The beginning of my issue is that I'm trying to use regular expressions in Cocos2d-x. For whatever reason, std::tr1::regex isn't working with C++98, so I'm trying to use std::regex with C++11 (along with some other C++11 features). This is working with iOS now, since it's really easy to change the version of C++ in Xcode, but I'm having all kinds of trouble getting this to work on Android.
I'm using the r8e version of the NDK with the gnustl_static library. I set the LOCAL_CPPFLAGS += -std=c++11 I've tried setting the toolchain version to clang (in addition to the default). Regardless of the toolchain, I am now able to compile my code, but it still crashes when I try to create a std::regex object std::regex reg1("[a-z][0-3]*"); It seems like some people are able to get C++11 to work with the Android NDK expanded library (not the "minimal C++ runtime support library"), but I can't figure it out. I've read lots of ideas and I've tried most of them, and I've seen some clues, such as the following from CHANGES.html in the NDK docs:
Patched GCC 4.4.3/4.6/4.7 libstdc++ to work with Clang in C++11
I don't know enough about how this all fits together, so could someone point me in the right direction? What am I missing here?
Open your Application.mk file and add following two lines at the end:
APP_CPPFLAGS += -std=c++11
NDK_TOOLCHAIN_VERSION=4.7
Note: As you mentioned that you are using NDK's version r8e the toolchain version you need is 4.7. If it is r9, you can set it to 4.8.
Hope this helps.
Alternatively, if you aren't restricted to using c++'s std::regex, you could try using standard C: regcomp() and regexec() .
Here a sample implementation (http://pubs.opengroup.org/onlinepubs/009695399/functions/regcomp.html):
#include <regex.h>
int match(const char *string, const char *pattern)
{
int status;
regex_t re;
if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB) != 0) {
return(0); /* Report error. */
}
status = regexec(&re, string, (size_t) 0, NULL, 0);
regfree(&re);
if (status != 0) {
return(0); /* Report error. */
}
return(1);
}
In Your android.mk add
LOCAL_CPPFLAGS += -std=gnu++0x
Related
I have recently installed PARI library on ubuntu 16.04. The set of examples provided with the source are running correctly but , if I use "gun", "ghalf", etc., gcc compilation fails with error :
error: ‘gun’ undeclared (first use in this function)
I am new to this library and know very little about it. Can anybody please help me in fixing this error.
This is the code that I am trying to compile :
#include<stdio.h>
#include <pari/pari.h>
int main(void)
{
GEN i,j,k;
pari_init(500000,2);
i=gun;
j=stoi(3);
k=gadd(i,j);
printf("1+3=%s\n",GENtostr(k));
return 0;
}
It looks like you're using code intended for a very old version of PARI. Modern versions use gen_1 rather than gun for the constant 1. With this change,
gcc -o test-pari test-pari.c -lpari && ./test-pari
yields
1+3=4
as desired. Alternatively (not recommended!), if you're trying to port a lot of old code, you could add
#define PARI_OLD_NAMES
before
#include <pari/pari.h>
and the code with work with gun.
After I declared a variable in this way:
#include <thread>
namespace thread_space
{
thread_local int s;
} //etc.
i tried to compile my code using 'g++ -std=c++0x -pthread [sourcefile]'. I get the following error:
example.C:6:8: error: thread-local storage is unsupported for the current target
static thread_local int s;
^
1 error generated.
If i try to compile the same code on Linux with GCC 4.8.1 whit the same flags, i get a functioning executable file. I'm using clang-503.0.40 (the one which comes with Xcode 5.1.1) on a MacBook Pro running OSX 10.9.3. Can anybody explain me what i'm doing wrong?
Thank you!!
Try clang++ -stdlib=libc++ -std=c++11. OS X's outdated libstdc++ doesn't support TLS.
Edit
Ok, this works for the normal clang version but not for the Xcode one.
I did a diff against Apple's clang (503.0.38) and the normal released one and found the following difference:
.Case("cxx_thread_local",
- LangOpts.CPlusPlus11 && PP.getTargetInfo().isTLSSupported() &&
- !PP.getTargetInfo().getTriple().isOSDarwin())
+ LangOpts.CPlusPlus11 && PP.getTargetInfo().isTLSSupported())
So I think this is a bug in Apple's clang version (or they kept it in there on purpose - but still weird, because -v says based on 3.4).
Alternatively, you can use compiler extensions such as __thread (GCC/Clang) or __declspec(thread) (Visual Studio).
Wrap it in a macro and you can easily port your code across different compilers and language versions:
#if HAS_CXX11_THREAD_LOCAL
#define ATTRIBUTE_TLS thread_local
#elif defined (__GNUC__)
#define ATTRIBUTE_TLS __thread
#elif defined (_MSC_VER)
#define ATTRIBUTE_TLS __declspec(thread)
#else // !C++11 && !__GNUC__ && !_MSC_VER
#error "Define a thread local storage qualifier for your compiler/platform!"
#endif
...
ATTRIBUTE_TLS static unsigned int tls_int;
The clang compiler included in the Xcode 8 Beta and GM releases supports the C++11 thread_local keyword with both -std=c++11 and -std=c++14 (as well as the GCC variants).
Earlier versions of Xcode apparently supported C-style thread local storage using the keywords __thread or _Thread_local, according to the WWDC 2016 video "What's New in LLVM" (see the discussion beginning at 5:50).
Seems like you might need to set the minimum OS X version you target to 10.7 or higher.
When I compile the following code containing the design C++11, in Windows7x64 (MSVS2012 + Nsight 2.0 + CUDA5.5), then I do not get errors, and everything compiles and works well:
#include <thrust/device_vector.h>
int main() {
thrust::device_vector<int> dv(10);
auto iter = dv.begin();
return 0;
}
But when I try to compile it under the Linux64 (Debian 7 Wheezey + Nsight Eclipse from CUDA5.5), I get errors:
../src/CudaCpp11.cu(5): error: explicit type is missing ("int"
assumed)
../src/CudaCpp11.cu(5): error: no suitable conversion function from
"thrust::detail::normal_iterator>" to "int"
exists
2 errors detected in the compilation of
"/tmp/tmpxft_00001520_00000000-6_CudaCpp11.cpp1.ii". make: *
[src/CudaCpp11.o] Error 2
When I added line:-stdc++11
in Properties-> Build-> Settings-> Tool Settings-> Build Stages-> Preprocessor options (-Xcompiler)
I get more errors:
/usr/lib/gcc/x86_64-linux-gnu/4.8/include/stddef.h(432): error:
identifier "nullptr" is undefined
/usr/lib/gcc/x86_64-linux-gnu/4.8/include/stddef.h(432): error:
expected a ";"
...
/usr/include/c++/4.8/bits/cpp_type_traits.h(314): error: namespace
"std::__gnu_cxx" has no member
"__normal_iterator"
/usr/include/c++/4.8/bits/cpp_type_traits.h(314): error: expected a
">"
nvcc error : 'cudafe' died due to signal 11 (Invalid memory
reference) make: * [src/CudaCpp11.o] Error 11
Only when I use thrust::device_vector<int>::iterator iter = dv.begin(); in Linux-GCC then I do not get an error. But in Windows MSVS2012 all c++11 features works fine!
Can I use C++11 in the .cu-files (CUDA5.5) in Windows7x64 (MSVC) and Linux64 (GCC4.8.2)?
You will probably have to split the main.cpp from your others.cu like this:
others.hpp:
void others();
others.cu:
#include "others.hpp"
#include <boost/typeof/std/utility.hpp>
#include <thrust/device_vector.h>
void others() {
thrust::device_vector<int> dv(10);
BOOST_AUTO(iter, dv.begin()); // regular C++
}
main.cpp:
#include "others.hpp"
int main() {
others();
return 0;
}
This particular answer shows that compiling with an officially supported gcc version (as Robert Crovella stated correctly) should work out at least for c++11 code in the main.cpp file:
g++ -std=c++0x -c main.cpp
nvcc -arch=sm_20 -c others.cu
nvcc -lcudart -o test main.o others.o
(tested on Debian 8 with nvcc 5.5 and gcc 4.7.3).
To answer your underlying question: I am not aware that one can use C++11 in .cu files with CUDA 5.5 in Linux (and I was not aware the shown example with host-side C++11 gets properly de-cluttered under MSVC). I even filed a feature request for constexpr support which is still open.
The CUDA programming guide for CUDA 5.5 states:
For the host code, nvcc supports whatever part of the C++ ISO/IEC
14882:2003 specification the host c++ compiler supports.
For the device code, nvcc supports the features illustrated in Code
Samples with some restrictions described in Restrictions; it does not
support run time type information (RTTI), exception handling, and the
C++ Standard Library.
Anyway, it is possible to use some of the C++11 features like auto in kernels, e.g. with boost::auto.
As an outlook, other C++11 features like threads may be quite unlikely to end up in CUDA and I heard no official plans about them yet (as of supercomputing 2013).
Shameless plug: If you are interested in more of these tweeks, feel free to have a look in our library libPMacc which provides multi-GPU grid and particle abstractions for simulations. We implemented lambda, a STL-like access concept for 1-3D matrices and other useful stuff there.
All the best,
Axel
Update: Since CUDA 7.0 C++11 support in kernels has been added officially. As BenC pointed our correctly, parts of this feature were already silently added in CUDA 6.5.
According to Jared Hoberock (Thrust developer), it seems that C++11 support has been added to CUDA 6.5 (although it is still experimental and undocumented). This may make things easier when starting to use C++11 in very large C++/CUDA projects, since splitting everything can be quite cumbersome for large projects when you use CMake for instance.
so, I'm trying to compile Gwen in Windows, for use with a project I have coming up. I downloaded the source from Garry's GitHub, and followed his instructions on building the compilation before importing it to Code::Blocks to compile. I import the .cbp file, start compiling, and after a few minutes I get:
Error: '_asm' was not declared in this scope.
The error comes from some code after a line containing #ifdef _WIN32.
Exact file: gwen.cpp, line 49.
More information:
OS: Windows 7 64bit.
Compiler: Latest gcc from the MinGW, 4.7.2 (MinGW32)
I think it is because MinGW doesn't understand the assembler, it should be asm for that compiler. I think this is cause by using _WIN32 instead of WIN32. The former is the platform and the latter is API.
Try changing it to:
void AssertCheck(bool b, const char* strMsg)
{
if (!b)
{
Msg("Assert: %s\n", strMsg);
#ifdef WIN32
MessageBoxA(NULL, strMsg, "Assert", MB_ICONEXCLAMATION|MB_OK);
_asm { int 3 }
#endif
}
}
EDIT: Alternatively you could try Gwork, which is a tidied up version of GWEN.
I wrote a c++ program using boost library in Xcode. Here is my code. It is very simple.
#include <iostream>
#include </usr/local/include/boost/math/special_functions/beta.hpp>
using namespace std;
using namespace boost::math;
int main (int argc, char * const argv[])
{
double a = 100.0;
double b = 100000.0;
double x = 0.3;
double result = beta(a, b, x);
cout << result << endl;
return 0;
}
But when I tried to build it in the Xcode, there popped up a lot of errors related to the library linking stuff. I noticed that the compiler that Xcode was using was "System Default: gcc 4.2". And all other options are gcc or LLVM gcc (I have no idea what this is).
I later tried to compile the file simply using terminal. Weird thing happened. If I compile it with g++, without any extra flags, the compilation completed successfully and the the program could be ran normally; but if I compile it with gcc, there are pages of errors.
So, to sum it up, while using g++, everything is OK; while using gcc, everything is not OK. Since the Xcode is using gcc, the program could not be compiled using Xcode.
(And I kind of need to use the Xcode because this is just a test program, I actually have a much bigger project to handle and I depend on the debugger of Xcode.)
So my question is, WHAT THE HELL is the difference between gcc and g++? Or how can I change the compiler of Xcode to g++?
gcc is a C compiler.
g++ is a C++ compiler.
You're trying to compile C++, ergo, you need to use a c++ compiler.
Googling "Using XCode for c++" brings up lots of results, but this one seemed fairly straightforward and had pictures:
https://www.cs.drexel.edu/~mcs171/Wi07/extras/xCode_Instructions/index.html
The gcc command compiles C files (although you can use -libstdc++) to link C++ files as well but I don't recommend it.
The g++ command works for C++ files which is why it worked in your case.
For XCode you have to change the compiler from GCC to G++ for it to successfully work.