barrier/COMPILATION_GUIDE.md

Barrier Linux Compilation Guide

Exact Steps Performed (What We Actually Did)

This section documents the exact sequence of commands and fixes applied to successfully build Barrier on WSL2/Ubuntu.

1. Fixed CMake Version Requirements

Updated minimum CMake version from 3.4 to 3.5 in three files:

File 1: CMakeLists.txt (line 18)

# Changed from:
cmake_minimum_required (VERSION 3.4)
# To:
cmake_minimum_required (VERSION 3.5)

File 2: cmake/Version.cmake (line 1)

# Changed from:
cmake_minimum_required (VERSION 3.4)
# To:
cmake_minimum_required (VERSION 3.5)

File 3: src/gui/CMakeLists.txt (line 1)

# Changed from:
cmake_minimum_required (VERSION 3.4)
# To:
cmake_minimum_required (VERSION 3.5)

2. Installed Dependencies

sudo apt install -y libcurl4-openssl-dev qtbase5-dev qttools5-dev-tools libssl-dev libx11-dev libxtst-dev libxinerama-dev libxss-dev libxi-dev libxrandr-dev libavahi-compat-libdnssd-dev

3. Fixed Missing Headers

File 1: src/lib/base/String.h Added missing header after line 25:

#include <stdarg.h>
#include <vector>
#include <cstdint>  // ADDED THIS LINE

File 2: src/lib/net/FingerprintData.h Added missing header after line 22:

#include <string>
#include <vector>
#include <cstdint>  // ADDED THIS LINE

4. Build

cd "/mnt/c/D Drive/CAPTAIN/CodeProjects/barrier"
./clean_build.sh

5. Verify Build Output

ls -la "/mnt/c/D Drive/CAPTAIN/CodeProjects/barrier/build/bin/"

Files created:

• barriers (12,709,936 bytes) - Server executable
• barrierc (10,165,752 bytes) - Client executable
• integtests (20,092,176 bytes) - Integration tests
• unittests (15,227,792 bytes) - Unit tests

6. Test Functionality

cd "/mnt/c/D Drive/CAPTAIN/CodeProjects/barrier/build/bin"
./barrierc <server-ip>

Result: ✅ Successfully connected to server

---

General Compilation Guide

Prerequisites

System Requirements

• Ubuntu/Debian-based Linux distribution
• CMake 4.0+ (installed via snap)
• GCC 13.3.0
• Git

Required Dependencies

Install the following packages:

sudo apt update
sudo apt install -y \
    libcurl4-openssl-dev \
    qtbase5-dev \
    qttools5-dev-tools \
    libssl-dev \
    libx11-dev \
    libxtst-dev \
    libxinerama-dev \
    libxss-dev \
    libxi-dev \
    libxrandr-dev \
    libavahi-compat-libdnssd-dev

Note on Package Names:

• Use qtbase5-dev instead of the deprecated qt5-default
• Use libavahi-compat-libdnssd-dev instead of avahi-compat-libdns_sd-dev

Source Code Fixes Required

The original Barrier source code requires several fixes to compile with modern toolchains:

1. CMake Minimum Version Updates

Files to modify:

• CMakeLists.txt (line 18)
• cmake/Version.cmake (line 1)
• src/gui/CMakeLists.txt (line 1)

Change:

# FROM:
cmake_minimum_required (VERSION 3.4)

# TO:
cmake_minimum_required (VERSION 3.5)

Reason: CMake 4.0+ no longer supports compatibility with CMake < 3.5

2. Missing C++ Headers

File: src/lib/base/String.h

Add after existing includes:

#include <stdarg.h>
#include <vector>
#include <cstdint>  // ADD THIS LINE

File: src/lib/net/FingerprintData.h

Add after existing includes:

#include <string>
#include <vector>
#include <cstdint>  // ADD THIS LINE

Reason: Modern C++ compilers require explicit inclusion of <cstdint> for std::uint8_t types

Compilation Process

1. Clone and Navigate

git clone <barrier-repo-url>
cd barrier

2. Initialize Submodules

git submodule update --init --recursive

3. Apply Source Code Fixes

Apply all the fixes mentioned in the "Source Code Fixes Required" section above.

4. Build

./clean_build.sh

Alternative manual build:

mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=Debug ..
make

Build Output

Successful Build Results

• Location: build/bin/
• Core executables:
  • barriers (~12.7MB) - Server component
  • barrierc (~10.2MB) - Client component
  • barrier - GUI application (if Qt build completes)
  • integtests - Integration tests
  • unittests - Unit tests

Expected Warnings

• OpenSSL deprecation warnings (non-critical)
• CMake compatibility warnings (non-critical)
• Clock skew warnings in WSL (non-critical)

Usage

Server Mode

cd build/bin
./barriers

Client Mode

cd build/bin
./barrierc <server-ip-address>

GUI Mode (if available)

cd build/bin
./barrier

Troubleshooting

Common Issues

1. Missing Qt5: Install qtbase5-dev instead of qt5-default
2. Missing Avahi: Use libavahi-compat-libdnssd-dev package name
3. uint8_t errors: Add #include <cstdint> to header files
4. CMake version errors: Update minimum version requirements to 3.5
5. CURL not found: Install libcurl4-openssl-dev

Build Environment Notes

• WSL Users: No GUI display available by default
• X11 Required: For actual mouse/keyboard sharing functionality
• Network: Ensure firewall allows Barrier traffic (default port 24800)

Platform-Specific Notes

Windows Build (Alternative)

If building on Windows instead of Linux:

• Requires Visual Studio 2019/2022
• Requires Qt 5.11.1 at C:\Qt\5.11.1\msvc2017_64
• Requires Bonjour SDK at C:\Program Files\Bonjour SDK
• Use clean_build.bat instead of clean_build.sh

Linux Desktop Environment

For full functionality, Barrier requires:

• X11 or Wayland display server
• Desktop environment (GNOME, KDE, etc.)
• Proper graphics drivers

Version Information

• Barrier Version: 2.4.0
• Build System: CMake + Make
• Compiler: GCC 13.3.0
• Target Platform: Linux x86_64

Summary of Changes Made

1. Updated CMake minimum version requirements (3 files)
2. Added missing #include <cstdint> headers (2 files)
3. Installed correct Linux development packages
4. Used appropriate package names for Ubuntu 24.04+

This guide should enable successful compilation of Barrier on modern Linux systems.