Would the .NET JIT compiler optimize out a method call?

Question

The stack trace I get back from an ASP.NET application, generated from an ArgumentNullException, gives the impression that an error occurs on the last line of the code below. As far as I can see, that is impossible, but if the JIT optimized out the call to Bar, which would result in a different stack trace, it would explain all. I know for sure its not the c# compiler, as the CIL looks like I would expect. Is it possible the JIT compiler removed the call to Bar?

c# 4, .NET 4.0.30319.1, ASP.NET 4.0.30319.1

EDIT: I should have mentioned this is a release configuration, with Optimize code = on, Debug Info = pdb-only.

Stack Trace:

[ArgumentNullException: Value cannot be null. Parameter name: value]
CreateHiddenField(HtmlTextWriter tr, String name, String value) in Foo.cs:129
Foo(IHttpContext context, HtmlTextWriter writer) in Foo.cs:106

---

private static void Foo(IHttpContext context, HtmlTextWriter writer)
{ // line 103
  Bar(writer, AuthorizationServerResponseDetailsHttpRequestParser.RequestSAMLFieldName, context);
  Bar(writer, AuthorizationServerResponseDetailsHttpRequestParser.RequestTargetFieldName, context);
  // line 106 - blank line in source code.
  CreateHiddenField(tr, name, string.Empty); // looks like its here
}

private static void Bar(HtmlTextWriter tr,string name, IHttpContext context)
{ // line 116
   #region Sanitation
   if (tr == null) { throw new System.ArgumentNullException("tr"); }
   if (name == null) { throw new System.ArgumentNullException("name"); }
   if (context == null) { throw new System.ArgumentNullException("context"); }
   #endregion

   CreateHiddenField(tr, name, context.RequestQueryString(name));
}

private static void CreateHiddenField(HtmlTextWriter tr, string name, string value)
{ // line 127
   #region Sanitation
   if (tr == null) { throw new System.ArgumentNullException("tr"); }
   if (name == null) { throw new System.ArgumentNullException("name"); }
   if (value == null) { throw new System.ArgumentNullException("value"); }
   #endregion

   // payload...
}

Answer 1

According to http://www.hanselman.com/blog/ReleaseISNOTDebug64bitOptimizationsAndCMethodInliningInReleaseBuildCallStacks.aspx, if the JITter inlines a method call, it will indeed be collapsed in the stack trace. If you don't want it to inline (which is probably not a good idea), you can use

[MethodImpl(MethodImplOptions.NoInlining)] 

on the method. For an exe, you can also use an INI file to tell the JITter to generate tracking information (at the bottom of the linked page), but I'm not sure how that would work for an ASP.NET app.