28. Visual Studio Code

Visual Studio Code is a lightweight, yet powerful source code editor that runs on multiple platforms.

With the C/C++ for Visual Studio Code extension it is possible to use the Calypsi C compiler tool chain in Visual Studio Code.

Visual Studio Code can be tailored to use various build and debugger tools. Its debugger integration, based on MI (Machine Interface), is supported by the Calypsi db68k debugger.

Visual Studio Code is an excellent GUI choice for Calypsi, being actively developed, lightweight, responsive, and highly configurable.

This guide does not fully document Visual Studio Code. For detailed information, refer to the official documentation.

Some basics on getting started are covered here, as its operation may differ from traditional IDEs.

28.1. Installation

Installation is easy to do by downloading it from the official site. After that you can update from inside Visual Studio Code itself.

Note

If you use Arch Linux or a derivative like Manjaro, install VS Code via its package system. The community code package currently cannot install the vscode-cpptools extension due to licensing. To make it work, install the Microsoft-branded visual-studio-code-bin from the AUR.

28.2. Project setup

In contrast to many IDEs you will not find any project setup in the menus.

To create a new project from scratch, use File>Open and create a new folder for your project and then press Open. You now have an empty project directory.

For an existing project, select File>Open, browse to its top folder, and press Open to load.

Project-specific files are stored in a .vscode directory within the project. Initially, this directory is empty.

28.3. Building

Once the project is populated and a Makefile created, add a build task. Select Tasks>Configure Tasks..., then Create tasks.json file from template, and Others. Edit the resulting tasks.json file, which may resemble:

{
    "version": "0.2.0",
    "tasks": [
        {
            "label": "build",
            "type": "shell",
            "command": "make -k",
            "options": {
                "cwd": "${workspaceRoot}"
            },
            "problemMatcher": [
                "$gcc"
            ]
        },
        {
        "label": "clean",
        "type": "shell",
        "command": "make -k clean",
        "problemMatcher": [],
        }
    ]
}

28.4. Running the debugger

The db68k debugger can be used inside Visual Studio Code. For basic use it uses a 68000 simulator and a memory system that is configured based on the executable image.

Configuration

Before starting the debugger, add a launch configuration.

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "C++ Launch",
            "type": "cppdbg",
            "request": "launch",
            "program": "${workspaceRoot}/src/myproject",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceRoot}/src",
            "environment": [],
            "externalConsole": false,
            "linux": {
                "MIMode": "lldb"
                "miDebuggerPath": "/usr/local/bin/db68k",
                "launchCompleteCommand": "exec-run",
                "setupCommands": []
            },
            "osx": {
                "MIMode": "lldb",
                "miDebuggerPath": "/usr/local/bin/db68k",
                "launchCompleteCommand": "exec-run",
                "setupCommands": []
            },
            "windows": {
                "MIMode": "lldb"
            }
        },
    ]
}

There are a couple of things to specify here.

1. You need to specify that you are using /usr/local/bin/db68k as the debugger using miDebuggerPath

2. You also need to tell that you want to use lldb as MIMode 1

The launch configuration is a text file stored in .vscode/launch.json.

Running the application

Once configured, run your application using Run >> Start Debugging (F5). Consider inserting a breakpoint or interrupting execution once started. If debugger windows (variables, call stack, etc.) don’t appear, click the bug icon to switch to the debugger view.

Footnotes

1

Even though db68k is much closer to gdb than lldb at the command level, you need to specify lldb as the MI mode. The reason is that in the gdb mode, Visual Studio Code works around a bug on UNIX style platforms for the MI command -exec-interrupt (which interrupts execution). The work around is to send a signal to a real UNIX process to interrupt it. This does not work with db68k as the application being debugged is not a UNIX process at all. Instead you need to use the lldb mode, where the MI command -exec-interrupt works properly, just as it does in db68k.

Reference https://sourceware.org/bugzilla/show_bug.cgi?id=20035