Fix ICE on attempt to add an addr space qual to a type qualified by an addr space

[Anastasia]

Summary

If cv2T2 has an address space and we are creating a qualified type cv1T4 adding new addr space qualifier an ICE is triggered.

To avoid this ICE we first create a duplicate of cv2T2 omitting its original addr space. Then we can safely use it to create combined type to use in the conversion.

This is the last patch that allows fixing PR38614!

[rjmccall]

lib/Sema/SemaInit.cpp

4692

Qualifiers::addQualifiers should let you do this in a single step. Also, you seem to be modifying T2Quals here after the last use of it.

[Anastasia]

lib/Sema/SemaInit.cpp

4692

Ok, I will update to use Qualifies methods directly.

As for T2Quals I was thinking it might make sense to restore the original value in case some code later will be added to use it (to prevent bugs)... but may be it's too hypothetical. :)

Thanks!

[rjmccall]

lib/Sema/SemaInit.cpp

4692

That's not unreasonable, but if you're going to do that, you should do it unconditionally, not just in a AS1 != AS2 block — or better yet, make new locals for T1QualsWithoutAS.

[Anastasia]

• Renamed variables and made other changes to improve readability.

[rjmccall]

Okay.

lib/Sema/SemaInit.cpp

if (!T1Function &&
     }
 
     // C++1z [dcl.init.ref]/5.2.1.2:
     //   If the converted initializer is a prvalue, its type T4 is adjusted
     //   to type "cv1 T4" and the temporary materialization conversion is
     //   applied.
     // Postpone address space conversions to after the temporary materialization
     // conversion to allow creating temporaries in the alloca address space.
-    auto AS1 = T1Quals.getAddressSpace();
-    auto AS2 = T2Quals.getAddressSpace();
-    T1Quals.removeAddressSpace();
-    T2Quals.removeAddressSpace();
-    QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1Quals);
-    if (T1Quals != T2Quals)
+    auto T1QualsIgnoreAS = T1Quals;
+    auto T2QualsIgnoreAS = T2Quals;
+    if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
+      T1QualsIgnoreAS.removeAddressSpace();
+      T2QualsIgnoreAS.removeAddressSpace();
+    }
+    QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS);
+    if (T1QualsIgnoreAS != T2QualsIgnoreAS)
       Sequence.AddQualificationConversionStep(cv1T4, ValueKind);
     Sequence.AddReferenceBindingStep(cv1T4, ValueKind == VK_RValue);
     ValueKind = isLValueRef ? VK_LValue : VK_XValue;
-    if (AS1 != AS2) {
-      T1Quals.addAddressSpace(AS1);
-      QualType cv1AST4 = S.Context.getQualifiedType(cv2T2, T1Quals);
-      Sequence.AddQualificationConversionStep(cv1AST4, ValueKind);
+    // Add addr space conversion if required.
+    if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
+      auto T4Quals = cv1T4.getQualifiers();
+      T4Quals.addAddressSpace(T1Quals.getAddressSpace());
+      QualType cv1T4WithAS = S.Context.getQualifiedType(T2, T4Quals);
+      Sequence.AddQualificationConversionStep(cv1T4WithAS, ValueKind);
     }
 
     //   In any case, the reference is bound to the resulting glvalue (or to
     //   an appropriate base class subobject).
     if (DerivedToBase)
       Sequence.AddDerivedToBaseCastStep(cv1T1, ValueKind);
     else if (ObjCConversion)
       Sequence.AddObjCObjectConversionStep(cv1T1);
     return;
   }
 

test/SemaOpenCLCXX/address-space-of-this.cl

+// RUN: %clang_cc1 %s -triple spir-unknown-unknown -cl-std=c++ -pedantic -verify -fsyntax-only
+// expected-no-diagnostics
+
+// Extract from PR38614
+struct C {};
+
+C f1() {
+ return C{};
+}
+
+C f2(){
+    C c;
+    return c;
+}