[2];