When adding built-in operator candidates for overload resolution

involving 'restrict', place restrict on the pointer type rather than
on the pointee type. Also make sure that we gather restrict from the
pointer type. Fixes PR12854 and the major part of PR11093.

llvm-svn: 157910

2 files changed, 129 insertions, 26 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 49170d6f327..2ead6a66f8e 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -6120,40 +6120,49 @@ BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
   const PointerType *PointerTy = Ty->getAs<PointerType>();
   bool buildObjCPtr = false;
   if (!PointerTy) {
-    if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) {
-      PointeeTy = PTy->getPointeeType();
-      buildObjCPtr = true;
-    }
-    else
-      llvm_unreachable("type was not a pointer type!");
-  }
-  else
+    const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
+    PointeeTy = PTy->getPointeeType();
+    buildObjCPtr = true;
+  } else {
     PointeeTy = PointerTy->getPointeeType();
-
+  }
+  
   // Don't add qualified variants of arrays. For one, they're not allowed
   // (the qualifier would sink to the element type), and for another, the
   // only overload situation where it matters is subscript or pointer +- int,
   // and those shouldn't have qualifier variants anyway.
   if (PointeeTy->isArrayType())
     return true;
+  
   unsigned BaseCVR = PointeeTy.getCVRQualifiers();
-  if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy))
-    BaseCVR = Array->getElementType().getCVRQualifiers();
   bool hasVolatile = VisibleQuals.hasVolatile();
   bool hasRestrict = VisibleQuals.hasRestrict();
 
   // Iterate through all strict supersets of BaseCVR.
   for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
     if ((CVR | BaseCVR) != CVR) continue;
-    // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere
-    // in the types.
+    // Skip over volatile if no volatile found anywhere in the types.
     if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
-    if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue;
+    
+    // Skip over restrict if no restrict found anywhere in the types, or if
+    // the type cannot be restrict-qualified.
+    if ((CVR & Qualifiers::Restrict) &&
+        (!hasRestrict ||
+         (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
+      continue;
+  
+    // Build qualified pointee type.
     QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
+    
+    // Build qualified pointer type.
+    QualType QPointerTy;
     if (!buildObjCPtr)
-      PointerTypes.insert(Context.getPointerType(QPointeeTy));
+      QPointerTy = Context.getPointerType(QPointeeTy);
     else
-      PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy));
+      QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
+    
+    // Insert qualified pointer type.
+    PointerTypes.insert(QPointerTy);
   }
 
   return true;
@@ -6350,6 +6359,8 @@ static  Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
         // as see them.
         bool done = false;
         while (!done) {
+          if (CanTy.isRestrictQualified())
+            VRQuals.addRestrict();
           if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
             CanTy = ResTypePtr->getPointeeType();
           else if (const MemberPointerType *ResTypeMPtr =
@@ -6359,8 +6370,6 @@ static  Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
             done = true;
           if (CanTy.isVolatileQualified())
             VRQuals.addVolatile();
-          if (CanTy.isRestrictQualified())
-            VRQuals.addRestrict();
           if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
             return VRQuals;
         }
@@ -6488,7 +6497,8 @@ class BuiltinOperatorOverloadBuilder {
   /// \brief Helper method to factor out the common pattern of adding overloads
   /// for '++' and '--' builtin operators.
   void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
-                                           bool HasVolatile) {
+                                           bool HasVolatile,
+                                           bool HasRestrict) {
     QualType ParamTypes[2] = {
       S.Context.getLValueReferenceType(CandidateTy),
       S.Context.IntTy
@@ -6511,6 +6521,33 @@ class BuiltinOperatorOverloadBuilder {
       else
         S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet);
     }
+    
+    // Add restrict version only if there are conversions to a restrict type
+    // and our candidate type is a non-restrict-qualified pointer.
+    if (HasRestrict && CandidateTy->isAnyPointerType() &&
+        !CandidateTy.isRestrictQualified()) {
+      ParamTypes[0]
+        = S.Context.getLValueReferenceType(
+            S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
+      if (NumArgs == 1)
+        S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
+      else
+        S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet);
+      
+      if (HasVolatile) {
+        ParamTypes[0]
+          = S.Context.getLValueReferenceType(
+              S.Context.getCVRQualifiedType(CandidateTy,
+                                            (Qualifiers::Volatile |
+                                             Qualifiers::Restrict)));
+        if (NumArgs == 1)
+          S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1,
+                                CandidateSet);
+        else
+          S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet);
+      }
+    }
+
   }
 
 public:
@@ -6565,7 +6602,8 @@ public:
          Arith < NumArithmeticTypes; ++Arith) {
       addPlusPlusMinusMinusStyleOverloads(
         getArithmeticType(Arith),
-        VisibleTypeConversionsQuals.hasVolatile());
+        VisibleTypeConversionsQuals.hasVolatile(),
+        VisibleTypeConversionsQuals.hasRestrict());
     }
   }
 
@@ -6589,8 +6627,10 @@ public:
         continue;
 
       addPlusPlusMinusMinusStyleOverloads(*Ptr,
-        (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() &&
-         VisibleTypeConversionsQuals.hasVolatile()));
+        (!(*Ptr).isVolatileQualified() &&
+         VisibleTypeConversionsQuals.hasVolatile()),
+        (!(*Ptr).isRestrictQualified() &&
+         VisibleTypeConversionsQuals.hasRestrict()));
     }
   }
 
@@ -7048,14 +7088,36 @@ public:
       S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
                             /*IsAssigmentOperator=*/ isEqualOp);
 
-      if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() &&
-          VisibleTypeConversionsQuals.hasVolatile()) {
+      bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
+                          VisibleTypeConversionsQuals.hasVolatile();
+      if (NeedVolatile) {
         // volatile version
         ParamTypes[0] =
           S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
         S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
                               /*IsAssigmentOperator=*/isEqualOp);
       }
+      
+      if (!(*Ptr).isRestrictQualified() &&
+          VisibleTypeConversionsQuals.hasRestrict()) {
+        // restrict version
+        ParamTypes[0]
+          = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
+        S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
+                              /*IsAssigmentOperator=*/isEqualOp);
+        
+        if (NeedVolatile) {
+          // volatile restrict version
+          ParamTypes[0]
+            = S.Context.getLValueReferenceType(
+                S.Context.getCVRQualifiedType(*Ptr,
+                                              (Qualifiers::Volatile |
+                                               Qualifiers::Restrict)));
+          S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2,
+                                CandidateSet,
+                                /*IsAssigmentOperator=*/isEqualOp);
+        }
+      }
     }
 
     if (isEqualOp) {
@@ -7076,14 +7138,36 @@ public:
         S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
                               /*IsAssigmentOperator=*/true);
 
-        if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() &&
-            VisibleTypeConversionsQuals.hasVolatile()) {
+        bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
+                           VisibleTypeConversionsQuals.hasVolatile();
+        if (NeedVolatile) {
           // volatile version
           ParamTypes[0] =
             S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
           S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2,
                                 CandidateSet, /*IsAssigmentOperator=*/true);
         }
+      
+        if (!(*Ptr).isRestrictQualified() &&
+            VisibleTypeConversionsQuals.hasRestrict()) {
+          // restrict version
+          ParamTypes[0]
+            = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
+          S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2,
+                                CandidateSet, /*IsAssigmentOperator=*/true);
+          
+          if (NeedVolatile) {
+            // volatile restrict version
+            ParamTypes[0]
+              = S.Context.getLValueReferenceType(
+                  S.Context.getCVRQualifiedType(*Ptr,
+                                                (Qualifiers::Volatile |
+                                                 Qualifiers::Restrict)));
+            S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2,
+                                  CandidateSet, /*IsAssigmentOperator=*/true);
+            
+          }
+        }
       }
     }
   }
diff --git a/clang/test/SemaCXX/overloaded-builtin-operators.cpp b/clang/test/SemaCXX/overloaded-builtin-operators.cpp
index b3c08085a69..6de4f64030a 100644
--- a/clang/test/SemaCXX/overloaded-builtin-operators.cpp
+++ b/clang/test/SemaCXX/overloaded-builtin-operators.cpp
@@ -237,3 +237,22 @@ namespace PR7851 {
     (void)(x - x);
   }
 }
+
+namespace PR12854 {
+  enum { size = 1 };
+  void plus_equals() {
+    int* __restrict py;
+    py += size;
+  }
+
+  struct RestrictInt {
+    operator int* __restrict &();
+  };
+
+  void user_conversions(RestrictInt ri) {
+    ++ri;
+    --ri;
+    ri++;
+    ri--;
+  }
+}