I want to use LEAP Motion in D.
Therefore It doesn't have C library and It has only C++ library.
I tried SWIG 2.0.9 below command.
swig -c++ -d -d2 leap.i
This command output Leap.d, Leap_im.d, Leap_wrap.cxx, Leap_wrap.h.
However, I don't know how to use to wrapper in D and I can't find how to use the wrapper.
Link error displays to use it intact.
How use these wrapper in D2?
And can I use without Leap.cpp (source of Leap.dll)?
Update:
Thanks two answers. and sorry for reply late because of busy.
Say first conclusion I could build Leap sample code on Win64 by following the steps below.
Output wrappers by above command.
Create x64 DLL with VC2010 from Leap_wrap.cxx, Leap_wrap.h, and import Leap.lib(x64).
Compile Leap.d and Leap_im.d with dmd -c.
Build LeapTest.d with Leap.obj and Leap_im.obj
all command is below.
swig -c++ -d -d2 leap.i
dmd -c Leap.d Leap_im.d -m64
dmd LeapTest.d Leap.obj Leap_im.obj -m64
execute LeapTest.exe (require x64 Leap.dll and Leap_wrap.dll)
I could run Leap Program.
But program crach onFrame event callback.
I'll try again on x86 and investigate the causes.
Few helpful links (some information may be outdated):
http://klickverbot.at/blog/2010/11/announcing-d-support-in-swig/
http://www.swig.org/Doc2.0/D.html
http://www.swig.org/tutorial.html
I have never used SWIG personally but my guess based on general knowledge about SWIG:
Leap_wrap.cxx is C++ source file that wraps calls to C++ functions from target library in extern(C) calls
Leap_wrap.h is header file with all extern(C) wrappers listed
Leap_im.d is D module based on Leap_wrap.h with same extern(C) function listed
Leap.d is D module that uses Leap_im.d as an implementation and reproduces API similar to original C++ one.
So in your D code you want to import Leap.d module. Than compile Leap_wrap.cxx to an object file with your C++ compiler and provide D object files, Leap_wrap.o and target library at linking stage. That should do the trick.
P.S. Leap.cpp source should not be needed. All stuff links directly from Leap_wrap.cxx to target library binary.
Go to IRC, either FreeNode, or OFTC, channel #D. In order to help you, we have to see what is in those files. My first guess is that you have to compile both D files, and the C++ file into object files, and link them together. I suppose SWIG is going to flatten the C++ API into bunch of C functions, and that is probably what Leap_wrap.cxx does.
If the LEAP API is not complex (ie. just bunch of simple C++ classes), it may be possible to directly interface with it. Read more about it here: http://dlang.org/cpp_interface.html .
Related
What I need: compile .aidl file to c++ code
What I found: Generating C++ Binder Interfaces with aidl-cpp
AIDL compiler for C++ on Linux Desktop
3.What I did:I had clone the "aidl-cpp" on the second link,after viewing the many files in the project,I was missing.
Some doubt here:
Can I compile this project and use the target to compile my
project?If yes,I need the whole android platformtsource code in my
system path?Because I try to compile one single file main_java.cpp
with g++ commandline , and it returns some "android-base" libs
cannot find.
Or I can write my own cpp file to implement the interfaces defined
in my .aidl files imitate the "aidl-cpp" project.This way I haven't
tried.
What's the right way to meet my need?
You can just use aidl of android sdk build-tools after 29.0.0.
aidl --lang=ndk <input.aidl>
I built Qt from source (dlls) and am trying to build an application that uses the Qt dlls. I don't have a lot of experience with C++ so I'm running into what I'm sure is a very basic issue.
My builds are failing on the includes with errors like so:
Fatal error: QNetworkProxy: No such file or directory
Here is the g++ command I am using (I also used -L to add the correct folder to the lib path, but that also didn't work):
g++ -l..\..\wkqt\bin\QtCore4.dll -l..\..\wkqt\bin\QtNetwork4.dll -l..\..\wkqt\bin\QtWebKit4.dll -I..\include -Ishared -Ipdf -Ilib -Iimage -o ..\bin\wkhtmltopdf.exe pdf\*.cc lib\*.cc image\*.cc shared\*.cc
I tried in Visual Studio as well (assuming it wouldn't build, but I wanted to see if I could at least include the Qt dlls from there properly) and I am getting the same errors. Am I doing something wrong with the way I am compiling with g++? If I am linking with the Dlls properly then what is the proper way to use Qt functions from my code?
To clarify, I am not looking for how to properly use Qt. My question is: what is the proper way to use functions defined in any Dll from native C++ code? I apologize if this is a very basic question, but I'm unable to find a clear answer on Google and I don't have any experience with C++ and including third party libraries for use from C++ code.
DLLs can be used by dynamicly loading them and calling their used functions.
to call the exposed functions first define their syntax in the begining
suppose function is syntax is
BOOL MyFunction(int a,char* pszString)
then define syntax
#typedef BOOL (WINAPI *PMYFUNCTION)(int a,char* pszString)
then make object
PMYFUNCTION pfnMyFunction;
and get valid pointer by calling GetProcaddress after loadlibrarycall
HMODULE hlib= Loadlibrary("c:\\Mylib.dll");
if(hlib)
{ pfnMyFunction = (PMYFUNCTION)Getprocaddress(hlib,"MyFunction"); }
Hope this helps...
I have been running into trouble recently trying to symbolicate a crash log of an iOS app. For some reason the UUID of the dSYM was not indexed in Spotlight. After some manual search and a healthy dose of command line incantations, I managed to symbolicate partially the crash log.
At first I thought the dSYM might be incomplete or something like that, but then I realized that the method calls missing were the ones occurring in C++ code: this project is an Objective-C app that calls into C++ libraries (via Objective-C++) which call back to Objective-C code (again, via Objective-C++ code). The calls that I'm missing are, specifically, the ones that happen in C++ land.
So, my question is: is there some way that the symbolication process can resolve the function calls of C++ code? Which special options do I need to set, if any?
One useful program that comes with the apple sdk is atos (address to symbol). Basically, here's what you want to do:
atos -o myExecutable -arch armv7 0x(address here)
It should print out the name of the symbol at that address.
I'm not well versed in Objective-C, but I'd make sure that the C++ code is being compiled with symbols. Particularly, did you make sure to include -rdynamic and/or -g when compiling the C++ code?
try
dwarfdump --lookup=0xYOUR_ADRESS YOUR_DSYM_FILE
you will have to look up each adress manually ( or write a script to do this ) but if the symbols are ok ( your dSym file is bigger than say 20MB) this will do the job .
I'm experimenting with python functions right now. I've found a way to import python functions into c/c++ code, but not the other way around.
I have a c++ program written and it has a certain function in it. I'd like to "import" the compiled c++ program into my python script and call the c++ function.
For simplicity, say the c++ function is as simple as:
int square(x)
{
return x*x;
}
and the compiled program is named Cprog.
I'd like my python script to be something like:
import Cprog
print Cprog.square(4)
Is this possible? I've searched the internet to no avail and I'm hoping one of you gurus might have a clever way of going about this...
Here is a little working completion of the simple example above. Although the thread is old, I think it is helpful to have a simple all-embracing guide for beginners, because I also had some problems before.
function.cpp content (extern "C" used so that ctypes module can handle the function):
extern "C" int square(int x)
{
return x*x;
}
wrapper.py content:
import ctypes
print(ctypes.windll.library.square(4)) # windows
print(ctypes.CDLL('./library.so').square(4)) # linux or when mingw used on windows
Then compile the function.cpp file (by using mingw for example):
g++ -shared -c -fPIC function.cpp -o function.o
Then create the shared object library with the following command (note: not everywhere are blanks):
g++ -shared -Wl,-soname,library.so -o library.so function.o
Then run the wrapper.py an the program should work.
If you build your program as a shared library/DLL, you could use ctypes to call it.
import ctypes
print ctypes.windll.cprog.square(4) # windows
print ctypes.CDLL('cprog.so').square(4) # linux
You need to create a python module with that function in it. There are three main ways:
Using Swig - this reads your c code and creates a python module from it.
Hand coded using the python c api.
Using Boost::Python (often the easiest way).
This pdf covers 1 and 2. This page will tell you how to use Boost::Python.
You cannot (easily) use a function that is in a c/c++ program - it must be in a static library (which you can also link your c/c++ program against).
EDIT -
Cython Is also worth a mention.
You want to extend python with a C/C++ module. The following Python documentation is a good place to start reading: http://docs.python.org/extending/extending.html
There are a lot of different ways to wrap C++ code to be used in Python. Most are listed on the Python wiki here.
I've found a decently easy way to automate it is to use py++ to automatically generate the wrappers, then compile the generated files. But this is more appropriate for larger projects where wrapping everything by hand is just not very feasible and would cause a maintenence nightmare.
I'm working on a C++ project on GNU/Linux and I'm looking for a way to test the existence and usability of IBM Informix's library with the Autotools - namely, editing a configure.in. I don't have experience with Autotools, so basically I'm picking up from the project's configure.in et al. scripts and copying&changing where I feel needs to be changed. IOW, I've been adapting from the existing text in configure.in.
So far I've been using successfully the AC_CHECK_LIB in configure.in to test whether a certain library both exists and is usable. But this only seems to work with libraries with functions, not e.g. classes. Namely, this fails when testing Informix's libifc++.so library:
AC_CHECK_LIB(ifc++, ITString,
INFORMIX_LIB="-L$INFORMIX_LIB_LOCATION/c++ -lifc++ -L$INFORMIX_LIB_LOCATION -L$INFORMIX_LIB_LOCATION/dmi -L$INFORMIX_LIB_LOCATION/esql -lifdmi -lifsql -lifasf -lifgen -lifos -lifgls -lifglx $INFORMIX_LIB_LOCATION/esql/checkapi.o -lm -ldl -lcrypt -lnsl",
echo "* WARNING: libifc++.so not found!"
INFORMIX_INC=""
INFORMIX_LIB=""
)
I've also tried using other combinations, like ITString::ITString, etc.
I haven't found a "pure" function in Informix's API (i.e., one that isn't contexted in a C++ class). So I'm hoping that either there's a way to use AC_CHECK_LIB in this context, or there's another autoconf/configure.in "command" for this specific use.
Thanks in advance for your feedback.
You've discovered a shortcoming of autotools, but one that can't really be helped. Autotools checks for symbol names in the library binary, and unlike C where symbol names of functions are identical to the function names, C++ "mangles" function's symbol names to accomplish things like function overloading. What's worse is that C++ doesn't really even have a "standard" mangling convention, so different C++ compilers may produce different symbol names for the same function. Thus, autotools can't check for C++ symbol names in a reliable manner.
Does the library you are trying to use have any functions that are declared with extern "C"? This causes the C++ compiler to generate standardized C-style symbol names, and autotools will be able to find them.
I ran into this issue trying to detect gtest and gmock (the Google unit testing and object mocking frameworks) with Autotools, and here's what I came up with:
# gtest has a main function in the gtest_main library with C linkage, we can test for that.
AC_CHECK_LIB([gtest_main], [main], [HAVE_GTEST=1] [TEST_LIBS="$TEST_LIBS -lgtest_main"],
AC_MSG_WARN([libgtest (Google C++ Unit Testing Framework) is not installed. Will not be able to make check.]))
# gmock has no functions with C linkage, so this is a roundabout way of testing for it. We create a small test
# program that tries to instantiate one of gmock's objects, and try to link it with -lgmock and see if it works.
if test "$HAVE_GTEST"
then
saved_ldflags="${LDFLAGS}"
LDFLAGS="${LDFLAGS} -lgtest -lgmock"
AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <gmock/gmock.h>], [testing::Cardinality dummy])],
[TEST_LIBS="$TEST_LIBS -lgmock"] [HAVE_GMOCK=1],
[AC_MSG_WARN([libgmock (Google C++ Object Mocking Framework) is not installed. Will not be able to make check.])])
LDFLAGS="${saved_ldflags}"
fi
There might be a cleaner way of achieving this, but I think your problem is that C++ methods get "mangled" to allow additional information about the method (argument & return types etc) to be encoded. For example; the method int A::foo(void) will get mangled to something like __ZN1A3fooEv.
So you need to find the mangled name of a method in the library. You can do this by using the nm command on Unix-like OSs:
$ nm libifc++.so | grep ITString
It's worth mentioning that the exact mangling format varies across different compilers; and so by embedding a certain compiler's mangled symbol in your configure.in it may not work on other platforms - YMMV.
Note: you can use the c++filt utility to demangle a name back to it's human-readable form; so for the example I gave previously:
$ c++filt __ZN1A3fooEv
A::foo()
See Name Mangling in C++ on Wikipedia for more information.
If the library you are checking for supports pkg-config, this becomes very easy. Here is all I added to my configure.in to check for and enable gtest and gmock:
dnl ************************************
dnl Check for googletest and googlemock
dnl ************************************
PKG_CHECK_MODULES(gtestmock, libgtest >= 0.4.0, libgmock >= 0.4.0)
AC_SUBST(gtestmock_LIBS)
AC_SUBST(gtestmock_CFLAGS)
And then in my Makefile.am somewhere:
sometarget_CXXFLAGS = $(gtestmock_CFLAGS) $(AM_CXXFLAGS)
sometarget_LDADD = $(gtestmock_LIBS)
Pretty trivial, eh?
AC_LANG_CPLUSPLUS
AC_CHECK_LIB(Sockets, main)
Caveat: http://lists.gnu.org/archive/html/autoconf/2006-09/msg00019.html