I am trying to run a code which compiles some c++ codes using mex.
I have set up mex with Microsoft Visual C++ 2010.
But when I execute the line
mex -O fconv.cc -o fconv
I get the error
compile
Usage:
MEX [option1 ... optionN] sourcefile1 [... sourcefileN]
[objectfile1 ... objectfileN] [libraryfile1 ... libraryfileN]
Use the -help option for more information, or consult the MATLAB API Guide.
C:\PROGRA~1\MATLAB\R2011A\BIN\MEX.PL: Error: Unrecognized switch: -o.
I have googled a lot but couldn't find anything of use. It would be great if you someone could help me out here. I have very limited knowledge of using mex.
From the R2013a docs for mex (and current version), there is no -o option, but there is -output:
-output resultname
Create binary MEX-file named resultname. Automatically appends the appropriate MEX-file extension. Overrides the default MEX-file naming mechanism.
BTW, the big O option (-O) is on by default unless you use -g.
Keep in mind that mex is not a compiler, but a frontend to the compiler. It has very different syntax from what you might be used to for a compiler.
Related
Before you asked, yes i did look this up FOR DAYS. Im completely stuck... I'm using MINGW32 (my shortcut says MSYS) to compile my c and cpp code. For about 2 or 3 days now I have been getting strange errors. (below) It was working JUST FINE before. I even ran the same code i've compiled before and it gave the same error. I then go into DevC++ and open then compile an it works just fine.
ERRORS:
namespace: command not found
using: command not found
syntax error:
int main(){
(sometimes it gives me a big unreadable mess)
I'm really stuck... I dont want to have to switch to DevC++... I like to use my own text editor and compile in a command line.
From your errors namespace: command not found and using: command not found says to me that you aren't compiling the code with an appropriate compiler.
For reference in MinGW32 toolchain:
gcc.exe = C
g++.exe = C++
You may find it useful to take a look at what the IDE's actualy do with your compiler.
My current IDE allows me to see all the commands that it runs to build my project:
C:/mingw32/bin/g++.exe -c "C:/MyProgram/main.cpp" -g -O0 -std=c++14 -Wall -o ./Obj/main.cpp.o -I. -IDependencies/Something/include
So lets examine what this does.
My current toolchain is MinGW32 which is located in C:/mingw32/bin/g++.exe
g++ is our c++ compiler so we call g++.exe and we pass the following switch:
-c "C:/MyProgramm/main.cpp"
This tells my compiler to compile the main.cpp from my project directory. then my IDE adds a few additional command line switches. For the purpose of the answer I will only consider -o. This tells us the output file from our code main.cpp into an output file.
The reason we produce such a file is to save us time compiling so that we do not have to compile the same file twice without making changes to it. We perform this step on each of our files creating a collection of .o files.
The new file is then saved in "C:/MyProgramm/Obj/main.cpp.o"
Which means that your command line function will look something like this:
C:/mingw32/bin/g++.exe -c "<my project directory>/<file>.cpp" -o ./Obj/<file>.cpp.o
I would recommend that you read up on documentation for the g++ function and learn from different IDE's as you will soon find that you need to do more advanced things with your compiler.
For example to enable features from c++14 I add -std=c++14
*Edited to reflect feedback.
I was trying to figure out how to link Fortran and C++ code, and one of the tutorials had written 2 programs, one in C++ in a file named testC.cpp, and the other in Fortran in a file named testF.f but I need to input the following compilation instructions:
gfortran -c testF.f
g++ -c testC.cpp
g++ -o test testF.o testC.o -lg2c
Problem is, I'm working in an IDE called Bloodshed Dev-C++ so I have no idea how to do this. I tried going in compiler options and in the general section I appended those instructions in the option "add the following commands when calling the compiler". Doesn't work.
Maybee you need use custom Makefile. Project->project options. Or include *.mak files
I was using flex and bison to build a simple calculator project I cloned from Github.
But after I typed make in terminal, I got the following message:
gcc -o calc calc.tab.c lex.yy.c -lfl
calc.y:48:1: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
main() {
^~~~
1 warning generated.
ld: library not found for -lfl
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [calc] Error 1
How could I resolve this problem?
let me guess, trying to use flex on OS/X?
Try -ll instead of -lfl
Using Flex on OS/X
So yea, the flex library name on OS/X is just arbitrarily different for some reason. OS/X is not exactly Linux, but it's pretty close. You have some options here.
You can just simply have a separate build system and source files for OS/X. Certainly Apple might like that with their pushing XCode, objective-C and not much interoperability.
You can build vs Linux and then engage with Mac Ports and Homebrew.
You can create your project using autotools. That's not an awesome link, learning this system is rough going, but it's a standard thing for Linux for sure. This will actually work, I find if you have the patience for it, OS/X is close enough that autotools based builds will work on it.
Lately, I've been turned on to Cocoapods, which I believe to be an attempt to join the open source community and XCode. It's kind of half 1 and 3 sorta with an emphasis on modularizing the external source and getting it compiled into a .app (via Xcode).
warning: type specifier missing, defaults to 'int'
mean that you should declare return type for main function. Place int in function difinition.
ld: library not found for -lfl
flag -l mean that compiller must use libfl.a to build programm. As #waTeim said above, for Mac OS you can use libl.a instead, but this lib can be not exist alse. There is another way is to place
%option noyywrap
at the top of flex *.l file. In this case you can compile without additional libs.
I am learning from The C++ Primer. One of the exercises is to compile a program with arguments in main(). For this I am trying to use mac terminal.
I need to compile a C++11 Unix executable file named main which takes f as an argument. I am using Xcode 4.6.3 on OS X Lion.
I compiled the program with clang++ -std=c++11 -stdlib=libc++ main.cpp -o main.
But don’t know what to do next.
I found -frecord-gcc-switches while searching compiler options on google. It does what I need to do. Is there a clang version of this?
Please use simple language. I have never used command line before. I tried going through the clang manual but a lot of it is out of my depth.
If the compiler didn't complain about anything, you should have a fresh new file named main in the same directory as the source file, and you can run it from the command line using ./main -f or the like.
I am trying to integrate CUDA and openCV in a project. Problem is openCV won't compile when NVCC is used, while a normal c++ project compiles just fine. This seems odd to me, as I thought NVCC passed all host code to the c/c++ compiler, in this case the visual studio compiler.
The errors I get are?
c:\opencv2.0\include\opencv\cxoperations.hpp(1137): error: no operator "=" matches these operands
operand types are: const cv::Range = cv::Range
c:\opencv2.0\include\opencv\cxoperations.hpp(2469): error: more than one instance of overloaded function "std::abs" matches the argument list:
function "abs(long double)"
function "abs(float)"
function "abs(double)"
function "abs(long)"
function "abs(int)"
argument types are: (ptrdiff_t)
So my question is why the difference considering the same compiler (should be) is being used and secondly how I could remedy this.
In general I would recommend keeping separation between host code and CUDA code, only using nvcc for the kernels and host "wrappers". This is particularly easy with Visual Studio, create your project as normal (e.g. a Console application) and then implement your application in .cpp files. When you want to run a CUDA function, create the kernel and a wrapper in one or more .cu files. The Cuda.rules file provided with the SDK will automatically enable VS to compile the .cu files and link the result with the rest of the .cpp files.
NVCC passes C++ code through to the host compiler, but it has to first parse and understand the code. Unfortunately, NVCC has troubles with STL. If at all possible, separate code that makes use of STL into .cpp files and have those compiled with Visual Studio (without passing them first through NVCC).
Compile the .cu code as a library and then link it to the main program. I suggest to use cmake as it makes the process a breeze
There's a project hosted at cuda-grayscale that shows how to integrate OpenCV + CUDA together. If you download the sources check the Makefile:
g++ $(CFLAGS) -c main.cpp -o Debug/main.o
nvcc $(CUDAFLAGS) -c kernel_gpu.cu -o Debug/kernel_gpu.o
g++ $(LDFLAGS) Debug/main.o Debug/kernel_gpu.o -o Debug/grayscale
It's a very simple project that demonstrates how to separate regular C++ code (OpenCV and stuff) from the CUDA code and compile them.
So there's no easy way to use nvcc to compile your current C++ code, you have to write wrappers and compile them using nvcc, while you compile the rest of your code using g++ or what-have-you?