I have just downloaded MinGW 64 bit for Windows (I'm not quite used to Linux) on http://sourceforge.net/projects/mingw-w64/?source=dlp
When I compile the following code, I get no errors:
#include <iostream>
int main()
{
std::cout << "Code 64 bit :D !" << std::endl;
return 0;
}
Also, when I execute the program in Code::Blocks, eveything works perfectly (using cb_console_runner.exe). The problem occurs when I execute my program outside Code::Blocks. I get the error "The application couldn't start properly (0xc000007b)". By the way, I translated the error from french. Do you have any idea what is the problem or how I can debug this? Oh I forgot: I don't get any errors when code is empty (i.e. when int main(){return0;}).
Thank you!
I've seen this happen here and there when GCC's standard C++ library (libstdc++) (or libgcc as well) is not in your %PATH%. Furthermore, this may also be the case that you have a mismatched version (i.e. a 32 bit version) of the same DLL in your path. Use something like Dependency Walker to determine this.
This doesn't happen when your program is empty since you are not using any symbols from the standard C++ library and thus it is not linked with your application. However when you use std::cout that references a symbol defined in the C++ library and thus it must be linked.
Related
We are compiling fmt with the Intel C compiler on Windows 32bit and 64 bit. On 32 bit we get a strange error. Maybe we are doing something wrong but the issue is what? Here is the error message:
../master/extern/fmt/8.0.1/include/fmt/format-inl.h(1126): error: expression must have a constant value
static constexpr const uint128_wrapper pow10_significands[] = {
^
Any suggestions for a fix? We could potentially build with MSVC.
Update: format-inl.h (=inline format) is only supposed to be used in a header only mode as far I understand and that is not what I want and has not turned on. So I have to figure why this happens.
PS: fmt is great.
The expression in question is constant so this looks like a bug in the compiler or possibly incomplete implementation of constexpr. The error message is misleading but you might be able to workaround the issue by removing constexpr or some other way.
Have you tried building with a C++17 compiler? constexpr isn’t a C keyword afaik.
I have a project that I converted from Visual Studio 2003 .NET to Visual Studio 2010. It's NOT a .NET project; it's Visual C++ (unmanaged).
The DLL pulls in additional DLLs. If I link an executable with this DLL, then the executable dies during the initialization of the DLL. (I can tell, there are constructors for static objects that are being called, and I can see their operation.) I've removed ALL VS 2010-created DLLs from my path, except for one of them, which causes the error. Replacing that one with the VS.NET-created version allows the program to run.
Since I'm not getting any useful information, I decided to write a test application that doesn't directly link to the DLL, but instead uses LoadLibrary to load the library. The idea was that I could use GetLastError() to help figure the issue with the library. No go; I get an error code -529697949, which isn't a Windows error code at all! (If I change the DLL to the VS.NET-created version, the program loads the DLL properly.)
I used the Dependency Walker (www.dependencywalker.com) to check the DLL, and it tells me that "At least one delay-load dependency module was not found," highlighting IESHIMS.DLL and WER.DLL. I am seeing no other error with that tool. Running it on the VS.NET-created DLL shows the same two warnings, so I figure this is a red herring.
static void showMessage(const wchar_t *wmsg)
{
std::wcout << wmsg << std::endl;
::MessageBox(NULL, wmsg, TEXT("Message"), MB_OK);
}
static void testLoadLibrary(const wchar_t *lib)
{
::SetLastError(0L);
::SetErrorMode(0);
std::wstringstream wss;
wss << "LoadLibrary: " << lib;
showMessage(wss.str().c_str());
HINSTANCE LoadME = ::AfxLoadLibrary(lib);
if (LoadME == NULL) {
DWORD dw = ::GetLastError();
wss << "Failed: Error code " << dw;
showMessage(wss.str().c_str());
ErrorExit(lib, dw);
} else {
wss << "LoadLibrary of " << lib << " succeeded.";
showMessage(wss.str().c_str());
::FreeLibrary(LoadME);
}
}
Finally, I ran Process Monitor (sysinternals.com) to monitor the test program, looking at all entries with Path containing the string "dll." I don't see anything particularly informative in this list--no idea why the DLL is failing to load.
If I use LoadLibraryEx with DONT_RESOLVE_DLL_REFERENCES, the library loads, so this really looks like a dependency issue, which is why I'm surprised that the dependency walker isn't being particularly helpful.
I've tried this on Windows 2008 R2 and Windows 2003; same behavior.
Any suggestions?
There is an OS tool to help diagnose problems like this. Download the SDK or DDK and use gflags.exe to set 'Show Loader Snaps' (+sls) for the process. That should reveal why the DLL load fails.
The loader snaps output will appear in the debugger output window.
Martyn
I'm using bison & flex (downloaded via cygwin) with vc++. When I compile the program I got an error:
...: fatal error C1083: Cannot open include file: 'unistd.h': No such file or directory
The corresponding code in the flex-generated file is:
#ifndef YY_NO_UNISTD_H
/* Special case for "unistd.h", since it is non-ANSI. We include it way
* down here because we want the user's section 1 to have been scanned first.
* The user has a chance to override it with an option.
*/
/* %if-c-only */
#include <unistd.h>
/* %endif */
/* %if-c++-only */
/* %endif */
#endif
If I define YY_NO_UNISTD_H in the flex file(.l) this error will disappear, but I get several other errors:
...: error C2447: '{' : missing function header (old-style formal list?)
...: warning C4018: '<' : signed/unsigned mismatch
...: error C3861: 'isatty': identifier not found
How can I fix this problem?
All these errors occur in the flex-generated scanner.
I know it's because unistd.h doesn't exist in windows. Do I have to write my own unistd.h? If so how to write it in order to eliminate those errors?
isatty is used by the lexer to determine if the input stream is a terminal or a pipe/file. The lexer uses this information to change its caching behavior (the lexer reads large chunks of the input when it is not a terminal). If you know that your program will never be used in an interactive kind, you can add %option never-interactive to you lexer. When the program is run with user input, use %option interactive. When both uses are desired, you can either generate an interactive lexer, which gives a performance loss when used in batch mode, or provide your own isatty function.
Use %option nounistd in your .l file to remove the dependence on unistd.h.
just in case somebody's still this problem, Flex comes with unistd.h within its devel files. I found this here:
http://sourceforge.net/tracker/index.php?func=detail&aid=931222&group_id=23617&atid=379173
to put it short, just make sure your compiler can reach it. in my case it's just adding "C:\GnuWin32\include" to the additional inclusion directories
use win_flex.exe with option --wincompat and you dont need to hack your lex file
unistd.h is a UNIX header, so it's not present in VC++; your best bet is probably to compile it using g++ in Cygwin (or mingw/msys). You could also look at this question for other suggestions.
I'm using flex 2.5.4 that comes from the GnuWin32 project, which doesn't check for YY_NO_UNISTD_H.
In my version, Flex looks for unistd.h only when being compiled as C++, so you can save yourself all this trouble if your yylval doesn't use any C++ constructs.
I had to use the STL in yylval (using a pointer to make it a POD type), so in order to make flex compile in C++ I created this simple unistd.h:
#include <io.h>
That's all it takes (actually, I could copy the unistd.h file that comes with GnuWin32, like flyontheweb suggests).
P.S. To wrap things up: in Bison I put yylval's required STL header files in %code requires {} and added the current directory to the INCLUDE paths in my makefile.
I am too late but anyway I will share my findings to save someone still looking for answer.
In my case having an empty unistd.h file in the location where compiler looks for headers works for me.
Well this post is old but I face the same problem and here is something that should work.
WinFlexBison
I ran into this problem recently after upgrading to Angular 14.
npm install -g latest-version
resolved my issue.
i got a new programing book (multicore programming by cameron hughes, tracey hughes).
so far i have not got one of their programs to work their book says that it should work on 99% of computers so im a little confused but at the end of each program in their book they have "compile and link instructions"... do i need to enter that? it looks something like this "C++ -o guess_it guess_it.cc". the code im runnning right now is:
#include <iostream>
#include <windows.h>
#include <string>
#include <spawn.h>
#include <sys/wait.h>
using namespace std;
int main(int argc,char *argv[],char *envp[])
{
pid_t ChildProcess;
pid_t ChildProcess2;
int RetCode1;
int RetCode2;
int Value;
RetCode1 = posix_spawn(&ChildProcess,"find_code",NULL,
NULL,argv,envp);
RetCode2 = posix_spawn(&ChildProcess2,"find_code",NULL,
NULL,argv,envp);
wait(&Value);
wait(&Value);
return(0);
}
im running windows 7(32-bit), AMD athion x2 7550 dual-core proessor, VC++ 2008 Express edition.
i get the following error : fatal error C1083: Cannot open include file: 'spawn.h': No such file or directory
anyone know why i can't get my code to run? do i need to download something? because i read the book and did not see anything about downloading anything but i might be wrong. :(
It looks like that book is using POSIX threading. Visual Studio uses Windows Threading by default, which has a completely different API.
You most likely just need to get a copy of a POSIX Thread library for Windows. That will include spawn.h and the appropriate lib files for you to use.
Forgive me if I'm misreading your level of experience here, but it sounds as though you are a complete beginner with this language.
The example compilation and link instruction in the book
C++ -o guess_it guess_it.cc
is an example of how to invoke a compiler and linker from the command line. If you're using Visaul C++ then the IDE will automate the compilation and link process for you when you click the "build" button, so you don't need to worry about doing this from the command line.
On to the error you're seeing in VC++:
The compiler is telling you that it can't find the header file spawn.h, which you've told it that your program needs in the line
#include <spawn.h>
As other on this page have mentioned, spawn.h is a file supplied by the POSIX standard libraries and contains functionality for spawning new processes.
Respectfully, it sounds to me from the way you asked your question ("compile and link instructions") as though you don't really understand what you're doing. Before you delve into multi-threading in C++, I recommend taking a step back and find a beginner's book on C++ using Visual Studio, and start from the beginning. I'm afraid you'll make very little progress unless you take the time to learn the fundamentals, and using the compiler is about as fundamental as it gets!
Good luck!
While migrating a program from windows in linux I encountered a problem using the c++ standard template library. I am trying to typedef a template and I am getting the error 'expected initializer before '<' token on this line
typedef std::list< std::pair< int,double> > PairList;
Any ideas why this would work using mvc++ and not using g++ and how I can fix it?
I think this is about #includes.
The following really minimal piece of code compiles perfectly here with g++ on Linux
#include <utility>
#include <list>
typedef std::list< std::pair< int,double> > PairList;
PairList x;
One thing to remember about standard include files is that they are allowed but not required to call each other. (It's not like they're potentially polluting the namespace by this, since they all use namespace std, which you aren't supposed to mess with.)
It is possible that, in MSVC++, includes , or vice versa, but this is not the case in the g++ headers. Therefore, a program might compile in MSVC++ and not in g++, with a required header missing in the source.
Make sure all of your required headers are actually included, and you should be fine.
Did you #include <utility> for pair?
I have had no problems with the code in G++, and generally found its STL support to be superb. Do you have all the #include directives there? Sometimes those differ from platform to platform (even when they shouldn't).