Tag: visual studio

Entries for tag "visual studio", ordered from most recent. Entry count: 56.

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# Visual C++: IntelliSense Versus Macros

21:48
Thu
17
Aug 2017

When you code in C++ using Visual Studio, you may meet following problem: Your code uses preprocessor directives that depend on some macro that is defined elsewhere, e.g. in one of CPP files including the header file you write, and so IntelliSense gets lost and stops working, or even completely grays out that part of your code as inactive. For example:

// Some code...

#ifdef EXTERNALLY_DEFINED_MACRO

// Some code where IntelliSense stops working...

#endif

I just found a solution to that. It turns out there is a special macro predefined when code is processed by Visual Studio IntelliSense. It's called just __INTELLISENSE__. By using it, you can change parts of your code as seen by IntelliSense parser, e.g. define some macros, without influencing logic seen by the compiler. For example:

#ifdef __INTELLISENSE__
#define EXTERNALLY_DEFINED_MACRO
#endif

// Some code...

#ifdef EXTERNALLY_DEFINED_MACRO

// Some more code where IntelliSense is working again...

#endif

Comments | #c++ #visual studio Share

# Microsoft Visual Studio 2017 - My Experience

20:08
Thu
30
Mar 2017

Visual Studio 2017 came out recently. The list of news looks like it has been written by some marketing rather than technial guys. It starts with "Unparalleled productivity for any dev, any app, and any platform. Use Visual Studio 2017 to develop apps for Android, iOS, Windows, Linux, web, and cloud. Code fast, debug and diagnose with ease, test often, and release with confidence. You can also extend and customize Visual Studio by building your own extensions. Use version control, be agile, and collaborate efficiently with this new release!" - I've never seen so many buzzwords in just one paragraph.

Rest of the page is not different. They even call their installer "a new setup experience". They've also introduced "Lightweight Solution load", which is disabled by default - like everyone is assumed to prefer slower option :) Some other changes: "Visual Studio starts faster, is more responsive, and uses less memory than before." - that's unexpected direction. "Performance improvement: basic_string::operator== now checks the string's size before comparing the strings' contents." - wow, that's genius! They should file a patent for that ;) I hope they do the same for std::vector and other STL containers.

OK, but jokes aside, I've installed it on my personal PC, it installed quite fast and it works good. It preserved my settings, like the list of Include and Library Directories. Upgrade of my home projects went smoothly, without any problems.

There are many changes valuable for native code developers. What's New for Visual C++ in Visual Studio 2017 page mentions over 250 bug fixes, other compiler improvements and improved support for C++11, 14, and 17. I've already heard stories of programs running much faster after recompilation with this new compiler.

Contrary to what I thought before, Microsoft didn't abandon Graphics Diagnostics embedded into MSVS after they released new standalone PIX. They've actually added some new features to it.

So I definitely recommend upgrading to Visual Studio 2017. It is IMHO the best C++ IDE, and the new version is just next step in the right direction.

It seems that there is no new version of "Microsoft Visual C++ Redistributable Package" this time. Programs compiled with VS 2017 use VCRUNTIME140.DLL, just like in 2015 version.

Comments | #c++ #visual studio Share

# How code refactoring can fix stack overflow error?

20:23
Sun
07
Feb 2016

tl;dr: A very long C++ function with multiple local variables, even if they are not very big and they are placed in separate scopes, can reserve as much as hundreds of kilobytes of stack frame, causing "Stack Overflow" even without bugs like infinite recursion. So you better split your long functions into shorter ones.

Can refactoring (or the lack of thereof) cause application crashes? If we understand refactoring as changes in code layout without changing its logic, we might think that it's just the matter of readability and unreadable code increases chances of introducing bugs. But here is a story in which refactoring actually fixed a bug.

Long time ago in a software project far far away, there was a bug submitted telling that the application crashes with "Stack Overflow" message. It was a Windows app, developed in C++ using Visual Studio. I thought: - I can handle that, it should be easy! Every beginner/intermediate programmer knows about the call stack and surely seen this error at least once when accidentally caused infinite recursion in his code. So my first idea was that infinite recursion happens because of some logical error in the code (that should be easy to fix) or some unfortunate, invalid input data (that should be validated for safety before usage).

As it turned out, this was not the case. After setting up all the test environment and catching the crash in Visual Studio debugger, I looked at Call Stack and noticed that it looks quite normal. Sure the call depth was significant (as for C++, I'm not talking about Java here ;) and there was even some recursion, but 20 or 30 functions is not that much. The stack ended with a call to non-recursive function that seemed correct, so it was not the recursion that caused stack overflow.

My second idea was that some of these functions allocate some big objects (like arrays) by value, as local variables on the stack and this causes the stack to grow too big. I reviewed code of the functions that I found on the stack and used "Immediate Window" panel to quickly check sizeof(xxx) of variables or their types when they used some class, but I didn't find anything particularly big. Local variable sizes varied from few bytes to at most several hundred bytes and I couldn't find any big arrays defined in these functions. I also fetched address of some local variable in a function near the bottom of the stack (which looks like 0x000000000009a370), address of a parameter from the function at the top of the stack and subtracted them to see how big the stack grown over all these calls. The result was around 50 KB - not that much.

My third idea was to check maximum size of the stack. It is 1 MB by default, but it can be changed in Visual Studio project settings, in Linker > System tab, as "Stack Reserve Size" parameter. I check my project and I found this parameter not changed from its default value.

OK, now this became more difficult than I thought. After many debugging sessions, where I looked at various pointers, addresses and numbers trying to spot some memory override, stack corruption, out-of-bounds indexing etc., I finally opened "Disassembly" and "Registers" panels. I'm not a fan of such low level stuff, so it took me some time and few Google queries to understand these RSP, RBP registers and make sense of some x86-64 opcodes. While debugging step-by-step in the assembly, I found something interesting. At the beginning of my function, there was a call to mysterious function __chkstk and the crash occurred inside it. That was a clue I could use to ask Google what this all means. I found this: Description of the stack checking for Windows NT-based applications and this: What is the purpose of the _chkstk() function? These articles say that as the stack grows, next 4 KB pages are reserved. Each next page is allocated by the system on first "touch". I could actually see in my debugger that functions which need less than 1 page (4096 B = 1000h) have an instruction at the beginning similar to this:

sub         rsp,0A9h

While my debugged function had this instead:

mov         eax,26B29h
call        __chkstk (018104AA00h)
sub         rsp,rax

The articles say that when reserving more than one page of stack memory, this function must be called to loop over addresses with 4 KB step and "touch" each page. This is really what it does:

--- f:\dd\vctools\crt\crtw32\startup\amd64\chkstk.asm ---
sub         rsp,10h
mov         qword ptr [rsp],r10
mov         qword ptr [rsp+8],r11
xor         r11,r11
lea         r10,[rsp+18h]
sub         r10,rax
cmovb       r10,r11
mov         r11,qword ptr gs:[10h]
cmp         r10,r11
jae         cs10+10h (018104AA40h)
and         r10w,0F000h
lea         r11,[r11-1000h]
mov         byte ptr [r11],0
cmp         r10,r11
jne         cs10 (018104AA30h)
mov         r10,qword ptr [rsp]
mov         r11,qword ptr [rsp+8]
add         rsp,10h
ret

Key sentence of the second linked article seems to be: "The parameter in rax is size of data you want to add." In my case, eax is set to 26B29h = 158505. Wait, what?! This is more than 150 KB! Is it really how much of the stack the function needs?!

It was finally the right conclusion. The function was more than 3000-lines long, with lots of nested conditions and all kinds of stuff, but mostly an all-encompassing switch with dozens of different cases. I refactored it, extracting code from under each case to a separate function. This fixed the "Stack Overflow" crash.

Apparently if you have a long function and define a lot of local variables, even if they are not particularly big and they are placed inside separate scopes like if-s or switch case-s, the function may need as much as 150 KB of stack frame, at least in Debug configuration. This can cause crash with "Stack Overflow" message even without infinite recursion or bugs like that. So please keep this in mind as additional argument for refactoring your code as soon as you see the need for it.

Comments | #visual studio #c++ Share

# type_safe_ptr - Idea for Type-Safe void* Pointer

13:33
Sat
21
Nov 2015

I was thinking recently about passing raw data pointers (like void* or char*), which we have to do sometimes in C++. Is there any way to check if the type that we cast it to is the same as the type of last assigned value? I came up with an idea of implementing a "smart pointer" class using RTTI (specifically typeof operator) to store type information next to the actual pointer. Example usage:

int i = 123;
type_safe_ptr ptr{&i};
int j = *ptr.get_typed<int>(); // OK
float f = *ptr.get_typed<float>(); // Error

Initially I wanted to store pointer to const type_info struct returned by typeid operator, and it seems to work in Visual Studio 2015, but language standard defines the object returned by typeid as temporary, so it is not formally correct. Finally I decided to store typeid(T).hash_code(). You can find my implementation of classes type_safe_ptr and type_safe_const_ptr in file: type_safe_ptr.hpp. Here is example tesing program:

#include <cstdio>
#include "type_safe_ptr.hpp"

int main()
{
    type_safe_ptr ptr1;
    // ptr1 is null.
    assert(!ptr1);
    assert(ptr1.get() == nullptr);

    int i = 123;
    type_safe_ptr ptr2{&i};
    // ptr2 is pointer to int.
    assert(*ptr2.get_typed<int>() == 123);
    // It would activate assert inside type_safe_ptr.get_typed, because ptr2 is int not float.
    //assert(*ptr2.get_typed<float>() == 123.f);

    struct STest { int i; } obj;
    // itr2 is now pointer to STest.
    ptr2 = &obj;
    ptr2.get_typed<STest>()->i = 124;
    assert(obj.i == 124);
    // It would activate assert inside type_safe_ptr.get_typed, because ptr2 is now STest not int.
    //assert(*ptr2.get_typed<int>() == 123);
    
    type_safe_const_ptr cptr = type_safe_const_ptr(ptr2);
    // cptr is pointer to const STest.
    assert(cptr.get_typed<STest>()->i == 124);

    const int* constIntPtr = &i;
    cptr.reset(constIntPtr);
    // cptr is now pointer to const int.
    assert(*cptr.get_typed<int>() == 123);
}

Some issues and open question regarding my solution are:

Final question is, whether this whole idea of "type-checking void* smart pointer" makes any sense? I am not sure about that, but anyway it was a funny experiment :)

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# Unicode w Visual C++ - My Old Article

22:10
Tue
15
Sep 2015

I just noticed that my old article "Unicode w Visual C++" (in Polish) was a dead link and restored it back online:

Unicode w Visual C++

It may not be "politically correct" if you believe in what they say in UTF-8 Everywhere manifesto, but I think the information that I have put there are still relevant and useful despite being 7 years old.

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# Adventures with Porting Code to Visual Studio 2015 and No DirectX SDK

22:40
Sat
08
Aug 2015

I just installed new Visual Studio 2015 Community Edition and ported my personal project to it. At the same time, I uninstalled old DirectX SDK Jun 2010 and started using new DirectX headers bundled with Windows SDK, which is installed together with Visual Studio. These two transitions are not connected - I could already switch to new DX headers years ago, but I decided to do it now. While transition to VS 2015 was smooth, abandoning DirectX SDK caused some problems, because new DirectX doesn't contain D3DX library. Here is a dump of the problems and solutions that I encountered during this effort:

1. I uninstalled DirectX SDK Jun 2010, Visual Studio 2013 Community Edition and all other components that seemed related to it, like Microsoft SQL. I left all "Microsoft Visual C++ XX Redistributable" though, because these are required by many applications and intended to be installed on target machine, not necessarily as a part of development environment.

Next, I downloaded and installed new Visual Studio 2015 Community Edition. During this long process, I was thinking what should I expect from the new IDE... Whether Microsoft did a good job this time? On one hand, it is suprising that C++ is now an optional installation component, so it seems like native code is in shadow comparing to all these new and trendy cloud/web/mobile/managed technologies. On the other hand, table: C++11/14/17 Features In VS 2015 RTM shows that the new C++ compiler caught up with many features of new C++11/14/17 language, which gives hope that authors still treat native code development seriously.

2. The looks of new IDE is so similar to the previous version it is hard to notice any differences. After launching it, I had to first recompile static libraries that my project depends on. That was zlib 1.2.8 and my CommonLib. Converting project to new version, as well as the build itself went smoothly, without any problems - which is unusual with C/C++ libraries :) Just as in previous version, headers and libs of standard C library, standard C++ library (STL) and WinAPI are already bundled with the Visual Studio, so there is no need to install or configure anything additional before you can use them.

Read full entry > | Comments | #visual studio #directx #c++ Share

# How to check size of structure during development in Visual C++?

12:59
Wed
08
Jul 2015

Today I wanted to know what is sizeof(SomeStructure) during my coding in C++ in Visual Studio, without compiling and running my program. I needed that to put it into an assertion. Sure I could run the program and then break into debugger and evaluate the sizeof(SomeStructure) e.g. in Watches window, but the project is big and takes long time to build.

It turns out there is no such feature in Visual Studio to check size of structure, but it can be easily hacked using IntelliSense. In just few seconds, from this Google query, through its first result - this StackOverflow page, I have found following solution:

1. Put this line somewhere into your code:

template<size_t S> class Sizer { }; Sizer<sizeof(MY_STRUCTURE)> foo;

2. Replace "MY_STRUCTURE" with the name of your structure, other type or a variable.

3. Hover mouse cursor over "foo" and observe evaluated expression, for example: "Sizer<1296U> foo". 1296 is the size of your structure, in bytes - same as operator sizeof would return in runtime, when your program is compiled in currently selected configuration. "U" is for "unsigned".

By the way, maybe it would be a good feature request to add printing size of a type to the information available in design-time in Visual Studio, e.g. to Properties window, where there already are information about the type like IsTemplate, IsValue etc.?

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# Installing Visual C++ Redistributable Package from Command Line

07:29
Wed
20
May 2015

You may think that unless you explicitly use some external library (like FMOD), your program will not require any additional libraries to work, but when coding in C++ using Visual Studio, this is not the case. The functions of standard C/C++ library are implemented in a package of DLL-s called Microsoft Visual C++ Redistributable Package. Each version of Visual Studio has their own set. For example, version for Visual Studio 2013 (Release configuration) consists of files: msvcr120.dll, msvcp120.dll.

You can make your application not requiring this library by setting your project options in Configuration Properties > C/C++ > Code Generation > Runtime Library to "Multi-threaded [Debug]" without the "DLL" part, which makes it statically linked. Alternatively, you can distribute these DLL files (although I'm not sure if this is legal) or the whole library installer together with your application. The library is small and free, available to download from Microsoft website:

The question is: can you launch the installer of these packages with some special parameter so the user doesn't have to go through all the setup wizard, confirming each step? The answer is yes, but as Microsoft likes to change everything very often :) the exact command line is different depending on version. Here is the whole set:

Visual Studio 2005:

Visual Studio 2005, x86 (32-bit version):
vcredist_x86.exe /q:a /c:"VCREDI~1.EXE /q:a /c:""msiexec /i vcredist.msi /qn""
Visual Studio 2005, x64 (64-bit version):
vcredist_x64.exe /q:a /c:"VCREDI~2.EXE /q:a /c:""msiexec /i vcredist.msi /qn"" "
Visual Studio 2005 SP1, x86:
vcredist_x86.exe /q:a /c:"VCREDI~3.EXE /q:a /c:""msiexec /i vcredist.msi /qn"" "
Visual Studio 2005 SP1, x64:
vcredist_x64.exe /q:a /c:"VCREDI~2.EXE /q:a /c:""msiexec /i vcredist.msi /qn"" "

If you would like to install it in unattended mode (which will show a small progress bar but not require any user interaction), you can change the "/qn" switch above to "/qb". Unattended mode + disabled "Cancel" button is "/qb!".

Visual Studio 2008: Just pass one of these parameters:

/q - quiet mode, no user interface.
/qb - unattended mode, shows progress bar but no user interaction required.
/qb! - unattended mode with "Cancel" button disabled.

Visual Studio 2010 and 2012:

/q /norestart - quiet mode
/passive /norestart - passive (unattended) mode

Visual Studio 2013, 2015, 2017:

/install /quiet /norestart - quiet mode
/install /passive /norestart - passive (unattended) mode

To quickly install all of these libraries on the machines where lots of different applications are launched that may require them, I gathered all the libraries in one directory and I have written following BAT script:

"2005 SP1\vcredist_x86.exe" /q:a /c:"VCREDI~3.EXE /q:a /c:""msiexec /i vcredist.msi /qb"" "
"2005 SP1\vcredist_x64.exe" /q:a /c:"VCREDI~2.EXE /q:a /c:""msiexec /i vcredist.msi /qb"" "

"2008 SP1\vcredist_x86.exe" /qb
"2008 SP1\vcredist_x64.exe" /qb

"2010 SP1\vcredist_x86.exe" /passive /norestart
"2010 SP1\vcredist_x64.exe" /passive /norestart

"2012 Update 4\vcredist_x86.exe" /passive /norestart
"2012 Update 4\vcredist_x64.exe" /passive /norestart

"2013\vcredist_x86.exe" /install /passive /norestart
"2013\vcredist_x64.exe" /install /passive /norestart "2015 Update 3\vc_redist.x86.exe" /install /passive /norestart "2015 Update 3\vc_redist.x64.exe" /install /passive /norestart "2017\vc_redist.x86.exe" /install /passive /norestart "2017\vc_redist.x64.exe" /install /passive /norestart

Update: I also prepared a full package with my script and "pirated" copy of all these installers for your convenience: Microsoft Visual C++ Redistributable Package.zip (77.9 MB).

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