hello world troubleshooting

Can not launch the executable

This can be caused by an antivirus program, which assumes unknown executables are suspicious. To workaround, most antiviruses have an option to exclude specified directories from automatic scanning.

Strange x86 / x86_64 error when launching the executable

You have a 32-bit computer but build the project for 64-bit. Your processor architecture can not run this instruction set.

Solution: change settings so that 32 bit programs are built instead.

• GCC / Clang: add -m32 to compiler and linker flags

• MSVC: open project properties and the linker settings

Works, but disappears immediately

This is a correct behaviour, since the only task for the program was to print the text and close (sometimes it may not even open a terminal if build with specific compiler/linker options). It's actually a feature in some IDEs that they stop the program when it finishes so the window does not disappear.

There are multiple workarounds:

• fiddle with IDE settings

• run the program in a console terminal (the program will close, but the terminal will not)

• insert std::cin.get(); at the end of main function - this will wait for a key press; may not work if you mix it with other input methods - if this is the case use these (identical) methods instead (I don't want to explain stream peculiarities here)

IDE can not find the compiler

This problem usually appears where after installing (or just unpacking) a compiler it's not automatically added to the PATH environmental variable. This variable is used by many programs to search for other programs.

Copy the path of your compiler binary directory and append it to the PATH in Control Panel -> environmental variables (this is a pretty deeply hidden option, search the internet for screens if you can't find it).

The path should be a sequence of directories leading to the one where the compiler executable resides. For example, if your compiler path is C:\MinGW\bin\g++.exe (the bin directory for various GCC ports is usually full of executables and some dll files) the added path should be C:\MinGW\bin. MinGW-w64 distributions may have longer paths such as C:\mingw-w64\i686-7.2.0-posix-dwarf-rt_v5-rev1\mingw32\bin).

• If the variable PATH does not exists in the list, just add it (name it PATH and the value is the actual path)

• if PATH already exists, append your path to it after semicolon: C:\foo;C:\bar;C:\compiler\bin. Newer Windows versions offer improved interface which presents PATH as an array of values - then just add a new entry.

Changes to environmental variables require to close all console terminals (e.g. cmd). If it doesn't work, try restarting the system.

After PATH is set, you should be able to call the compiler from the command line, regardless of the working directory:

C:\Users\admin>g++ --version
g++ (i686-posix-dwarf-rev1, Built by MinGW-W64 project) 7.2.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

IDE sees the compiler but can not find make

This problem is similar to the one above - this time the make program can not be found.

Go to your compiler installation directory and check that make actually exists in the bin directory. You may find something like mingw-make32.exe or i686-w64-mingw32-make.exe. It is because various GCC distributions prefix some executable names with architecture name in case someone wanted to have a multi-architecture toolchain installed in 1 place. I hardly doubt you want to compile now for something other than x86 (i686) / x86_64 (these are the architecture names of standard 32-bit and 64-bit PC).

If this is the case - simply copy the executable and give the copy a make.exe name. Do not just rename - copy and leave both variants - this is because some other tools might have hardcoded expectation of the original name.

You might also find more executables with prefixed names - in case of problems do the same.

Test that it works by calling make from the command line:

TODO make --version

Nothing happens when the executable is launched

If you are trying to launch it from the Explorer (the file/directory browsing program), open command line in this directory (as a shortcut you can click the path and just write "cmd") and attempt to launch it from the terminal. This sometimes results in displaying what has gone wrong.

Missing dll

This means that the program has been built successfully but some compiled code is missing - usually the implementation of the C++ standard library (libstdc++-6.dll) or other dynamically linked libraries that are needed in order to run (they vary depending on the compiler).

These files can be found in the bin directory of the compiler's installation. To avoid DLL Hell, simply copy required files to your executable's directory.

An alternative would be to use static linking instead, which copies required machine code into the executable. See https://stackoverflow.com/questions/26103966/how-can-i-statically-link-standard-library-to-my-c-program for more information.

something stdafx.h or fatal error C1010

This comes from a popular feature known as precompiled headers. The purpose of it is to speed up building process, though I have to admit that no IDE does it in a so intrusive way as Visual Studio (this is the only implementation of precompiled headers I know which requires changes in code).

You have few options:

• Create a file named stdafx.h and add it to your project (the file can be empty)

• Disable precompiled headers

• Change precompiled headers to use a non-code-intrusive way (I heard this is somehow possible)

• Use a different project wizard (VS has a lot of options in the "new project" menu)

See https://stackoverflow.com/questions/4726155/ for more information.

Permission denied when trying to launch the program

Check that the executable is actually an executable. Verify that it has x flag on by using ls -l /path/to/executable. If not, add the flag by chmod +x /path/to/executable.

IDE can not find the compiler

Some distributions may come with GCC already, but it may have only C components installed or have an old version of the C++ compiler. Check the version of both gcc and g++. On some system configurations gcc --version might print a different number from g++ --version.

Various distributions offer C and C++ compilers in their package managers (apt, yum, etc.), installing them using commands like sudo apt install g++ is the simplest way although the delivered programs may not be very recent.