I am testing C code using googleTest.
My test.cpp file look like that
#include <gtest/gtest.h>
extern "C" {
#include "list.h"
#include "list.c"
}
TEST(ListTest, singleInsertion) {
// some tests
}
int main(int argc, char **argv) {
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
However trying to run the test from the terminal using
g++ test.cpp -lgtest gives Errors and warning as if the code being tested is C++ not C.
Error and warning Examples :
error: invalid conversion for mallocs and
warning: ISO C++ forbids converting a string constant to ‘char*'
how can I declare that my tested files are C not C++ ?
However trying to run the test from the terminal using g++ test.cpp -lgtest gives Errors and warning as if the code being tested is C++ not C.
That's because you are compiling it as C++ by using the g++ compiler. Use gcc to compile as C.
Unfortunately, this code won't compile as C - it'll choke on the google::InitGoogleTest() call because C doesn't recognize the :: scoping operator. I'm not familiar with this testing framework, but at first glance it looks like it's meant to be used with C++, not C.
The way to fix this is to remove the #include "list.c" directive
extern "C" {
#include "list.h"
}
and compile it separately as C:
gcc -c list.c
then compile your tester:
g++ -c test.cpp
and then link the object files with the library:
g++ -o test test.o list.o -lgtest
Related
I'm attempting to write a simple program that calls a function written in a pair of Header and CPP files.
I'm doing this on a Raspberry Pi 3 Model B, and the Geany IDE v1.37.1.
Compile Command:
g++ -Wall -c "%f" -c test.cpp
Build Command:
g++ -Wall -o "%e" "%f" -o test test.cpp
main.cpp:
#include "test.h"
int main()
{
test_function();
return 0;
}
test.h:
#ifndef _test_h_
#define _test_h_
#include <iostream>
void test_function();
#endif
test.cpp:
#include "test.h"
void test_function()
{
std::cout << "hello world";
}
The code above compiles & builds fine, however attempting to run it yields the following error:
./main: not found
(program exited with code: 127)
Perhaps I am messing something up with the Compile & Build Commands?
Thank you for reading my post, any guidance is apprecaited!
Notice the compile command:
-o test
This means that the output binary will be test, so you can execute the application in your terminal or shell via ./test.
I know there are many similar topics but there are equally many unique mistakes that may lead to this problem (so I think). Therefore I ask, after some research.
My problem is that the compiler, GNU GCC, when compiling one file does not see my namespace declared in another file. The IDE (CodeBlocks) evidently does see it as it auto-completes the name of the namespace. I tried to isolate the problem and came up with this:
File main.cpp:
namespace MyName
{
int MyVar;
}
#include "T1.cpp"
int main()
{
return 0;
}
File T1.cpp:
using namespace MyName;
error: 'MyName' is not a name-space name.
In my project I have a header file, say T1.h, and an implementation file T1.cpp — and MyName isn't accessible in either of them.
Any help or guidance would be appreciated.
What's happening is that CodeBlocks is compiling both main.cpp and T1.cpp. Here is what happens when you try to compile each one:
main.cpp:
$ g++ main.cpp
$
T1.cpp
$ g++ T1.cpp
T1.cpp:1:17: error: ‘MyName’ is not a namespace-name
using namespace MyName;
^
T1.cpp:1:23: error: expected namespace-name before ‘;’ token
using namespace MyName;
^
$
T1.cpp, when compiled on it's own, has no knowledge of MyName. To fix this, don't include .cpp files, and put your declarations in header files.
Edit: From what I gather, this may be a better way to organize your example:
T1.h:
namespace MyName {
extern int MyVar;
}
T1.cpp
#include "T1.h"
int MyName::MyVar = 5;
main.cpp
#include "T1.h"
#include <iostream>
using namespace MyName;
int main()
{
std::cout << MyVar << std::endl;
return 0;
}
Now it will compile correctly:
$ g++ -c T1.cpp -o T1.o
$ g++ -c main.cpp -o main.o
$ g++ T1.o main.o
$ ./a.out
5
I installed the SystemC library 2.3.1 using this tutorial.
I wrote this hello world example:
//hello.cpp
#include <systemc.h>
SC_MODULE (hello_world) {
SC_CTOR (hello_world) {
}
void say_hello() {
cout << ”Hello World systemc-2.3.0.\n”;
}
};
int sc_main(int argc, char* argv[]) {
hello_world hello(“HELLO”);
hello.say_hello();
return(0);
}
and compiled with this command:
export SYSTEMC_HOME=/usr/local/systemc230/
g++ -I. -I$SYSTEMC_HOME/include -L. -L$SYSTEMC_HOME/lib-linux -Wl,-rpath=$SYSTEMC_HOME/lib-linux -o hello hello.cpp -lsystemc -lm
When I compile the code, I got a error with the library:
In file included from hello.cpp:1:0:
/usr/local/systemc230/include/systemc.h:118:16: error: ‘std::gets’ has not been declared
using std::gets;
^~~~
How can I solve this?
std::gets has been removed in C++11 (See What is gets() equivalent in C11?)
If you're building using C++11 flag (maybe with a g++ alias), you have to disable this line in systemc.h.
Replace
using std::gets;
with
#if defined(__cplusplus) && (__cplusplus < 201103L)
using std::gets;
#endif
As guyguy333 mentioned, in new versions, g++ is an alias for C++11.
so adding -std=c++98 would solve the problem.
The compile command may like
$ g++ -std=c++98 -lsystemc -pthread main.cpp -o main
You seem to have copy pased the code from webpage as it is. Please remember “” and "" are not the same thing. On line 8
cout << ”Hello World systemc-2.3.0.\n”;
replace it with
cout << "Hello World systemc-2.3.0.\n";
and on line 13
hello_world hello(“HELLO”);
replace it with
hello_world hello("HELLO");
And then execute the code again.
GoodLuck.
I moved from Windows to Ubuntu and I wanted to try some C++ programming on Ubuntu. So here is very simple code and very stupid error which I can't resolve:
horse.h
#ifndef _horse_
#define _horse_
class Horse{
int speed;
public:
void saySomething();
};
#endif
horse.cpp
#include "horse.h"
#include <iostream>
using namespace std;
void Horse::saySomething(){
cout << "iiiihaaaaaaa brrrrr."<<endl;
}
and Main.cpp
#include "horse.h"
int main(){
Horse h;
h.saySomething();
}
After I compile (compilation is successful) and run this I get this error message:
/tmp/ccxuDyrd.o: In function `main':
Main.cpp:(.text+0x11): undefined reference to `Horse::saySomething()'
collect2: ld returned 1 exit status
Please help me somehow.
Try
g++ -c main.cpp horse.cpp (to compile)
g++ -o a.out main.o horse.o (to link)
It seems you only compiled your code but did not link the resulting object files. You probably invoked the compiler like this:
g++ main.cpp
You should instead compile every *.cpp file separately and then link each resulting *.o file. And you should do this with a Makefile.
Actually, the basic idea is the same on Windows with MSVC. The compiler produces object files, the linker links them together.
I've installed GCC 4.8 using this method on my Mac. Everything works fine except that for certain functions like scanf and printf, the program compiles fine without any error/warning even when I did not include their respective libraries like cstdio. Is there any way that I can do to for GCC (more specifically G++, as I am dealing with C++ programs) to throw an error when such code is being fed? The following code compiles fine on my machine:
#include <iostream>
//Notice I did not include cstdio but my program uses printf later on
int main()
{
printf("Hello World!\n");
return 0;
}
I was given the suggestion to use -Werror-implicit-function-declaration -Werror or -Wall -Werror, but they don't work.
-Wimplicit-function-declaration -Werror works for me. There must be some other problems as well.
h2co3-macbook:~ h2co3$ cat baz.c
#ifndef BAILZ_OUT
#include <stdio.h>
#endif
int main()
{
printf("Hello world!\n");
return 0;
}
h2co3-macbook:~ h2co3$ gcc -o baz baz.c -Wimplicit-function-declaration -Werror
h2co3-macbook:~ h2co3$ echo $?
0
h2co3-macbook:~ h2co3$ gcc -o baz baz.c -Wimplicit-function-declaration -Werror -DBAILZ_OUT
cc1: warnings being treated as errors
baz.c: In function ‘main’:
baz.c:7: warning: implicit declaration of function ‘printf’
baz.c:7: warning: incompatible implicit declaration of built-in function ‘printf’
h2co3-macbook:~ h2co3$ echo $?
1
h2co3-macbook:~ h2co3$
The reason you get no diagnostic is that <iostream> is including the declaration of printf, which it seems to do with the c++0x or c++11 flags.
This compiles on a gcc 4.8 snapshot with the following command line:
g++ -Wall -Wextra -pedantic-errors -std=c++0x
#include <iostream>
int main()
{
printf("Hello World!\n");
return 0;
}
If you comment out the <iostream> include, or remove the C++11 compilation flags, you get an error.
impl_decl.cpp: In function 'int main()':
impl_decl.cpp:5:28: error: 'printf' was not declared in this scope
From the Annex C/Compatibility of the C++ standard from 2003:
C.1 C++ and ISO C:
C.1.3 Clause 5: expressions [diff.expr]
5.2.2
Change: Implicit declaration of functions is not allowed
Rationale: The type-safe nature of C++.
That means that implicit declarations must cause a compilation error in C++.
I'm guessing you're compiling not C++ files, but C files and you're doing that in some pre-C99 mode, which is the default in gcc. The C standard from 1999 disallows implicit declarations as well.
You may want to pass to gcc a combination of these options: -std=c99 -Werror.