A number of answers to this exact error have been put upon this website but I am quite the beginner to C++ and Code::Block so i'm afraid I do not understand them.
I have been following a very simple C++ tutorial that started me out with one simple program that I was told to copy and paste into the compiler.
#include <iostream>
using namespace std;
int main()
{
cout<<"HEY, you, I'm alive! Oh, and Hello World!\n";
cin.get();
return 1;
}
I actually did not write any of this code so my own syntax errors cannot be an issue. Basically that means I'm out of ideas for troubleshooting. Any ideas as to why I can't run this?
Okay so saving the file as a .cpp worked for the building, but when my program actually runs nothing appears in the menu that pops up in which, I assume, the text is supposed to appear. Again, I'm decent at troubleshooting but this code has been confirmed to work by thousands of others and there must be something else wrong.
Save your file in .cpp format instead of .c format which is default for Code::Blocks. Your workspace(that is the file where you saved this code in) will be renamed to xyz.cpp and you can easily check this fact in the tab.Furthermore, change the cout and cin statements to std::cout and std::cin.
Just to make sure we are on the same page.Goto Settings>>>Compiler.Selected compiler should be GNU GCC compiler. Goto Toolchain Executables tab and autodetect the compiler's installation directory (should be something like CodeBlocks\MinGW).
Code::Blocks compiles using some built-in .dlls and i have sometimes found it needed the dll in the folder with the compliled .exe
if not that, try the console application template
i use TDM-GCC it compiles fine.
Related
I'm trying to switch from JetBrains CLion to VS Code. When I was trying some code that worked in CLion perfectly, I ran into troubles. I was trying to open only a basic coroutine implementation.
Line:
#include <coroutine>
is good, without errors, but when I try something like:
std::suspend_always initial_suspend()...
or:
co_await std::suspend_never() {}
VS Code shows problems that "namespace std contains no member suspend_always", etc.
Like I said- the only thing I did was that I opened the same code, that worked in CLion.
The first thing I tried was checking paths to compiler (mingw gcc) - the same as in CLion.
Then I tried to add the line
using namespace std;
, but it helped only on one line. I don't get it.
I tried also change standard in cpp_properties.json file to "C++20".
Nothing on google helped me, but maybe I just don´t know what to search for.
This code will run on your machine, but not on mine:
#include <iostream>
#include <vector>
using namespace std;
int main(){
vector<int> vv;
vv.push_back(1); //<--- without this, everything works
cout << "X\n";
return 0;
}
The reason, is that it appears my windows machine is missing a (or has a conflicting) specific DLL related to Vectors which is causing my other projects to crash without a report if I use vectors.
However, what's even more entertaining is:
If I comment the push back line, it executes normally without a crash.
Other programs work completely fine as long as they avoid vector, as in using list or an array.
GDB Reports "During startup program exited with code 0xc0000139." Which means it couldn't find the dll it wants. Looking through the dependencies of my executable with Dependency Walker is rather inconclusive, I can't tell what is wrongly missing and what is normally missing among the dlls.
It could also be that there is a second dll that is conflicting with it (like I downloaded two different compilers). Investigating with Process Monitor informs me that instead of using the MinGw64 files located in the MSYS2 folder, the process uses the dlls inside of my ProgramFiles/Git/mingw64/bin location.
So it could be an issue? But Process Monitor doesn't tell me why or what is causing the process to exit unsuccessfully...
How would I get Windows to use the dlls in MSYS2 instead of the Git location? The solution that the post I linked above says is to remove the "erroneous dlls." But I can't just remove dlls that git uses?
Also, how am I guaranteed that switching to the dlls within MSYS2 is going to fix my problem? I just want to use vectors lol, how hard does this have to be?
Other solutions include leaving this spyware infested OS and enter the world of Linux, but that's a huge change.
I have a simple program, written in C++, on a Windows 10 machine, compiled with the MinGW g++ compiler.
I am including the <string> header, and it runs fine. When I include the string data type, it will compile, but it will not run.
The minimum amount of code to reproduce this is:
#include <iostream>
#include <string>
using namespace std;
int main() {
string greeting;
cout << "hi" << endl;
return 1;
}
Please note, this works fine:
#include <iostream>
#include <string>
using namespace std;
int main() {
//string greeting;
cout << "hi" << endl;
return 1;
}
The version of the compiler is 6.3.0
g++.exe (MinGW.org GCC-6.3.0-1) 6.3.0
I downloaded it 3 days ago, so I assume it is the most recent version. (Maybe not?)
I have googled and browsed stackoverflow for answers.
The closest question I could find, the person gave up and changed operating systems.
One other solution I found was to use Cygwin's compiler. I would rather not, as I already have a seemingly otherwise fine compiler. It seems that MinGW tools are widely used enough that I should be able to use the compiler.
Any other forum/blog/etc resources have problems about converting strings or calling string methods.
NOTE: The same exact code runs fine on Ubuntu 16.04, with the included compiler.
EDITS:
While I realize that "It does not run" is not helpful, I don't know how else to describe it. I run the compiled program, and it behaves the same as if I entered echo ''. There is no output, no indication that anything has happened. What is the most helpful way to phrase that behavior?
If I use a debugger, I get program exited with code 0xc0000139
A quick google search returns results indication that it is a problem with the compiler. Same as the comments below about my compiler version...
To compile the program, I run g++ main.cpp -o b.exe
To execute it, I run ./b.exe
Mingw has a long standing issue with certain consoles (see their faq). It might be worth checking whether it's failing to output rather than execute by e.g. redirecting to a file ./b.exe >out.txt.
After some useful comments, and much frustration, I decided to try to build the most current compiler. I caved and used Cygwin. (I really have no problem with Cygwin, I just wanted to get MinGW to work.)
I followed this site's instructions (after downloading the current source from https://gcc.gnu.org).
http://preshing.com/20141108/how-to-install-the-latest-gcc-on-windows/
Notes:
This is for an older version of gcc, but I replaced the appropriate version numbers with 8.2.0 (current at this time).
I was missing some prerequisites, and had to cd into the source directory and run ./contrib/download_prerequisites from the Cygwin terminal. It handled everything seamlessly, and while it took a little bit, I am now able to use string data types and run the program (successfully).
Don't forget the final make install command. I did, and it was a headache.
Lastly, thanks to all the helpful comments, and those that asked for clarification. When I call the mechanic, and say, "my car won't run", they ask helpful questions, and we work together to get them the relevant information they need. That's what happened above, and I learned some things (and solved my issue).
I had the same issue. I downloaded mingw a few days from sourceforge and everything complied fine except when I declared a string. Then it would show no output. Maybe it was some problem with the old version (6.3.0). I deleted all the files and re-installed using the given tutorial : https://code.visualstudio.com/docs/cpp/config-mingw . This is a newer version (8.1.0). Now it works just fine!
I'm very new to C++; I've worked with several SDKs now on various applications and every time come across the problem that I can't get the 'example code' to compile. This is a very broad question basically regarding ANY example code that is given over the net - what is the standard procedure to make things compile? I know how to compile code that I've written myself but when given a large project containing several CPP and H files, what do I start with? My first port of call, to open 'main.cpp' in Dev-C++ and hit the 'compile' button generally throws up errors about header files not being available and so on.
I won't give a specific example as this has happened several times. I feel as someone getting to grips with C++ that I would learn a lot quicker if I could start with code that works and tweak it myself rather than having to fumble around building things up piece by piece.
The most recent example is a set of example code provided by a company which 10 files:
-Arial.ttf
-demo_resources.rc
-icon.ico
-main.c
-simple.dsp
-simple.dsw
-simple.exe
-simple.h
-trial.c
-trials.c
Running the .exe file works absolutely fine; however if I open main.c and press compile, I receive many error messages. As an example, the first two lines of code in main.c are:
#include "simple.h"
#include <sdl_text_support.h>
This alone spews the error messages:
1: expected unqualified-id before "public"
1: expected `,' or `;' before "public"
2: In file included from trial.c
Clearly I am doing something very wrong as this code must have compiled for someone else in the past to have generated the .exe file. Again this is not an isolated issue, I have this problem all the time.
Since Dev-C++ is perfectly equipped to deal with plain old C files, I can't see that that is the issue. Secondly, simple.h is definitely included in the correct directory. The second include though, sdl_text_support.h is obviously not in my file list above. I have searched the rest of the SDK and found the file lurking elsewhere. How do I explicitly reference the location of the header file using Dev-C++?
Any general tutorial to how to compile pre-made projects or help of any kind would be greatly appreciated.
I like this page:
http://www.cprogramming.com/tutorial.html
I am not familiar with DevC++, but you cannot assume that if you can open main.c and press a button, then everything will work out. No build system is that smart.
If you write your own code (and you understand compiling and linking) then you can keep your files in order and know exactly how to build everything; someone else's codebase may come with a makefile or some other guide to it's organization, but you'll have to learn how to use a good build system, and the one you're using sounds inadequate.
open the project by simple.dsw instead of main.cpp and it should work .
I am running a very simple C++ program:
#include <list>
#include <vector>
int main(int argc, char **args) {
}
I go to the command prompt and compile and run:
g++ whatever.cpp
a.exe
Normally this works just fine. It compiles fine, but when I run it it says Access Denied and AVG pops up telling me that a threat has been detected Trojan Horse Generic 17.CKZT. I tried compiling again using the Microsoft Compiler (cl.exe) and it runs fines. So I went back, and added:
#include <iostream>
compiled using g++ and ran. This time it worked fine.
So can anyone tell me why AVG would report an empty main method as a trojan horse but if the iostream header is included it doesn't?
UPDATE:
I added a return statement to the main method and now I find that I only get the error if I return 0. Any other return value and it seems to work fine.
What's going on here?
You're not the first person to encounter false positives by antivirus software.
What probably happened is that the antivirus heuristics tripped up on the standard runtime libraries present in your programs, since malware uses them as well. Of course, legitimate software uses them too! The fact that it didn't trip up on iostream probably means that iostream isn't very popular among malware writers.
If you only want to overcome the problem as fast as possible,
just put the folder of the executables into AVG's whitelist.
My preferred steps:
For safety's sake, you should send your executable
to an online virus/malware scanner like these:
www.virustotal.com : VirusTotal - Free Online Virus and Malware Scan
virusscan.jotti.org/en : Jotti's malware scan
if they report 'false positive', then insert the path of the compiled executables
into AVG's whitelist,
so it doesn't scan that folder.
I'm not conversant with AVG, but every antivirus
has an option to exclude files from scan.
If you're brave enough, debug the executable and find the causing call.
An alternative solution may be to virtualize a lightweight linux system,
install gcc (with g++, of course) on it, and use that "g++ dedicated environment"
to
develop your commandline apps.
// The 1st step is a sum-up of this conversation.
// If you send me the source and the 'infected' executable that you compiled, then I'll check it.
// The missing return statement in the (C++) main function means returns 0.