more PR feedback

src/coreclr/vm/class.h

@@ -1384,12 +1384,12 @@ class EEClass // DO NOT CREATE A NEW EEClass USING NEW!
         LIMITED_METHOD_CONTRACT;
         m_VMFlags |= (DWORD)VMFLAG_HAS_FIELDS_WHICH_MUST_BE_INITED;
     }
-    BOOL HasInlineArrayFlagSet()
+    DWORD IsInlineArray()
     {
         LIMITED_METHOD_CONTRACT;
         return (m_VMFlags & VMFLAG_INLINE_ARRAY);
     }
-    void SetInlineArrayFlag()
+    void SetIsInlineArray()
     {
         LIMITED_METHOD_CONTRACT;
         m_VMFlags |= (DWORD)VMFLAG_INLINE_ARRAY;

src/coreclr/vm/jitinterface.cpp

@@ -2169,7 +2169,7 @@ static unsigned ComputeGCLayout(MethodTable* pMT, BYTE* gcPtrs)
     _ASSERTE(pMT->IsValueType());
 
     unsigned result = 0;
-    bool isInlineArray = pMT->GetClass()->HasInlineArrayFlagSet();
+    bool isInlineArray = pMT->GetClass()->IsInlineArray();
     ApproxFieldDescIterator fieldIterator(pMT, ApproxFieldDescIterator::INSTANCE_FIELDS);
     for (FieldDesc *pFD = fieldIterator.Next(); pFD != NULL; pFD = fieldIterator.Next())
     {
@@ -3569,7 +3569,7 @@ uint32_t CEEInfo::getClassAttribsInternal (CORINFO_CLASS_HANDLE clsHnd)
         if (pClass->HasExplicitFieldOffsetLayout() && pClass->HasOverlaidField())
             ret |= CORINFO_FLG_OVERLAPPING_FIELDS;
 
-        if (pClass->HasInlineArrayFlagSet())
+        if (pClass->IsInlineArray())
             ret |= CORINFO_FLG_DONT_DIG_FIELDS;
 
         if (VMClsHnd.IsCanonicalSubtype())

src/coreclr/vm/methodtablebuilder.cpp

@@ -1715,7 +1715,7 @@ MethodTableBuilder::BuildMethodTableThrowing(
                 if (repeat > 0)
                 {
                     bmtFP->NumInlineArrayElements = repeat;
-                    GetHalfBakedClass()->SetInlineArrayFlag();
+                    GetHalfBakedClass()->SetIsInlineArray();
                 }
                 else
                 {
@@ -1749,7 +1749,7 @@ MethodTableBuilder::BuildMethodTableThrowing(
 
         _ASSERTE(HasLayout());
 
-        if (bmtFP->NumInlineArrayElements)
+        if (bmtFP->NumInlineArrayElements != 0)
         {
             GetLayoutInfo()->m_cbManagedSize *= bmtFP->NumInlineArrayElements;
         }
@@ -11556,7 +11556,6 @@ VOID MethodTableBuilder::HandleGCForValueClasses(MethodTable ** pByValueClassCac
         DWORD repeat = 1;
         if (bmtFP->NumInlineArrayElements > 1)
         {
-            _ASSERTE(bmtEnumFields->dwNumInstanceFields == 1);
             repeat = bmtFP->NumInlineArrayElements;
         }
 
@@ -11583,6 +11582,9 @@ VOID MethodTableBuilder::HandleGCForValueClasses(MethodTable ** pByValueClassCac
                     DWORD       dwCurrentOffset = pFieldDescList[i].GetOffset_NoLogging();
                     DWORD       dwElementSize = pByValueMT->GetBaseSize() - OBJECT_BASESIZE;
 
+                    // if we have an inline array, we will have only one formal instance field,
+                    // but will have to replicate the layout "repeat" times.
+                    // otherwise every field will be matched with 1 serie.
                     for (DWORD r = 0; r < repeat; r++)
                     {
                         // The by value class may have more than one pointer series

src/coreclr/vm/siginfo.cpp

@@ -4862,11 +4862,11 @@ class ByRefPointerOffsetsReporter
         _ASSERTE(pMT != nullptr);
         _ASSERTE(pMT->IsByRefLike());
 
-        bool isValArray = pMT->GetClass()->HasInlineArrayFlagSet();
+        bool isValArray = pMT->GetClass()->IsInlineArray();
         ApproxFieldDescIterator fieldIterator(pMT, ApproxFieldDescIterator::INSTANCE_FIELDS);
         for (FieldDesc* pFD = fieldIterator.Next(); pFD != NULL; pFD = fieldIterator.Next())
         {
-            if(isValArray)
+            if (isValArray)
             {
                 _ASSERTE(pFD->GetOffset() == 0);
                 DWORD elementSize = pFD->GetSize();

src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/InlineArrayAttribute.cs

@@ -5,6 +5,9 @@
 
 namespace System.Runtime.CompilerServices
 {
+    /// <summary>
+    /// Indicates that the instance's storage is sequentially replicated "length" times.
+    /// </summary>
     [EditorBrowsable(EditorBrowsableState.Never)]
     [AttributeUsage(AttributeTargets.Struct, AllowMultiple = false)]
     public sealed class InlineArrayAttribute : Attribute

src/tests/Loader/classloader/InlineArray/InlineArrayInvalid.cs

@@ -74,6 +74,29 @@ public static void TooLarge_Fails()
         });
     }
 
+    [InlineArray(-1)]
+    private struct NegativeLength
+    {
+        public long field;
+    }
+
+    [Fact]
+    public static void NegativeLength_Fails()
+    {
+        Console.WriteLine($"{nameof(NegativeLength_Fails)}...");
+        Assert.Throws<TypeLoadException>(() => { var t = typeof(NegativeLength); });
+
+        Assert.Throws<TypeLoadException>(() =>
+        {
+            var t = new NegativeLength()
+            {
+                field = 1
+            };
+            return t;
+        });
+    }
+
+
     [InlineArray(123)]
     private struct NoFields
     {

src/tests/issues.targets

@@ -1530,7 +1530,7 @@
         </ExcludeList>
 
         <ExcludeList Include="$(XunitTestBinBase)/Loader/classloader/InlineArray/**">
-            <Issue>InlineArray support is not yet implemented in the Mono runtime.</Issue>
+            <Issue>https://github.com/dotnet/runtime/issues/80798</Issue>
         </ExcludeList>
 
         <ExcludeList Include="$(XunitTestBinBase)/baseservices/exceptions/stackoverflow/stackoverflowtester/**">