Whenever I try to compile this code it always ends up with this error:
In file included from /usr/include/wchar.h:6:0,
from /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/cwchar:44,
from /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/bits/postypes.h:40,
from /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/iosfwd:40,
from /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/ios:38,
from /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/ostream:38,
from /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/iostream:39,
from test.cpp:1:
/usr/include/sys/reent.h:14:20: fatal error: stddef.h: No such file or directory
#include <stddef.h>
^
compilation terminated.
The code I was trying to compile is:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World! :D";
return 0;
}
The error is because your gcc-core package and gcc-g++ are not of the same version. Either downgrade one of them to solve the problem or update both the libraries. Updating both the libraries is the recommended way.
I had this error on a fresh MinGW install, it had nothing to do with the installed packages mentioned in the current accepted answer by "Prasanth Karri". In my case the issue was caused by -nostdinc in my Makefile. I actually only needed that compiler flag when building for a different target platform (not when using MinGW) so I fixed the issue by removing that flag from MinGW builds.
When I was incorporating a software library written in C into an existing demo project(used a C++ mbed library) I encountered this problem. The demo project would compile just fine, but after I replaced the existing main file by my own, this error occurred.
At this point I hadn't yet thought about the fact that the mbed library that I needed was written in C++. My own main file was a .c file that #include the mbed header file. As a result I used my normal C source as if it was a C++ source. Therefore the compiler that was used to compile my main file was the C compiler.
This C compiler then encountered a #include of a module that actually does not exist (within its scope), as it's not a C++ compiler.
Only after I inspected the output of the build log I realised the various source C and C++ files were compiled by more that 1 compiler(the c++ compiler). The project used used compilers arm-none-eabi-c++ and arm-none-eabi-gcc (for embedded systems) as seen below.
Compile log:
Building file: ../anyfile.cpp
Invoking: MCU C++ Compiler
arm-none-eabi-c++ <A lot of arguments> "../anyfile.cpp"
Finished building: ../anyfile.cpp
Building file: ../main.c
Invoking: MCU C Compiler
arm-none-eabi-gcc <A lot of arguments> "../main.c"
In file included from <Project directory>\mbed/mbed.h:21:0,
from ../main.c:16:
<Project directory>\mbed/platform.h:25:19: fatal error: cstddef: No such file or directory
compilation terminated.
Of course in a C++ environment cstddef exists, but in a C environment cstddef doesn't exist, in stead it's just C's implementation of stddef.
In other words, cstddef does not exist in the C compiler.
I resolved this problem by renaming my main.c file to main.cpp and the rest of the code compiled smoothly too.
TLDR/Conclusion: When building a C++ project, avoid mixing C files with C++ files(sources and headers). If possible rename .c files to .cpp files to use the C++ compiler in stead of the C compiler where required.
In order to update it, follow below.
If you are on Windows, just run these on command prompt or powershell
Update the package list: mingw-get update
After updating the package list, run: mingw-get upgrade
Source: How to update GCC in MinGW on Windows?
This problem was solved for me as I installed codeblocks with mingw compiler then I copied the mingw folder from codeblocks to C drive and added
C\mingw\bin to the environment variables.
If you try to compile and see a message like, "fatal error: stddef.h: No such file or directory", the error is because your gcc-core and gcc-g++ packages are not of the same version. Rerun the Cygwin install and make sure that you select the highest numbered versions of gcc-core and gcc-g++.
After installing the C++ compiler with MinGW I encountered this problem as well. Apparently, you have to also install mingw32-base. Go to C:/MinGW/bin/mingw-get.exe (my path) and check it for installation at the Basic Setup tab.
Related
I recently installed include-what-you-use (IWYU) to try it out. I am on version include-what-you-use 0.12 based on clang version 9.0.1-10. (My OS is Ubuntu 20.04 on WSL1)
I tried to do a very simple example on a source code file, but it quickly comes back as an error on the very first include? (Which is just a c standard library file)
After running
include-what-you-use myutils.cpp:
In file included from myutils.cpp:8:
In file included from ./myutils.h:11:
/usr/bin/../lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/cfloat:42:10: fatal error: 'float.h' file not found
#include <float.h>
^~~~~~~~~
Why is it error'ing out on a c standard library include?
I cannot post the entire source here, and without extensive testing I am not sure what minimal example would cause this problem.
Am I just mis-using IWYU? I installed it via apt rather than building it and llvm/clang/etc from scratch. Is that fine?
I can't build this simple program on cygwin:
#include <nan.h>
int main(){}
I get this error message:
$ g++ a.cpp
a.cpp:1:17: fatal error: nan.h: No such file or directory
compilation terminated.
Is it possible to install something on cygwin to get correct nan.h?
nan.h is an obsolete include of old gcc. On Cygwin NAN is defined on math.h
You can not use a software written in 2008
https://boutell.com/fracster-src/doubledouble/doubledouble.html
for such specific issue and just hope than it works out of the box.
You need to figure out where nan.h is located and than Add this path to the includes.
How to make g++ search for header files in a specific directory?
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
The actual error is a linker error. Undefined reference to get_driver_instance.
Any ideas what the problem is?
This is what I did to install.
Download and install MinGW to C:\MinGW. http://www.mingw.org/
Download boost and move the boost folder to C:\MinGW\include
Download Connector/C++ 1.1.3 http://dev.mysql.com/downloads/connector/cpp/
Move the mysql_connector/include/*.h (recursively) to C:\MinGW\include\
Move the mysql_connector/lib/mysqlcppconn-static.lib to C:\MinGW\lib\libmysqlcppconn-static.a
Move the mysql_connector/lib/mysqlconncpp.dll to C:\MinGW\lib\mysqlconncpp.dll
Alter cppconn/config.h to remove dupication
Copy the C++ example and name it test.cpp http://dev.mysql.com/doc/refman/5.1/en/connector-cpp-examples-complete-example-1.html
add "using namespace sql::mysql" to the file (as recommended)
run "g++ test.cpp -L C:\MinGW\lib -l mysqlcppconn-static"
It's likely in a namespace.
throw in this and see what happens:
using namespace sql::mysql;
edit: Also, did you look through the approximately 869 other times people have asked this same question on stack overflow before posting?
https://www.google.com/search?q=mysql+get_driver_instance+site:stackoverflow.com
If that isn't it, it can be a problem with c++ name mangling.
https://en.wikipedia.org/wiki/Name_mangling#Name_mangling_in_C.2B.2B
Because the name-mangling systems for such features are not standardized across compilers, few linkers can link object code that was produced by different compilers.
and I think the final answer is here:
http://www.mingw.org/wiki/MixingCompilers
another stack overflow answer saying this:
What problems can appear when using G++ compiled DLL (plugin) in VC++ compiled application?
You'll need to build the connector from source using your g++ compiler:
http://dev.mysql.com/doc/refman/5.1/en/connector-cpp-installation-source.html
I'm doing an application for Android using NDK. This is the code received when I compile de C++ code:
Compile++ thumb : pfc_paquete_libreria_PFClib <= pfc_paquete_libreria_PFClib.cpp
In file included from jni/opencv2/core/core.hpp:4342,
from jni/pfc_paquete_libreria_PFClib.cpp:5:
jni/opencv2/core/operations.hpp:62:33: error: ext/atomicity.h: No such file or directory
I found "atomicity.h" in libraries of Cygwin, but GCC compiler don't fount them.
Any idea to solve this problem?
If you know where atomicity.h is, simply add the directory where it resides to the include directories using your compiler's -I switch.