Question 304831 in Visual Studio Code Question posted in
View the official documentation.

Visual Studio Code – unable to use headers with vscode

I am trying to use headers in vscode but I run through a lot of problems

this is print.c

#include <stdio.h>

void print1to10()
{
    for (int i = 1; i <= 10; i++)
        printf("%d ", i);
}

this is print.h

#ifndef PRINT_TO_10_H
#define PRINT_TO_10_H

#include <stdio.h>
void print1to10();

#endif

this is the main file main.c

#include <stdio.h>
#include "print.h"

int main()
{
    print1to10();
    return 0;
}

Just a simple program but it seems that vscode doesn’t like it
and it gives me this error
K:/test/main.c:6: undefined reference to 'print1to10' collect2.exe: error: ld returned 1 exit status

one more thing
I don’t know if it is relevant or not but I have played a little bit with C/C++ Configurations

{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [
                "_DEBUG",
                "UNICODE",
                "_UNICODE"
            ],
            "windowsSdkVersion": "10.0.22000.0",
            "compilerPath": "C:/msys64/mingw64/bin/gcc.exe",
            "cStandard": "c99",
            "cppStandard": "c++17",
            "intelliSenseMode": "windows-gcc-x64"
        }
    ],
    "version": 4
}

I tried putting the print.c & print.h files in another folder in the same folder but then it gives me another error that it cannot even find the header file

  K:testmain.c:2:10: fatal error: print.h: No such file or directory
  2 | #include "print.h"
    |          ^~~~~~~~~
compilation terminated.
Tags:

2

Answers


  1. 0

    If you have a multiple files of multiple folders, for example with the following structure:

    project
 |
 |- library_1
 |   |
 |   |- library_1.h
 |   |- library_1.c
 |
 |- main.c

    you can pass something like this to GCC.

    gcc main.c -I ./library_1 library_1/library_1.c -o program.exe

    And it would compile.

    Alternatively you can try my VSCode extension that takes care of all the build configurations, running, debugging etc and also helps you create new, multi-library projects.

    It’s called C Toolkit

    Login or Signup to reply.
  2. 0

    The issue that you are having is that the file print.c is not linked to the executable. That’s why the function print1to10 is undefined.

    When I run your main.c with the extension C/C++ it generates the following file in the folder .vscode

    tasks.json

    {
    "tasks": [
        {
            "type": "cppbuild",
            "label": "C/C++: gcc.exe build active file",
            "command": "C:\msys64\ucrt64\bin\gcc.exe",
            "args": [
                "-fdiagnostics-color=always",
                "-g",
                "${file}",
                "-o",
                "${fileDirname}\${fileBasenameNoExtension}.exe"
            ],
            "options": {
                "cwd": "${fileDirname}"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": {
                "kind": "build",
                "isDefault": true
            },
            "detail": "Task generated by Debugger."
        }
    ],
    "version": "2.0.0"
}

    With this you can add the file print.c in the args section, so it’d look like this:

    {
    "tasks": [
        {
            "type": "cppbuild",
            "label": "C/C++: gcc.exe build active file",
            "command": "C:\msys64\ucrt64\bin\gcc.exe",
            "args": [
                "${file}",
                "${fileDirname}\print.c",
                "-o",
                "${fileDirname}\${fileBasenameNoExtension}.exe"
            ],
            "options": {
                "cwd": "${fileDirname}"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": {
                "kind": "build",
                "isDefault": true
            }
        }
    ],
    "version": "2.0.0"
}

    This will basically do the following command:

    gcc main.c print.c -o main.exe

    For more information you can check the documentation.

    Additionally I modified a bit your code to remove redundace, however what you have should compile correctly.

    print.h

    // Changed PRINT_TO_10_H to PRINT_H since the name of the
// file is print.h
#ifndef PRINT_H
# define PRINT_H

#include <stdio.h>

void    print1to10(void);

#endif

    print.c

    // Removed stdio.h because is already included in print.h

#include "print.h"

void    print1to10(void)
{
    for (int i = 0; i <= 10; i++)
        printf("%d ", i);
}

    main.c

    // Removed stdio.h because is already included in print.h
// besides it is not used in this file.
#include "print.h"

int main(void)
{
    print1to10();
    return 0;
}

    Note: I have every file in the same folder, if you want to organise them in multiple folders, Usman Mehwood‘s answer is very accurate!

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search