commit 7849eeb0359e086870633437529c7f8a6a30a952
author Nico Weber <nicolasweber@gmx.de> Wed Dec 14 21:38:18 2016 +0000
committer Nico Weber <nicolasweber@gmx.de> Wed Dec 14 21:38:18 2016 +0000
tree f6e8d655f9a1feba6677efeb815d749321625ee1
parent 65aedad62862a356c49fc5457277fb0c9cd3a75a

Revert 289252 (and follow-up 289285), it caused PR31374

llvm-svn: 289713

clang/lib/AST/ExprConstant.cpp

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index c57b782..5dd493c 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1088,7 +1088,6 @@
     unsigned InvalidBase : 1;
     unsigned CallIndex : 31;
     SubobjectDesignator Designator;
-    bool IsNullPtr;
 
     const APValue::LValueBase getLValueBase() const { return Base; }
     CharUnits &getLValueOffset() { return Offset; }
@@ -1096,15 +1095,13 @@
     unsigned getLValueCallIndex() const { return CallIndex; }
     SubobjectDesignator &getLValueDesignator() { return Designator; }
     const SubobjectDesignator &getLValueDesignator() const { return Designator;}
-    bool isNullPointer() const { return IsNullPtr;}
 
     void moveInto(APValue &V) const {
       if (Designator.Invalid)
-        V = APValue(Base, Offset, APValue::NoLValuePath(), CallIndex,
-                    IsNullPtr);
+        V = APValue(Base, Offset, APValue::NoLValuePath(), CallIndex);
       else
         V = APValue(Base, Offset, Designator.Entries,
-                    Designator.IsOnePastTheEnd, CallIndex, IsNullPtr);
+                    Designator.IsOnePastTheEnd, CallIndex);
     }
     void setFrom(ASTContext &Ctx, const APValue &V) {
       assert(V.isLValue());
@@ -1113,17 +1110,14 @@
       InvalidBase = false;
       CallIndex = V.getLValueCallIndex();
       Designator = SubobjectDesignator(Ctx, V);
-      IsNullPtr = V.isNullPointer();
     }
 
-    void set(APValue::LValueBase B, unsigned I = 0, bool BInvalid = false,
-             bool IsNullPtr_ = false, uint64_t Offset_ = 0) {
+    void set(APValue::LValueBase B, unsigned I = 0, bool BInvalid = false) {
       Base = B;
-      Offset = CharUnits::fromQuantity(Offset_);
+      Offset = CharUnits::Zero();
       InvalidBase = BInvalid;
       CallIndex = I;
       Designator = SubobjectDesignator(getType(B));
-      IsNullPtr = IsNullPtr_;
     }
 
     void setInvalid(APValue::LValueBase B, unsigned I = 0) {
@@ -1136,7 +1130,7 @@
                           CheckSubobjectKind CSK) {
       if (Designator.Invalid)
         return false;
-      if (IsNullPtr) {
+      if (!Base) {
         Info.CCEDiag(E, diag::note_constexpr_null_subobject)
           << CSK;
         Designator.setInvalid();
@@ -1165,22 +1159,9 @@
       if (checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real))
         Designator.addComplexUnchecked(EltTy, Imag);
     }
-    void clearIsNullPointer() {
-      IsNullPtr = false;
-    }
-    void adjustOffsetAndIndex(EvalInfo &Info, const Expr *E, uint64_t Index,
-                              CharUnits ElementSize) {
-      // Compute the new offset in the appropriate width.
-      Offset += Index * ElementSize;
-      if (Index && checkNullPointer(Info, E, CSK_ArrayIndex))
-        Designator.adjustIndex(Info, E, Index);
-      if (Index)
-        clearIsNullPointer();
-    }
-    void adjustOffset(CharUnits N) {
-      Offset += N;
-      if (N.getQuantity())
-        clearIsNullPointer();
+    void adjustIndex(EvalInfo &Info, const Expr *E, uint64_t N) {
+      if (N && checkNullPointer(Info, E, CSK_ArrayIndex))
+        Designator.adjustIndex(Info, E, N);
     }
   };
 
@@ -2055,7 +2036,7 @@
   }
 
   unsigned I = FD->getFieldIndex();
-  LVal.adjustOffset(Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I)));
+  LVal.Offset += Info.Ctx.toCharUnitsFromBits(RL->getFieldOffset(I));
   LVal.addDecl(Info, E, FD);
   return true;
 }
@@ -2109,7 +2090,9 @@
   if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfPointee))
     return false;
 
-  LVal.adjustOffsetAndIndex(Info, E, Adjustment, SizeOfPointee);
+  // Compute the new offset in the appropriate width.
+  LVal.Offset += Adjustment * SizeOfPointee;
+  LVal.adjustIndex(Info, E, Adjustment);
   return true;
 }
 
@@ -5095,9 +5078,7 @@
     return true;
   }
   bool ZeroInitialization(const Expr *E) {
-    auto Offset = Info.Ctx.getTargetNullPointerValue(E->getType());
-    Result.set((Expr*)nullptr, 0, false, true, Offset);
-    return true;
+    return Success((Expr*)nullptr);
   }
 
   bool VisitBinaryOperator(const BinaryOperator *E);
@@ -5196,8 +5177,6 @@
       else
         CCEDiag(E, diag::note_constexpr_invalid_cast) << 2;
     }
-    if (E->getCastKind() == CK_AddressSpaceConversion && Result.IsNullPtr)
-      ZeroInitialization(E);
     return true;
 
   case CK_DerivedToBase:
@@ -5239,7 +5218,6 @@
       Result.Offset = CharUnits::fromQuantity(N);
       Result.CallIndex = 0;
       Result.Designator.setInvalid();
-      Result.IsNullPtr = false;
       return true;
     } else {
       // Cast is of an lvalue, no need to change value.
@@ -8414,13 +8392,8 @@
       return true;
     }
 
-    uint64_t V;
-    if (LV.isNullPointer())
-      V = Info.Ctx.getTargetNullPointerValue(SrcType);
-    else
-      V = LV.getLValueOffset().getQuantity();
-
-    APSInt AsInt = Info.Ctx.MakeIntValue(V, SrcType);
+    APSInt AsInt = Info.Ctx.MakeIntValue(LV.getLValueOffset().getQuantity(), 
+                                         SrcType);
     return Success(HandleIntToIntCast(Info, E, DestType, SrcType, AsInt), E);
   }