NS3 -Configuring VS Code for IntelliSence, Building and Debugging

Environments

• Umbundu Linux 22.04
• gcc 11.2.0
• gdb 12.0.90
• vs code , with extension c/c++
• NS3.5 installed under ~/NS3, build completed following https://www.nsnam.org/docs/release/3.35/tutorial/html/getting-started.html#building-ns-3

Configuring Visual Studio Code for Auto-Completion & Syntax Highlighting

Lunch VS Code at the NS3 directory:

justin@justin-vm:~# cd NS3/ns-allinone-3.35/ns-3.35/
justin@justin-vm:~# code .
#  or root user
root@justin-vm:~# code . --user-data-dir=/root/.vscode-root

Press F1 or (Ctrl + Shift + P) to access VS Code Command Palette, run “C/C++: Edit Configurations(JSON) ” to create/open a c_cpp_properties.json file and modify it

"includePath": [
                "${workspaceFolder}/build/**"
            ]

The full file like

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}/build/**"
            ],
            "defines": [],
            "compilerPath": "/usr/bin/gcc",
            "cStandard": "gnu17",
            "cppStandard": "gnu++14",
            "intelliSenseMode": "linux-gcc-x64"
        }
    ],
    "version": 4
} 

Save and close c_cpp_properties.json file. Auto-Completion & Syntax Highlighting function should work now.

Configuring Build

Click Menu→Terminal→Configure Default Build Task to edit tasks.jason file under .vscode folder

{
	"version": "2.0.0",
	"tasks": [
		{
			"type": "cppbuild",
			"label": "C/C++: cpp build active file",
			//"command": "/usr/bin/cpp",
			"command": "./waf",
			"args": [
				//"-fdiagnostics-color=always",
				//"-g",
				//"${file}",
				//"-o",
				//"${fileDirname}/${fileBasenameNoExtension}"
			],
			"options": {
				"cwd": "${workspaceFolder}"
			},
			"problemMatcher": [
				"$gcc"
			],
			"group": {
				"kind": "build",
				"isDefault": true
			},
			"detail": "compiler: /usr/bin/cpp"
		}
	]
}

Save and exit tasks.jason. The click Menu→Terminal→ Run Build Task or shortcut key (Ctrl + Shift + B), you should see build works.

Config gdb Debugging

Open ./scratch/scratch-simulator.cc in the VS Code. Press F5, choose “C++(GDB/LLB)”, then select “Waf - build and debug active file …” a window pop out and hit Open ‘launch.json’

Replace the content of ‘launch.json’ with the following

{
	"version": "2.0.0",
	"tasks": [
		{
			"type": "cppbuild",
			"label": "C/C++: cpp build active file",
			//"command": "/usr/bin/cpp",
			"command": "./waf",
			"args": [
				//"-fdiagnostics-color=always",
				//"-g",
				//"${file}",
				//"-o",
				//"${fileDirname}/${fileBasenameNoExtension}"
			],
			"options": {
				"cwd": "${workspaceFolder}"
			},
			"problemMatcher": [
				"$gcc"
			],
			"group": {
				"kind": "build",
				"isDefault": true
			},
			"detail": "compiler: /usr/bin/cpp"
		}
	]
}

Save and exit. Now set a breakpoint in scratch-simulator.cc source file and hit F5, you should see that the debugging works. Be patient, the pdb is generally slow.