I have MinGW installed on my computer (I just use the one shipped with Strawberry perl). I can compile things just fine from the command line. Using Eclipse CDT, however, results in weird errors. Using the c++ hello world default project which comes with Eclipse, compilation in CDT fails with these errors:
\**** Internal Builder is used for build \****
g++ -O0 -g3 -Wall -c -fmessage-length=0 -osrc\hw.o ..\src\hw.cpp
..\src\hw.cpp:9:20: error: iostream: No such file or directory
..\src\hw.cpp: In function 'int main()':
..\src\hw.cpp:13: error: 'cout' was not declared in this scope
..\src\hw.cpp:13: error: 'endl' was not declared in this scope
Build error occurred, build is stopped
Time consumed: 263 ms.
But when I run g++ -O0 -g3 -Wall -c -fmessage-length=0 -osrc\hw.o ..\src\hw.cpp on my command line compilation goes just fine. All of the proper header files (like iostream) are in my path variable. What eclipse settings do I need to change to make this work?
Here's the file I'm trying to compile:
#include <iostream>
using namespace std;
int main() {
cout << "!!!Hello World!!!" << endl; // prints !!!Hello World!!!
return 0;
}
I experienced this only a few days ago, the problem turned out to be that I had both g++4.3 and g++4.4 installed and Eclipse was getting confused. I uninstalled 4.3 and the problem went away.
Related
I'm using atom to practice C++ (I'm very new). I just learned to initialize variables like the following:
#include <iostream>
using namespace std;
int main() {
int myInt {};
return 0;
}
When I build and run the previous code in codelite I receive no errors. However, if I compile my atom file dailyPractice10.cpp using my MacBook terminal (zsh) I get the following error:
dailyPractice10.cpp:7:12: error: expected ';' at end of declaration
int myInt {};
^
;
1 error generated.
I'm using the following command to compile it on terminal:
g++ -o dailyPractice10 dailyPractice10.cpp (compiles)
./dailyPractice10 (runs program)
Does anyone have any feedback why this code runs in codelite but doesn't compile in terminal?
Because this feature is added from c++11.
if you will like to try below command.it will work.
$ g++ -std=c++0x -o dailyPractice10 dailyPractice10.cpp
The key to fixing this issue is to set the C++11 (or above) standards while building your code.
In the console tab of the IDE, the following output is generated before the error. Notice that no standard is being defined while building the code:
make all
Building file: ../1.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"1.d" -MT"1.o" -o "1.o" "../1.cpp"
We need to add the --std=c++1x flag to the g++ command. The following solution is for the ones using the Eclipse IDE and the MacOSX C++ compiler:
Right click on the project from the "Project Explorer".
Go to Properties > C/C++ Build > Settings.
Under the "Tool Settings" tab, find "GCC C++ Compiler" > "Miscellaneous"
In the "Other Flags" text box, edit the text such that it looks like:
-std=c++17 -c -fmessage-length=0
If you intend to use any other c++ standard, replace "c++17" with the standard of your choice ( eg. c++20).
Apply Changes.
Run Clean, and the Build again.
you should try this to compile the Code
g++ -std=c++20 -o dailyPractice10 dailyPractice10.cpp
After updating my Arch Linux system on my laptop, I ran into a lot of compilation errors when trying to compile the project I am working on. The same code compiles well on other machines.
So, I tried a little hello world program, and it fails with the same error.
I have spent quite some time trying to figure out what is happening, but I get nowhere, so I would very much appreciate any hints.
The file I try to compile is very simple:
#include <iostream>
int main ()
{
std::cout << "Hello, world!\n";
return 0;
}
I compile it like this:
$ g++ -Wall -Wfatal-errors hello.cpp -o hello
And get the following error:
In file included from /usr/include/c++/8.2.1/memory:74,
from /usr/local/include/format.h:36,
from /usr/local/include/time.h:11,
from /usr/include/pthread.h:24,
from /usr/include/c++/8.2.1/x86_64-pc-linux-gnu/bits/gthr-default.h:35,
from /usr/include/c++/8.2.1/x86_64-pc-linux-gnu/bits/gthr.h:148,
from /usr/include/c++/8.2.1/ext/atomicity.h:35,
from /usr/include/c++/8.2.1/bits/ios_base.h:39,
from /usr/include/c++/8.2.1/ios:42,
from /usr/include/c++/8.2.1/ostream:38,
from /usr/include/c++/8.2.1/iostream:39,
from hello.cpp:4:
/usr/include/c++/8.2.1/ext/concurrence.h:124:5: error:
'__gthread_mutex_t' does not name a type; did you mean
'__pthread_mutex_s'?
__gthread_mutex_t _M_mutex;
^~~~~~~~~~~~~~~~~
__pthread_mutex_s
compilation terminated due to -Wfatal-errors
If I remove the -Wfatal-errors switch, I just get tons of more errors.
It was the two header files in /usr/local/include, i.e. format.h and time.h that was the cause of my problems. After removing them I am now able to compile my project again.
I have a basic C++ program in Eclipse CDT:
#include <iostream>
using namespace std;
int main()
{
std::cout << "Hello World!";
}
However, when I try to build it, I get an Exec Format Error. Here is the output produced by the compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -o hey.o "..\\hey.cpp"
g++: error: spawn: Exec format error
I am using MinGW Toolchain. I am on 64-bit Windows, and I think that may have something to do with it. Would anyone know how to get this program running?
Edit
Running the exact command in command prompt in the directory where my source file is works just fine, without throwing errors, but it still doesn't work in Eclipse
So, I have fixed this myself by installing the 64-bit version of MinGW (http://sourceforge.net/projects/mingw-w64/). It now compiles and builds noramlly
I installed MinGW and CDT following some tutorials. I'm trying to compile and run "hello world" code. There are no errors in eclipse but when I compile the code I get this error:
22:48:32 **** Incremental Build of configuration Debug for project test3 ****
Info: Internal Builder is used for build
g++ "-IC:\\MinGW\\lib\\gcc\\mingw32\\4.8.1\\include\\c++" "-IC:\\MinGW\\lib\\gcc\\mingw32\\4.8.1\\include\\c++\\mingw32" -O0 -g3 -Wall -c -fmessage-length=0 -o "src\\test3.o" "..\\src\\test3.cpp"
g++: error: CreateProcess: No such file or directory
22:48:32 Build Finished (took 135ms)
The code:
#include <iostream>
using namespace std;
int main() {
cout << "!!!Hello World!!!" << endl; // prints !!!Hello World!!!
return 0;
}
Might be a silly question to ask, but did you save the file somewhere before building it? I've had an error like this that was solved by saving it on my Desktop or wherever.
Edit: There seems to be several people with problems using MinGW. You mentioned you looked at previous stackoverflow questions, do they include these:
Eclipse CDT error: Unable to compile
MinGW error: No such file or directory exists
Other solutions suggest you should try compiling the program via command line, which...shouldn't be a problem since it's just "Hello, World".
GoogleTest 1.6 with Cygwin 1.7: 'fileno' was not declared in this scope
Error message when building a simple test on Factorial() function in Eclipse CDT:
Invoking: Cygwin C++ Compiler
g++ -std=c++0x -DGTEST_OS_CYGWIN=1 -I"E:\source\gtest-1.6.0\include" -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/challenge.d" -MT"src/challenge.d" -o "src/challenge.o" "../src/challenge.cpp"
In file included from E:\source\gtest-1.6.0\include/gtest/internal/gtest-internal.h:40:0,
from E:\source\gtest-1.6.0\include/gtest/gtest.h:57,
from ../src/challenge.cpp:11:
E:\source\gtest-1.6.0\include/gtest/internal/gtest-port.h: In function 'int testing::internal::posix::FileNo(FILE*)':
E:\source\gtest-1.6.0\include/gtest/internal/gtest-port.h:1589:51: error: 'fileno' was not declared in this scope
E:\source\gtest-1.6.0\include/gtest/internal/gtest-port.h:1595:57: error: 'strdup' was not declared in this scope
E:\source\gtest-1.6.0\include/gtest/internal/gtest-port.h:1627:71: error: 'fdopen' was not declared in this scope
Eclipse CDT 8.1 running gcc 4.7.3 on Cygwin 1.7.22
gTest 1.6 succesfully built including demo tests, with cmake 2.8.9 on Cygwin 1.7.22
I've linked the built lib with full path, E:\lib\gtest-1.6.0\Cygwin\libgtest.a
The following command option was added manually, got same error without it.
-DGTEST_OS_CYGWIN=1
Seems the errors have nothing to do with my code. Anyone using gTest with Eclipse and Cygwin?
Thank you,
unsigned long Factorial(unsigned n) {
return n==0? 0 : n*Factorial(n-1);
}
// Tests factorial of 0.
TEST(FactorialTest, HandlesZeroInput) {
EXPECT_EQ(1, Factorial(0));
}
// Tests factorial of positive numbers.
TEST(FactorialTest, HandlesPositiveInput) {
EXPECT_EQ(1, Factorial(1));
EXPECT_EQ(2, Factorial(2));
EXPECT_EQ(6, Factorial(3));
EXPECT_EQ(40320, Factorial(8));
}
Setting the C++ standard to -std=gnu++0x rather than -std=c++0x, worked for me. You can try the statement:
g++ -std=gnu++0x -DGTEST_OS_CYGWIN=1 -I"E:\source\gtest-1.6.0\include" -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/challenge.d" -MT"src/challenge.d" -o "src/challenge.o" "../src/challenge.cpp"
Setting symbol (-DGTEST_OS_CYGWIN=1) has got nothing to do with this error.
Some functions go beyond the ANSI standard.
These are disabled when you use std=c++11 (or std=c++0x).
Among them are fdopen, fileno and strdup.
There are two possibilities to use them:
Use the GNU dialect (std=gnu++11).
If you want to compile without dialect and make a local exception, you can include stdio.h with the __STRICT_ANSI__ undefined. (see: Error "'fdopen' was not declared" found with g++ 4 that compiled with g++3)
I have tested both on Suse Linux Enterprise 11, MinGW and Cygwin.
Addition: Another (possibly better) way to access non-ANSI symbols would be to add
#define _POSIX_C_SOURCE 200809L
before the first #include in your file. This will give you access to most of the non-standard routines.
Some functions (e.g. realpath(...)) require
#define _BSD_SOURCE
to be inserted on top of your file.