Add F# compiler timing data extraction for regression tests

- Modified PrepareRepoForRegressionTesting.fsx to inject --times flag
- Created ExtractTimingsFromBinlog.fsx to parse binlogs and extract timing data
- Updated regression-test-jobs.yml to inject -bl and extract timings

Co-authored-by: T-Gro <46543583+T-Gro@users.noreply.github.com>

Author: Copilot

eng/scripts/ExtractTimingsFromBinlog.fsx

@@ -0,0 +1,64 @@
+/// Script to extract F# compiler timing data from MSBuild binary logs
+/// Usage: dotnet fsi ExtractTimingsFromBinlog.fsx <path-to-binlog-file>
+
+#r "nuget: MSBuild.StructuredLogger"
+
+open System
+open Microsoft.Build.Logging.StructuredLogger
+
+// Get the binlog file path from command line args
+let binlogPath = 
+    let args = Environment.GetCommandLineArgs()
+    // When running with dotnet fsi, args are: [0]=dotnet; [1]=fsi.dll; [2]=script.fsx; [3...]=args
+    let scriptArgs = args |> Array.skipWhile (fun a -> not (a.EndsWith(".fsx"))) |> Array.skip 1
+    if scriptArgs.Length > 0 then
+        scriptArgs.[0]
+    else
+        failwith "Usage: dotnet fsi ExtractTimingsFromBinlog.fsx <path-to-binlog-file>"
+
+// Helper function to find the project node by walking up the parent chain
+let rec findProject (node: TreeNode) =
+    match node with
+    | null -> None
+    | :? Project as p -> Some p.Name
+    | _ -> findProject node.Parent
+
+// Load the binlog
+let build = BinaryLog.ReadBuild(binlogPath)
+
+// Track whether we found any Fsc tasks
+let mutable foundFscTasks = false
+
+// Walk the build tree looking for Fsc tasks
+build.VisitAllChildren<Task>(fun task ->
+    if task.Name = "Fsc" then
+        foundFscTasks <- true
+        
+        // Get the project name
+        let projectName = 
+            match findProject task with
+            | Some name -> name
+            | None -> "Unknown Project"
+        
+        // Collect all Message children
+        let messages = 
+            task.Children
+            |> Seq.choose (function
+                | :? Message as m -> Some m.Text
+                | _ -> None)
+            |> Seq.toList
+        
+        // Print the project header and messages
+        if messages.Length > 0 then
+            printfn "=== %s ===" projectName
+            for msg in messages do
+                printfn "  %s" msg
+            printfn ""
+)
+
+// If no Fsc tasks were found, print a message
+if not foundFscTasks then
+    printfn "No Fsc task output found in binlog."
+
+// Always exit 0 (this is informational)
+exit 0

eng/scripts/PrepareRepoForRegressionTesting.fsx

@@ -48,8 +48,8 @@ if File.Exists(propsFilePath) then
     if isNull projectElement then
         failwith "Could not find Project element in Directory.Build.props"
 
-    // Check if our import already exists
-    let xpath = sprintf "//Import[contains(@Project, 'UseLocalCompiler.Directory.Build.props')]"
+    // Check if our import already exists (look for any import with this exact path)
+    let xpath = sprintf "//Import[@Project='%s']" absolutePropsPath
     let existingImport = doc.SelectSingleNode(xpath)
 
     if isNull existingImport then
@@ -71,11 +71,46 @@ if File.Exists(propsFilePath) then
         printfn "✓ Added UseLocalCompiler import to Directory.Build.props"
     else
         printfn "✓ UseLocalCompiler import already exists"
+    
+    // Check if --times flag already exists in any OtherFlags element
+    let otherFlagsWithTimes = doc.SelectSingleNode("//OtherFlags[contains(text(), '--times')]")
+    
+    if isNull otherFlagsWithTimes then
+        // Create PropertyGroup with OtherFlags element
+        let propertyGroup = doc.CreateElement("PropertyGroup")
+        let otherFlags = doc.CreateElement("OtherFlags")
+        otherFlags.InnerText <- "$(OtherFlags) --times"
+        propertyGroup.AppendChild(otherFlags) |> ignore
+        
+        // Find the import element (either just created or existing)
+        let importNode = doc.SelectSingleNode("//Import[contains(@Project, 'UseLocalCompiler.Directory.Build.props')]")
+        
+        // Find the text node after the import (if it exists)
+        let nodeAfterImport = 
+            if not (isNull importNode) && not (isNull importNode.NextSibling) && importNode.NextSibling.NodeType = XmlNodeType.Text then
+                importNode.NextSibling
+            else
+                null
+        
+        // Insert PropertyGroup after the import's trailing newline (if present) or after the import itself
+        if not (isNull nodeAfterImport) then
+            projectElement.InsertAfter(propertyGroup, nodeAfterImport) |> ignore
+        else
+            projectElement.InsertAfter(propertyGroup, importNode) |> ignore
+        
+        // Add newline for formatting after PropertyGroup
+        let newlineAfter = doc.CreateTextNode("\n  ")
+        projectElement.InsertAfter(newlineAfter, propertyGroup) |> ignore
+        
+        doc.Save(propsFilePath)
+        printfn "✓ Added --times flag to OtherFlags"
+    else
+        printfn "✓ --times flag already exists in OtherFlags"
 else
     printfn "Directory.Build.props does not exist, creating it..."
-    let newContent = sprintf "<Project>\n  <Import Project=\"%s\" />\n</Project>\n" absolutePropsPath
+    let newContent = sprintf "<Project>\n  <Import Project=\"%s\" />\n  <PropertyGroup>\n    <OtherFlags>$(OtherFlags) --times</OtherFlags>\n  </PropertyGroup>\n</Project>\n" absolutePropsPath
     File.WriteAllText(propsFilePath, newContent)
-    printfn "✓ Created Directory.Build.props with UseLocalCompiler import"
+    printfn "✓ Created Directory.Build.props with UseLocalCompiler import and --times flag"
 
 // Print the final content
 printfn ""

eng/templates/regression-test-jobs.yml

@@ -198,6 +198,10 @@ jobs:
 
         function Run-Command {
           param([string]$cmd)
+          # Ensure binlog is produced for dotnet build/test/msbuild commands
+          if ($cmd -match '^dotnet\s+(build|test|msbuild)') {
+            $cmd = "$cmd -bl"
+          }
           if ($cmd -like "dotnet*") {
             Write-Host "Executing built-in command:  $cmd"
             if ($IsWindows) {
@@ -272,6 +276,32 @@ jobs:
       condition: always()
       continueOnError: true
 
+    - pwsh: |
+        $binlogDir = "$(Pipeline.Workspace)/BinaryLogs"
+        $script = "$(Build.SourcesDirectory)/eng/scripts/ExtractTimingsFromBinlog.fsx"
+        
+        if (-not (Test-Path $binlogDir)) {
+          Write-Host "No binary logs directory found, skipping timing extraction"
+          exit 0
+        }
+        
+        $binlogs = Get-ChildItem -Path $binlogDir -Filter "*.binlog" -ErrorAction SilentlyContinue
+        if ($binlogs.Count -eq 0) {
+          Write-Host "No binlog files found, skipping timing extraction"
+          exit 0
+        }
+        
+        Write-Host "##[group]F# Compiler Timing Summary for ${{ item.displayName }}"
+        foreach ($bl in $binlogs) {
+          Write-Host ""
+          Write-Host "--- Timings from $($bl.Name) ---"
+          dotnet fsi $script "$($bl.FullName)"
+        }
+        Write-Host "##[endgroup]"
+      displayName: Extract compiler timing from binlogs for ${{ item.displayName }}
+      condition: always()
+      continueOnError: true
+
     - task: PublishPipelineArtifact@1
       displayName:  Publish ${{ item.displayName }} Binary Logs
       inputs: