To Log output I am using the following code.
System.Diagnostics.Debug.WriteLine("Hello");
Now, its always advisory to remove such logs before the app is submitted.
So, is that we have to remove such lines, before we submit it for release or its done implicitly.
Is there any another better way to log output in C#, which removes the logging to the console when its released. I see Log4Net is one of them.
All methods on the System.Diagnostics.Debug class have the ConditionalAttribute, so under most compilers they will not be compiled into a Release build (unless you define the DEBUG attribute in the release build). 1
This is certainly true for the compilers within Visual Studio.
Your second question about log4Net is actually the reverse, and something to be careful about if you do decide to start using log4Net - log4Net debug calls are included within debug builds and are emitted if you have the logger set to the debug trace level (usually done with runtime configuration).
1. The MSDN pages are actually (IMO) a little bit unclear, but these SO posts agree with my interpretation:
System.Diagnostics.Debug.WriteLine in production code
C# Do Debug statements get compiled out when running in Release mode?
You can use preprocessor directive:
#if DEBUG
System.Diagnostics.Debug.WriteLine("Hello");
#endif
That line will be skipped when you'll build your application in Release build configuration.
Related
I want to detect and report bugs in specific cases, using the same behavior as Debug.Assert(), but in a Release build. How can I do that?
You should be able to use Trace.Assert().
From MSDN:
Use the Trace.Assert method if you want to do assertions in release builds. The Debug.Assert method works only in debug builds.
You can manually add the DEBUG constant while still having Release optimizations enabled.
In the Build tab of your project settings just check the box that enables the DEBUG constant.
This allows all functions that have [ConditionalAttribute("DEBUG")] (like Assert()) to still function in your compiled program.
EDIT: Grant's answer is even better, if possible use Trace.Assert instead. That function triggers on if the constant TRACE is defined and it is defined by default in Release builds. That will make sure you don't get any unforeseen side effects of enabling any other code that uses #if DEBUG or [ConditionalAttribute("DEBUG")] in your code.
Can't you turn on Tracing and perform tracing? You can use conditional tracing in Release mode. Also, you can implement some conditionally logging with log4net
Take the following example:
public void Foo()
{
//Code...
Debug.Assert(ExpensiveTest());
//Code...
}
What happens to the the Debug.Assert method when I compile in release mode? Would ExpensiveTest() still run? If not, then how does it work (since it is not a macro that can be set to evaluate to nothing)? If it does run, then doesn't that defeat the purpose of debug assertions?
What happens to the the Debug.Assert method when I compile in release mode?
It's completely removed (including the call to ExpensiveTest), assuming you don't have the DEBUG conditional compilation symbol defined in your release configuration.
If you look at the documentation, the declaration uses [ConditionalAttribute("DEBUG")]:
[ConditionalAttribute("DEBUG")]
public static void Assert(
bool condition
)
ConditionalAttribute is used for conditional compilation. See Bart de Smet's blog post on conditional compilation for more details, along with section 17.4.2 of the C# 4 specification.
Assertions in Managed Code - MSDN
In Visual Basic and Visual C#, you can use the Assert method from
either Debug or Trace, which are in the System.Diagnostics namespace.
Debug class methods are not included in a Release version of your program, so they do not increase the size or reduce the speed of
your release code.
Also from the same link:
Note that calls to the Debug.Assert method disappear when you create
a Release version of your code. That means that the call that checks
the balance disappears in the Release version. To solve this problem,
you should replace Debug.Assert with Trace.Assert, which does not
disappear in the Release version
According to Debug.Assert Method (Boolean) Debug methods are compiled only in debug builds.
So, it you build correct release build (see menu item Debug/Configuration Manager for details) this method call will be removed.
Q. In C#, is a Debug.Assert test run in release mode?
The answer is "No." From Microsoft support: How to trace and debug in Visual C#:
You can use the Trace and the Debug classes separately or
together in the same application. In a Debug Solution Configuration
project, both Trace and Debug output are active. The project
generates output from both of these classes to all Listener
objects. However, a Release Solution Configuration project only
generates output from a Trace class. The Release Solution
Configuration project ignores any Debug class method invocations.
In particular, the last sentence makes it clear that Debug.Assert() statements (as well as other Debug class method invocations) are ignored in a Release build.
I want to throw exceptions while debugging but in release mode I don't want to throw them. I am logging them into EventLog. This is the source of my problem but if I'm not wrong in C and Delphi there are some directives to make this.
In C# is there any way(directives or something else) which can ignore the lines in debug mode or release mode?
You can do it like this:
#if DEBUG
Console.WriteLine("Debug version");
#endif
http://msdn.microsoft.com/en-us/library/4y6tbswk.aspx
For your purposes (logging), you might also be interested in the ConditionalAttribute. It lets you mark an entire method as "remove all calls to this method in release builds".
If you do your logging in a lot of different places in your code, this would be much simpler than adding #if DEBUG around every single call site.
Use the #if DEBUG directive (and end with #endif). The DEBUG constant is defined when you run your application in debug mode (the Define DEBUG constant should be checked under the Build tab of your project properties).
I have a component which can be referenced in some projects (for example, Component.dll). I publish it, of course, in release mode.
In another project (for example, Project.exe) I reference Component.dll.
If I build Project.exe in Debug mode, is there a way to find out about that in my Component.dll library?
To clarify more: if I have a class and a method named Test within Component.dll. Can I do something like:
public void Test(){
if(Debug.IsInDebugMode)
...
}
Keep in mind that Component.dll is built in release mode.
Whether your code is built in Release or Debug mode doesn't matter a great deal. The generated IL is very nearly the same. The Debug version will have an attribute that the jitter uses to set compilation defaults, that attribute is missing in yours. The next thing that matters is exactly how you debug or run your application. The setting that's important is Tools + Options, Debugging, General, "Suppress JIT optimization on module load". It is ticked by default.
Which now makes it matter whether your app gets started by a debugger or not. That's easy to find out, use the System.Diagnostics.Debugger.IsAttached property. When false, the machine code generated from your IL is going to be optimized by the jitter. A degenerate case is attaching a debugger after the code got started. Kinda important that this doesn't make any difference to you btw.
Continuing from my previous question, is there a comprehensive document that lists all available differences between debug and release modes in a C# application, and particularly in a web application?
What differences are there?
"Debug" and "Release" are just names for predefined project configurations defined by Visual Studio.
To see the differences, look at the Build Tab in Project Properties in Visual Studio.
The differences in VS2005 include:
DEBUG constant defined in Debug configuration
Optimize code enabled in Release configuration
as well as other differences you can see by clicking on the "Advanced" button
But you can:
Change the build settings for Debug and Release configurations in Project Propeties / Build
Create your own custom configurations by right-clicking on the solution in Solution Explorer and selecting Configuration Manager
I think the behaviour of the DEBUG constant is fairly clear (can be referenced in the #if preprocessor directive or in the ConditionalAttribute). But I'm not aware of any comprehensive documentation on exactly what optimizations are enabled - in fact I suspect Microsoft would want to be free to enhance their optimizer without notice
I'm not aware of one concise document, but:
Debug.Write calls are stripped out in Release
In Release, your CallStack may look a bit "strange" due to optimizations, as outlined by Scott Hanselman
There isn't one document that lists the differences. In addition to some of the differences already listed, compiling in Debug mode turns off most of the JIT compiler optimizations that are performed at runtime and also emits more complete debug information in to the symbol database file (.pdb).
Another big difference is that the GC behavior is somewhat different in that the JIT compiler will insert calls to GC.KeepAlive() as appropriate/needed in order to support debugging sessions.
Debug and Release are just labelling for different solution configurations. You can add others if you want. If you wish you can add more configurations from configuration manager–
http://msdn.microsoft.com/en-us/library/kwybya3w.aspx
Major differences –
In a debug DLL several extra instructions are added to enable you to set a breakpoint on every source code line in Visual Studio. Also, the code will not be optimized, again to enable you to debug the code.
In the release version, these extra instructions are removed.
PDB file is created in only Debug mode and not in release mode.
In release mode, code is optimized by the optimizer that's built into the JIT compiler. It makes the following optimizations:
• Method inlining - A method call is replaced by the injecting the code of the method.
• CPU register allocation - Local variables and method arguments can stay stored in a CPU register without ever (or less frequently) being stored back to the stack frame
• Array index checking elimination - An important optimization when working with arrays (all .NET collection classes use an array internally). When the JIT compiler can verify that a loop never indexes an array out of bounds then it will eliminate the index check.
• Loop unrolling - Short loops (up to 4) with small bodies are eliminated by repeating the code in the loop body.
• Dead code elimination - A statement like if (false) { /.../ } gets completely eliminated.
• Code hoisting- Code inside a loop that is not affected by the loop can be moved out of the loop.
• Common sub-expression elimination. x = y + 4; z = y + 4; becomes z = x
One major performanance area if you are using any of the ASP.NET Ajax controls: debug information is removed from the JavaScript library when running in release, and I have seen major preformance improvements on complicated pages. Other web based resources may be either cached or not cached based on this setting.
Also, remember that Debug / Release in a web application is dictated by the web.config file, not your settings within Visual Studio.
<system.web>
<compilation debug="true">
More information:
Don’t run production ASP.NET Applications with debug=”true” enabled
You can also manage some part of code that you want to run only in debug or only in release with preprocessor markups:
#if DEBUG
// Some code running only in debug
#endif
or
#if NOT DEBUG
// Some code running only in release
#endif
Drawing with GDI+ is considerably slower in Debug mode.
Release version:
is considerable faster (most important), optimized
can't be debuged (step by step)
and code written in "debug" directive is not included
See What's the difference between a Debug vs Release Build?.
I got an error message when I distribute executable file to another machine indicating that the system missed MSVCP110D.dll.
The solution to this issue is stated in Stack Overflow question Visual Studio MSVCP110D.dll is missing.
IN XXXXD.dll D means that the DLL file is a debug version of the DLL file. But MS Visual C++ Redistributable packages include only the release version of DLL files.
That means if you need to distribute a program developed by Visual C++ you need to build it in Release mode. And also you need to install MS Visual C++ Redistributable (correct version) on the target machine.
So I think this a one of key difference between debug and release mode.