Various dependency analysis fixes

- Add sorting support to SignatureVariable
  - Needed to allow all kinds of generic lookups to be sorted
- Fix typo in DictionaryLayoutNode
  - only emit the fixed entries when asked to do so
- Adjust dependency handling in NativeLayoutDictionarySignatureNode
  - The WriteVertex method always takes a dependency on DictionaryLayoutNode, so explicitly make it a static dependency

[tfs-changeset: 1677801]

4 files changed, 35 insertions, 6 deletions

diff --git a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/DictionaryLayoutNode.cs b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/DictionaryLayoutNode.cs
index e700ab4d6..3838ae189 100644
--- a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/DictionaryLayoutNode.cs
+++ b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/DictionaryLayoutNode.cs
@@ -69,6 +69,15 @@ namespace ILCompiler.DependencyAnalysis
             }
         }
 
+        /// <summary>
+        /// Ensure that a generic lookup result can be resolved. Used to add new lookups to a dictionary which HasUnfixedSlots
+        /// Must not be used after any calls to GetSlotForEntry
+        /// </summary>
+        public abstract void EnsureEntry(GenericLookupResult entry);
+
+        /// <summary>
+        /// Get a slot index for a given entry. Slot indices are never expected to change once given out.
+        /// </summary>
         public abstract int GetSlotForEntry(GenericLookupResult entry);
 
         /// <summary>
@@ -120,7 +129,7 @@ namespace ILCompiler.DependencyAnalysis
 
             IEnumerable<GenericLookupResult> entriesToEmit = fixedLayoutOnly ? FixedEntries : Entries;
 
-            foreach (GenericLookupResult lookupResult in Entries)
+            foreach (GenericLookupResult lookupResult in entriesToEmit)
             {
 #if DEBUG
                 int offsetBefore = builder.CountBytes;
@@ -210,6 +219,17 @@ namespace ILCompiler.DependencyAnalysis
             _layout = l.ToArray();
         }
 
+        public override void EnsureEntry(GenericLookupResult entry)
+        {
+            int index = Array.IndexOf(_layout, entry);
+
+            if (index == -1)
+            {
+                // Using EnsureEntry to add a slot to a PrecomputedDictionaryLayoutNode is not supported
+                throw new NotSupportedException();
+            }
+        }
+
         public override int GetSlotForEntry(GenericLookupResult entry)
         {
             int index = Array.IndexOf(_layout, entry);
@@ -247,7 +267,7 @@ namespace ILCompiler.DependencyAnalysis
         {
         }
 
-        public void EnsureEntry(GenericLookupResult entry)
+        public override void EnsureEntry(GenericLookupResult entry)
         {
             Debug.Assert(_layout == null, "Trying to add entry but layout already computed");
             _entries.AddOrGetExisting(entry);
diff --git a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/NativeLayoutVertexNode.cs b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/NativeLayoutVertexNode.cs
index ce2d934a6..a74c60242 100644
--- a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/NativeLayoutVertexNode.cs
+++ b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/NativeLayoutVertexNode.cs
@@ -737,11 +737,18 @@ namespace ILCompiler.DependencyAnalysis
         {
             if ((ContextKind & GenericContextKind.HasDeclaringType) != 0)
             {
-                return new DependencyListEntry[] { new DependencyListEntry(context.NativeLayout.TypeSignatureVertex((TypeDesc)_owningMethodOrType), "DeclaringType signature") };
+                return new DependencyListEntry[] 
+                {
+                    new DependencyListEntry(context.NativeLayout.TypeSignatureVertex((TypeDesc)_owningMethodOrType), "DeclaringType signature"),
+                    new DependencyListEntry(context.GenericDictionaryLayout(_owningMethodOrType), "Dictionary Layout")
+                };
             }
             else
             {
-                return Array.Empty<DependencyListEntry>();
+                return new DependencyListEntry[]
+                {
+                    new DependencyListEntry(context.GenericDictionaryLayout(_owningMethodOrType), "Dictionary Layout")
+                };
             }
         }
 
@@ -752,6 +759,7 @@ namespace ILCompiler.DependencyAnalysis
             VertexSequence sequence = new VertexSequence();
 
             DictionaryLayoutNode associatedLayout = factory.GenericDictionaryLayout(_owningMethodOrType);
+            Debug.Assert(associatedLayout.Marked);
             ICollection<NativeLayoutVertexNode> templateLayout = associatedLayout.GetTemplateEntries(factory);
 
             foreach (NativeLayoutVertexNode dictionaryEntry in templateLayout)
diff --git a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ReadyToRunGenericHelperNode.cs b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ReadyToRunGenericHelperNode.cs
index b60b54691..99e717c40 100644
--- a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ReadyToRunGenericHelperNode.cs
+++ b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/ReadyToRunGenericHelperNode.cs
@@ -74,14 +74,14 @@ namespace ILCompiler.DependencyAnalysis
             {
                 // When the helper call gets marked, ensure the generic layout for the associated dictionaries
                 // includes the signature.
-                ((LazilyBuiltDictionaryLayoutNode)layout).EnsureEntry(_lookupSignature);
+                layout.EnsureEntry(_lookupSignature);
 
                 if ((_id == ReadyToRunHelperId.GetGCStaticBase || _id == ReadyToRunHelperId.GetThreadStaticBase) &&
                     factory.TypeSystemContext.HasLazyStaticConstructor((TypeDesc)_target))
                 {
                     // If the type has a lazy static constructor, we also need the non-GC static base
                     // because that's where the class constructor context is.
-                    ((LazilyBuiltDictionaryLayoutNode)layout).EnsureEntry(factory.GenericLookup.TypeNonGCStaticBase((TypeDesc)_target));
+                    layout.EnsureEntry(factory.GenericLookup.TypeNonGCStaticBase((TypeDesc)_target));
                 }
             }
         }
diff --git a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/UtcDictionaryLayoutNode.cs b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/UtcDictionaryLayoutNode.cs
index 408ccea42..c5038e064 100644
--- a/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/UtcDictionaryLayoutNode.cs
+++ b/src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/UtcDictionaryLayoutNode.cs
@@ -39,6 +39,7 @@ namespace ILCompiler.DependencyAnalysis
         }
 
 #if CORERT
+        public override void EnsureEntry(GenericLookupResult lookupResult) => throw new NotImplementedException();
         public override int GetSlotForEntry(GenericLookupResult entry) => throw new NotImplementedException();
         public override IEnumerable<GenericLookupResult> Entries => throw new NotImplementedException();
         public override ICollection<NativeLayoutVertexNode> GetTemplateEntries(NodeFactory factory) => throw new NotImplementedException();