I'm a complete newbie to C++. I'm trying to write a simple c++
program but I got an error message. I suspect this is due to me
accidentally deleting some .h files on my mac which might have ruined
my Clang compiler. How can I fix this? Do I need to reinstall Xcode or
change a compiler?
Error message from terminal:
192:desktop ivanlee$ gcc test.cpp
In file included from test.cpp:1:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/iostream:38:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/ios:215:
In file included from /Library/Developer/CommandLineTools/usr/bin/../include/c++/v1/iosfwd:90:
In file included from /usr/include/wchar.h:70:
In file included from /usr/include/_types.h:27:
/usr/include/sys/_types.h:32:10: fatal error: 'sys/cdefs.h' file not found
#include <sys/cdefs.h>
^
1 error generated.
Code:
#include <iostream>
int main(){
return 0;
std::cout << "Hey";
}
At first I ought to recommend you the definitive stackoverflow c++ books list. Read these books and get your skills grow. This also will prevent questions like this.
Your question needs very-very basic knowledges and answers may be too long and your problem can be solved by many different methods.
I can tell you one but you should not ask questions like this.
Answer
Your code contains a mistakes:
return 0 before your other instructions (it should be the last). Now your program will just do nothing.
You should always compile C++ code with C++ compiler. gcc is not a c++ compiler but c compiler - use g++ instead.
Even if you correct 2 errors above, your std::cout call may fail because it does not flush the stream. You should also add << std::endl to this call.
Execute
g++ test.cpp -o out
Instead of
gcc text.cpp
run Terminal
execute gcc -v
Read the info and copy the include path. Copy it to your IDE that allows you to add the include path.
Mine, for an example, is:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/c++/4.2.1
Related
I have this simple file, called lol.c
#include <iostream>
using namespace std;
int main() {
return(0);
}
From terminal, i type g++ lol.c
This is the output:
In file included from /usr/include/wchar.h:36:0,
from /usr/include/c++/4.9/cwchar:44,
from /usr/include/c++/4.9/bits/postypes.h:40,
from /usr/include/c++/4.9/iosfwd:40,
from /usr/include/c++/4.9/ios:38,
from /usr/include/c++/4.9/ostream:38,
from /usr/include/c++/4.9/iostream:39,
from lol.c:1:
/usr/include/stdio.h:30:22: fatal error: SDL_main.h: File o directory non esistente
#include "SDL_main.h"
^
compilation terminated.
I don't know if the problem is something with SDL, but when i try to run ../configure to install it, i have this:
configure: error: cannot run C compiled programs.
See `config.log' for more details
If is this needed, i can put config.log file too.
There are multiple problems:
you gave a .c extension to a C++ source file; that is wrong, C++ files should have a .cpp (or .cxx, .C, .c++, the last two are a bit frowned upon) extension, or the compiler may try to compile it as C code;
you are invoking gcc instead of g++; this is wrong too, calling gcc on C++ files misses several options required to compile and link correctly (including, but not limited to, linking against the C++ standard library); that was in an older revision of the question, now it says g++;
but most importantly, your build environment is completely broken (some would say "FUBAR"); it is not normal that /usr/include/stdio.h includes stuff from SDL (the fact that it cannot be found is just a minor incident compared to this); you should really purge and reinstall anything related to gcc and to the headers of the C library; look for some libc6-dev package (or similar) to reinstall (be careful not to mess with the C library proper, or your system may be rendered essentially unbootable).
You can't give .c (c extension) to a c++ file.
1 - Change it to .cpp (c++ extension, lol.cpp)
2 - You have to give options to g++ (in your case use -o to create executable file) g++ lol.cpp -o nameofyourprogram
3 - Execute through your terminal ./nameofyourprogram
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.
Earlier, I posed a related question.
I have the following program extracted from a large project in my Mac OS
#include <iostream>
int main(){
std::cout<<"hello"<<std::endl;
return 0;
}
Compiling it with Clang fails with the following error:
$ clang test.cpp
test.cpp:1:10: fatal error: 'iostream' file not found
#include <iostream>
^
1 error generated.
For information,
A) I have already installed xcode command line tools, using xcodeselect --install. But it seems iostream does not locate in the default search path of clang.
B) Using g++ instead of clang compiles the program. But in my problem, I am not allowed to use other compiler than clang, or to change the source program.
C) I can see workaround techniques, e.g, by tweaking the search path in .bashrc or with some symbolic link, etc. But I feel reluctant to use them, because it seems that I have an installation problem with my Clang and tweaking the path only helps to avoid one of these path issues.
clang and clang++ do different things. If you want to compile C++ code, you need to use clang++
Alternatively you can invoke c++ compiler directly by providing language name explicitely:
clang -x=c++
I'm trying to use shared_ptr from std:: in c++ 11 so I'm including which apparently uses typeinfo. The problem is that I'm getting the error bellow.
In file included from /usr/include/c++/4.8/memory:71:0,
from /home/dev/openclTest/modules/Quant.cpp:10:
/usr/include/c++/4.8/typeinfo:39:37: error: expected ‘}’ before end of line
#pragma GCC visibility push(default)
From what it sounds like, this is a known bug listed here:
https://lists.debian.org/debian-gcc/2007/09/msg00497.html
Anyway, I was hoping I didn't have to use boosts library, so if there's a quick fix anyone knows about, please let me know. I'm using cmake and g++ to build the project.
Thanks!
I just had a similar issue with GCC 4.9.2. It seems to be the common error message in case you forget some braces in a file included prior to typeinfo.
I did not find the code to exactly reproduce the message but got something very similar using this minimal test:
test.cpp:
{
#include <typeinfo>
int main() {}
I guess it is likely the same error as yours as it happens in very different GCC versions. In case it really is the same issue, check your other includes.
I have the following very simple application that compiles and runs fine:
EDIT: changed the example to be simpilar to end confusion of the real issue
int main() {
return 0;
}
As soon as I add #include <string> (and not even reference std::string), it fails to compile and I get the following error:
/usr/include/c++/4.1.2/bits/allocator.h:82 error: expected template-name before '<' token
Along with about 456 other, similar errors.
Any ideas? Thanks!
UPDATE:
Line 82 of /usr/include/c++/4.1.2/bits/allocator.h references the template __glibcxx_base_allocator at the location of the error. That template is defined in bits/c++allocator.h. When I search the system for that file, I get 3 hits, but none of them are in /usr/include/c++/4.1.2/bits/ as one would expect.
I have version 3.1.6, 4.1.1, and 4.3.2, but not 4.1.2 as the rest of the includes I am using. I am not sure which one is being used (if any, however, I don't get any error for an unknown file), but it seems the problem may stem from this.
The problem appears to be the installed development packages are not correct or incomplete (not to be confused with corrupt). Forcing g++ to use different include versions corrects that:
g++ -nostdic++ hello.cc -o hello -I/usr/include/c++/3.4.6
All the alternative directories (4.1.1, 4.1.2 and 4.3.2) are incomplete causing inappropriate files to be included causing the unusually errors. For example:
/usr/include/c++/4.1.2/bits/allocator.h requires __glibcxx_base_allocator located in bits/c++allocator.h which is being included from either /usr/include/c++/4.1.1 or /usr/include/c++/4.3.2 and appear to be incompatible. Forcing the compiler to use the only complete set of includes rectifies this.
Almost certainly g++ is detecting .cc as a C source file, not C++ and passes it through to gcc instead of compiling as C++. You can easily test by renaming your file to hello.C. There's also a language parameter to g++ you can use.
EDIT: This seems to work fine in g++ 4.2 with a .cc extension so that might not be it. Do you have any other headers included you aren't showing us? They could be interfering with <string>.
EDIT2: Alternatively your headers might not be set up right. Does this work:
#include <string>
int main()
{
return 0;
}
Errors like this have been heard of to occur when the C++ standard library headers are corrupted/not fully installed – maybe there is even a message referring to a missing include among your 456 other errors.
In any case, make sure that libstdc++-devel, resp. the package containing the C++ standard library header files of your distribution, is properly installed.
Check your include path. The paths can be specified as environment variables or specified on the command line. You could be using an include file from a different compiler or different version of the same compiler.
Also, try using <cstdio> rather than <stdio.h>.
Another suggestion: change <> to "".
This could be error caused at preprocess stage. Just preprocess your cpp file by passing flag -E to gcc and Look at the place the compiler complains.