Extension Scripts

Some repetitive formatting tasks can be handled with automatic scripts. This is especially useful for inline data, which can confuse the code analyzer.

An earlier tutorial demonstrated how to manually mark bytes as inline data. We're going to do it a faster way. For this tutorial, start a new project with the Generic 6502 profile, and in the SourceGen Examples/Tutorial directory select "Tutorial4".

We'll need to load scripts from the project directory, so we have to save the project. File > Save, use the default name ("Tutorial4.dis65").


Take a look at the disassembly listing. The file starts with a JSR followed by a string that begins with a small number. This appears to be a string with a leading length byte. We want to load a script that can handle that, so use Edit > Project Properties, select the Extension Scripts tab, and click Add Scripts from Project. The file browser opens in the project directory. Select the file "InlineL1String.cs", click Open, then OK.


Nothing happened. If you look at the script with an editor (and you know some C#), you'll see that it's looking for a JSR to a function called PrintInlineL1String. So let's give it one.

Double-click the JSR opcode on line $1000 to jump to address $1036. The only thing there is an RTS. It's supposed to be a routine that prints a string with a leading length byte, but for the sake of keeping the example code short it's just a place-holder. Use the curly toolbar arrow (or Alt+LeftArrow) to jump back to $1000.


This time, double-click the JSR operand ("L1036") to edit the operand. Click Create Label, and enter PrintInlineL1String. Remember that labels are case-sensitive; you must enter it exactly as shown. Hit OK to accept the label, and OK to close the operand editor.


If all went well, address $1003 should now be an L1 string "How long?", and address $100D should be another JSR.

The next JSR appears to be followed by a null-terminated string, so we'll need something that handles that.


Go back into Project Properties and add the script called "InlineNullTermString.cs" from the project directory. This script is slightly different, in that it handles any JSR to a label that starts with PrintInlineNullString. So let's give it a couple of those.


Double-click the operand on line $100D ("L1037"), click Create Label, and set the label to "PrintInlineNullStringOne". Hit OK twice. That formatted the first one and got us to the next JSR. Repeat the process on line $1019 ("L1038"), setting the label to "PrintInlineNullStringTwo".


Things are looking good, but we've got one left, and it's got a twist. Instead of a string, the JSR at $1025 is followed by a pointer to a string. We'd like to format the pointer as an address, and then format the string it points to.


We're going to add a third extension script. Sometimes it's convenient to collect all inline data handlers for a project into a single script, so we'll demonstrate that here. The new script handles the previous two cases as well as this new case. Go into Project Properties, click the Extension Scripts tab, select the two scripts you added earlier, and click Remove. Then add the script "InlineMulti.cs" from the project directory. Click OK twice. Note that the strings formatted earlier remain formatted.


Double-click the operand on line $1025 ("L1039"), click Create Label, and set the label to "PrintInlineAddrString". Hit OK twice. This formatted the address at $1028, and also formatted the string at $102b as a null-terminated string. Because the bytes were formatted as an address and not a just a 16-bit value, a label was generated automatically.

The entire project is now nicely formatted. In a real project the "Print Inline" locations would be actual print functions, not just RTS instructions. There would likely be multiple JSRs to the print function, so labeling a single function entry point could format dozens of inline strings and clean up the disassembly automatically. The reason for allowing wildcard names is that some functions may have multiple entry points or chain through different locations.

Extension scripts can make your life much easier, but they do require some programming experience. See the SourceGen manual for more details.

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