Remove RegexOptions.Compiled for code paths executed during cold start. (#6708)

Author: safihamid

src/WebJobs.Script/Description/DotNet/Compilation/Raw/RawAssemblyCompilation.cs

@@ -14,7 +14,8 @@ namespace Microsoft.Azure.WebJobs.Script.Description
 {
     public class RawAssemblyCompilation : IDotNetCompilation
     {
-        private static readonly Regex _entryPointRegex = new Regex("^(?<typename>.*)\\.(?<methodname>\\S*)$", RegexOptions.Compiled);
+        // RegexOptions.Compiled is specifically removed as it impacts the cold start. The default uses interpreter.
+        private static readonly Regex _entryPointRegex = new Regex("^(?<typename>.*)\\.(?<methodname>\\S*)$");
         private readonly string _assemblyFilePath;
         private readonly string _entryPointName;
 

src/WebJobs.Script/Description/FunctionDescriptorProvider.cs

@@ -19,7 +19,7 @@ namespace Microsoft.Azure.WebJobs.Script.Description
 {
     public abstract class FunctionDescriptorProvider
     {
-        private static readonly Regex BindingNameValidationRegex = new Regex(string.Format("^([a-zA-Z][a-zA-Z0-9]{{0,127}}|{0})$", Regex.Escape(ScriptConstants.SystemReturnParameterBindingName)), RegexOptions.Compiled);
+        private static readonly Regex BindingNameValidationRegex = new Regex(string.Format("^([a-zA-Z][a-zA-Z0-9]{{0,127}}|{0})$", Regex.Escape(ScriptConstants.SystemReturnParameterBindingName)));
 
         protected FunctionDescriptorProvider(ScriptHost host, ScriptJobHostOptions config, ICollection<IScriptBindingProvider> bindingProviders)
         {

src/WebJobs.Script/Host/ProxyFunctionProvider.cs

@@ -23,7 +23,7 @@ namespace Microsoft.Azure.WebJobs.Script
 {
     public class ProxyFunctionProvider : IFunctionProvider, IDisposable
     {
-        private static readonly Regex ProxyNameValidationRegex = new Regex(@"[^a-zA-Z0-9_-]", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+        private static readonly Regex ProxyNameValidationRegex = new Regex(@"[^a-zA-Z0-9_-]", RegexOptions.IgnoreCase);
         private readonly ReaderWriterLockSlim _metadataLock = new ReaderWriterLockSlim();
         private readonly IOptions<ScriptJobHostOptions> _scriptOptions;
         private readonly IEnvironment _environment;

src/WebJobs.Script/Utility.cs

@@ -33,7 +33,7 @@ public static class Utility
         // i.e.: "f-<functionname>"
         public const string AssemblyPrefix = "f-";
         public const string AssemblySeparator = "__";
-        private static readonly Regex FunctionNameValidationRegex = new Regex(@"^[a-z][a-z0-9_\-]{0,127}$(?<!^host$)", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
+        private static readonly Regex FunctionNameValidationRegex = new Regex(@"^[a-z][a-z0-9_\-]{0,127}$(?<!^host$)", RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
 
         private static readonly string UTF8ByteOrderMark = Encoding.UTF8.GetString(Encoding.UTF8.GetPreamble());
         private static readonly FilteredExpandoObjectConverter _filteredExpandoObjectConverter = new FilteredExpandoObjectConverter();