Quick and dirty extraction of aot compile times from a diagnostic build log ("Dealing with AOT-unfriendly assemblies" in https://ryandavis.io/improving-dotnet-ios-release-build-times-on-apple-silicon/)

parse-aotcompile.cs

void Main()
{
	var logPath = /* path to build log produced using -flp:v=diag -flp:logfile=mylog.log */ ;
	foreach (var aotTime in ParseFile(logPath))
		Console.WriteLine($"{aotTime.TotalTime:N2}\t\t\t\t{aotTime.Assembly}");	
}

public List<AOTTime> ParseFile(string path)
{
	const string opener = "Mono Ahead of Time compiler - compiling assembly ";
	const string closer = "JIT time:";

	return
	
	File.ReadLines(path)
		.BatchBy(open: x => x.Trim().StartsWith(opener), close: x => x.Trim().StartsWith(closer))
		.Select(x =>
		{
			var asm = Path.GetFileName(x[0].Split(opener, StringSplitOptions.RemoveEmptyEntries)[1]);
			var stats = 
				x.Last()[..^1]
				 .Split(',')
				 .Select(y => y.Trim().Replace(" ms", ""))
				 .Select(y => y.Split(' ').Last())
				 .ToList();
				
			return new AOTTime
			{
				Assembly = asm,
				JitTime = Int32.Parse(stats[0]) / 1000.0,
				GenTime = Int32.Parse(stats[1]) / 1000.0,
				LinkTime = Int32.Parse(stats[2]) / 1000.0,
				Lines = x
			};
		})
		.OrderBy(x => x.Assembly)
		.OrderByDescending(x => x.TotalTime)
		.ToList();
}

public class AOTTime
{
	public string Assembly { get; set; }
	public double JitTime { get; set; }
	public double GenTime { get; set; }
	public double LinkTime { get; set; }
	public double TotalTime => Math.Round(JitTime + GenTime + LinkTime, 2);
	
	internal List<string> Lines { get; set; }
}

public static class BatchExtensions
{
	public static IEnumerable<List<T>> BatchBy<T>(this IEnumerable<T> items, Func<T, bool> open, Func<T, bool> close)
	{
		var curr = new List<T>();	
		foreach (var item in items)
		{
			if (close(item))
			{
				curr.Add(item);
				yield return curr;
				curr = new();
				
				continue;
			}

			if (open(item))
			{
				// not expecting to see an open when we have any curr
				if (curr.Any())
					Debugger.Break();
					
				curr.Add(item);
				continue;
			}
			
			// don't add if we haven't seen an open
			if (curr.Any())
				curr.Add(item);
		}
		
		if (curr.Any())
			Debugger.Break();
	}

}