a.cpp:
#include <iostream>
int main()
{
std::cout << "hello world" << std::endl;
return 0;
}
cmd input:
arm-none-eabi-g++ -specs=nosys.specs a.cpp
cmd output:
/usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/lib/thumb/nofp/libstdc++.a(random.o): in function `std::(anonymous namespace)::__libc_getentropy(void*)':
/build/arm-none-eabi-gcc/src/gcc-12.2.0/libstdc++-v3/src/c++11/random.cc:179: undefined reference to `getentropy'
/usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/lib/thumb/nofp/libstdc++.a(random.o): in function `std::random_device::_M_init(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
/build/arm-none-eabi-gcc/src/gcc-12.2.0/libstdc++-v3/src/c++11/random.cc:452: undefined reference to `getentropy'
/usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/lib/thumb/nofp/libc.a(lib_a-arc4random.o): in function `_rs_stir':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/nofp/newlib/libc/stdlib/../../../../../../../newlib-4.2.0.20211231/newlib/libc/stdlib/arc4random.c:89: undefined reference to `getentropy'
collect2: error: ld returned 1 exit status
I don't know why arm-none-eabi-g++ compilation fails, if I use arm-none-eabi-gcc to compile C language, it can be compiled successfully. Is there some missing parameter that is causing the compilation to fail?
I had a look at the official GCC Bug List where this problem is mentioned but it is marked as resolved.
GCC Bug Description
Related
I found this code in a tutorial
http://www.penguinprogrammer.co.uk/c-beginners-tutorial/introduction/
// This line is necessary to be able to output information to the screen
#include <iostream>
// The program starts here and carries on line by line
int main(){
// Create two integers a and b containing 10 and 5
int a = 10;
int b = 5;
/* Add them together and store the result in another
integer called sum */
int sum = a + b;
// Output the sum to the screen
std::cout << sum << std::endl;
// End the program and send a value of 0 (success) back
// to the operating system
return 0;
}
I want to compile it
Have installed clang by doing
apt-get install clang
Compiling by doing
clang -x c++ tutorial.cpp
error
/tmp/tutorial-aa5f7a.o: In function `main':
tutorial.cpp:(.text+0xa): undefined reference to `std::cout'
tutorial.cpp:(.text+0x34): undefined reference to `std::ostream::operator<<(int)'
tutorial.cpp:(.text+0x3a): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
tutorial.cpp:(.text+0x46): undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))'
/tmp/tutorial-aa5f7a.o: In function `__cxx_global_var_init':
tutorial.cpp:(.text.startup+0x13): undefined reference to `std::ios_base::Init::Init()'
tutorial.cpp:(.text.startup+0x19): undefined reference to `std::ios_base::Init::~Init()'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Use clang++ tutorial.cpp - the -x c++ is useful if you only want to compile the source file, using -c, but if you are also linking the application into an executable, you want clang to know that you are linking a C++ application, and add the c++ libraries to the link command (if you want to see what clang actually does, add the -v option.
I have created a simple C++ application. I can compile it, and it works fine. But now I need to load the library dynamically, and I have added dlfnc.h to my project and added some more code:
#include <iostream>
#include <dlfcn.h>
void *mylib;
int eret;
using namespace std;
int main() {
mylib = dlopen("mylib.so", RTLD_LOCAL | RTLD_LAZY);
eret = dlclose(mylib);
cout << "!!!Hello, World!!!" << endl; // Prints !!!Hello, World!!!
return 0;
}
Compiling:
cd ~/workspace/LinuxGcc/src
g++ LinuxGcc.cpp
And I got a compilation error:
/tmp/ccxTLiGY.o: In function `main':
LinuxGcc.cpp:(.text+0xf): undefined reference to `dlopen'
LinuxGcc.cpp:(.text+0x25): undefined reference to `dlclose'
collect2: error: ld returned 1 exit status
dlfcn.h exist in /usr/include/.
Where is the problem?
From dlopen(3):
Link with -ldl.
so
g++ LinuxGcc.cpp -ldl
will be OK.
The solution is very simple. Add the -ldl flag for linking.
In case of the Bazel build system, linkopts = ['-ldl'].
Here's my code. I'm just testing Boost::process so I'll be able to use it if/when I need to. I don't know why I'm getting the linking error that I am getting. I'm a rather novice C++ programmer. I know the concepts, but I make frequent errors in practice and am bad at debugging. I appreciate any help I can get with this.
#include<iostream>
#include<boost/process.hpp>
#include<boost/iostreams/device/file_descriptor.hpp>
namespace bp = ::boost::process;
namespace bpi = ::boost::process::initializers;
namespace bio = ::boost::iostreams;
int main(int argc, char *argv[])
{
bp::pipe p = bp::create_pipe();
bio::file_descriptor_sink sink(p.sink, bio::close_handle);
bp::execute(
bpi::run_exe("/usr/bin/ls"),
bpi::bind_stdout(sink)
);
return(0);
}
And here is my error…
/tmp/cc7cmrV8.o: In function `main':
test.cpp:(.text+0x2b): undefined reference to `boost::iostreams::file_descriptor_sink::file_descriptor_sink(int, boost::iostreams::file_descriptor_flags)'
/tmp/cc7cmrV8.o: In function `boost::process::posix::initializers::bind_stdout::bind_stdout(boost::iostreams::file_descriptor_sink const&)':
test.cpp:(.text._ZN5boost7process5posix12initializers11bind_stdoutC2ERKNS_9iostreams20file_descriptor_sinkE[_ZN5boost7process5posix12initializers11bind_stdoutC5ERKNS_9iostreams20file_descriptor_sinkE]+0x2b): undefined reference to `boost::iostreams::file_descriptor_sink::file_descriptor_sink(boost::iostreams::file_descriptor_sink const&)'
/tmp/cc7cmrV8.o: In function `void boost::process::posix::initializers::bind_stdout::on_exec_setup<boost::process::posix::executor>(boost::process::posix::executor&) const':
test.cpp:(.text._ZNK5boost7process5posix12initializers11bind_stdout13on_exec_setupINS1_8executorEEEvRT_[_ZNK5boost7process5posix12initializers11bind_stdout13on_exec_setupINS1_8executorEEEvRT_]+0x18): undefined reference to `boost::iostreams::file_descriptor::handle() const'
collect2: error: ld returned 1 exit status
Platform: Linux 64-bit
Boost: 1.55 (installed via pacman)
Boost::process: 0.5
Compile command: g++ -Wall test.cpp -o spegh.elf -lboost_system
A simple search threw me at -This-.
Seeing you posted your compile command, I'm guessing you are simply missing -lboost_iostreams in your linker settings.
I am trying to get OGDF working to see if it is suitable for my project, but I am having trouble with a sample program.
I am trying to compile this example program:
#include <ogdf/basic/Graph.h>
#include <ogdf/basic/graph_generators.h>
#include <ogdf/layered/DfsAcyclicSubgraph.h>
using namespace ogdf;
int main()
{
Graph G;
randomSimpleGraph(G, 10, 20);
DfsAcyclicSubgraph DAS;
DAS.callAndReverse(G);
G.writeGML("test.gml");
return 0;
}
using this command:
$g++ -pthread -I ./OGDF/ -L ./OGDF/_release/ -lOGDF test2.cpp
But I get the following error
/tmp/ccbpkfdt.o: In function `main':
test2.cpp:(.text+0x12): undefined reference to `ogdf::Graph::Graph()'
test2.cpp:(.text+0x2e): undefined reference to `ogdf::randomSimpleGraph(ogdf::Graph&, int, int)'
test2.cpp:(.text+0x4e): undefined reference to `ogdf::AcyclicSubgraphModule::callAndReverse(ogdf::Graph&)'
test2.cpp:(.text+0x62): undefined reference to `ogdf::Graph::writeGML(char const*) const'
test2.cpp:(.text+0x7f): undefined reference to `ogdf::Graph::~Graph()'
test2.cpp:(.text+0xa1): undefined reference to `ogdf::Graph::~Graph()'
/tmp/ccbpkfdt.o: In function `__static_initialization_and_destruction_0(int, int)':
test2.cpp:(.text+0xfb): undefined reference to `ogdf::Initialization::Initialization()'
test2.cpp:(.text+0x112): undefined reference to `ogdf::Initialization::~Initialization()'
/tmp/ccbpkfdt.o: In function `ogdf::DfsAcyclicSubgraph::DfsAcyclicSubgraph()':
test2.cpp:(.text._ZN4ogdf18DfsAcyclicSubgraphC2Ev[_ZN4ogdf18DfsAcyclicSubgraphC5Ev]+0x16): undefined reference to `vtable for ogdf::DfsAcyclicSubgraph'
/tmp/ccbpkfdt.o: In function `ogdf::DfsAcyclicSubgraph::~DfsAcyclicSubgraph()':
test2.cpp:(.text._ZN4ogdf18DfsAcyclicSubgraphD2Ev[_ZN4ogdf18DfsAcyclicSubgraphD5Ev]+0xb): undefined reference to `vtable for ogdf::DfsAcyclicSubgraph'
collect2: error: ld returned 1 exit status
I tried compiling hello world, with an include from OGDF, and I still got:
undefined reference to `ogdf::Initialization::Initialization()'
I think I am not linking properly or something?
You have to be very careful in which order you type stuff when linking with a library.
Try putting test2.cpp before -lOGDF instead, like this:
g++ -pthread -I ./OGDF/ -L ./OGDF/_release/ test2.cpp -lOGDF
You must build your program using the -DOGDF_DLL when using OGDF as a shared library.
See here: http://www.ogdf.net/doku.php/tech:defines
I am a leda-6.3 library user.
I used graphwin to manipulate and display graphs, but I found that references
to graphwin methods are undefined while compiling the code although they
are declared in the LEDA/incl/LEDA/graphics/graphwin.h
So I think it is a problem of object file.
#include <LEDA/graphics/graphwin.h>
#include <LEDA/graph/graph_alg.h>
using namespace leda;
int main()
{
GraphWin gw("LEDA Graph Editor");
node u=gw.new_node(point(100,100));
node v=gw.new_node(point(100,200));
gw.new_edge(u,v);
gw.display();
gw.get_window().read_mouse();
graph& G=gw.get_graph();
G.new_node();
gw.get_window().read_mouse();
gw.update_graph();
gw.get_window().read_mouse();
return 0;
}
compilation: g++ -I$LEDAROOT/incl -L$LEDAROOT gw.cpp -lleda -lX11 -lm -o gw
ERROR :
/tmp/ccVHyRbL.o: In function `main':
gw.cpp:(.text+0x1e): undefined reference to `leda::GraphWin::GraphWin(char const*)'
gw.cpp:(.text+0x58): undefined reference to `leda::GraphWin::new_node(leda::point const&)'
gw.cpp:(.text+0xc6): undefined reference to `leda::GraphWin::new_node(leda::point const&)'
gw.cpp:(.text+0x11c): undefined reference to `leda::GraphWin::new_edge(leda::node_struct*, leda::node_struct*)'
gw.cpp:(.text+0x128): undefined reference to `leda::GraphWin::display()'
gw.cpp:(.text+0x17e): undefined reference to `leda::GraphWin::update_graph()'
collect2: ld returned 1 exit status
Which edition of LEDA are you using?
Please consider that free edition of LEDA does not contain GraphWin.
So, it dos not contain GraphWin libraries, which results to getting such errors while compiling your program.