Cope with an amusingly little anomaly with dependent types and

incomplete array initialization, where we have the following in a
template:

  int a[] = { 1, 2, something-value-dependent };
  // ...
  sizeof(a);

The type of "a" appears to be a non-dependent IncompleteArrayType, but
treating it as such makes the sizeof(a) fail at template definition
time. We now correctly handle this by morphing the IncompleteArrayType
into a DependentSizedArrayType with a NULL expression, indicating that
its size has no corresponding expression (and, therefore, the type is
distinct from others).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89366 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 1 deletions

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 0f973d6d9b..fbc4680f8f 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -136,8 +136,29 @@ bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType,
                                  SourceLocation InitLoc,
                                  DeclarationName InitEntity, bool DirectInit) {
   if (DeclType->isDependentType() ||
-      Init->isTypeDependent() || Init->isValueDependent())
+      Init->isTypeDependent() || Init->isValueDependent()) {
+    // We have either a dependent type or a type- or value-dependent
+    // initializer, so we don't perform any additional checking at
+    // this point.
+
+    // If the declaration is a non-dependent, incomplete array type
+    // that has an initializer, then its type will be completed once
+    // the initializer is instantiated, meaning that the type is
+    // dependent. Morph the declaration's type into a
+    // dependently-sized array type.
+    if (!DeclType->isDependentType()) {
+      if (const IncompleteArrayType *ArrayT
+                           = Context.getAsIncompleteArrayType(DeclType)) {
+        DeclType = Context.getDependentSizedArrayType(ArrayT->getElementType(),
+                                                      /*NumElts=*/0,
+                                                     ArrayT->getSizeModifier(),
+                                           ArrayT->getIndexTypeCVRQualifiers(),
+                                                      SourceRange());
+      }
+    }
+
     return false;
+  }
 
   // C++ [dcl.init.ref]p1:
   //   A variable declared to be a T& or T&&, that is "reference to type T"