I'm using CMake version 2.8 on WinXP SP3. Whenever i run my CMakeLists script by default CMake use Visual Studio 10 compiler. I've tried to do:
SET( CMAKE_CXX_COMPILER "C:/MinGW/bin/g++" )
without success. How can i set MinGW as my default compiler so that i do not have to worry about setting compiler in the CMakeLists?
CMake 3.15 or later supports overriding the default generator by setting the environment variable CMAKE_GENERATOR.
E.g., using PowerShell, set the environment variable in the following way to make MinGW the default generator:
$Env:CMAKE_GENERATOR = 'MinGW Makefiles'
For older CMake versions (< 3.15), CMake uses the newest Visual Studio installation as default generator, unless the generator is explicitly specified upon invoking CMake. This behavior is hard coded and cannot be changed.
As a work-around you can use a batch wrapper script titled cmake.cmd with the following contents:
#cmake.exe -G "MinGW Makefiles" %*
The script should be placed in a directory on the system PATH and should take precedence over the CMake executable cmake.exe.
The script invokes cmake.exe with MinGW as a generator and forwards all other parameters to it.
You only have to set the toolchain/output format once, typically you'd do this upon running cmake for the first time:
cmake -G "MinGW Makefiles" .
Instead of the dot you can use your own parameters (if any) and/or the path to the source.
As an alternative, especially when you're new to CMake, use the GUI version under windows (run cmake-gui without parameters instead of cmake).
Once opened, set your paths and click on "Configure". If there's no compiler set, it will ask you to pick one (otherwise you have to clear the cache to make it reappear).
Updated configuration values will appear in red and it will also allow you to select files and paths using the common Windows dialog boxes.
Once configuration is complete and without errors you can hit "generate" to create your makefiles or project files. To update these later on, you can use cmake-gui again or just use the usual command line version cmake.
With CMake version 3.15 or later, you can set the CMAKE_GENERATOR environment variable to specify the default generator to be used on your system.
Related
I am using Visual Studio Community 2019.
I always need to change the CMakeSettings.json for every new CMake Project I make.
SET( CMAKE_CXX_COMPILER "C:/MinGW/bin/g++" )
How can i set MinGW as my default compiler so that i do not have to worry about setting compiler every time I create a new CMake Project.
There are solution given on this link:
Setting default compiler in CMake
but I am unable to follow any of them because they are not very clear for me.
Like the accepted solution says:
Set CMAKE_GENERATOR environment variable to specify the default generator to be used on your system.
But I don't know how to set CMAKE_GENERATOR environment variable to specify the default generator to be used on my system.
I can do for my current project but i am unable to set the compiler at "C:/MinGW/bin/g++" as default for every new CMake Project.
I know people have given working solutions but even after hours, due to very general instructions, i am unable to follow. Please provide step by step instructions with where to look for the file which i need to change.
Perhaps, the easiest way to do this globally for all your new CMake projects is to set the CMAKE_GENERATOR environment variable on your system (available with CMake 3.15 or greater). Since it appears you are using Windows, here is how to set it on Windows 10:
Open the Windows Start Search (by pressing the Windows Key), type
"env", and choose "Edit the system environment variables".
Click "Environment Variables...".
Under "System variables", click the "New..." button to add a new environment variable.
For "Variable name:", use CMAKE_GENERATOR, and for "Variable value:" use "MinGW
Makefiles".
Click "OK", then "OK" again to save the new environment variable.
Now, CMake will use this environment variable to set MinGW Makesfiles as the default generator when new projects are invoked. You should also make sure the path to MinGW (C:/MinGW/bin/g++) is included in your Path environment variable.
If you are using an earlier version of CMake (< 3.15), you have to specify the generator manually when invoking CMake:
cmake -DCMAKE_GENERATOR="MinGW Makefiles" ..
or
cmake -G "MinGW Makefiles" ..
But I don't know how to set CMAKE_GENERATOR environment variable to specify the default generator to be used on my system.
That variable is taken from the environment, but can also be sent as a parameter to CMake commands:
cmake .. -DCMAKE_GENERATOR="Mingw Makefiles"
In the command line you can also set the desired compiler:
cmake .. -DCMAKE_GENERATOR="Mingw Makefiles" -DCMAKE_CXX_COMPILER="C:/MinGW/bin/g++"
I want to build my C++ applications from the Windows PowerShell command line using CMake and MinGW.
When I do this in the "normal way," with these commands:
mkdir build
cd build
cmake ..
make
CMake chooses Visual Studio as the default compiler, and doesn't generate any Makefiles for me.
I want CMake to use MinGW as the default compiler, and generate Makefiles.
It works exactly the way that I want it to when I run these commands, adding the -G "MinGW Makefiles" flag:
mkdir build
cd build
cmake .. -G "MinGW Makefiles"
make
How can I make CMake behave this way all the time, without adding the -G "MinGW Makefiles" flag?
I've tried setting up a CMAKE_GENERATOR environment variable in Windows, and pointing it to "path\to\mingw\bin", "path\to\mingw\bin\mingw32-make.exe", as well as a string that reads "MinGW Makefile".
None of these worked for me after running refreshenv and then trying to run cmake .. again.
Does anybody know if this is the correct environment variable to use in order to specify CMake's default behavior? If it is, what value should I be using?
How can I make CMake behave this way all the time, without adding the -G "MinGW Makefiles" flag?
You can't, not in any version of CMake released to date. CMake chooses a generator before it starts evaluating any CMakeLists.txt files. By default, it chooses a generator based on runtime platform and available toolsets, and command-line options are the only way presently available to influence or override CMake's choice of generator.
In comments, #Tsyvarev pointed out an open CMake issue report asking for the very same feature you are asking for. The associated comment thread provides more detail, and the last comment was earlier this year. I would guess that eventually CMake will add support for specifying a generator via environment variable, but for now, your -G option is the only available alternative. You could consider scripting it if you want to save keystrokes and reduce the risk of typos.
I know this is late. but in case someone came here and find this answer useful
all you have to do is to create a function something like this:
function gcmake {cmake .. -G "MinGW Makefiles"}
then you can simply type
mkdir build
cd build
gcmake ..
make
tip: you can add this function to your profile so that it will be saved to any new session. you can follow this nice guide
cmake uses Visual Studio generator for MinGW on Windows by default (even without Visual Studio!), this is the real annoying issue (Cygwin is not affected).
We need to work around MinGW only. What will be the most reliable hook for MinGW? I think MSYSTEM is very popular environment variable that will always be defined for MinGW.
You can place PreLoad.cmake in the project root with the following content:
if (NOT "$ENV{MSYSTEM}" STREQUAL "" AND "$ENV{VisualStudioVersion}" STREQUAL "")
find_program (CMAKE_NINJA_BINARY NAMES "ninja")
if (CMAKE_NINJA_BINARY)
set (
CMAKE_GENERATOR "Ninja"
CACHE INTERNAL "Cmake generator"
)
return ()
endif ()
find_program (CMAKE_MAKE_BINARY NAMES "gmake" "make")
if (CMAKE_MAKE_BINARY)
set (
CMAKE_GENERATOR "Unix Makefiles"
CACHE INTERNAL "Cmake generator"
)
return ()
endif ()
endif ()
Unfortunately this solution is not universal:
MSYSTEM=MINGW64 cmake -G "Unix Makefiles" ..
CMake Error: Error: generator : Unix Makefiles
Does not match the generator used previously: Ninja
Either remove the CMakeCache.txt file and CMakeFiles directory or choose a different binary directory.
If you are setting CMAKE_GENERATOR inside PreLoad.cmake than you are loosing ability to use -G cmake option. If you don't need this option, than this solution will be just fine.
PS It is not possible to access -G option value inside PreLoad.cmake as CMAKE_GENERATOR or another option. So it is not possible to add guard case like NOT DEFINED CMAKE_GENERATOR to check whether generator has been provided explicitly using -G option.
I am creating and building a c++ project using cmake from scratch.
The executable requires command line arguments.
I am specifying them in Visual studio.
Is it possible to specify them by default when cmake builds the project (in my CmakeLists.txt for example) ?
So that I (or others) won't need to specify these arguments each time I build the project for the first time (I would want to just run the project without worrying about that but still can change them in visual studio of course if needed) ?
If you are using CMake 3.13 and above you can add the VS_DEBUGGER_COMMAND_ARGUMENTS property to your executable target in order specify those arguments.
Using the following:
Python version 2.7.13, Scons version 2.5.1, Visual Studio 2012 express is installed, but I am not planning to use it.
Code blocks and MinGW-W64-builds-4.3 are installed.
Using Scons to compile C++ code (networkit toolkit) under windows. Scons adds "/Fo" as compile option. This option works only with VC++ and not with MinGW which I am trying to use. Why does Scons add this flag? I have checked my Sconstruct and the reference build.conf files and cannot seem to find this flag getting set explicitly.
My Sconstruct file is here(http://www103.zippyshare.com/v/jSrMapGz/file.html) and the build.conf file is here (http://www11.zippyshare.com/v/aXGQA5b5/file.html).
I want to get the compilation done with "-o" flag for g++, which is the equivalent of /Fo flag for VC++. I just cant figure out where Scons is picking this flag from :(
I am a novice with python and scons. I typically use VC++ 2012 but have to use networkit toolkit for a project, but it uses C11 features. And I cannot update to VC++ 2015/2017 yet.
Thanks for your help!
I checked your SConstruct file, and you are initialising your build environment as
env = Environment()
, which leaves the environment variable "tools" set to its standard value "default". The latter setting means: let SCons figure out which tools/compilers are installed in the current system, and add corresponding Builders to the build environment automatically. Under Windows, SCons will prefer "vc" over "mingw"...this is hardcoded at the moment (we're working on changing this for future versions of the core source).
What you can do, since you know that you have a "mingw" compiler installed that you want to use explicitly, is to tell SCons that you want to work with "mingw" only.
The following example from the page https://bitbucket.org/scons/scons/wiki/SconstructShortMingwWin32 shows the basic recipe for this:
import os
#don't use the default environment
DefaultEnvironment(tools=[])
#create an environment that uses mingw tools
env = Environment(ENV=os.environ, tools=['mingw'])
#the target will be myprogram.exe (in win32)
#the source files will be every file in the
#current directory that matches "*.cpp"
env.Program(target='myprogram', source = Glob('*.cpp'))
For further help and as reference, please consider checking out our User Guide and Man page.
for around 5 consecutive days i have been trying to set up my computer with the c++ environment for programming with libraries such as sdl,glm,opengl. its important for us to be able to run it on unix machines on presentations so im running with cmake.
i finally got it to work with the cmake-gui, i wont even bother trying anymore with any IDE.
i specified my folder project and where to build the binaries, i got a folder "CMakeFiles" along with a txt "CMakeCache", a CMAKE file "cmake_install.cmake" and a file "Makefile". also in my folder "CMakeFiles" there are lots of other folders such as "CMakeTmp", "CompilerIdC", "CompilerIdCXX etc" and in both folders "Compiler*" has each an .exe which doesnt work! so where is my wanted executable?
i opened cmd and navigated to my folder and tried to write "make" as we are supposed to do according to the intruction. alas, it didnt work very well. hoping you could share your wisdom and help a newbie like me!
so what exactly is needed for compiling projects containing additional libraries? so far i have a compiler, Mingw32, the latest CMake and using the cmake-gui for extracting the binaries but gets makefiles.
EDIT:
hrrm. is it only me who gets these kind of problems? i can add that i have look thorough about 10 tutorials and 90% of the steps are similar (if compiling with VS which i tried at first):
Download latest SDL
Make a folder on e.g C:\SDL with two folders, include and lib
Copy the libs and includes from the downloaded SDL
Make new VS project, open VC++ directories and add lib/incl folder on e.g C:\SDL
Add to linker SDL.lib and SDLmain.lib (i made sure they got linked, no problem here)
Change system to WINDOWS (optional if you dont want two windows)
Added include to "additional libraries"
Put the SDL.dll file (which i got from the latest SDL) in my C:\windows\system32(64SysWoW)
and also in my project file.
so what i am actually looking for is gettning the CMake to work, since it generates and builds sources successfully (with the gui) and i feel im closing in. do i need to add any additional libraries from sdl to my compiler mingw32 and/or cmake?
if you run cmake by command:
cmake -G "Visual Studio 14 Win64" path\to\source\dir
you need to run this command to continue(in Visual Studio Command Prompt):
msbuild Project.sln
either if you run cmake:
cmake -G "NMake Makefiles" path\to\source\dir
you need to run this cmd to continue(in Visual Studio Command Prompt):
nmake
You were almost there with Visual Studio. Select Visual Studio as target. Open the generated project in Visual Studio, build it. (just like you alread did). Then, instead of trying to run BUILD_ALL, run a real project that creates an executable, it should also be in that list. Just right click it and 'play' it.
If you still get errors, post them in detail including what you did before the error. Note: a carefully configured cross platform CMake project (aka the CMakeLists.txt) should not require any fiddling with VC++ directories. It should work automagically, especially with well known libs such as SDL.
If I understood it correctly you want to use CMake in your project. I'm using CMake in all my projects. I won't give you exact step-by-step howto, since I use Arch Linux but I used it in Windows 7 too.
To make CMake find the libraries, it is often needed to set up the CMAKE_PREFIX_PATH environment variable so it points to the directories where dependencies of your project are installed.
Set you PATH environment varible so you can invoke you compiler and make just by calling by calling eg. make. I think you need to do than manually for Mingw32, for Visual Studio you can use the "Visual Studio Command Propt" which has these variables already set.
Run CMake with desired generator. To select the generator from command line use the -G switch. You will probably use one of the following (the ... means other options you want to pass to cmake)
For GNU make used in MinGW use cmake -G "MinGW Makefiles" ...
For NMake from visual studio use cmake -G "NMake Makefiles" ...
It is also possible to create a Visual Studio project but I do not recommend it, since it quite difficult to set up automatic builds then. I also had some problems with dependencies when I tried to use VS project.
change directory to your build directory (ie. the one where you called cmake, it contains the CMakeCache file) and run make or nmake
Quoting from "CMake support in Visual Studio":
Visual Studio 2017 introduces built-in support for handling CMake projects. This makes it a lot simpler to develop C++ projects built with CMake without the need to generate VS projects and solutions from the command line. This post gives you an overview of the CMake support, how to easily get started and stay productive in Visual Studio.