From: Anastasia Stulova <anastasia.stulova@arm.com>
Date: Fri, 21 Jun 2019 11:36:15 +0000 (+0000)
Subject: [Sema] Fix diagnostic for addr spaces in reference binding
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=73ad46cd4756a43f9ae7d4c9257a9e50ffde2dfe;p=clang

[Sema] Fix diagnostic for addr spaces in reference binding

Extend reference binding behavior to account for address spaces.

Differential Revision: https://reviews.llvm.org/D62914



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@364032 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index c8674d781c..2abf7d73c1 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1852,7 +1852,7 @@ def err_lvalue_reference_bind_to_unrelated : Error<
   "cannot bind to a value of unrelated type}1,2">;
 def err_reference_bind_drops_quals : Error<
   "binding reference %diff{of type $ to value of type $|to value}0,1 "
-  "drops %2 qualifier%plural{1:|2:|4:|:s}3">;
+  "%select{drops %3 qualifier%plural{1:|2:|4:|:s}4|changes address space}2">;
 def err_reference_bind_failed : Error<
   "reference %diff{to %select{type|incomplete type}1 $ could not bind to an "
   "%select{rvalue|lvalue}2 of type $|could not bind to %select{rvalue|lvalue}2 of "
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 128809175e..d2a4a0979d 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -4631,7 +4631,10 @@ static void TryReferenceInitializationCore(Sema &S,
   //     - Otherwise, the reference shall be an lvalue reference to a
   //       non-volatile const type (i.e., cv1 shall be const), or the reference
   //       shall be an rvalue reference.
-  if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile())) {
+  //       For address spaces, we interpret this to mean that an addr space
+  //       of a reference "cv1 T1" is a superset of addr space of "cv2 T2".
+  if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile() &&
+                       T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
     if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
       Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
     else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
@@ -4640,7 +4643,10 @@ static void TryReferenceInitializationCore(Sema &S,
                                   ConvOvlResult);
     else if (!InitCategory.isLValue())
       Sequence.SetFailed(
-          InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
+          T1Quals.isAddressSpaceSupersetOf(T2Quals)
+              ? InitializationSequence::
+                    FK_NonConstLValueReferenceBindingToTemporary
+              : InitializationSequence::FK_ReferenceInitDropsQualifiers);
     else {
       InitializationSequence::FailureKind FK;
       switch (RefRelationship) {
@@ -8521,12 +8527,16 @@ bool InitializationSequence::Diagnose(Sema &S,
     Qualifiers DroppedQualifiers =
         SourceType.getQualifiers() - NonRefType.getQualifiers();
 
-    S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
-      << NonRefType
-      << SourceType
-      << Qualifiers::fromCVRMask(DroppedQualifiers.getCVRQualifiers())
-      << DroppedQualifiers.getCVRQualifiers()
-      << Args[0]->getSourceRange();
+    if (!NonRefType.getQualifiers().isAddressSpaceSupersetOf(
+            SourceType.getQualifiers()))
+      S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
+          << NonRefType << SourceType << 1 /*addr space*/
+          << Args[0]->getSourceRange();
+    else
+      S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
+          << NonRefType << SourceType << 0 /*cv quals*/
+          << Qualifiers::fromCVRMask(DroppedQualifiers.getCVRQualifiers())
+          << DroppedQualifiers.getCVRQualifiers() << Args[0]->getSourceRange();
     break;
   }
 
diff --git a/test/SemaOpenCLCXX/address-space-references.cl b/test/SemaOpenCLCXX/address-space-references.cl
index c359bbd713..851d3023df 100644
--- a/test/SemaOpenCLCXX/address-space-references.cl
+++ b/test/SemaOpenCLCXX/address-space-references.cl
@@ -3,3 +3,13 @@
 __global const int& f(__global float &ref) {
   return ref; // expected-error{{reference of type 'const __global int &' cannot bind to a temporary object because of address space mismatch}}
 }
+
+int bar(const __global unsigned int &i); // expected-note{{passing argument to parameter 'i' here}}
+//FIXME: With the overload below the call should be resolved
+// successfully. However, current overload resolution logic
+// can't detect this case and therefore fails.
+int bar(const unsigned int &i);
+
+void foo() {
+  bar(1) // expected-error{{binding reference of type 'const __global unsigned int' to value of type 'int' changes address space}}
+}