Modular visualizers in Visual Studio 11

Posted on November 22, 2011 by mloskot

Previously, I talked about the new debugger visualizers in Visual Studio 11 (Developer Preview) based on XML. By the way, I haven’t any luck trying to figure out where does the file type .NATVIS come from.

In previous versions of the Visual Studio, all templates of debugger visualizers have to be saved in single file: %VSINSTALLDIR%\Common7\Packages\Debugger\autoexp.dat. In case one wants to extend or improve the templates definition, maintaining everything in one system-wide file is neither practical nor safe.

The visualizers in Visual Studio 11 seem to solve the maintenance hassle by allowing more modular approach. First nice feature is that custom templates can be defined without touching any of the installed Visual Studio files and can be put in %USERPROFILE%\Documents\Visual Studio 11\Visualizers. Second nice feature I’ve just discovered is that definitions of visualizers can be split into several separate .natvis files. It is especially useful if one wants to maintain visualizers grouped according to libraries (e.g. Loki, Boost, POCO).

Basically, %USERPROFILE%\Documents\Visual Studio 11\Visualizers works like a package of custom visualizers now:

Having the visualizers diagnostics enabled, whole process of parsing and loading .natvis files will be traced in Visual Studio 11 output window:

No more copying and pasting debugger visualizers for Boost and others into big muddy autoexp.dat.

BTW, who knows where does NATVIS come from, hmm? :-)

Setting EnableNatvisDiagnostics in Visual Studio 11

Posted on November 20, 2011 by mloskot

Previously, I posted about the new XML-style debugger visualizers I discovered in Visual Studio 11. I mentioned that one of reasons the feature has been redesigned is to enable debugging of the visualizers templates defined in default or user-defined .natvis files. So, it looks there is something more to discover: how to actually make use of the diagnostics capability.

Unfortunately, it seems the new debugger visualizers have not been documented anywhere. At the time of writing this blog, Google reports one link about defaultvis.natvis, it is the brief post on Visual C++ forum.

Luckily, there is a short manual included as comment in header of the %ProgramFiles%\Microsoft Visual Studio 11.0\Common7\Packages\Debugger\Visualizers\defaultvis.natvis file. It says:

1) give better diagnostic reporting.
a) Set the name-value entry under the Debugger registry key: EnableNatvisDiagnostics which is a REG_DWORD to a value of 1 this will output each expression string that is evaluated under the native visualizer into the output window and is good for debugging type definition typos in .natvis files.

The first thing is to figure out where to set the EnableNatvisDiagnostics flag. The Visual Studio 11 installer does not put it into the registry. Also, there are several Debugger keys. However, a few experiments proved the flag should be set under HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\11.0\Debugger:

Once it is set, every time Visual Studio 11 debugger is launched and use of visualized types is determined, the .natvis files are parsed and evaluated templates validated. The process is reported in the Output window:

If anything goes wrong, a type definition template is incorrect and its evaluation fails, it is also reported in the Output window:

It will be a very useful feature especially when defining visualizers of complex types. Previous versions of Visual Studio used old format of templates defined in autoexp.dat file which stated its own DSL based on regular expressions, so the syntax was complex and fragile, and as Andy Pennel has confessed, not documented. (Here kudos to Avery Lee who did great job reverse-engineering the autoexp.dat syntax.)

At least, this time folks get the XML Schema for the Visual Studio debugger visualizers.

Debugger visualizers in Visual Sudio 11 Developer Preview

Posted on November 19, 2011 by mloskot

Visual Studio 11 Developer Preview introduces new style debugger visualizers. The autoexp.dat definition of templates in previous versions of the Visual Studio debugger is being replaced with new style definitions based on XML and stored in defaultvis.natvis file.

Microsoft explains the motivation behind redesigning the native type visualization mechanism is to give better diagnostic reporting (visualizer expressions can be now evaluated and displayed in the output window to help debugging .natvis file), provide XSD schema defining type definition, support of multiple files for type definition: system-wide in %ProgramFiles%\Microsoft Visual Studio 11.0\Common7\Packages\Debugger\Visualizers\defaultvis.natvis and user-defined in %USERPROFILE%\My Documents\Visual Studio Dev11\Visualizers\xxx.natvis.

It sounds really good and has a great usability potential for programmers who uses C++ generative programming capabilities, defines complex C++ types, heavily uses C++ Standard Library and Boost C++ Libraries.

Here is example of new style visualizer defined in XML copied from the defaultvis.natvis:

  <!--std::unique_ptr from <memory>-->
  <Type Name="std::unique_ptr<*>">
    <DisplayString Condition="_Myptr == 0">empty</DisplayString>
    <DisplayString>unique_ptr {*_Myptr}</DisplayString>
    <Expand>
      <Item Name="[ptr]" Condition="_Myptr != 0">_Myptr</Item>
    </Expand>
  </Type>

For most types from C++ Standard Library and Windows SDK, the new visualizers work very well. However, the currently available Visual Studio 11 Developer Preview (Version 11.0.40825.2 PREREL) is shipped with incorrect definitions in the defaultvis.natvis. The C++TR1 definitions introduced in Visual Studio 2008 are only forwarded (aliased) from std:tr1:: to std:: in Visual Studio 2010. In Visual Studio 11, they have completely moved from std::tr1:: to std:: to align with C++11 standard. But, the new visualizers in defaultvis.natvis define templates are still referring to the C++11 types in std::tr1:: namespace.

This prevents the correct visualization for types like std::shared_ptr:

There is an easy workaround possible:

Make private copy of defaultvis.natvis in %USERPROFILE%\My Documents\Visual Studio Dev11\Visualizers\xxx.natvis where xxx is your preferred name.
Open xxx.natvis in a text editor.
Find std::tr1:: and replace with std::.
Save the changes and relaunch the Visual Studio 11.
You should see objects of the C++11 types correctly visualized.

I have reported this issue to Microsoft Connect in Incorrect Type Name references in defaultvis.natvis visualizers for standard library ticket.

File version is not supported by the launcher

Posted on November 10, 2011 by mloskot

UPDATE: This bug (see below) has been fixed a few days ago. The fix is available in CMake git repo and should be release in the upcoming CMake 2.8.7 release.

What is the difference between these two Visual Studio solution (.sln) files?

They both have been generated using CMake 2.8.6. However, having Visual Studio 11 Developer Preview installed, every time I try to launch the Hello2011.sln I’m getting mysterious error message: File version is not supported by the launcher.

Quick look at what CMake actually outputs in to .sln confirms there is a bug. CMake generates .sln file signature which does not match release version/name of the Visual Studio 11. In Hello2011.sln CMake generated:

Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 2011

but correct version of the output, fixed in Hello11.sln, is this:

Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 11

Bug report submitted to CMake developers.

By the way, I have to admit different icons displayed for correct and incorrect .sln file are quite useful.

Building Boost with Visual Studio 11 Developer Preview

Posted on November 6, 2011 by mloskot

Yesterday, I installed Visual Studio 11 Developer Preview. The new release is available for free and is usable for free until June 2012, so it’s a great opportunity to try and learn what Microsoft has to offer for C++ programmers. And, it looks it offers a lot, including SCARY features.

The first test I usually do when it comes to test a new C++ toolset is to build Boost C++ Libraries using mainstream development sources.

The Boost simply builds well. I have even configured build of Boost.Python using Python version 3.2.

There are no hacks required to make the build happen. Simply, follow Boost Getting Started on Windows, section 5.3. Or, Build Binaries From Source. Once the Boost.Build tools bootstrapped, I issued the following command:

b2 --toolset=msvc variant=debug runtime-link=shared threading=multi define=_CRT_NONSTDC_NO_DEPRECATE define=_CRT_SECURE_NO_DEPRECATE define=_SCL_SECURE_NO_DEPRECATE stage

Fifteen minutes later, the Boost build was ready and staged.

By the way, some time ago Christian Henning posted a quick cheat sheet of bjam commands for Visual Studio. It’s very handy.

shared_ptr almost like intrusive_ptr

Posted on November 2, 2011 by mloskot

The current C++11 Standard consists of a very important remark in section 20.9.11.2.6. It is about creation of shared_ptr object. The remarks state:

Implementations are encouraged, but not required, to perform no more than one memory allocation.
[Note: this provides efficiency equivalent to an intrusive smart pointer. end note]

At work [1], I use Visual C++ 2010+ implementation of C++. I couldn’t resist myself to check if the standard managed to encourage Stephan T. Lavavej (STL) and his team at Microsoft to go for this optimisation.

I compiled and run a quick test:


#include <memory>
int main()
{
    std::shared_ptr<int> p0(
       new int(3)); // #1

    std::shared_ptr<int> p1
        = std::make_shared<int>(3); // #2
    return 0;
}

Quick check using breakpoints confirmed that Visual C++ 2010 indeed optimises construction of the shared_ptr. The difference between #1 and #2 is an important one: the second version causes 50% less memory allocations than the first one. Namely, one allocation. std::make_shared packs bookkeeping data and the user-defined data into a single block of memory.

Know your tools or suffer fragmented.

GCC At Home

I couldn’t leave a blog post alone without some kind of unrelated off-topic and pointless digression. So, here is one: Stephan T. Lavavej on his homepage provides custom-built distribution of MinGW toolset with What MinGW Is section starting as follows:

I recommend that anyone who is learning Standard C++ and who uses Windows for a primary development environment should use two compilers: the most modern version of Microsoft Visual C++ (currently 2010 SP1) and the most modern version of GCC, the GNU Compiler Collection.

Stephan works at Microsoft. I admire this kind of professionalism free from strategically competitive marketing b******t. GCC should definitely be included in the list of New Seven Wonders of the World. Recently, a new wonder has emerged: LLVM/Clang. I’m a user of all the three compilers (and related toolsets). It is easy for me to dream about ~~Visual C++~~Visual Studio IDE based on LLVM/Clang as C++ compiler and shipped with C/C++ standard libraries provided by GCC. That would be a real C++ Renaissance

Microsoft Announces SQL Server ODBC Driver for Linux!

Posted on October 28, 2011 by mloskot

Thanks to my, hopefully, open minded attitude, I sometimes let myself to dive into unknown with honest hope to find unexpected.

Today at lunchtime I let myself loose across Twitter archives and I came across an interesting account, or I rather should say: I fell into evil ways. It is @OpenAtMicrosoft. Hmm, another marketing specialist at Microsoft buzz’ing about the NKTOB ™, means new keyword on the block. Or, it is just Microsoft twitting daily menu from their newly opened cafeteria. But now, they presumably say what they mean:

source for info on Microsoft and interoperability, open source and open standards

Interoperability @ Microsoft

By the way, it is a foothold of Interoperability @ Microsoft. (For those who may have problems with interpreting the @ sign, like my grandfather for example, it means the same as English word “at” as in Kids at the House.)

In spite of that my eyes nearly dried out of the openness, I went for it and skimmed and voil?: Microsoft Announces SQL Server ODBC Driver for Linux!. It will soon be widely available to customers. Yay!

Yes, you read that right

Brian Swan – MSFT

It’s an evil good news of the day and I’m keen in trying it out as soon as I polish the ODBC backend in SOCI. I hope to stop worrying about which one to use, unixODBC or iODBC, for SQL Server at least. Life may become easier for OGR SQL Server driver users too.

I also hope, Microsoft will consider to offer the fastest development environment for C/C++ programmers for Linux. Namely, Visual Studio.

Yes, I am radically open minded. I can take on the most incredible of challenges, even surfing an inflatable crocodile.

Mateusz Loskot

mloskot's life, programming, c++, geo and adventures

Tag Archives: microsoft