vscode-cc65-debugger

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This is an extension to let you debug CC65 C code (and ASM code to a small degree) made for the Commodore platforms (well-tested) and NES (experimental), including the Commodore 64, using VICE emulator and Visual Studio Code.

Install it here

If you're having trouble understanding how this extension is supposed to be used, any other issues setting it up, or any features to suggest, please let me know by creating an issue or messaging me on Twitter.

Have you found this project useful, or even utter rubbish? The Flying Spaghetti Monster and I would really appreciate your rating on the Visual Studio Marketplace or OpenVSX!

Setup

To make sure all the features work, you'll want to install VICE 3.6 or later. A modified build of CC65 for Linux, Windows, and Mac OS is already included.

Windows-specific instructions

You will need to install VICE 3.6 or later and make. A modified build of CC65 is included. The easiest way to install VICE to your PATH is to use Chocolatey.

# Make sure you use an Administrator shell!

# Skip this command if you have Chocolatey already.
Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))

# Install the packages
choco install --version 3.6.1 winvice-nightly
choco install make

Make sure these directories are not on your PATH. They will break the Makefile:

C:\Program Files\Git\bin
C:\Program Files\Git\usr\bin

These directories are okay:

C:\Program Files\Git\cmd

Mac-specific instructions

You will need to install VICE. The easiest way to do this is with Brew.

brew install vice

Alternatively, use the official release from Sourceforge. You will need to point the viceDirectory setting to the bin path. So if you dropped the folder in Applications, that would look similar to this:

/Applications/vice-arm64-gtk3.6.1/bin

You may also want to add that path to your PATH so you can use tools like c1541 in your Makefile.

Linux-specific instructions (Debian [and probably also Ubuntu])

You will need to install VICE 3.6 or later and make. A modified build of CC65 is included.

To install VICE 3.6 before it is packaged for your distribution, you will need to build VICE from source, to do that, download the source from the VICE website, then follow the below steps:

sudo apt install build-essential subversion dos2unix xa65 automake autoconf zip
sudo apt build-dep vice
cd vice-3.6.0
./autogen.sh
./configure
make -j$(nproc)
sudo make install

The last two commands will take a while, but afterwards VICE should be installed.

Project Configuration

After installing go to your launch.json and create a new section using the snippet. If you don't have a launch.json, the "create a launch.json file" link in the debug section should create a simple one.

Obsolete settings:

• viceCommand: Please see the setting cc65vice.viceDirectory in your user settings.

Required settings for both launch and attach:

• name: The name in the debug dropdown menu.
• request: launch will launch, attach will attach.
• type: Always cc65-vice for this debugger.
• build: Attributes for the build command. You need this for attachment as well, so the debugger can find relative paths in your debug file.
  • command: Your actual build command. Defaults to make if unspecified. You will need to change your Makefile to support being debugged with this.
  • args: An array with args for your command. Defaults to [] if unspecified.
  • cwd: The working directory for your build command. You need this for attachment as well, so the debugger can find relative paths in your debug file.
  • skip: Should we skip building before execution?

Required for attach mode only:

• port: The port to attach to in attach mode. This is the port configured with VICE's -binarymonitoraddress option. If you specify this for a launch, it will force it to use that port instead of a random one.

Required for launch mode only:

• emulatorArgs: You'll want to set your C64 model here, and any other special hardware options that you need for your program. Either NTSC or one of the PAL models (jap, drean, etc). Look at the VICE manual for the full list.

Other shared settings:

• stopOnEntry: This will break at the beginning of the program. Otherwise it will continue automatically after the debugger connects.
• stopOnExit: This will break at the end of the program. Otherwise it will terminate automatically.
• program: Specify this if the debugger can't find your binary file. By default it will look for a d81/d64 and if it can't find any a PRG. If you have multiple of those types of files, it will try some fanciness to determine which one is the "real" one, such as looking at the modification date and how many files are in your disk image, but those may fail.
• machineType: The machine type to use, instead of the autodetected one.
• mapFile: Manually specify the path of your map file. Use this if auto detection fails. When this is unset it will look for a file in the same folder as your program named PROGRAMNAME.map
• debugFile: Manually specify the path of your debug file. Use this if auto detection fails. When this is unset it will look for a file in the same folder as your program named PROGRAMNAME.dbg

There are also some user settings to note:

• cc65vice.enableCycleCounters: Enable cycle counters next to each code line.
• cc65vice.viceDirectory: Set this to specify the directory that contains the VICE executables. You'll probably need this on Windows. If this is omitted then it will look on the system PATH.
• cc65vice.appleWinDirectory: Set this to specify the directory that contains the AppleWin executables. You'll probably need this on Windows. If this is omitted then it will look on the system PATH.
• cc65vice.mesenDirectory: Set this to specify the directory that contains the Mesen executables. You'll probably need this on Windows. If this is omitted then it will look on the system PATH.
• cc65vice.cc65Home: Set this to specify the directory that contains the CC65 build. This is the CC65_HOME directory, and not the bin directory, so the folder above bin. If your system doesn't have prebuilt binaries, you probably want to use CC65 on your PATH, and not this.
• cc65vice.preferX64OverX64sc: Set to true to use x64, which is not recommended.
• cc65vice.disableMetrics: This disables metric reporting, which tracks when the extension is activated or a debug session is requested or fails.
• cc65vice.runAhead: When hitting a breakpoint, step ahead by one frame so that any screen updates that may have been made become visible immediately.

You may have some problems with autostart-warp working correctly. The way VICE detects this may be to blame. To turn it off, just add +warp and +autostart-warp to your emulatorArgs:

{
    ...
    "emulatorArgs": [
        "+autostart-warp", "+warp",
        "-model", "ntsc"
    ]
    ...
}

Changes needed to your Makefile

If you've used the default Makefile at the CC65 project wiki, it's required to use a slightly modified Makefile.

If instead you made a custom Makefile, you will need to tell the linker that you want a debug file and a map file. You would add the following options to your linker:

-g -Wl "--mapfile,build/PROGRAMNAME.map" -Wl "--dbgfile,build/PROGRAMNAME.dbg"

And the following to your compiler:

--debug-tables "FILENAME.tab"

Make sure that the paths on the files are in the same folder and have the same name (minus the extension, of course) as your main program!

If you have included any optimizations (-Osir) you should probably turn those off, however, effort has been made to trace some of them.

You may also want to look at the full Assembly project template, and the C project template.

Please also note the mk.sh and mk.bat. These will help you run make (or anything else with minor modifications) from the proper context outside of vscode, so that you use the builtin cc65 compiler when possible, instead of the one installed on your machine.

What works

• Starting the program and stopping at the beginning of main()
• Setting and consistently hitting breakpoints
• Stepping over lines.
• Stepping out of functions.
• Stepping into functions.
• Array types
• Viewing structs
• Local variables
• Static local variables
• Global variables
• Registers
• Variable and memory drilldown. With any variable, even ones that were determined to be a single byte, you can use it as a two byte pointer to jump to other blocks of memory by expanding the dropdown triangle. Once you get to actual memory, you'll get 8x16 bytes (128 bytes). You can expand a row of 8 bytes and it will give you 8 options for pointer referencing (01,12,23,34,...) which you can expand and get another 128 byte chunk of memory, and on and on forever...
• Pausing and resuming works pretty much as you might expect. If you pause in the middle of a library function it will look strange but the state of VICE will be okay, but that's pretty typical for this sort of thing (think Microsoft's scary "no symbols for this file" window when you pause on a compiled DLL in VS proper).

Building

You will need node >=13, vscode >=1.42, pnpm >=5.5, Python 3 (to generate the font), and Subversion. Jest Test Explorer extension is also recommended.

For more details about what is needed to build, please look at the Dockerfile

To test:

pnpm install --shamefully-hoist
pnpm build:full
pnpm test

To build, run the following commands:

pnpm install --shamefully-hoist
pnpm build:full

If you want to debug the extension, use the Extension + Server debug target in VSCode after running the build commands above at least once. This will start two debug sessions. You will need to restart the Server if you change any code called by the main debug session process. Basically anything referenced by src/dbg/runtime.ts.

You will need to restart the Extension if you change anything in the Extension which is not UI code. All the UI side code is located under src/webviews/stats-webview-content.ts since there is only one screen at the moment. All the non-UI code is under src/ext.

If you change UI code while debugging, it will automatically be reloaded. However you may need to close the webview and restart the cc65-vice session to get it to reappear correctly.

Some other package.json scripts of note:

• clean: Will remove all generated outputs such as files in dist. Use this If something doesn't seem to update.
• distclean: Will remove all files including node_modules and the 3rdparty directories. Use this if something is really sideways.
• compiler: Will build all the versions of cc65 to dist/cc65
• compiler:quick: Will only build the x86 versions of cc65 for your platform. This is used when you launch the project in VSCode.
• webpack and webpack:debug: Builds all the webpacked parts of the project. The debug adapter, monitor, extension, and extension UI code.
• tisk: Builds all the source with standard tsc. Called by Ctrl+Shift+B in VSCode. This doesn't actually build the project, just quickly verifies that the code isn't broken. Also used before the Webpack build so each component doesn't revalidate the syntax, making it faster overall.
• build:full: Builds everything for deployment.
• build:test: Only builds the parts needed to run the tests, and to debug the extension in VSCode.
• vscode:prepublish: Used for vsce packaging. Will run the tests before generating a vsix file.
• vscode:prepublish:github: Only called on the build server. Skips the tests since they are run separately as a PR check.
• vice:choose: Selects a version of VICE to test against. Look at build.env.sample
• applewin:choose: Selects a version of AppleWin to test against. Look at build.env.sample
• lint: Project linting. Not as important since TypeScript itself prevents a lot of obvious mistakes.
• jest: Run only some of the tests. For example: pnpm jest -- src/__tests__/runtime-other-platforms.test.ts
• jest:compile: Runs only the compile tests. This is separate because the other tests are dependent on the cc65 projects being compiled.
• jest:noncompile: The tests that come after compilation.
• test: Run the tests in the correct order. Does not build anything, so use build:test for that.
• package: Run vsce package using pnpm. The project is using a modified version of vsce that has support for pnpm.

Contributing

All work happens on master, and releases are merged from pull requests using Google's Release Please. Commit messages should start with fix: for bug fixes or feat: for new features, which will appear as bullet points in the changelogs. You can only have one fix: or feat: per commit message, and it must be on the first line. Do not manually edit the version or the CHANGELOG, unless your name is empathicqubit. Breaking changes should use fix!: and feat!:. Force pushes occassionally happen on master because I forget to add the tags to my commit messages.

Usage in Vim with Vimspector (experimental)

Download the file vimspector-gadget.json from the Release page and run a command similar to the following:

.vim/plugged/vimspector/install_gadget.py --enable-custom ./vimspector-gadget.json

An example .vimspector.json is included in the example projects. Note that you will need to set build.skip to true.

Using Mesen-X with NES

To use Mesen-X with NES, download Mesen-X and set your cc65vice.mesenDirectory setting to the path where Mesen-X is. The file should be named Mesen.exe. Additionally, disable the cc65vice.runAhead setting. Then add NES to your targets in your Makefile:

TARGETS := nes

Keep in mind that stdio is not implemented correctly, so printf and file operations will not work. This is a limitation of the NES platform in CC65.

Additional Credits (see also LICENSE.md)

• Terminal: mintty, from Git for Windows
• Compilation: A modified version of CC65 is included with this project, in order to generate detailed type information at compile time.
• Assembly syntax highlighting: Borrowed from tlgkccampbell/code-ca65
• Font: Font for the screen text viewer is generated using atbrask/c64ttf
• Icon: Based on a character that appears on the box art for Bug Blaster.