how to "use unicode character set" in g++? - c++

i'm working on a program in c++ where i'm trying to use the WriteProcessMemory() function in windows. for that i need a function that gets the target process id. i'm able to do that using the following function:
#pragma once
#include <Windows.h>
#include <TlHelp32.h>
#include <iostream>
//get process id from executable name using tlhelp32snapshot
DWORD GetProcID(wchar_t *exeName){
PROCESSENTRY32 procEntry = {0};
HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if (!hSnapshot) {
return 0;
}
procEntry.dwSize = sizeof(procEntry);
if (!Process32First(hSnapshot, &procEntry)) {
return 0;
}
do {
if (!wcscmp(procEntry.szExeFile, exeName)) {
CloseHandle(hSnapshot);
return procEntry.th32ProcessID;
}
} while (Process32Next(hSnapshot, &procEntry));
CloseHandle(hSnapshot);
return 0;
}
//main function
int main() {
using namespace std;
cout << "some output" << endl;
return 0;
}
i'm able to compile using visual studio if i set the character set to unicode but when i try using g++ i get a conversion error:
g++ -std=c++17 write.cpp
write.cpp:1:9: warning: #pragma once in main file
#pragma once
^
write.cpp: In function 'DWORD GetProcID(wchar_t*)':
write.cpp:21:43: error: cannot convert 'CHAR* {aka char*}' to 'const wchar_t*' for argument '1' to 'int wcscmp(const wchar_t*, const wchar_t*)'
if (!wcscmp(procEntry.szExeFile, exeName)) {
^
write.cpp: In function 'MODULEENTRY32 GetModule(DWORD, wchar_t*)':
write.cpp:40:46: error: cannot convert 'char*' to 'const wchar_t*' for argument '1' to 'int wcscmp(const wchar_t*, const wchar_t*)'
if (!wcscmp(modEntry.szModule, moduleName)) {
^
i'm able to compile with cl using the arguments:
cl /EHsc /D UNICODE write.cpp
here /D UNICODE is the same as going in visual studio > rmb on project > properties and seting Character Set to Use Unicode Character Set.
is there an option to force unicode in g++ like in cl?

cl (Microsoft C/C++ Compiler) and g++ (Gnu C++ Compiler) have a very close arguments syntax on certain parameter. The delta is more of the usual difference Dos / Shell (slash vs dash).
The equivalent of /DMY_IDENTIFIER (cl) is on g++:
-DMY_IDENTIFER
Which means in your case: -DUNICODE
The complete compilation command line would have to look like:
g++ -DUNICODE -std=c++17 write.cpp

The correct answer here is to use the compiler switch -municode which defines everything you need, and links to the correct CRT files as to provide you with the proper definition of _wmain.
This is not available on ye olde MinGW, so you'll need a MinGW-w64 toolchain for that. Chances are you are already using that anyway. If that is not the case, you can download the installer from here.

Related

A problem when compiling a simple C++ program

When I compile a simple C++ program like this:
#include<iostream>
using namespace std;
int main()
{
cout << "hello word" << endl;
return 0;
}
I got some error message,
This is part of the error message:
In file included from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\cstdlib:75,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ext\string_conversions.h:41,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\bits\basic_string.h:6391,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\string:52,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\bits\locale_classes.h:40,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\bits\ios_base.h:41,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ios:42,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ostream:38,
from e:\mingw\lib\gcc\mingw32\8.2.0\include\c++\iostream:39,
from F:\Desktop\web\web\work_one\test.cpp:1:
e:\mingw\include\stdlib.h:90:1: error: '_BEGIN_C_DECLS' does not name a type
_BEGIN_C_DECLS
^~~~~~~~~~~~~~
e:\mingw\include\stdlib.h:363:1: error: '__CRT_ALIAS' does not name a type
__CRT_ALIAS __cdecl __MINGW_NOTHROW
^~~~~~~~~~~
e:\mingw\include\stdlib.h:367:1: error: '__CRT_ALIAS' does not name a type
__CRT_ALIAS __cdecl __MINGW_NOTHROW
^~~~~~~~~~~
e:\mingw\include\stdlib.h:444:55: error: '_locale_t' has not been declared
__int64 _wcstoi64_l(const wchar_t *, wchar_t **, int, _locale_t);
^~~~~~~~~
e:\mingw\include\stdlib.h:447:65: error: '_locale_t' has not been declared
unsigned __int64 _wcstoui64_l(const wchar_t *, wchar_t **, int, _locale_t);
^~~~~~~~~
e:\mingw\include\stdlib.h:866:1: error: '_END_C_DECLS' does not name a type
_END_C_DECLS
^~~~~~~~~~~~
This seems to be a problem with the header file syntax, but I did not modify the head file.
I use this command to compile:
g++ -g -std=c++11 F:\Desktop\web\web\work_one\test.cpp -o test.exe
My operating system is Win10.
The g++ version is g++ (MinGW.org GCC-8.2.0-3) 8.2.0
G++ I got from http://www.mingw.org/
Possible solution to this already exists here
Just change -std=c++11 with -std=gnu++11
Finally, I fixed the problem. The reason for this problem is that I installed codeblocks.
codeblocks adds environment variables to my computer, like C_INCLUDEDE_PATH, CPLUS_INCLUDE_PATH, and LIBRARY_PATH. When I deleted these environment variables, the problem was fixed.

Problems compiling C++ programs with wineg++/winelib

I am having trouble compiling C++ programs with wineg++. To illustrate my problem, I have written two test programs.
msgbox.cpp
#include <algorithm>
#include <iterator>
#include <cstdio>
#include <windows.h>
int APIENTRY WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
char buf[30], *pos = buf;
int xs[] = {1,3,2,4,3,5,4,6,5,7,6,8,7,9};
std::sort( std::begin(xs), std::end(xs) );
for (int x : xs) {
pos += std::sprintf(pos, "%d ", x);
}
MessageBox(0, buf, "Hello", 0);
return 0;
}
frame.cpp
#include "../win32xx/include/wxx_wincore.h"
#include "../win32xx/include/wxx_frame.h"
int APIENTRY WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
CWinApp winApp;
CFrame frame;
CWnd view;
frame.SetView(view);
frame.Create();
winApp.Run();
}
The second program uses the Win32++ library, which I can't recommend enough.
Both programs compile and run just fine using a cross-compiler:
okuu% x86_64-w64-mingw32-g++ msgbox.cpp -o msgbox.exe
okuu% wine ./msgbox.exe
okuu% x86_64-w64-mingw32-g++ frame.cpp -o frame.exe -lgdi32 -lcomctl32 -static
okuu% wine ./frame.exe
okuu% rm *exe*
But I want to use winelib so that I can use both the Windows API and Unix libraries. This is what I tried first:
okuu% wineg++ msgbox.cpp -o msgbox.exe
okuu% ./msgbox.exe
okuu% wineg++ frame.cpp -o frame.exe -mwindows
In file included from ../win32xx/include/wxx_appcore.h:57:0,
from ../win32xx/include/wxx_wincore.h:96,
from frame.cpp:1:
../win32xx/include/wxx_appcore0.h:120:12: fatal error: process.h: No such file or directory
#include <process.h>
^~~~~~~~~~~
compilation terminated.
winegcc: g++ failed
Then I read wineg++'s man page, which says:
-mno-cygwin
Use Wine implementation of MSVCRT, instead of linking against the host system libc. This is necessary for the vast majority of Win32 applications, as they typically depend on various features of MSVCRT. This switch is also used by the MinGW compiler to link against MSVCRT on Windows, instead of linking against Cygwin libc. Sharing the syntax with MinGW makes it very easy to write Makefiles that work under Wine, MinGW+MSYS, or MinGW+Cygwin.
So I tried again with -mno-cygwin, and got a 2000-line error message that begins with:
okuu% wineg++ frame.cpp -o frame.exe -mwindows -mno-cygwin
In file included from /usr/include/c++/7.2.1/cstdlib:75:0,
from /usr/include/c++/7.2.1/bits/stl_algo.h:59,
from /usr/include/c++/7.2.1/algorithm:62,
from ../win32xx/include/wxx_appcore0.h:110,
from ../win32xx/include/wxx_appcore.h:57,
from ../win32xx/include/wxx_wincore.h:96,
from frame.cpp:1:
/usr/include/stdlib.h:310:5: error: ‘int32_t’ does not name a type; did you mean ‘wint_t’?
int32_t *fptr; /* Front pointer. */
^~~~~~~
wint_t
/usr/include/stdlib.h:311:5: error: ‘int32_t’ does not name a type; did you mean ‘wint_t’?
int32_t *rptr; /* Rear pointer. */
^~~~~~~
wint_t
/usr/include/stdlib.h:312:5: error: ‘int32_t’ does not name a type; did you mean ‘wint_t’?
int32_t *state; /* Array of state values. */
^~~~~~~
wint_t
/usr/include/stdlib.h:316:5: error: ‘int32_t’ does not name a type; did you mean ‘wint_t’?
int32_t *end_ptr; /* Pointer behind state table. */
^~~~~~~
wint_t
/usr/include/stdlib.h:320:8: error: ‘int32_t’ has not been declared
int32_t *__restrict __result) __THROW __nonnull ((1, 2));
^~~~~~~
So it seems C99's fixed-size integer types are not available. That seems easy enough to solve:
frame.cpp
#include <stdint.h>
#include "../win32xx/include/wxx_wincore.h"
#include "../win32xx/include/wxx_frame.h"
// etc. etc. etc.
And I tried again, but got a different 2000-line error message that begins with:
okuu% wineg++ frame.cpp -o frame.exe -mwindows -mno-cygwin
In file included from /usr/include/c++/7.2.1/cwchar:44:0,
from /usr/include/c++/7.2.1/bits/postypes.h:40,
from /usr/include/c++/7.2.1/bits/char_traits.h:40,
from /usr/include/c++/7.2.1/string:40,
from ../win32xx/include/wxx_appcore0.h:111,
from ../win32xx/include/wxx_appcore.h:57,
from ../win32xx/include/wxx_wincore.h:96,
from frame.cpp:2:
/usr/local/include/wine/msvcrt/wchar.h:398:23: error: conflicting declaration of C function ‘size_t mbstowcs(wchar_t*, const char*, size_t)’
size_t __cdecl mbstowcs(wchar_t*,const char*,size_t);
^~~~~~~~
At this point I have run out of ideas. This is what I have understood so far:
My system's libc and Wine's MSVCRT have conflicting definitions. (This was probably to be expected.)
My system's libc++ is hardwired to work with my system's libc.
Wine comes with a MSVCRT, but not with a C++ standard library implementation.
The logical course of action with the information I have so far would be to look for a C++ standard library implementation that's compatible with Wine's MSVCRT, but I don't know of one. Does anybody here know of one?
The only solution I can think of is to stick with the system libc and write your own process.h. This file should either #include the standard header files that have the functions Win32++ needs or provide its own implementations of those functions. If Win32++ won't compile without a particular function but your program does not actually depend on that function, the implementation of that function can simply return 0 or another fake value.
If the system libc has a header file that Win32++ asks for, but the file does not declare all of the functions that Win32++ expects, you'll have to write a header file such as win32xx-compat.h that defines those functions and #include it before any Win32++ header.

<thread>: no match for operator <

I am trying to implement mutlithreading in a C++11 program.
I separated the threading from my main program and tried to get the most basic example working:
#include <iostream>
#include <thread>
void first_procedure() {
std::cout << "First procedure output." << std::endl;
}
void second_procedure() {
std::cout << "Second procedure output." << std::endl;
}
int main() {
std::thread first_thread(first_procedure);
std::thread second_thread(second_procedure);
first_thread.join();
second_thread.join();
return 0;
}
However, even with this example, I get the following error:
c:\program files (x86)\dev-cpp\mingw64\lib\gcc\x86_64-w64-mingw32\4.8.1\include\c++\thread In function 'bool std::operator<(std::thread::id, std::thread::id)':
88 30 c:\program files (x86)\dev-cpp\mingw64\lib\gcc\x86_64-w64-mingw32\4.8.1\include\c++\thread [Error] no match for 'operator<' (operand types are 'std::thread::native_handle_type {aka ptw32_handle_t}' and 'std::thread::native_handle_type {aka ptw32_handle_t}')
I am using the Orwell Dev-C++ 5.7.1 with TDM-GCC 4.7.1 64-bit on Windows 8. When calling the linker, I add -static-libgcc -std=c++11.
Edit 1: I joined the threads and get the same error message.
This was noticed in the comments first:
From your error messages and supplementary details:
compiler: TDM-GCC 4.7.1
includes: gcc\x86_64-w64-mingw32\4.8.1\include
Your compiler is attempting to use libraries that are for a different compiler.
Either use 4.7.1 or 4.8.1, not a mix of the two.
The good news is that your code looks fine. Sort out the toolchain and it should compile without issue.

Why are std::stoi and std::array not compiling with g++ c++11?

I've been learning C++ and using the Terminal for the last couple of months. My code was compiling and running fine using g++ and C++11, but in the last couple of days it started giving errors and I have had problems compiling since. The only programs I can compile and run depend on older C++ standards.
The errors I first got related to #include < array > in the header file. Not sure why this happened, but I got around it by using boost/array instead. Another error I can't solve is with std::stoi. Both array and stoi should be in the C++11 standard library. I made the following simple code to demonstrate what's going on:
//
// stoi_test.cpp
//
// Created by ecg
//
#include <iostream>
#include <string> // stoi should be in here
int main() {
std::string test = "12345";
int myint = std::stoi(test); // using stoi, specifying in standard library
std::cout << myint << '\n'; // printing the integer
return(0);
}
Try to compile using ecg$ g++ -o stoi_trial stoi_trial.cpp -std=c++11
array.cpp:13:22: error: no member named 'stoi' in namespace 'std'; did you mean
'atoi'?
int myint = std::stoi(test);
~~~~~^~~~
atoi
/usr/include/stdlib.h:149:6: note: 'atoi' declared here
int atoi(const char *);
^
array.cpp:13:27: error: no viable conversion from 'std::string' (aka
'basic_string') to 'const char *'
int myint = std::stoi(test);
^~~~
/usr/include/stdlib.h:149:23: note: passing argument to parameter here
int atoi(const char *);
^
2 errors generated.
I also get these errors at compilation when using gcc or clang++ and with -std=gnu++11 (I guess they all depend on the same file structure). I also get the same error whether I specify std:: in the code, or if I specify using namespace std;
I worry that these issues arose because of the September Command Line Tools update via Xcode or because I installed boost and this somehow messed up my C++11 libraries. Hopefully there is a simple solution.
My system:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-> dir=/usr/include/c++/4.2.1
Apple LLVM version 5.0 (clang-500.2.76) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix
Thanks for any insight you can offer.
clang has a weird stdlib, you need to add the following flag when you compile
-stdlib=libc++
your snippet works on my mac with
g++ -std=gnu++11 -stdlib=libc++ test.cpp -o test
This answer describes the problem

MinGw 4.7.0 doesnt compile code with #include <boost/thread>

MinGw 4.7.0 Boost 1.47
code:
#include <iostream>
#include <boost/thread.hpp>
int main(int argc, char *argv[])
{
std::cout<<"In main"<<std::endl;
}
Compiler string:
g++.exe -Wall -fexceptions -g -IC:\soft\ides_comp\mingw\include\boost_1_47_0 -c D:\work\cpp_cb\mt1\main.cpp -o obj\Debug\main.o
It doesnt compile and i have same error whatever compiler options i tried.
Warning:
In file included from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/win32/thread_data.hpp:12:0,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/thread.hpp:15,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread.hpp:13,
from D:\work\cpp_cb\mt1\main.cpp:2:
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/win32/thread_heap_alloc.hpp:59:40: warning: inline function 'void* boost::detail::allocate_raw_heap_memory(unsigned int)' declared as dllimport: attribute ignored [-Wattributes]
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/win32/thread_heap_alloc.hpp:69:39: warning: inline function 'void boost::detail::free_raw_heap_memory(void*)' declared as dllimport: attribute ignored [-Wattributes]
Error:
In file included from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/smart_ptr/shared_ptr.hpp:30:0,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/shared_ptr.hpp:17,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/date_time/time_clock.hpp:17,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/thread_time.hpp:9,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/win32/thread_data.hpp:10,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread/thread.hpp:15,
from C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/thread.hpp:13,
from D:\work\cpp_cb\mt1\main.cpp:2:
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/checked_delete.hpp: In instantiation of 'void boost::checked_delete(T*) [with T = boost::error_info<boost::tag_original_exception_type, const std::type_info*>]':
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/smart_ptr/detail/shared_count.hpp:95:13: required from 'boost::detail::shared_count::shared_count(Y*) [with Y = boost::error_info<boost::tag_original_exception_type, const std::type_info*>]'
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/smart_ptr/shared_ptr.hpp:183:50: required from 'boost::shared_ptr<T>::shared_ptr(Y*) [with Y = boost::error_info<boost::tag_original_exception_type, const std::type_info*>; T = boost::error_info<boost::tag_original_exception_type, const std::type_info*>]'
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/exception/info.hpp:171:69: required from 'const E& boost::exception_detail::set_info(const E&, const boost::error_info<Tag, T>&) [with E = boost::unknown_exception; Tag = boost::tag_original_exception_type; T = const std::type_info*]'
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/exception/info.hpp:192:46: required from 'typename boost::enable_if<boost::exception_detail::derives_boost_exception<E>, const E&>::type boost::operator<<(const E&, const boost::error_info<Tag, T>&) [with E = boost::unknown_exception; Tag = boost::tag_original_exception_type; T = const std::type_info*; typename boost::enable_if<boost::exception_detail::derives_boost_exception<E>, const E&>::type = const boost::unknown_exception&]'
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/exception/detail/exception_ptr.hpp:182:13: required from 'void boost::unknown_exception::add_original_type(const E&) [with E = std::exception]'
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/exception/detail/exception_ptr.hpp:161:32: required from here
Warning 2:
C:\soft\ides_comp\mingw\include\boost_1_47_0/boost/checked_delete.hpp:34:5: warning: deleting object of polymorphic class type 'boost::error_info<boost::tag_original_exception_type, const std::type_info*>' which has non-virtual destructor might cause undefined behaviour [-Wdelete-non-virtual-dtor]
What can it be? Thanks
This has been fixed in later boost versions. Check here:
https://svn.boost.org/trac/boost/ticket/6165
Update boost/config/stdlib/libstdcpp3.hpp:
#if defined(_GLIBCXX_HAVE_GTHR_DEFAULT) \
|| defined(_GLIBCXX_HAS_GTHREADS) \
|| defined(_GLIBCXX__PTHREADS) \
|| defined(WIN32)
Added _GLIBCXX_HAS_GTHREADS and/or WIN32 (from the link above, see patch).
WIN32 seems a bit brute force, but doesn't work without (at least not for me. I am using an older boost version 1.42).
If you compiled the thread library for using Win32 threads, you might need
-DBOOST_USE_WINDOWS_H
in your compiler flags. While I don't think that's the issue (I get a different set of errors for not using it), you might give it a try.
This answer maybe not very straight, but:
I do use g++ 4.7.0 20111209 and it has support for threads.
#include <iostream>
#include <thread>
using namespace std;
void foo()
{
cout << "Hello from thread\n";
}
int main()
{
thread th1(foo);
th1.join();
return 0;
}
During compilation use -std=c++11 option to use the latest standard which supports threads
PS:
boost 1.48 compiled on my pc with mingw 4.7.0 gives an error (when trying to use boost::thread):
Threading support unavailable: it has been explicitly disabled with BOOST_DISABLE_THREADS
So I guess it was disabled by default with g++ 4.7.0 (with g++ 4.6.2 it was not).