I am trying to use SetDisplayConfig in a c++ project in order to manage the dysplays. I use windows 7 as OS and Visual Studio 2008 as editor. I include the header Winuser.h as suggested but when I try to compile the error 'SetDisplayConfig': identifier not found occurs. Any idea about the reason?
Thanks,
Giorgio
The MSDN documentation for the Windows API usually names both the header file, that declares an identifier, as well as the header file you should include. SetDisplayConfig is no different in that respect:
Header Winuser.h (include Windows.h)
To use SetDisplayConfig you need to include Windows.h.
Since this API is available in Windows 7 and later versions, you also have to set the _WIN32_WINNT preprocessor symbol, prior to including Windows.h:
#define _WIN32_WINNT 0x0601
Alternatively, you can define the preprocessor symbol inside the IDE, to have it passed to the compiler on the command line. Doing it this way ensures, that the symbol is defined prior to any includes. Additional information is available at Using the Windows Headers.
Related
I have exactly the opposite problem to VSCode turn of _WIN32 define - Visual Studio Code is failing to define _WIN32 for me. This is in a cross-platform project that is being developed on Windows with the Microsoft compiler, but needs to also be able to compile on Linux, so I have
#ifdef _WIN32
#include <windows.h>
failing, and VS Code then marks all references to Windows API types etc. with red underlines. (The include mechanism itself is working fine, e.g. it has no problem including regular C++ headers.)
Is there any known reason why VS Code on Windows might fail to define _WIN32? The question I linked suggests it should, and I haven't knowingly changed any settings related to it.
Most likely, the problem is VSCode is using the wrong C++ compiler to gather the predefined macros, and that compiler does not predefine _WIN32.
To check, in Command Palette (Ctrl+Shift+P), run "C/C++: Log Diagnostics". The output will show you which compiler VSCode found and what it detected as its built-in include path and preprocessor defines. If my guess is correct, the diagnostics will show the wrong compiler being used, and _WIN32 missing.
Assuming so, to solve this, use the command Palette to run "C/C++: Edit Configurations (UI)", then set "Compiler path" to point at your compiler executable (cl.exe in this case). That should solve the problem because VSCode will then query that compiler to determine the predefined macros, which will include _WIN32. Re-run the diagnostics to confirm.
(I just gave a similar answer to the question linked to in the question above, as I think both questions have essentially the same problem and solution, just with different details.)
I have a dll file, irig106.dll, that I produced from a compile in Visual Studio 2010. (The source code is here). Notice the multitude of .h files in there; the main one is called irig106ch10.h, as far as I can tell.
I would like to import it into MATLAB via loadlibrary. I put all the .h files into their own folder, called "headers". Here's what I get:
loadlibrary('irig106.dll', 'headers\irig106ch10.h', 'addheader', 'config', 'addheader', 'stdint', 'includepath', '.\headers');
Warning: Warnings messages were produced while parsing. Check the functions you intend to use for correctness. Warning text can be viewed using:
[notfound,warnings]=loadlibrary(...)
Error using loadlibrary (line 418)
There was an error loading the library
"mydir\irig106.dll"
mydir\irig106.dll
is not a valid Win32 application.
So I'm not sure of a few things:
Why is loadlibrary claiming that the dll is not a valid Win32 application? It looks like based on my Visual Studio settings, I am compiling for Win32.
Per the loadlibrary documentation, I need to explicitly use addheader for each header file I want to include, and those headers need to be #included in the base header file. In this case, I only include config.h and stdint.h in irig106ch10.h but I'd like to use all those other headers. Do I need to make a "header header" file where I include everything?
I guess I'm looking for a tutorial on how to use loadlibrary for complicated dlls with multiple headers like this, because there really isn't much in the way of examples on the internet. I'd love to see someone build the .dll (uncomment the #define IRIG_NETWORKING in config.h) and give a step-by-step.
In Xcode, I've created a "Cocoa application" project. One of its dependencies is a framework containing C++ code. I renamed AppDelegate.m to AppDelegate.mm and included the framework.
The project fails to compile. The problem is that the C++ header files in the framework are using some symbols that conflict with Objective-C or Cocoa.
The C++ header files are defining functions called verify() and check(), which conflict with /usr/include/AssertMacros.h in the MacOSX10.8 SDK.
The C++ header files contain a variable called NO, which conflicts with the Objective-C macro NO.
A workaround would be to modify the C++ code in the framework to avoid these conflicts. But since it's a large C++ project maintained by another organization, this would take time and would possibly break in future updates of the C++ project.
Is there some way just to tell Clang/Xcode to treat those C++ header files as C++ instead of Objective-C++?
Reading through the /usr/include/AssertMacros.h that comes with Mac OS 10.8, it looks like you could do:
#define __ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORES 0
before including AssertMacros.h, which will prevent it from defining macros called verify() and check().
Regarding NO: you could use the preprocessor to rename that variable for you. For example:
#define NO NO_libraryname_renamed
#include <libraryname.hh>
#undef NO
Depending on how the NO variable is used by the library, this might cause problems — if the header is declaring it as extern, then your Cocoa app will refer to it by the wrong name, and you'll get an undefined symbol error. But as long as you're not using that variable, and the library isn't depending on your app to define that variable, then you should be fine.
(And please file a bug report with the offending library, requesting that they rename their variable.)
Mixing several languages is calling for grief. Even more so mixing Objective C++ (itself a strange hybrid) with C++. Don't do it.
I use Intel Parallel Studio XE 2011 .It says it supports Cilk.When I include a cilk_for statement in the code it does not compile.It says symbol undefined.I have included the cilk.h at the beginning of my code and also under include directories I put the location of cilk.h (C:\Program Files (x86)\Intel\ComposerXE-2011\compiler\include\cilk).Can someone tell me what am I missing? How can i successfully compile my code.
My guess is that you are not picking up the cilk header correctly. Try using the cilk keywords (_Cilk_spawn, _Cilk_sync, and _Cilk_for) instead and see if that works without the header. If it does, at least you know that the Cilk stuff in the compiler is working and it is the header. Then try using "#include <cilk/cilk.h>" and using cilk_for to see if it picks up the header correctly. You shouldn't have to be specifying the location of the cilk.h file yourself if everything is set up correctly. Are you doing this on the command line or using Microsoft's Visual Studio? If you are using MS VS are you sure that you are specifying to use the Intel compiler?
we're building a cross-platform utility which must have a small footprint. We've been pulling header files from boost as and when we need them but now we must link against some boost C++ thread code. The easiest immediate solution was to create our own custom library using CMake's "add_library" command to create a static library composed of some boost thread source files. These compile without any problems.
The difficulty arises when I try to link to this library from an executable. Visual Studio 2008 returns an error saying that it cannot link to "libboost_thread-vc90-mt-sgd-1_40.lib". What really puzzles me is that I've grepped through all the source code and CMake config files and I can't find any reference to this libboost library, leading me to think that this has been autogenerated in some way.
This works OK in Linux, can anyone point out why I'm experiencing these issues in Windows?
#Gearoid
You found the correct reason for your problem, but not the correct solution. The BOOST_AUTO_LINK_NOMANGLE is an internal, i.e. for library authors, definition to control the auto-linking. The user level definition is BOOST_ALL_NO_LIB which when defined disables the auto-linking feature for all Boost Libraries code you use. This is described in the user.hpp configuration header (see user.hpp near the bottom and the Boost Config documentation). You can also control this on a per library level as describe in that header.
Ok, well, it turns out that Boost uses this auto-link feature for Visual Studio which embeds references to a mangled (ie, platform-compiler-mult-threaded, etc) boost library name.
The header file which controls this is called "auto_link.hpp" which lives in the config directory of the boost include tree. There's a special preprocessor definition called "BOOST_AUTO_LINK_NOMANGLE" which toggles this behaviour.
Another triumph of mediocrity for Microsoft.