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Programmatically detecting Release/Debug mode (.NET) [duplicate]
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C# if/then directives for debug vs release
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Closed 7 years ago.
I've an application built in VS2013 (written in C#), how can I know if it was built in Debug or Release mode? Is it enough to check is files .pdb are present?
It's not a duplicate of C# if/then directives for debug vs release .. suppose I don't have the source code, only compiled files, looking at them is it possible to determine the build mode? Can I just look for .pdb files?
how can I know if it was built in Debug or Release mode? Is it enough to check is files .pdb are present?
Building in debug mode typically entails three things:
Optimizations are disabled
PDBs are emitted
DEBUG preprocessor symbol is defined
I said "typically" because there is no requirement that any of these things happen consistently; it is possible to emit PDBs without optimizations, for example.
You do not say which of these three things you are interested in, or for that matter, why. I'll describe how to detect the first: was an assembly built with optimizations disabled?
The easiest way to do it is to simply run ILDASM on the assembly and examine the IL for any method. Methods built with optimization disabled will have nop instructions throughout. These are "no operation" instructions which do nothing; they exist solely to make the code easier to debug by providing more locations upon which the developer can place breakpoints.
For example, the IL of a "hello world" method with optimizations disabled is:
nop
ldstr "Hello world"
call void [mscorlib]System.Console::WriteLine(string)
nop
ret
But with optimizations enabled, the nops go away.
If you are interested in other ways of detecting debug vs release mode, see the links in this duplicate question:
Programmatically detecting Release/Debug mode (.NET)
There are a couple of ways:
File size is greater when built in debug vs release.
If you follow a proper deploybuild then the release version should have updated assembly info.
Use DebugView.exe, if the application shows debug output in DebugView then its built in Debug mode.
I used Dependency Walker on both a release and debug version of a test program.
In Dependency Walker, I did a save as type: Text with Import/Export Lists on both programs.
I then did a file compare of the outputs:
The only significant difference was that the Release version had a Page File Memory Used of Zero.
Related
This question already has answers here:
Closed 11 years ago.
Possible Duplicates:
Debug/Release difference
Performance differences between debug and release builds
What exactly is the different in compiling and running an asp.net/c# project in Debug mode VS Release Mode?
In Debug Mode your .exe has debug information inside of it (source code, variable names and other similar stuff like that).
In Release Mode your .exe lack of debug information makes it smaller and probably performs better due to its smaller footprint.
The biggest difference between these is that:
In a debug build the complete symbolic debug information is emitted to help while debugging applications and also the code optimization is not taken into account.
While in release build the symbolic debug info is not emitted and the code execution is optimized.
Also, because the symbolic info is not emitted in a release build, the size of the final executable is lesser than a debug executable.
One can expect to see funny errors in release builds due to compiler optimizations or differences in memory layout or initialization. These are ususally referred to as Release - Only bugs :)
In terms of execution speed, a release executable will execute faster for sure, but not always will this different be significant.
Other compile arguments who giving you more debug info in producted executable and many more options who you wan read at msdn.
http://social.msdn.microsoft.com/Forums/en/csharpgeneral/thread/74db169a-e244-496e-ae97-8dfec18ff2e5
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Disassembly view of C# 64-bit Release code is 75% longer than 32-bit Debug code?
I have an extremely simple C# Console Application, hat does some sorting on a big number of elements (only a few lines of code with array operations).
When I start the release code from Visual Studio IDE with F5 or Ctrl-F5 the program is about 3x slower than when started directly from Win-Explorer.
41.140 seconds when launched from VS 2010 IDE
13.950 seconds when launched by double-clicking myprogram.exe
Why???
First some details...
Be aware that there are 2 main "optimization" stages in .NET.
At the C# Compiler level...the production of different IL (Intermediate Language)...optimized or non-optimized....controlled by whether your project sets the DEBUG flag or not
At the JITer level...when the IL is translated into machine code (either through Just-in-Time compilation or via NGEN)....optimized machine code may or may not be producedNote: it is NOT the IL produced via the compiler in DEBUG or RELEASE mode that controls the JITter optimization setting...it's an independent setting.
The main optimization "wins" occur at the JIT level.
http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/57db50f1-54c7-4730-a097-c4976bb3a30b/
When you are debugging a NET program through Visual Studio, normally you don't want the JITter to produce optimized machine code, because then your program source statements aren't closely in sync with the executing code when you step through it.
So that's why there is an option in Visual Studio to turn off JITter optimizations (this is comparable to turning off JITter optimizations with the AllowOptimize=0 flag)...and by default Visual Studio turns JITter optimizations off:
See this for an explanation of the Suppress option:
http://msdn.microsoft.com/en-us/library/ms241594(v=vs.85).aspx
When you run a NET application outside of Visual Studio it doesn't matter if that program was compiled as DEBUG (non-optimized IL) or RELEASE (optimized IL)....the JITter will produce optimized machine code by default.
So the behaviour to be noticed is that a NET program will run
substantially faster when started outside of Visual Studio than when
started from Visual Studio due to the different JITter optimization
setting...even when it's a RELEASE mode application....as #Knasterbax
observed. In addition, there's additional overhead to add when debugging (F5) and not just running (CTRL+F5) from Visual Studio.
If you run your application (whether RELEASE or DEBUG) from Explorer and then you "attach" to the process with Visual Studio, then your application will be using a JITter that is applying optimizations....your code will run faster...but any source code stepping will not be in sync.
If you untick the "Suppress JIT optimizations" then you can gain faster execution at the expense of a poorer debugging experience in Visual Studio.
To end, there is a way to turn off JITter Optimizations for your application code should you need/want to:
disable JITter for entire application by putting this into app.config
[.NET Framework Debugging Control] AllowOptimize=0
you can tell the JITter not to optimize specified methods by using this attribute
[MethodImpl(MethodImplOptions.NoOptimization)]
on method bodies.
F5 is start debugging, not "run", it will be doing a lot of things like loading symbols in the background, even if you're attempting to debug a release build.
Starting a program with the debugger attached will always be significantly slower than without it.
When you compile the code in debug mode, the compiler switches off some optimisations, and it adds some extra instructions, to make it possible to put breakpoints everywhere and to make it possible to single step through the code.
This will make code compiled in debug mode slower than code compiled in release mode.
In Visual Studio for a C# project, if you go to Project Properties > Build > Advanced > Debug Info you have three options: none, full, or pdb-only.
Which setting is the most appropriate for a release build?
So, what are the differences between full and pdb-only?
If I use full will there be performance ramifications? If I use pdb-only will it be harder to debug production issues?
I would build with pdb-only. You will not be able to attach a debugger to the released product, but if you get a crash dump, you can use Visual Studio or WinDBG to examine the stack traces and memory dumps at the time of the crash.
If you go with full rather than pdb-only, you'll get the same benefits, except that the executable can be attached directly to a debugger. You'll need to determine if this is reasonable given your product & customers.
Be sure to save the PDB files somewhere so that you can reference them when a crash report comes in. If you can set up a symbol server to store those debugging symbols, so much the better.
If you opt to build with none, you will have no recourse when there's a crash in the field. You won't be able to do any sort of after-the-fact examination of the crash, which could severely hamper your ability to track down the problem.
A note about performance:
Both John Robbins and Eric Lippert have written blog posts about the /debug flag, and they both indicate that this setting has zero performance impact. There is a separate /optimize flag which dictates whether the compiler should perform optimizations.
WARNING
MSDN documentation for /debug switch (In Visual Studio it is Debug Info) seems to be out-of-date! This is what it has which is incorrect
If you use /debug:full, be aware that there is some impact on the
speed and size of JIT optimized code and a small impact on code
quality with /debug:full. We recommend /debug:pdbonly or no PDB for
generating release code.
One difference between /debug:pdbonly and /debug:full is that with
/debug:full the compiler emits a DebuggableAttribute, which is used to
tell the JIT compiler that debug information is available.
Then, what is true now?
Pdb-only – Prior to .NET 2.0, it helped to investigate the crash dumps from released product (customer machines). But it didn't let attaching the debugger. This is not the case from .NET 2.0. It is exactly same as Full.
Full – This helps us to investigate crash dumps, and also allows us to attach debugger to release build. But unlike MSDN mentions, it doesn't impact the performance (since .NET 2.0). It does exactly same as Pdb-only.
If they are exactly same, why do we have these options? John Robbins (windows debugging god) found out these are there for historical reasons.
Back in .NET 1.0 there were differences, but in .NET 2.0 there isn’t.
It looks like .NET 4.0 will follow the same pattern. After
double-checking with the CLR Debugging Team, there is no difference at
all.
What controls whether the JITter does a debug build is the /optimize
switch. <…>
The bottom line is that you want to build your release builds with
/optimize+ and any of the /debug switches so you can debug with source
code.
then he goes on to prove it.
Now the optimization is part of a separate switch /optimize (in visual studio it is called Optimize code).
In short, irrespective of DebugInfo setting pdb-only or full, we will have same results. The recommendation is to avoid None since it would deprive you of being able to analyze the crash dumps from released product or attaching debugger.
You'll want PDB only, but you won't want to give the PDB files to users. Having them for yourself though, alongside your binaries, gives you the ability to load crash dumps into a debugger like WinDbg and see where your program actually failed. This can be rather useful when your code is crashing on a machine you don't have access to.
Full debug adds the [Debuggable] attribute to your code. This has a huge impact on speed. For example, some loop optimizations may be disabled to make single stepping easier. In addition, it has a small effect on the JIT process, as it turns on tracking.
I'm in the process of writing a unhandled exception handler and the stack trace includes the line number when pdb-only is used, otherwise I just get the name of the Sub/Function when I choose None.
If I don't distribute the .pdb I don't get the line number in the stack trace even with the pdb-only build.
So, I'm distributing (XCOPY deploy on a LAN) the pdb along with the exe from my VB app.
This question already has answers here:
Closed 11 years ago.
Possible Duplicates:
Debug/Release difference
Performance differences between debug and release builds
What exactly is the different in compiling and running an asp.net/c# project in Debug mode VS Release Mode?
In Debug Mode your .exe has debug information inside of it (source code, variable names and other similar stuff like that).
In Release Mode your .exe lack of debug information makes it smaller and probably performs better due to its smaller footprint.
The biggest difference between these is that:
In a debug build the complete symbolic debug information is emitted to help while debugging applications and also the code optimization is not taken into account.
While in release build the symbolic debug info is not emitted and the code execution is optimized.
Also, because the symbolic info is not emitted in a release build, the size of the final executable is lesser than a debug executable.
One can expect to see funny errors in release builds due to compiler optimizations or differences in memory layout or initialization. These are ususally referred to as Release - Only bugs :)
In terms of execution speed, a release executable will execute faster for sure, but not always will this different be significant.
Other compile arguments who giving you more debug info in producted executable and many more options who you wan read at msdn.
http://social.msdn.microsoft.com/Forums/en/csharpgeneral/thread/74db169a-e244-496e-ae97-8dfec18ff2e5
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.