[OpenCL] Fix address space for implicit conversion (PR43145)

svenvh · svenvh · commit 62364965619b · 2019-12-02T14:20:15.000Z
Clang was creating a DerivedToBase ImplicitCastExpr that was also casting between address spaces as part of the second step in the standard conversion sequence. Defer the address space conversion to the third step in the sequence instead, such that we get a separate ImplicitCastExpr for the address space conversion. Differential Revision: https://reviews.llvm.org/D70605
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4095,9 +4095,26 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
             << From->getSourceRange();
     }
 
+    // Defer address space conversion to the third conversion.
+    QualType FromPteeType = From->getType()->getPointeeType();
+    QualType ToPteeType = ToType->getPointeeType();
+    QualType NewToType = ToType;
+    if (!FromPteeType.isNull() && !ToPteeType.isNull() &&
+        FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) {
+      NewToType = Context.removeAddrSpaceQualType(ToPteeType);
+      NewToType = Context.getAddrSpaceQualType(NewToType,
+                                               FromPteeType.getAddressSpace());
+      if (ToType->isObjCObjectPointerType())
+        NewToType = Context.getObjCObjectPointerType(NewToType);
+      else if (ToType->isBlockPointerType())
+        NewToType = Context.getBlockPointerType(NewToType);
+      else
+        NewToType = Context.getPointerType(NewToType);
+    }
+
     CastKind Kind;
     CXXCastPath BasePath;
-    if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))
+    if (CheckPointerConversion(From, NewToType, Kind, BasePath, CStyle))
       return ExprError();
 
     // Make sure we extend blocks if necessary.
@@ -4108,8 +4125,8 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
       From = E.get();
     }
     if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers())
-      CheckObjCConversion(SourceRange(), ToType, From, CCK);
-    From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
+      CheckObjCConversion(SourceRange(), NewToType, From, CCK);
+    From = ImpCastExprToType(From, NewToType, Kind, VK_RValue, &BasePath, CCK)
              .get();
     break;
   }
diff --git a/clang/test/CodeGenOpenCLCXX/addrspace-derived-base.cl b/clang/test/CodeGenOpenCLCXX/addrspace-derived-base.cl
@@ -69,3 +69,14 @@ void pr43145_3(int n) {
   // CHECK: bitcast i8 addrspace(4)* %add.ptr1 to %class.B2 addrspace(4)*
   // CHECK: call {{.*}} @_ZNU3AS42B26getRefEv
 }
+
+// Implicit conversion of derived to base.
+
+void functionWithBaseArgPtr(class B2 *b) {}
+void functionWithBaseArgRef(class B2 &b) {}
+
+void pr43145_4() {
+  Derived d;
+  functionWithBaseArgPtr(&d);
+  functionWithBaseArgRef(d);
+}
