[Sema] add cast from IncompleteArrayType to ConstantArrayType in TryReferenceListInitialization (#65918)

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index cb57a2d..de576cc 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -18,6 +18,7 @@
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/CharInfo.h"
 #include "clang/Basic/SourceManager.h"
+#include "clang/Basic/Specifiers.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Sema/Designator.h"
 #include "clang/Sema/EnterExpressionEvaluationContext.h"
@@ -4528,6 +4529,17 @@ static void TryReferenceListInitialization(Sema &S,
   if (Sequence) {
     if (DestType->isRValueReferenceType() ||
         (T1Quals.hasConst() && !T1Quals.hasVolatile())) {
+      if (S.getLangOpts().CPlusPlus20 &&
+          isa<IncompleteArrayType>(T1->getUnqualifiedDesugaredType()) &&
+          DestType->isRValueReferenceType()) {
+        // C++20 [dcl.init.list]p3.10:
+        // List-initialization of an object or reference of type T is defined as
+        // follows:
+        // ..., unless T is “reference to array of unknown bound of U”, in which
+        // case the type of the prvalue is the type of x in the declaration U
+        // x[] H, where H is the initializer list.
+        Sequence.AddQualificationConversionStep(cv1T1, clang::VK_PRValue);
+      }
       Sequence.AddReferenceBindingStep(cv1T1IgnoreAS,
                                        /*BindingTemporary=*/true);
       if (T1Quals.hasAddressSpace())