There are various Go libraries that rely on the cuda.h file and the cuda library (specifically ML libraries). Every time I try to install one of these libraries on Windows, I get an error saying
fatal error: cuda.h: No such file or directory
//#include <cuda.h>
I am aware of what I need to do (link the Cuda library/header files to the go library that I am trying to install), however, I am not sure how to go about doing this especially on windows. I am using GCC and not MSVC for various reasons, but even when I've tried using MSVC, I've had the same issues.
Is there some way that I can link the cuda compiler/header files directly to my Go env or do I need to manually point the go/cgo compiler to the directory holding the Cuda headers and how do I go about doing this?
I've tried asking a few of the developers who make these libraries for help but most of them are linux users so they don't really know. An exhaustive google search has really lead me nowhere so I'm asking here.
I was able to find the answer.
The windows cuda installer installs things by default into a weird path:
C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\include
This path caused a lot of pain for the compiler as a result of the spaces in the folder names. After reinstalling Cuda into C:\CUDA\v8.0 and then appending my CFLAGS and LDFLAGS appropriately in my CGO file I was able to get things to run correctly.
For reference here are the CFLAGS and LDFLAGS that I used to get this to work:
//#cgo windows LDFLAGS:-LC:/cuda/v8.0/lib/x64
//#cgo windows CFLAGS: -IC:/cuda/v8.0/include
import "C"
This was with the github.com/chewxy/cu go library. I also appended the new flags into that library in the cgoflags.go file because the maintainer did not have version 8 or version 9 in there already. I mentioned this to him and he might update it later but for now that's what you have to do.
Related
I'm currently trying to write an app for Raspberry Pi 3B under Rasbpian with aid of Linux Development plugin in Visual Studio 2017 Community. I managed to successfully deploy 'Blink' example, nobly attached by Microsoft folks, according to tutorial, and that went well. I even made some transmission over SPI thanks to wiringPi library. Then I would like to add some GUI to my app, so that one could, for example, make some transmission on click of a button on screen.
IntelliSense hinted me, that, in fact, there is gtk-3.0 library present in toolset. It seems that libraries are being copied from target device on every connection or so and I installed gtk on my Raspberry. So I added a simple line to this Blink example:
#include <gtk-3.0/gtk/gtk.h>
On compilation attempt, of course there was nearly 4k errors. Well, enough said, with a little hint from this old tutorial and a bit of trial and error, I managed to add this set of links under Debugging/Project properties/Configuration properties/VC++ directories/Header files directories:
Everything goes in promising direction, as errors number diminished from 4k to just one:
gtk-3.0\gtk\gtk.h: No such file or directory
No matter that this file is ACTUALLY in this location:
Regardless of combination of links in configuration above and using statement composition, compiler (?) can't find this damn file.
Please Halp
EDIT
I just confirmed, that it is indeed problem with target configuration. This is bad or good, depending on point of view. Good, because there is probably all good with VS setup. Bad, because I don't know a thing about compiling things under Linux.
On target (Raspberry Pi 3B) all ingredients for compilation are copied by Linux Development plugin. So in Terminal I executed line:
g++ main.cpp -o Blink2onRPi
and got
main.cpp:4:21: fatal error: gtk/gtk.h: no such file or directory
Now, I altered include line in main.cpp on target RPi, to this:
#include <gtk-3.0/gtk/gtk.h>
And now its missing <gdk/gdk.h>! When this change is made on host windows device - same result, but in VS.
As I dealt with similar problem in VS, upon setting links for IntelliSense (now apparently they're for this purpose), now probably similar dependencies have to be set somewhere on Raspbian. But where?
EDIT2
Upon execution of:
g++ main.cpp -o Blink2onRPi `pkg-config --cflags --libs gtk+-3.0`
on target RPi there is no more GTK-related errors, just wiringPi (also present in project) undefined references. It raises two possible questions:
1) How can I setup wiringPi on RPi so that the project could be manually compiled on target and
2) How/where add above line to Visual Studio, so it execute remotely with all GTK dependencies added properly on target
Researching stock present wiringPi library (as this is Blink led example for cross-compile Linux Development) I've found, that in Project Properties/Linker/Input/Library Dependencies there is mysterious entry:
wiringPi
Just that, nothing more. After removing this entry, on compilation pops out same errors as before on target (which apparently lacks proper wiringPi setup) - undefined references (not mensioned any missing headers). Can this be relevant for the case? If so, how could I add there such entry which would deal with missing GTK dependencies?
TL;DR
Use screenshot below to know where to add pkg-config calls in VS configuration so that it forwards it to the compiler and linker on the target.
Thanks to #zaguoba for providing these.
ORIGINAL ANSWER:
The list of directories to include is provided by pkg-config. For example pkg-config --cflags-only-I gtk+-3.0 will give you the list of include directories required. Those are the ones you need to add to the directories where VC++ wil look at include files. If you add the relative path you use in the #include, to one of those paths, you are able to find the file.
Example:
If you add to the directories C:\Program Files\foo\bar\gtk+-3.0
and have in your C file:
#include <gtk/gtk.h>
then the compiler will look for C:\Program Files\foo\bar\gtk+-3.0\gtk\gtk.h.
EDIT:
This all means the 'file not found' errors are because you're really building on the target and the target has no idea what C:\Program Files\... means. Those should be paths on the target filesystem, where the compiler is called. And this is exactly what pkg-config provides.
The copy of those files on the Windows machine filesystems is merely for Intellisense use, not for compiler use.
EDIT 2:
So that's that Visual Studio 2017 Community Linux Development plugin is what need to be undestood. It's not for cross compilation from Windows to Linux, istead it merely synchronizes code to the Windows host (for Intellisense use), but builds on the target. This means that all the paths and commands are Linux paths and commands, run on the target.
Here's the OP working configuration:
With that setup, you should
#include <gtk\gtk.h>
instead of
#include <gtk-3.0\gtk\gtk.h>
Alternatively remove all those VC++ directories/Header files directories, and just keep one of them that ends with include/ instead of listing up all the sub directiores.
I am using the MinGW-w64 installer found here:
https://mingw-w64.org/doku.php/download/mingw-builds
Installing to a directory creates a folder called mingw32 or mingw64 that contains the compiler. I already know that the additional batch script, HTML link, and uninstall executable in the same directory can be deleted.
The mingw32/64 folder contains these folders:
bin
etc
include
lib
libexec
licenses
opt
share
i686-w64-mingw32 (mingw32) or x86_64-w64-mingw32 (mingw64)
I only wish to compile with C and nothing else. So what files can I delete in order to reduce the file count because the compiler contains files for Ruby, Fortran and other languages which as I stated, I don't need it.
Why are people still using Mingw or Mingw64 instead of TDM-GCC ? You have to rely on the default builds or build it yourself from source. Trying to install it on your own terms sucks.
TDM-GCC on the other hand, you can specify where and which components to install as you wish. You can upgrade or remove it without any worries. It's more fast, easy,modern and equivelant these days.
Now for your question, you can download and install TDM-GCC by it's installer. I don't really think you need any further instructions as a 5 year old would understand how to use it. Just select only the components required for c.
If you don't understand,I would gladly help you more if needed. ^_^
If you want a smaller GCC toolset, try MinGW Distro.
Scroll down to "How To Build Your Own Distro", download components-14.1.7z, extract it, extract binutils 2.27 and GCC 6.3.0 inside the same folder. The total size is about 270MB.
as far as i know the minimum are yours
1, bin
5. libexec
not all tools in bin you may need but generally i would hold both of those dirs
you also ned libraries and headers if you want to build abainst standard c library and windows.h, so
include
lib
is also needed (hovever part of it may contain also headers and libraries for c++ standard library) all those main 3 libs are kinda mixed there afaik so it might be a bit hard to find what comes for what
I hope this is a basic question. I am trying to build a Go package which includes functions from a library written in C. The structure is basically as follows:
package too
/*
#cgo LDFLAGS: -L/usr/local/lib include -lbar
#include mybar.h
*/
import "C"
func MyGoWrapper () {
C.orig_func()
}
Running go build foo.go fails with an "undefined reference" for orig_func. Note that the header is mybar.h; I created a prototype for orig_func that was not included in the original library. Do I need to recompile the library first, including this header file, before it will link with the Go build? Or am I misunderstanding something else entirely?
When linking against an external library, you do need to separately compile it for your target architecture. cgo can't replace the configure/make (or whatever) to compile the library; it only knows how to build a few .c files in your package directory, and a library's build process might be more complex.
I'm less sure of how to accomplish the larger task of linking in an external library when cross-compiling (and I'm not sure what you've already done). The (closed) Go bug on cross-compilation with cgo looks useful here. You may want to build the Go toolchain with some environment variables set that are described in godoc cmd/cgo:
To enable cgo during cross compiling builds, set the CGO_ENABLED
environment variable to 1 when building the Go tools with make.bash.
Also, set CC_FOR_TARGET to the C cross compiler for the target. CC will
be used for compiling for the host.
After the Go tools are built, when running the go command, CC_FOR_TARGET
is ignored. The value of CC_FOR_TARGET when running make.bash is the
default compiler. However, you can set the environment variable CC, not
CC_FOR_TARGET, to control the compiler when running the go tool.
CXX_FOR_TARGET works in a similar way for C++ code.
The bug also mentions someone who uses -ldflags="-extld=$(CC)" (where $(CC) is the name of the cross-compiler they want to use).
In your example code there's an explicit -L/usr/local/lib and I don't think that'll work: I think when you build libraries for the target, you're going to want to put them in a directory distinct from the lib for your host arch. For example, this ARM cross-compilation HOWTO uses a /usr/local/arm-linux prefix or install_root in some places.
I am trying to add C Flags for a particular package to CMAKE_C_FLAGS. But I do not know how to find the C flags for the package using cmake. Does anybody know how
There is no general way (cross platform) to get the correct cflags for a certain package, for windows for example you have no way to check even if the package is installed at all since there is no default location. In unix systems you can expect to find cflags for a certain package by running
pkg-config --cflags packagename
Cmake usually has specific scripts to find package and build correct compile flags for them, which fall back to pkg-config if it is available and the package has no specific script (for example, if its unknown by Cmake). See
http://www.cmake.org/Wiki/CMake:How_To_Find_Libraries
for details.
In your case you probably have to supply an ad-hoc recipe for libxml2 package. Other users wrote them and shared, you can find a lot by searching google for "libxml2 cmake". Actually, libxml2 is the one used as example on the same page I linked before on "how to write a custom recipe for a library that is unknown by cmake"
I'm a complete beginner to Apple's Xcode, but I have followed the Xcode documentation and the advice of a few related questions without success.
I installed GMP to /usr/local/bin, wrote a short program using the library, and compiled with gcc main.c -lgmp. It compiled with no warnings or errors, and the executable worked flawlessly.
I started a new Xcode project (Command Line Tool; Type: C), copied the code to the newly created main.c, and opened the project build settings. From there I set Linking > Other Linker Flags to -lgmp and Search Paths > Library Search Paths to /usr/local/bin. However, the build fails with the preprocessor error "Gmp.h: No such file or directory".
I have tried almost every header imaginable:
#include "gmp.h"
#include <gmp.h>
#include "gmp"
#include "libgmp.a" . . .
This has been my main obstacle over the last three months which has prevented me from learning C. Any help leading me to an eventual solution would be greatly appreciated.
There's a few things you have to set up in your Xcode project. For example, I have gmp installed in /opt/gmp/5.0.2 and I will use that as an example. The actual library is installed into /opt/gmp/5.0.2/lib and the header files into /opt/gmp/5.0.2/include. When installing the library setting the --PREFIX flag to /opt/gmp/5.0.2 would handle this automatically. If you don't set this flag the prefix is usually set to /usr/local by default.
The Other Linker Flags looks right, it should be the name of the library.
Set the Header Search Path to the include directory, in my case /opt/gmp/5.0.2/include.
Set the Library Search Path to the lib directory, in my case /opt/gmp/5.0.2/lib.
Since the header search path has been set, you should now be able to include the header file like this:
#include <gmp.h>
Of course, replace /opt/gmp/5.0.2 with the PREFIX path you used when you installed gmp.
Lastly, you typically don't install libraries to /usr/local/bin, you would install to /usr/localand let any binaries be installed into bin while libraries like these would be installed into lib. Of course any path scheme would work, I usually recommend /opt/<project-name>/<version-number> since it allows me to keep better track of what I have installed and have multiple versions of the same libraries and tools without having to deal with collisions.
I have updated my system from snow leopard to mountain lion and had to install gmp.
First of all I have installed Xcode CommandLineTools set.
Secondly, installed Homebrew. Then with it I have done steps in this topic: https://apple.stackexchange.com/questions/38222/how-do-i-install-gcc-via-homebrew
In my last step, made changes to an xcode project as colleague Marcus Karlsson told.
It's finally working! Very big Thank You :)