July 2016

Warning! Some information on this page is older than 6 years now. I keep it for reference, but it probably doesn't reflect my current knowledge and beliefs.

# How to disable C++ exception handling using macros?

Thu
28
Jul 2016

Some time ago my colleague showed me a clever way to disable exception handling in C++ using a set of preprocessor macros:

#define throw
#define try          if(true)
#define catch(...)   if(false)

Please note that:

throw is a macro without arguments that resolves to just nothing, so the expression following it will become a standalone expression with its result discarded.
try is a macro without arguments that resolves to an "if" statement, that will smoothly merge with the following { } braces.
catch is also a macro that resolves to "if" statement, but it takes variable number or arguments and doesn't use them in its definition.

So following code that uses exception:

try
{
    // Do something
    if(somethingFailed)
        throw std::exception("Message.");
}
catch(const std::exception& e)
{
    // Handle the exception.
}

Will resolve after defining these three macros to following:

if(true)
{
    // Do something
    if(somethingFailed)
        std::exception("Message.");
}
if(false)
{
    // Handle the exception.
}

Of course it's not a solution to any real problem, unless you just want your try...catch blocks to stop working. Disabling exception handling for real (and associated performance penalty, as well as binary code size overhead) is the matter of compiler options. And of course this trick makes errors not handled properly, so when an exception would be thrown, the program will just continue and something bad will happen instead.

But I think the trick is interesting anyway, because it shows how powerful C++ is (it empowers you to do stupid things :)

Comments | #c++ Share

# Upgrade to Windows 10 - My Story

Wed
20
Jul 2016

I upgraded my system to Windows 10. Free upgrade is avaiable until July 28th for all genuine users of Windows 7, 8 and 8.1, so now it's high time to do it if you don't want to pay for it later. My upgrade went well, but not without problems. Here is my story:

First some basic information:

There are two ways to upgrade Windows. First is to use the "Get Windows 10" app that pops up for several months on everyone's desktop, also known as GWX. Second is to go to Get Windows 10 website and download a small tool "MediaCreationTool.exe". This tool can also be used to download and create a bootable DVD ISO image or USB flash drive with offline Windows installer.
To get your free license of Windows 10, you need to perform an upgrade. After the upgrade you will have a product key for your new Windows, which you could use to reinstall the system from scratch if you want to. Product key of the current system, whether it's Windows 7, 8, or 10, can be retrieved using a small tool called ProduKey.

On my old Toshiba laptop with Windows 7, bought in 2011, the upgrade failed. The system is not broken though - Windows 7 still works. After the failure I checked manufacturer's website and found that there are no drivers for this model for any operating system newer than Windows 7, so it's good to stay this way.

On my new Lenovo laptop with Windows 8.1, bought in 2015, I was able to successfully perform the upgrade suggested by the system. All the devices work correctly. All installed programs and settings are also preserved.

On my PC, with most components bought in 2013, upgrade to Windows 10 also failed. I can remember fighting with this annoying upgrade window and deleting some system files few months ago, so that might be the reason. I was ready to format my system disk and install everything from scratch anyway, so here is what I did:

I made all necessary backups - an obvious step :)
I launched "MediaCreationTool.exe", selected "Create installation media for another PC" and created a DVD ISO file with offline installer.
I burned the file to a DVD disk.
I booted my PC from Windows 7 installation DVD, formatted my system disk and installed fresh Windows 7 on it, with proper product key.
I launched "MediaCreationTool.exe" and performed upgrade to Windows 10. It succeeded this time.
I launched ProduKey and written down the new product key of my upgraded Windows 10.
I booted my PC from Windows 10 installation DVD, formatted my system disk again and installed fresh Windows 10, with the new product key.
Finally I could install all the needed apps, apply my preferred settings, set some nice wallpaper etc. (I especially recommend Mandelbulb Maniaces Facebook group as a source of wallpapers :)

I could find drivers for Windows 10 for all my components and peripherals and they all work correctly (except only an old, little webcam - ModeCom MC-1.3M, but I don't use it anyway). I could also install all the programs that I need and they seem to work.

I recommend you to also get your free upgrade to Windows 10. I had an opportunity to work with this system a lot and I could say it's not that bad :) I know there are some arguments against the new Windows version, so let's look at them:

Privacy concerns. They say that Microsoft introduced telemetry code that is spying on its users and sending everything to Microsoft. That might be true, but:
- There are ways to disable or at least minimize it - just search for "windows 10 disable telemetry".
- Microsoft introduced telemetry to Windows 7 and 8 as well, and even to programs compiled using Visual Studio 2015.
- Whether we like it or not (and I don't like it either), technology world evolves in the direction where our data is moved to the cloud and so corporations and governments are spying on us. It's impossible to avoid, unless you want to be an outsider using only free software and give up on all the goodness that is available to us, like smartphones.
New user interface is flat and ugly. I agree with that. There are even leaks from Microsoft that explain why it looks this way. But only the new part of the system (like Settings window) are made in this new style. All other windows and apps have similar looks as they had before.
People commonly believe that new version of the system always works slower. I can see this is not the case. Since Windows 7, 8 and now 10 developers put a lot of effort to make it work fast, especially in terms of startup time. I think that Windows 10 boots and works as fast as previous versions.

There are some advantages of the new Windows as well, especially compared to Windows 8.x. There is no Charms Bar and Hot Corners when you but your mouse cursor in the corner of the screen. Start Menu is back with just few tiles you can configure and the old good list of installed applications. (You can always get even more old-fashioned Start Menu by installing free app: Classic Shell).

But the most important is what's not visible to the naked eye. As a developer I know that a new operating system is not about new looks of buttons and menus or new Calc application, but mostly about new technologies under the hood. Some of them (like Direct3D 12 and WDDM 2.0, to name just these related to graphics) are available in Windows 10 only. Some applications and games will require them to work sooner or later. That's the reason I believe it's worth upgrading to Windows 10 as long as it's free.

I plan to update my blog more often now, so I invite you to come back here from time to time or subscribe to my RSS channel.

Comments | #microsoft #windows Share