Having trouble compiling the following C++ code on Windows 7:
#include <boost/asio.hpp>
#include <iostream>
void handler1(const boost::system::error_code &ec)
{
std::cout << "5 s." << std::endl;
}
void handler2(const boost::system::error_code &ec)
{
std::cout << "10 s." << std::endl;
}
int main()
{
boost::asio::io_service io_service;
boost::asio::deadline_timer timer1(io_service, boost::posix_time::seconds(5));
timer1.async_wait(handler1);
boost::asio::deadline_timer timer2(io_service, boost::posix_time::seconds(10));
timer2.async_wait(handler2);
io_service.run();
}
I have MinGW installed (gcc 4.8.1) in c:\mingw with my PATH set up correctly. I have downloaded boost and declared environment variable BOOST_ROOT to be the path where it resides. I have gone through the bootstrap and b2 procedure for boost. I now try and compile:
c:\path\to\sandbox> g++ -I%BOOST_ROOT% -o main main.cpp
Gives a bunch of error: '::UnregisterWaitEx' has not been declared errors
I then search a bit and see I may need to link boost_system. So:
c:\path\to\sandbox> g++ -I%BOOST_ROOT% -lboost_system -o main main.cpp
Same errors. Thought I'd try specify library path. Did a search for boost_system and found static libs (libboost_system-mgw48-mt-1_55.a) in %BOOST_ROOT%/stage/lib. So
c:\path\to\sandbox> g++ -I%BOOST_ROOT% -L%BOOST_ROOT%/stage/lib -lboost_system-mgw48-mt-1_55 -o main main.cpp
Same errors. So I search again and see others suggesting appending a -D-D_WIN32_WINNT=0x0601. So
c:\path\to\sandbox> g++ -I%BOOST_ROOT% -L%BOOST_ROOT%/stage/lib -lboost_system-mgw48-mt-1_55 -o main main.cpp -D_WIN32_WINNT=0x0601
And the inevitable errors:
c:\mingw\include\mswsock.h:125:20: error: 'WSAPOLLFD' was not declared in this scope
int WSAAPI WSAPoll(WSAPOLLFD, ULONG, INT);
^
c:\mingw\include\mswsock.h:125:36: error: expected primary-expression before ',' token
int WSAAPI WSAPoll(WSAPOLLFD, ULONG, INT);
^
c:\mingw\include\mswsock.h:125:41: error: expected primary-expression before ')' token
int WSAAPI WSAPoll(WSAPOLLFD, ULONG, INT);
^
c:\mingw\include\mswsock.h:125:41: error: expression list treated as compound expression in initializer [-fpermissive]
Where am I going wrong?
I went ahead and rebuilt Boost again with b2 toolset=gcc --build-type=complete. Same thing happened. Finally, after all that, it turned out all I needed was to put the linking at the end of the command:
C:\path\to\sandbox> g++ -D_WIN32_WINNT=0x0601 -I%BOOST_ROOT% -L%BOOST_ROOT%\stage\lib -o boosttest boosttest.cpp -lwsock32 -lws2_32 -lboost_system-mgw48-mt-d-1_55
C:\path\to\sandbox> boosttest.exe
5 s.
10 s.
The -D_WIN32_WINNT was still necessary and, for anyone who has skipped the other comments, I had to patch winsock.h as detailed http://sourceforge.net/p/mingw/bugs/1980/. And remember to put %BOOST_ROOT%\stage\lib in your PATH so Windows can find the dll at runtime.
Arduous
Related
I am trying to compile the following code ([cuShiftOr]) to a linux box. Original code is running on Visual Studio 2013 in Windows.
My strategy is to compile all .cu files like below:
nvcc -std=c++11 -Icpp11-range -gencode=arch=compute_52,code=\"sm_52,compute_52\" --use-local-env --cl-version 2013 -maxrregcount=0 --machine 64 --compile -cudart static -DWIN32 -DWIN64 -DNDEBUG -D_CONSOLE -D_MBCS -I$HOME/cuShiftOr/CuShiftOr -I$HOME/cuShiftOr/CuShiftOrBenchmark -I$HOME/cuShiftOr/tinyformat -Xcompiler "-fPIC -fexceptions -ffunction-sections -fdata-sections -fpermissive" -ccbin=/opt/cray/pe/craype/2.5.10/bin/CC -c CuShiftOr/device/hybrid.cu -o objs/CuShiftOr/device/hybrid.cu.o
Likewise for the rest.
At the final stage link everything together by running:
nvcc -std=c++11 -Icpp11-range -gencode=arch=compute_52,code=\"sm_52,compute_52\" --use-local-env --cl-version 2013 -maxrregcount=0 --machine 64 -cudart static -DWIN32 -DWIN64 -DNDEBUG -D_CONSOLE -D_MBCS -I$HOME/cuShiftOr/CuShiftOr -I$HOME/cuShiftOr/CuShiftOrBenchmark -I$HOME/cuShiftOr/tinyformat -Xcompiler "-fPIC -std=c++11 -Icpp11-range -fexceptions -ffunction-sections -fdata-sections -fpermissive -Wnon-template-friend" -ccbin=/opt/cray/pe/craype/2.5.10/bin/CC -o CuShiftOrBenchmark.a objs/CuShiftOr/device/hybrid.cu.o objs/CuShiftOr/util/op.cu.o objs/CuShiftOr/device/segment.cu.o objs/CuShiftOr/host.cu.o objs/CuShiftOr/util/timer.cu.o objs/CuShiftOr/util/file.cu.o objs/CuShiftOr/util/generator.cu.o objs/CuShiftOrBenchmark/kernel.cu.o -lm
However that leads me this undefined reference issue:
objs/CuShiftOrBenchmark/kernel.cu.o: In function `void run_benchmark<unsigned int>(std::ostream&, cushiftor::device::Handler<unsigned int>*, long, unsigned int, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
tmpxft_00003ea2_00000000-4_kernel.cudafe1.cpp:(.text._Z13run_benchmarkIjEvRSoPN9cushiftor6device7HandlerIT_EEljiNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_Z13run_benchmarkIjEvRSoPN9cushiftor6device7HandlerIT_EEljiNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x203): undefined reference to `cushiftor::util::op::bit<unsigned int>::size'
collect2: error: ld returned 1 exit status
inside op.cuh it is defined as:
template<typename type>
struct bit {
static const int size = sizeof(type) * 8;
};
template<typename word>
__host__ __device__ __forceinline__ word ones(int m) {
return ~word(0) >> (bit<word>::size - m);
}
and then on kernel.cu we have:
#include "util/op.cuh"
using cushiftor::util::op::bit;
using cushiftor::util::op::bytepack;
using cushiftor::util::op::div_up;
using cushiftor::util::op::round_up;
using cushiftor::util::op::shuffle_up;
Further more compiling with Visual Studio 2013 (which works since the project was made on that) shows some instantiations that I am not sure if g++ is doing e.g:
2>C:/Users/A/Desktop/cuShiftOr/CuShiftOrBenchmark/kernel.cu(209): warning C4244: 'argument' : conversion from 'int64_t' to 'cushiftor::env::datasize_t', possible loss of data
2> C:/Users/A/Desktop/cuShiftOr/CuShiftOrBenchmark/kernel.cu(230) : see reference to function template instantiation 'void benchmark_with_file<word>(cushiftor::device::Handler<word> *)' being compiled
2> with
2> [
2> word=unsigned int
2> ]
2>C:/Users/A/Desktop/cuShiftOr/CuShiftOrBenchmark/kernel.cu(86): warning C4018: '<=' : signed/unsigned mismatch
2> C:/Users/A/Desktop/cuShiftOr/CuShiftOrBenchmark/kernel.cu(132) : see reference to function template instantiation 'void run_benchmark<word>(std::ostream &,cushiftor::device::Handler<word> *,int64_t,cushiftor::env::datasize_t,int,std::string)' being compiled
2> with
2> [
2> word=unsigned int
2> ]
Now my C++11 template knowledge is very limited but I did try to instantiate also inside the kernel.cu by adding:
template class cushiftor::util::op::bit<unsigned int>;
However to no avail... Any tips are very welcomed!
I believe this question is essentially a duplicate of this one. However simply marking it as such with no explanation may be a bit obscure. Therefore I'm going to provide a CW answer in the hopes that someone may improve it or correct me if I am wrong.
A possible MCVE derived from the code is as follows (note that I'm converting to using g++ directly rather than nvcc, as the manifestation and workarounds are the same):
$ cat test.cpp
#include <iostream>
namespace cushiftor {
namespace util {
namespace op {
template<typename type>
struct bit {
static const int size = sizeof(type) * 8;
};
}
}
}
#ifdef FIX2
void f(const int data){
#else
void f(const int &data){
#endif
std::cout << "size of type in bits is: " << data << std::endl;
}
using cushiftor::util::op::bit;
#ifdef FIX1
template <typename T> const int bit<T>::size;
#endif
template<typename word>
void run_benchmark() {
f(bit<word>::size);
}
int main(){
run_benchmark<unsigned>();
}
$ g++ -o test test.cpp
/tmp/ccCW51e3.o: In function `void run_benchmark<unsigned int>()':
test.cpp:(.text._Z13run_benchmarkIjEvv[_Z13run_benchmarkIjEvv]+0x5): undefined reference to `cushiftor::util::op::bit<unsigned int>::size'
collect2: error: ld returned 1 exit status
$ g++ -DFIX1 -o test test.cpp
$ g++ -DFIX2 -o test test.cpp
$
This MCVE was created based on inspection of relevant code in kernel.cu, tinyformat.h, and op.cuh, in the original cuShiftOr project (and paper).
We see that if we compile the code as-is, it generates a similar error to that reported in the question.
Compiling with -DFIX2 demonstrates that taking the item in question (bit::size) as a reference argument is essential to witnessing of the issue.
Compiling with -DFIX1 eliminates the issue, and I believe is the correct approach in this case.
The explanation for this issue seems to be that the compiler may treat the static const member as a compile-time constant, unless it is "used" in the code. ("Used" has a special language-specific meaning here.) If it is "used" in the code, then the compiler must be able to take the address of it (sensible in the case of a reference parameter) and to take the address of it, the class/struct definition is not sufficient. (It is apparently only a declaration even though it appears in the class/struct definition. The declaration is sufficient for usage equivalently to a compile-time constant, but is not sufficient for the case where we wish to take the address of it.)
From here:
If a static data member is of const integral or const enumeration type, its declaration in the class definition can specify a constant-initializer which shall be an integral constant expression (5.19) In that case, the member can appear in integral constant expressions. The member shall still be defined in a namespace scope if it is used in the program
I believe the FIX1 code modification satisfies the bolded requirement above.
With the above preamble, I believe it is valid to mark this as a duplicate.
With respect to the behavior of the original project on windows, I would conjecture that compilers may have leeway in enforcement of this, and may in fact provide referenceable member symbols even when the program does not explicitly define them.
I am trying to build a static library using MinGW.
Everything was going fine until I tried to use the library and got an error saying that add_numbers is an undefined function.
Many other people have had this problem and sorted it out by moving their library to be linked after the source files were included, but that was how I had written my batch file anyway, so that was not of much help.
Here are my sources.
mylib.h
#ifndef MYLIB_H
#define MYLIB_H
int add_numbers(int a, int b, int c);
#endif
mylib.c
#include "mylib.h"
int add_numbers(int a, int b, int c)
{
return a+b+c;
}
I'm building my .a file with the following commands
gcc --std=c89 -c mylib.c -o mylib.o
ar rcs libmylib.a mylib.o
I've also tried with out specifying the standard.
There are no errors or warnings when running this command.
Next, my test program looks like this.
#include <stdio.h>
#include "mylib.h"
int main()
{
printf("The sum of 1, 2, and 3 is %d", add_numbers(1, 2, 3));
getchar();
return 0;
}
And lastly, we build the test with this command.
gcc mylibtest.c -L -lmylib -o test.exe
I've tried moving around those commands into many many different sequences, but always receiving the following error:
C:\Users\Aaron\AppData\Local\Temp\cc0ERpBi.o:mylibtest.c:(.text+0x26): undefined
reference to `add_numbers'
collect2.exe: error: ld returned 1 exit status
E:\my_first_static_library>
Any help would be very appreciated, I've read every tutorial I could find on the art of writing static libraries, as well as a good ten stackoverflow questions.
You are missing a dot after -L:
gcc mylibtest.c -L . -lmylib -o test.exe
std::defaultfloat doesn't seem to be defined in GCC, despite being in the standard (I think it's §27.5.6.4). I've isolated it to this simple program:
// test.cpp
#include <iostream>
int main()
{
std::cout << std::defaultfloat << 1.3;
return 0;
}
This compiles in VC++11. I tried compiling this with g++ 4.7.2 and g++ 4.9.0 using both of these commands:
g++ test.cpp
g++ test.cpp -std=c++11
I also tried an online compile on GCC 4.8.1 here, always with the same result:
user#office-debian:~/Documents/test$ g++ test.cpp -std=c++11
test.cpp: In function ‘int main()’:
test.cpp:5:15: error: ‘defaultfloat’ is not a member of ‘std’
std::cout << std::defaultfloat << 1.3;
Why am I getting this error?
GCC libstdc++ just doesn't support these C++11 manipulators in any of
the versions you've compiled against. A patch was submitted exactly one month ago
Why am I not able to compile my code to c++ 11 and use the srand48 function?
I have a program where I play around with some matrices.
The problem is that when I compile the code with the -std=c++0x flag.
I want to use some c++11 only functions and this is my approach to do so.
It compiles without any problems if I do not specify the c++ version. Like this:
g++ -O2 -Wall test.cpp -o test -g
Please correct me if I have misunderstood what the mentioned flag does.
I run my code on a Windows 7 64-bit machine and compile through cygwin. I use g++ version 4.5.3 (GCC). Please comment if more information is required.
For some unknown reason (even to myself) then all my code is written in one compilation unit.
If the error is caused by a structural error then you should also feel free to point it out. :)
I receive the following errors:
g++ -std=c++0x -O2 -Wall test.cpp -o test -g
test.cpp: In function ‘void gen_mat(T*, size_t)’:
test.cpp:28:16: error: there are no arguments to ‘srand48’ that depend on a template parameter, so a declaration of ‘srand48’ must be available
test.cpp:28:16: note: (if you use ‘-fpermissive’, G++ will accept your code, but allowing the use of an undeclared name is deprecated)
test.cpp:33:28: error: there are no arguments to ‘drand48’ that depend on a template parameter, so a declaration of ‘drand48’ must be available
Here is a sub of my code, it generates the errors shown above.
#include <iostream>
#include <cstdlib>
#include <cassert>
#include <cstring>
#include <limits.h>
#include <math.h>
#define RANGE(S) (S)
// Precision for checking identity.
#define PRECISION 1e-10
using namespace std;
template <typename T>
void gen_mat(T *a, size_t dim)
{
srand48(dim);
for(size_t i = 0; i < dim; ++i)
{
for(size_t j = 0; j < dim; ++j)
{
T z = (drand48() - 0.5)*RANGE(dim);
a[i*dim+j] = (z < 10*PRECISION && z > -10*PRECISION) ? 0.0 : z;
}
}
}
int main(int argc, char *argv[])
{
}
Regards Kim.
This is the solution that solved the problem for me:
First n.m. explained that srand() can not be used when compiling with -std=c++0x.
The correct flag to use is -std=gnu++11 however it require g++ version 4.7+
Therefore, the solution for me was to compile my code with -std=gnu++0x
The compile command = g++ -O2 -Wall test.cpp -o test -g -std=gnu++0x
If you explicitly set -stc=c++03 you will get the same error. This is because drand48 and friends are not actually a part of any C++ standard. gcc includes these functions as an extension, and disables them if standard behaviour is requested.
The default standard mode of g++ is actually -std=gnu++03. You may want to use -std=gnu++11 instead of -std=c++0x, or pass -U__STRICT_ANSI__ to the compiler.
I'm using g++(GCC) 4.7.2 on Ubuntu.
Just trying to figure out how to get the "u8" string literal prefix to compile.
I thought it was "built in" with this version of gcc.
#include <iostream>
#include <string>
int
main ()
{
std::string example1 = u8"Abcd";
std::cout << "Hello, world!\n";
return 0;
}
$ g++ -Wall -B/usr/lib/x86_64-linux-gnu/ helloworld.cpp -o hello helloworld.cpp: In function ‘int main()’: helloworld.cpp:12:26: error:
‘u8’ was not declared in this scope helloworld.cpp:12:28: error:
expected ‘,’ or ‘;’ before string constant helloworld.cpp:12:15:
warning: unused variable ‘example1’ [-Wunused-variable]
I use the "-B" option because that is where my crt1.o and crti.o reside.
It's a c++11 feature, so add -std=c++0x to your command line. That works for me with g++ 4.6.3, on 4.7.2 -std=c++11 might work too