Added ILReading benchmark (#6038)

* Added benchmark for ILModuleReader

Author: TIHan

benchmarks/Benchmarks.sln

@@ -5,9 +5,9 @@ VisualStudioVersion = 16.0.28407.52
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "CompilerServiceBenchmarks", "CompilerServiceBenchmarks\CompilerServiceBenchmarks.fsproj", "{9A3C565C-B514-4AE0-8B01-CA80E8453EB0}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "FSharp.Core", "..\src\fsharp\FSharp.Core\FSharp.Core.fsproj", "{DED3BBD7-53F4-428A-8C9F-27968E768605}"
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "FSharp.Core", "..\src\fsharp\FSharp.Core\FSharp.Core.fsproj", "{DED3BBD7-53F4-428A-8C9F-27968E768605}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "FSharp.Compiler.Private", "..\src\fsharp\FSharp.Compiler.Private\FSharp.Compiler.Private.fsproj", "{2E4D67B4-522D-4CF7-97E4-BA940F0B18F3}"
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "FSharp.Compiler.Private", "..\src\fsharp\FSharp.Compiler.Private\FSharp.Compiler.Private.fsproj", "{2E4D67B4-522D-4CF7-97E4-BA940F0B18F3}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution

benchmarks/CompilerServiceBenchmarks/Program.fs

@@ -1,12 +1,15 @@
 open System
 open System.IO
-open BenchmarkDotNet.Attributes
-open BenchmarkDotNet.Running
+open System.Text
 open Microsoft.FSharp.Compiler.ErrorLogger
 open Microsoft.FSharp.Compiler.SourceCodeServices
 open Microsoft.FSharp.Compiler.Text
-open System.Text
+open Microsoft.FSharp.Compiler.AbstractIL
+open Microsoft.FSharp.Compiler.AbstractIL.IL
+open Microsoft.FSharp.Compiler.AbstractIL.ILBinaryReader
 open Microsoft.CodeAnalysis.Text
+open BenchmarkDotNet.Attributes
+open BenchmarkDotNet.Running
 
 module private SourceText =
 
@@ -77,8 +80,8 @@ type SourceText with
     member this.ToFSharpSourceText() =
         SourceText.weakTable.GetValue(this, Runtime.CompilerServices.ConditionalWeakTable<_,_>.CreateValueCallback(SourceText.create))
 
-[<ClrJob; MemoryDiagnoser>]
-type CompilerServiceParsing() =
+[<MemoryDiagnoser>]
+type CompilerService() =
 
     let mutable checkerOpt = None
 
@@ -95,6 +98,17 @@ type CompilerServiceParsing() =
             IsExe = false
         }
 
+    let mutable assembliesOpt = None
+
+    let readerOptions =
+        {
+            pdbDirPath = None
+            ilGlobals = mkILGlobals ILScopeRef.Local
+            reduceMemoryUsage = ReduceMemoryFlag.No
+            metadataOnly = MetadataOnlyFlag.Yes
+            tryGetMetadataSnapshot = fun _ -> None
+        }
+
     [<GlobalSetup>]
     member __.Setup() =
         match checkerOpt with
@@ -105,8 +119,16 @@ type CompilerServiceParsing() =
         | None ->
             sourceOpt <- Some <| SourceText.From(File.OpenRead("""..\..\..\..\..\src\fsharp\TypeChecker.fs"""), Encoding.Default, SourceHashAlgorithm.Sha1, true)
         | _ -> ()
+
+        match assembliesOpt with
+        | None -> 
+            assembliesOpt <- 
+                System.AppDomain.CurrentDomain.GetAssemblies()
+                |> Array.map (fun x -> (x.Location))
+                |> Some
+        | _ -> ()
 
-    [<IterationSetup>]
+    [<IterationSetup(Target = "Parsing")>]
     member __.ParsingSetup() =
         match checkerOpt with
         | None -> failwith "no checker"
@@ -124,7 +146,59 @@ type CompilerServiceParsing() =
             let results = checker.ParseFile("TypeChecker.fs", source.ToFSharpSourceText(), parsingOptions) |> Async.RunSynchronously
             if results.ParseHadErrors then failwithf "parse had errors: %A" results.Errors
 
+    [<IterationSetup(Target = "ILReading")>]
+    member __.ILReadingSetup() =
+        // With caching, performance increases an order of magnitude when re-reading an ILModuleReader.
+        // Clear it for benchmarking.
+        ClearAllILModuleReaderCache()
+
+    [<Benchmark>]
+    member __.ILReading() =
+        match assembliesOpt with
+        | None -> failwith "no assemblies"
+        | Some(assemblies) ->
+            // We try to read most of everything in the assembly that matter, mainly types with their properties, methods, and fields.
+            // CustomAttrs and SecurityDecls are lazy until you call them, so we call them here for benchmarking.
+            assemblies
+            |> Array.iter (fun (fileName) ->
+                let reader = OpenILModuleReader fileName readerOptions
+
+                let ilModuleDef = reader.ILModuleDef
+
+                let ilAssemblyManifest = ilModuleDef.Manifest.Value
+
+                ilAssemblyManifest.CustomAttrs |> ignore
+                ilAssemblyManifest.SecurityDecls |> ignore
+                ilAssemblyManifest.ExportedTypes.AsList
+                |> List.iter (fun x ->
+                   x.CustomAttrs |> ignore
+                )
+
+                ilModuleDef.CustomAttrs |> ignore
+                ilModuleDef.TypeDefs.AsArray
+                |> Array.iter (fun ilTypeDef ->
+                    ilTypeDef.CustomAttrs |> ignore
+                    ilTypeDef.SecurityDecls |> ignore
+
+                    ilTypeDef.Methods.AsArray
+                    |> Array.iter (fun ilMethodDef ->
+                        ilMethodDef.CustomAttrs |> ignore
+                        ilMethodDef.SecurityDecls |> ignore
+                    )
+
+                    ilTypeDef.Fields.AsList
+                    |> List.iter (fun ilFieldDef ->
+                        ilFieldDef.CustomAttrs |> ignore
+                    )
+
+                    ilTypeDef.Properties.AsList
+                    |> List.iter (fun ilPropertyDef ->
+                        ilPropertyDef.CustomAttrs |> ignore
+                    )
+                )
+            )
+
 [<EntryPoint>]
 let main argv =
-    let _ = BenchmarkRunner.Run<CompilerServiceParsing>()
-    0
+    let _ = BenchmarkRunner.Run<CompilerService>()
+    0

benchmarks/Directory.Build.props

@@ -0,0 +1,3 @@
+<Project>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove('FSharp.Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
+</Project>

benchmarks/Directory.Build.targets

@@ -0,0 +1,3 @@
+<Project>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove('FSharp.Directory.Build.targets', '$(MSBuildThisFileDirectory)../'))" />
+</Project>

src/absil/ilread.fs

@@ -4002,6 +4002,8 @@ let OpenILModuleReaderFromBytes fileName bytes opts =
     let ilModule, ilAssemblyRefs, pdb = openPE (fileName, pefile, opts.pdbDirPath, (opts.reduceMemoryUsage = ReduceMemoryFlag.Yes), opts.ilGlobals, true)
     new ILModuleReaderImpl(ilModule, ilAssemblyRefs, (fun () -> ClosePdbReader pdb)) :> ILModuleReader
 
+let ClearAllILModuleReaderCache() = ilModuleReaderCache.Clear(ILModuleReaderCacheLockToken())
+
 let OpenILModuleReader fileName opts = 
     // Pseudo-normalize the paths.
     let (ILModuleReaderCacheKey (fullPath,writeStamp,_,_,_,_) as key), keyOk = 

src/absil/ilread.fsi

@@ -80,6 +80,8 @@ type ILModuleReader =
 /// PDB files may not be read with this option. 
 val internal OpenILModuleReader: string -> ILReaderOptions -> ILModuleReader
 
+val internal ClearAllILModuleReaderCache : unit -> unit
+
 /// Open a binary reader based on the given bytes. 
 val internal OpenILModuleReaderFromBytes: fileNameForDebugOutput:string -> assemblyContents: byte[] -> options: ILReaderOptions -> ILModuleReader
 

src/fsharp/FSharp.Compiler.Private/FSharp.Compiler.Private.fsproj

@@ -59,6 +59,7 @@
     <InternalsVisibleTo Include="HostedCompilerServer" />
     <InternalsVisibleTo Include="FSharp.Tests.FSharpSuite" />
     <InternalsVisibleTo Include="LanguageServiceProfiling" />
+    <InternalsVisibleTo Include="CompilerServiceBenchmarks" />
   </ItemGroup>
 
   <ItemGroup>