Basically, I have a cython code where i want to call C's inline assembly. I tried below:
cdef extern from *:
"""
#include <stdio.h>
void print_endln(){
asm("nop");
}
"""
void print_endln()
print_endln()
But I get below error:
ids.obj : error LNK2001: unresolved external symbol asm
Location\iaa.cp39-win_amd64.pyd : fatal error LNK1120: 1 unresolved externals
error: command 'C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29910\bin\HostX86\x64\link.exe' failed with exit code 1120
My OS is windows 10 x64, python version Python 3.9.1 (tags/v3.9.1:1e5d33e, Dec 7 2020, 17:08:21) [MSC v.1927 64 bit (AMD64)] on win32
I compile the code as python setup.py build_ext --inplace && python program.py
Is there something wrong I am doing?
Related
Consider the following CUDA program, in a file named foo.cu:
#include <cooperative_groups.h>
#include <stdio.h>
__global__ void my_kernel() {
auto g = cooperative_groups::this_grid();
g.sync();
}
int main(int, char **) {
cudaLaunchCooperativeKernel( (const void*) my_kernel, 2, 2, nullptr, 0, nullptr);
cudaDeviceSynchronize();
}
This program needs to be compiled with -rdc=true (see this question); and needs to be explicitly linked against libcudadevrt. Ok, no problem... or is it?
$ nvcc -rdc=true -o foo -gencode arch=compute_61,code=sm_61 foo.cu -lcudadevrt
nvlink error : Undefined reference to 'cudaCGGetIntrinsicHandle' in '/tmp/tmpxft_000036ec_00000000-10_foo.o'
nvlink error : Undefined reference to 'cudaCGSynchronizeGrid' in '/tmp/tmpxft_000036ec_00000000-10_foo.o'
Only if I explicitly add the library's folder with -L/usr/lib/x86_64-linux-gnu, is it willing to build my program.
This is strange, because all of the CUDA libraries on my system are in that folder. Why isn't NVCC/nvlink looking in there?
Notes:
I'm using Devuan GNU/Linux 3.0.
CUDA 10.1 is installed as a distribution package.
An x86_64 machine with a GeForce 1050 Ti card.
NVCC, or perhaps nvlink, looks for paths in an environment variable named LIBRARIES. But - before doing so, the shell script /etc/nvcc.profile is executed (at least, it is on Devuan).
On Devuan 3.0, that file has a line saying:
LIBRARIES =+ $(_SPACE_) -L/usr/lib/x86_64-linux-gnu/stubs
so that's where your NVCC looks to by default.
You can therefore do one of two things:
Set the environment variable outside NVCC, e.g. in your ~/.profile or ~/.bashrc file:
export LIBRARIES=-L/usr/lib/x86_64-linux-gnu/
Change that nvcc.profile line to say:
LIBRARIES =+ $(_SPACE_) -L/usr/lib/x86_64-linux-gnu -L/usr/lib/x86_64-linux-gnu/stubs
and NVCC will successfully build your binary.
I installed CUDA 7.0 as described here on Ubuntu 14.04. I look at matrix mul example, if I start executable file matrixMul that runs, but if I try to compile it gives me error on libraries.
i.e
user#Mars:~/Documenti/Bello/NVIDIA_CUDA-7.0_Samples/0_Simple/matrixMul$ nvcc matrixMul.cu
matrixMul.cu:36:30: fatal error: helper_functions.h: File o directory non esistente
#include <helper_functions.h>
^
compilation terminated.
The problem was caused by trying to compile the sample using nvcc without the correct compiler options, rather than with the supplied makefile. Using the makefile allowed the compilation to work successfully.
I have followed all steps mentioned in Compiling the SDK for HTML5 to compile the Minko framework to HTML5.
When I run the batch file build_html5.bat, i have this error
000000000000000), RtlUserThreadStart() + 0x21 bytes(s)
clang++.exe: error: clang frontend command failed with exit code 255 (use -v to see invocation)
ERROR root: compiler frontend failed to generate LLVM bitcode, halting
mingw32-make1: *** [obj/html5/release/Picking.o] Error 1
mingw32-make: *** [minko-framework] Error 2
Here is my Emscripten conf :
LLVM_ROOT='C:/Program Files/Emscripten/clang/e1.30.0_64bit'
EMSCRIPTEN_NATIVE_OPTIMIZER='C:/Program
Files/Emscripten/clang/e1.30.0_64bit/optimizer.exe'
NODE_JS='C:/Program Files/Emscripten/node/0.12.2_64bit/node.exe'
PYTHON='C:/Program Files/Emscripten/python/2.7.5.3_64bit/python.exe'
EMSCRIPTEN_ROOT='C:/Program Files/Emscripten/emscripten/1.30.0'
MINGW_ROOT='C:/Program Files/Emscripten/mingw/4.6.2_32bit'
JAVA='C:/Program Files/Emscripten/java/7.45_64bit/bin/java.exe'
Im on windows 7 64 bit.
Anyone know what causes this error and how can I resolve it?
This is a known problem with Emscripten 1.30, it should be resolved in future versions. For the moment, stick to Emscripten 1.29.
I'm implementing a program by using dynamic parallelism. Whenever I'm compiling the code, it is throwing fatal error as follows:
ptxas fatal : Unresolved extern function 'cudaGetParameterBuffer'
Compiling as below:
nvcc -o dyn_par dyn_par.cu -arch=sm_35
How to resolve it?
The cudaGetParameterBuffer is part of the cudadevrt library which you need to specify in your compiler command and specify --relocatable-device-code as true
nvcc -o dyn_par dyn_par.cu -arch=sm_35 -lcudadevrt --relocatable-device-code true
Have a look at the CUDA Dynamic Parallelism Programming Guide from Nvidia (Page 21 describes the above) for more information
I am connecting the Mysql using c program in eclipse, I am using CYGWIN compiler to compile program. I have installed the mysql c connector and added the include files to the compiler and linker
but i am getting error
**** Build of configuration Debug for project DbConnectionC ****
make all
Building file: ../connection.c
Invoking: Cygwin C Compiler
gcc -I"C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include" -include"C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\include\mysql.h" -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"connection.d" -MT"connection.d" -o "connection.o" "../connection.c"
cygwin warning:
MS-DOS style path detected: D:\java\workspace\DbConnectionC\Debug
Preferred POSIX equivalent is: /cygdrive/d/java/workspace/DbConnectionC/Debug
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
../connection.c: In function `main':
../connection.c:57: warning: char format, different type arg (arg 2)
../connection.c:57: warning: char format, different type arg (arg 2)
../connection.c:61: warning: char format, different type arg (arg 2)
../connection.c:61: warning: char format, different type arg (arg 2)
Finished building: ../connection.c
Building target: DbConnectionC.exe
Invoking: Cygwin C Linker
gcc -L"C:\Program Files (x86)\MySQL\MySQL Connector C 6.0.2\lib\opt" -o "DbConnectionC.exe" ./connection.o -llibmysql.lib -lmysqlclient.lib
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld: cannot find -llibmysql.lib
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld: cannot find -lmysqlclient.lib
collect2: ld returned 1 exit status
make: *** [DbConnectionC.exe] Error 1
makefile:29: recipe for target `DbConnectionC.exe' failed
**** Build Finished ****
Please help me on this
thanks in advance
In the first part you have some warnings about possible problems:
../connection.c:39: warning: implicit declaration of function `exit'
This means function exit() is not declared, your source needs an #include <stdlib.h>
../connection.c:46: warning: control reaches end of non-void function
You don't return a value at the end of main(), add a return 0; if the program succeeds.
In the second part are linker warnings:
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld: cannot find -llibmysql.lib
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/bin/ld: cannot find -lmysqlclient.lib
which means the linker needs a path to the libraries or the libraries do not exist or the library names are misspelled.
One possible solution is using -lmysql -lmysqlclient instead of -llibmysql.lib -lmysqlclient.lib, but I'm not that familiar with Windows.
Having said that, I suggest strongly, you look at https://stackoverflow.com/tags/c/info and look at some book links.