Avoid hitting object pool when not needed

src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Utilities/FixedSizeArrayBuilder.cs → src/Dependencies/Collections/Extensions/FixedSizeArrayBuilder.cs

@@ -5,6 +5,10 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.PooledObjects;
@@ -45,32 +49,46 @@ internal struct FixedSizeArrayBuilder<T>(int capacity)
     public void Add(T value)
         => _values[_index++] = value;
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static void ThrowIfTrue([DoesNotReturnIf(parameterValue: true)] bool condition, [CallerLineNumber] int lineNumber = 0, [CallerFilePath] string? filePath = null)
+    {
+#if MICROSOFT_CODEANALYSIS_CONTRACTS_NO_CONTRACT
+        if (condition)
+        {
+            var fileName = filePath is null ? null : Path.GetFileName(filePath);
+            throw new InvalidOperationException($"Unexpected true - file {fileName} line {lineNumber}");
+        }
+#else
+        Contract.ThrowIfTrue(condition, lineNumber, filePath);
+#endif
+    }
+
     #region AddRange overloads.  These allow us to add these collections directly, without allocating an enumerator.
 
     public void AddRange(ImmutableArray<T> values)
     {
-        Contract.ThrowIfTrue(_index + values.Length > _values.Length);
+        ThrowIfTrue(_index + values.Length > _values.Length);
         Array.Copy(ImmutableCollectionsMarshal.AsArray(values)!, 0, _values, _index, values.Length);
         _index += values.Length;
     }
 
     public void AddRange(List<T> values)
     {
-        Contract.ThrowIfTrue(_index + values.Count > _values.Length);
+        ThrowIfTrue(_index + values.Count > _values.Length);
         foreach (var v in values)
             Add(v);
     }
 
     public void AddRange(HashSet<T> values)
     {
-        Contract.ThrowIfTrue(_index + values.Count > _values.Length);
+        ThrowIfTrue(_index + values.Count > _values.Length);
         foreach (var v in values)
             Add(v);
     }
 
     public void AddRange(ArrayBuilder<T> values)
     {
-        Contract.ThrowIfTrue(_index + values.Count > _values.Length);
+        ThrowIfTrue(_index + values.Count > _values.Length);
         foreach (var v in values)
             Add(v);
     }
@@ -104,7 +122,7 @@ public ImmutableArray<T> MoveToImmutable()
 
     public T[] MoveToArray()
     {
-        Contract.ThrowIfTrue(_index != _values.Length);
+        ThrowIfTrue(_index != _values.Length);
         var result = _values;
         _values = [];
         _index = 0;

src/Dependencies/Collections/Extensions/ImmutableArrayExtensions.cs

@@ -185,13 +185,13 @@ public static ImmutableArray<TResult> SelectAsArray<TItem, TArg, TResult>(this I
                     return ImmutableArray.Create(map(items[0], 0, arg), map(items[1], 1, arg), map(items[2], 2, arg), map(items[3], 3, arg));
 
                 default:
-                    var builder = ArrayBuilder<TResult>.GetInstance(items.Length);
+                    var builder = new FixedSizeArrayBuilder<TResult>(items.Length);
                     for (int i = 0; i < items.Length; i++)
                     {
                         builder.Add(map(items[i], i, arg));
                     }
 
-                    return builder.ToImmutableAndFree();
+                    return builder.MoveToImmutable();
             }
         }
 
@@ -518,12 +518,13 @@ public static ImmutableArray<TResult> ZipAsArray<T1, T2, TArg, TResult>(this Imm
                 return ImmutableArray<TResult>.Empty;
             }
 
-            var builder = ArrayBuilder<TResult>.GetInstance(self.Length);
+            var builder = new FixedSizeArrayBuilder<TResult>(self.Length);
             for (int i = 0; i < self.Length; i++)
             {
                 builder.Add(map(self[i], other[i], i, arg));
             }
-            return builder.ToImmutableAndFree();
+
+            return builder.MoveToImmutable();
         }
 
         /// <summary>

src/Dependencies/Collections/Microsoft.CodeAnalysis.Collections.projitems

@@ -10,6 +10,7 @@
     <Import_RootNamespace>Microsoft.CodeAnalysis.Collections</Import_RootNamespace>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="$(MSBuildThisFileDirectory)Extensions\FixedSizeArrayBuilder.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Segmented\ImmutableSegmentedDictionary.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Segmented\ImmutableSegmentedDictionary`2+Builder+KeyCollection.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Segmented\ImmutableSegmentedDictionary`2+Builder+PrivateMarshal.cs" />

src/Workspaces/MSBuild/BuildHost/Microsoft.CodeAnalysis.Workspaces.MSBuild.BuildHost.csproj

@@ -68,7 +68,6 @@
     <Compile Include="..\..\..\Workspaces\SharedUtilitiesAndExtensions\Compiler\Core\ObjectPools\Extensions.cs" Link="SharedUtilities\Extensions.cs" />
     <Compile Include="..\..\..\Workspaces\SharedUtilitiesAndExtensions\Compiler\Core\ObjectPools\PooledObject.cs" Link="SharedUtilities\PooledObject.cs" />
     <Compile Include="..\..\..\Workspaces\SharedUtilitiesAndExtensions\Compiler\Core\ObjectPools\SharedPools.cs" Link="SharedUtilities\SharedPools.cs" />
-    <Compile Include="..\..\..\Workspaces\SharedUtilitiesAndExtensions\Compiler\Core\Utilities\FixedSizeArrayBuilder.cs" Link="SharedUtilities\FixedSizeArrayBuilder.cs" />
     <Compile Include="..\..\..\Workspaces\SharedUtilitiesAndExtensions\Compiler\Core\Utilities\SerializableBytes.cs" Link="SharedUtilities\SerializableBytes.cs" />
 
   </ItemGroup>

src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/CompilerExtensions.projitems

@@ -453,7 +453,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)Utilities\CancellableLazy`1.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Utilities\CommonFormattingHelpers.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Utilities\ComparerWithState.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)Utilities\FixedSizeArrayBuilder.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Utilities\InterceptsLocationUtilities.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Utilities\ISpeculationAnalyzer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Utilities\OptionalExtensions.cs" />