I am trying same,
http://www.linuxforums.org/forum/suse-linux/135465-gcov-g.html
Code from the link,
#include <iostream>
using namespace std;
void one(void);
void two(void);
void __gcov_flush(void);
int main(void)
{
int i;
while(true)
{
__gcov_flush();
cout << "Enter a number(1-2), 0 to exit " << endl;
cin >> i;
if ( i == 1 )
one();
else if ( i == 2 )
two();
else if ( i == 0 )
break;
else
continue;
}
return 0;
}
void one(void)
{ cout << "One is called" << endl; }
void two(void)
{ cout << "Two is called" << endl; }
but for me also it gives,
test.cpp:(.text+0x1d9): undefined reference to `__gcov_flush()'
collect2: ld returned 1 exit status
Tried the followings,
g++ -fprofile-arcs test.cpp
g++ -fprofile-arcs -g test.cpp
g++ -fprofile-arcs -ftest-coverage -g test.cpp
g++ -fprofile-arcs -ftest-coverage -g test.cpp -lgcov
I have also tried the "-lgcov" & "extern void __gcov_flush(void)" as mentioned in link above. I am currently on Ubuntu12.04 and g++ 4.6
So, I want to know if there is solution for this or gcov_flush doesnt work anymore.
void __gcov_flush();
Since the code is compiled as C++, this declares the existence of a C++ function of that name. C++ functions are subject to name mangling, so the (C++) symbol is not found in the (C) link library, and the linker (rightfully) complains about it.
If you declare the function, declare it as a function with C linkage:
extern "C" void __gcov_flush();
This should do the trick.
Note the commend by Paweł Bylica -- __gcov_flush() has been removed in GCC 11, you should use __gcov_dump().
I fixed this issue changing the settings.
Test Project --> Build Settings
Instrument Program Flow = Yes
Related
I'm trying a very simple exmaple to create a shared library and link to it. The shared library is as follows:
#ifndef ARDUGRAB_H_
#define ARDUGRAB_H_
#include <iostream>
using namespace std;
namespace ArduGrabLibrary{
class ArduGrab{
public:
ArduGrab();
virtual void initCamera();
virtual void setSim(bool sim);
virtual void setDebug(bool debug);
private:
bool debug = false;
bool sim = false;
};
}
Then the source code file is just as simple:
#include "ardugrab.h"
namespace ArduGrabLibrary
{
ArduGrab::ArduGrab(){
std::cout << "IMX298 Constructor" << std::endl;
}
void ArduGrab::initCamera(){
if (this->debug){
cout << "init camera" << std::endl;
}
}
void ArduGrab::setSim(bool sim){
this->sim = sim;
if (this->debug){
cout << "set sim to " << std::boolalpha << this->sim << std::endl;
}
}
void ArduGrab::setDebug(bool debug){
this->debug = debug;
if (this->debug){
cout << "set debug to " << std::boolalpha << this->sim << std::endl;
}
}
}
I'm then compiling that into a shared library with:
g++ -fPIC -shared -o ardugrab.so ardugrab.cpp
All good, we get an ardgrab.so library so to test it, with the following code in teh same directory as the .so and .h files from above:
#include "ardugrab.h"
using namespace ArduGrabLibrary;
int main() {
std::cout << "starting program" << std::endl;
ArduGrab* ardu = new ArduGrab();
ardu->setDebug(true);
//imx298->setSim(true);
//imx298->initCamera();
return 0;
}
So now we need to compile this into an executable with:
g++ -L. -lardugrab -o testardugrab testardugrab.cpp
This however fails to find the ardugrab.so file, the follow error message appears:
pi#raspberrypi:~/ArduMipiGrab $ g++ -L. -lardugrab -o testardugrab testardugrab.cpp
/usr/bin/ld: cannot find -lardugrab
collect2: error: ld returned 1 exit status
I've tried setting LD_LIBRARY_PATH to . export LD_LIBRARY_PATH=. but still nothing.
As you can see I'm a bit new with compiling c++, can someone please advise me as to what I'm doing wrong?
Thanks.
Reagrds,
Neil
This is becuase you are using the -l flag.
When you use this flag (Rather than specify a library specifically) it assumes a certain naming convention.
-lX
The linker assumes the file name is
libX.so (or libX.a)
So the commands you want are:
> g++ -fPIC -shared -o libardugrab.so ardugrab.cpp
> # ^^^
> g++ -L. -lardugrab -o testardugrab testardugrab.cpp
Note: The environment variable LD_LIBRARY_PATH is used at runtime when the standard library tries to find and load required shared libraries. I.E. it is not used during compilation to find shared libraries to link with.
I have a C++ project based on CMake that uses Ninja. It's been build and ran using eclipse for C/C++. My current machine is a Mac OS.
The file:
#include <iostream>
#include <exception>
#include <string>
#include <stdexcept>
#include <vector>
#include <cmath>
using namespace std;
class Server {
private:
static int load;
public:
static int compute(long long A, long long B) {
load += 1;
if(A < 0) {
throw std::invalid_argument("A is negative");
}
vector<int> v(A, 0);
int real = -1, cmplx = sqrt(-1);
if(B == 0) throw 0;
real = (A/B)*real;
int ans = v.at(B);
return real + A - B*ans;
}
static int getLoad() {
return load;
}
};
int Server::load = 0;
int main() {
int T;
cin >> T;
while(T--) {
long long A, B;
cin >> A >> B;
/* Enter your code here. */
try{
cout << Server::compute(A, B) << endl;
} catch(invalid_argument e){
cout << "Exception: A is negative" << endl;
} catch(bad_alloc &e){
cout << "Not enough memory" << endl;
} catch(exception &e){
cout << "Exception: ";
cout << e.what() << endl;
} catch(...){
cout << "Other Exception" << endl;
}
}
cout << Server::getLoad() << endl;
return 0;
}
Build info:
cmake --build . -- -v
[1/2] /Library/Developer/CommandLineTools/usr/bin/c++ -O3 -DNDEBUG -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk -MD -MT CMakeFiles/deleteme.dir/deleteme.cpp.o -MF CMakeFiles/deleteme.dir/deleteme.cpp.o.d -o CMakeFiles/deleteme.dir/deleteme.cpp.o -c ../../deleteme.cpp
[2/2] : && /Library/Developer/CommandLineTools/usr/bin/c++ -O3 -DNDEBUG -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk -Wl,-search_paths_first -Wl,-headerpad_max_install_names CMakeFiles/deleteme.dir/deleteme.cpp.o -o deleteme && :
Build complete (0 errors, 0 warnings):
When I run:
Building in:
cmake --build . -- -v
ninja: no work to do.
Build complete (0 errors, 0 warnings):
It does not give me the chance to input the values. It just skips everything and finishes execution. If I put a cout right at the beginning, then the program works as expected.
Why is this happening?
Ps: The project complete path was removed from here for safety reasons. And yes, my project was created with the name 'deleteme'.
Pss: I took this snippet from HackerRank for studing purposes, so It should be fine. I've only added the try/catch and method call.
You are confusing building your program with running your program.
When you run the command cmake --build . -- -v, cmake will build your project. That means it will launch the appropriate tools to compile and link your program, which will produce an executable called deleteme somewhere in your build directory.
The subsequent invocation of the same command correctly reports that no work needs to be done (since you presumably haven't modified any of the source code between invocations).
To be clear, normally this will not run your program, which is why you don't get a prompt to input any values.
To run your program, which, if I understand correctly is what you are trying to do, simply run the executable deleteme that was produced by the build process. You will most likely find this executable in the build directory, that is, the directory where you ran the cmake --build . command. (Depending on your CMake project structure, you may also find it in a subdirectory of your build directory.)
I've figured It out how to solve this. I don't know what have caused It. It looks like ninja is not need if you have properly configured your environment variables, related to your compiler, inside Eclipse.
After doing that, everything works fine.
This code fails to compile with an error that it can't resolve stio. Have I made some newbie mistake here?
Eclipse Version: 3.8.1 Mint KDE should all be up to date.
GCC Version: gcc (Ubuntu 5.4.0-6ubuntu1~16.04.10) 5.4.0 20160609
#include <iostream>
#include <string>
#include <fstream>
#include <cstdlib>
#include <vector>
using namespace std;
int main() {
string numberGuessed;
int intNumberGuessed = 0;
int answer = 0;
answer = (rand() % 100) + 1;
do {
cout << "Guess a number "; // prints !!!Hello World!!!
getline(cin, numberGuessed);
intNumberGuessed = stoi(numberGuessed);
cout << "You guessed "<< numberGuessed << endl;
cout << "You are not correct. Try again" << endl;
} while (answer != intNumberGuessed);
cout << "you got it";
return 0;
}
The error message.
16:39:14 **** Incremental Build of configuration Debug for project Hello2 ****
make all
Building file: ../src/Hello2.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/Hello2.d" -
MT"src/Hello2.d" -o "src/Hello2.o" "../src/Hello2.cpp"
../src/Hello2.cpp: In function ‘int main()’:
../src/Hello2.cpp:27:40: error: ‘stoi’ was not declared in this scope
intNumberGuessed = stoi(numberGuessed);
^
make: *** [src/Hello2.o] Error 1
src/subdir.mk:18: recipe for target 'src/Hello2.o' failed
16:39:14 Build Finished (took 613ms)
The std::stoi function is available since the c++11 standard.
Apparently your compiler version of GCC is too old, to take c++11 as the current default standard.
You may try to specify the -std=c++11 or -std=c++0x compiler flags, or update your gcc compiler to one of the most recent versions.
Here's a link explaining in detail how to set the compiler flags.
This might help you with updating your compiler version to the latest.
So I'm working on a project for a class and I cannot seem to get things to work. 1) Did I do this right? 2) How do I get rid of the errors?
#include <iostream>
#include <thread>
using namespace std;
void countdown(){
int count;
count = 21;
while (count<=0)
{
count--;
cout << "Count is " << count << '.' << endl;
}
}
int main() {
std::thread t1(countdown);
t1.join();
int count1;
count1 = 0;
while (count1<20)
{
count1++;
cout << "Count is " << count1 << '.' << endl;
}
return 0;
}
Error messages:
g++ -O0 -g3 -Wall -c -fmessage-length=0 -std=c++11 -Wl,--no-as-needed -o "src\\Critical7.o" "..\\src\\Critical7.cpp"
..\src\Critical7.cpp: In function 'int main()':
..\src\Critical7.cpp:27:2: error: 'thread' is not a member of 'std'
std::thread t1(countdown);
^
..\src\Critical7.cpp:28:2: error: 't1' was not declared in this scope
t1.join();
I've tried setting things the way other posts have said but I can't seem to get it to work.
Two modifications are necessary to run the code correctly:
replace while (count<=0) with while(count>=0), else the loop in countdown() exits immediately.
Use the -pthread linker option in order to compile the code.
I'm trying to compile my project in Eclipse.
However, it says that the main() is defined more than once. I grep'd my project dir and it found only one definition of main(), in main.cpp.
Apparently it is somewhere else.maybe a dir I linked to.
The only dirs I linked to are:
-ljson_linux-gcc-4.5.2_libmt
The compiler output is:
make all
Building file: ../src/main.cpp
Invoking: GCC C++ Compiler
g++ -Ijson_linux-gcc-4.5.2_libmt -I/usr/include/mysql -I/usr/include/jsoncpp-src-0.5.0/include -O0 -g3 -Wall -c -fmessage-length=0 -Ijson_linux-gcc-4.5.2_libmt -MMD -MP -MF"src/main.d" -MT"src/main.d" -o"src/main.o" "../src/main.cpp"
Finished building: ../src/main.cpp
Building target: Atms
Invoking: GCC C++ Linker
g++ -L-L/usr/include/jsoncpp-src-0.5.0/include/ -o"Atms" ./src/atmstypes.o ./src/base64.o ./src/hregex.o ./src/libparser.o ./src/log.o ./src/main.o ./src/serv.o ./src/sqlfeeder.o ./src/teleindex.o ./src/telepipe.o ./src/telesharedobject.o ./src/treet.o ./src/ttable.o -l-ljson_linux-gcc-4.5.2_libmt
./src/serv.o: In function `main':
/usr/include/c++/4.4/new:101: multiple definition of `main'
./src/main.o:/home/idan/workspaceCpp/Atms/Debug/../src/main.cpp:12: first defined here
/usr/bin/ld: cannot find -l-ljson_linux-gcc-4.5.2_libmt
collect2: ld returned 1 exit status
make: *** [Atms] Error 1
main.cpp:
#include <stdio.h>
#include <stdlib.h>
#include <regex.h>
#include <iostream>
#include <string.h>
#include <string>
#include "../h/hregex.h"
using namespace std;
string s = "this and7 that";
int main(int argc,char** argv){
cout << hregex::InitRegex() << endl;
cout << hregex::CheckHostnameField(s)<< "= this and7 that" << endl;
s = "this and7 that";
cout << hregex::CheckURLField(s)<< "= this and7 that" << endl;
s = "/lol/idan.html";
cout << hregex::CheckURLField(s)<< "= /lol/idan.html" << endl;
s = "/lol2#/idan.html";
cout << hregex::CheckURLField(s)<< "= /lol2#/idan.html" << endl;
return 0;
}
How can I prevent the error from appearing?
g++ says serv.o has a main function.
If there actually is no main() it serv.cpp, check the includes, maybe you did a bad #include and included a .cpp instead of a .h ?
As an extra remark :
it tries to bind against the library "-ljson_linux-gcc-4.5.2_libmt"
So there is "-l-ljson_linux-gcc-4.5.2_libmt" in the link command line. Remove the -l in your configuration