1 files changed, 36 insertions, 22 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 6da530c..dc11dac 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6023,6 +6023,31 @@ TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
   return FixedTInfo;
 }
 
+/// Attempt to fold a variable-sized type to a constant-sized type, returning
+/// true if we were successful.
+static bool tryToFixVariablyModifiedVarType(Sema &S, TypeSourceInfo *&TInfo,
+                                            QualType &T, SourceLocation Loc,
+                                            unsigned FailedFoldDiagID) {
+  bool SizeIsNegative;
+  llvm::APSInt Oversized;
+  TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
+      TInfo, S.Context, SizeIsNegative, Oversized);
+  if (FixedTInfo) {
+    S.Diag(Loc, diag::ext_vla_folded_to_constant);
+    TInfo = FixedTInfo;
+    T = FixedTInfo->getType();
+    return true;
+  }
+
+  if (SizeIsNegative)
+    S.Diag(Loc, diag::err_typecheck_negative_array_size);
+  else if (Oversized.getBoolValue())
+    S.Diag(Loc, diag::err_array_too_large) << Oversized.toString(10);
+  else if (FailedFoldDiagID)
+    S.Diag(Loc, FailedFoldDiagID);
+  return false;
+}
+
 /// Register the given locally-scoped extern "C" declaration so
 /// that it can be found later for redeclarations. We include any extern "C"
 /// declaration that is not visible in the translation unit here, not just
@@ -6861,6 +6886,12 @@ NamedDecl *Sema::ActOnVariableDeclarator(
     }
   }
 
+  // If this variable has a variable-modified type and an initializer, try to
+  // fold to a constant-sized type. This is otherwise invalid.
+  if (D.hasInitializer() && R->isVariablyModifiedType())
+    tryToFixVariablyModifiedVarType(*this, TInfo, R, D.getIdentifierLoc(),
+                                    /*DiagID=*/0);
+
   bool IsMemberSpecialization = false;
   bool IsVariableTemplateSpecialization = false;
   bool IsPartialSpecialization = false;
@@ -16658,27 +16689,9 @@ FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
   // C99 6.7.2.1p8: A member of a structure or union may have any type other
   // than a variably modified type.
   if (!InvalidDecl && T->isVariablyModifiedType()) {
-    bool SizeIsNegative;
-    llvm::APSInt Oversized;
-
-    TypeSourceInfo *FixedTInfo =
-      TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
-                                                    SizeIsNegative,
-                                                    Oversized);
-    if (FixedTInfo) {
-      Diag(Loc, diag::ext_vla_folded_to_constant);
-      TInfo = FixedTInfo;
-      T = FixedTInfo->getType();
-    } else {
-      if (SizeIsNegative)
-        Diag(Loc, diag::err_typecheck_negative_array_size);
-      else if (Oversized.getBoolValue())
-        Diag(Loc, diag::err_array_too_large)
-          << Oversized.toString(10);
-      else
-        Diag(Loc, diag::err_typecheck_field_variable_size);
+    if (!tryToFixVariablyModifiedVarType(
+            *this, TInfo, T, Loc, diag::err_typecheck_field_variable_size))
       InvalidDecl = true;
-    }
   }
 
   // Fields can not have abstract class types
@@ -16904,8 +16917,9 @@ Decl *Sema::ActOnIvar(Scope *S,
   // C99 6.7.2.1p8: A member of a structure or union may have any type other
   // than a variably modified type.
   else if (T->isVariablyModifiedType()) {
-    Diag(Loc, diag::err_typecheck_ivar_variable_size);
-    D.setInvalidType();
+    if (!tryToFixVariablyModifiedVarType(
+            *this, TInfo, T, Loc, diag::err_typecheck_ivar_variable_size))
+      D.setInvalidType();
   }
 
   // Get the visibility (access control) for this ivar.