Debugger screenshotting

The debugger integration in MonoDevelop is progressing, lots of work in the past weeks. I'm going to show what is supported right now, altough much work is still left to make everything stable.

Everything I'm showing here works both for the MDB and GDB backends, unless explicitly stated.

First of all, this is the Attach to Process window. Notice the "Debugger" combo at the bottom. It allows you selecting which debugger you want to use to start the debug session (MDB or GDB):



Breakpoints have a nicer look, and there is support for enabling/disabling. Also, when starting a debug session, invalid breakpoints (e.g. breakpoints placed in lines without statements) will be rendered as disabled.



The dissassembly window shows the assembler mixed with the source code when available. This mixed view is not supported in MDB, due to limitations in the API (for MDB, dissassembly without source code will be shown). The disassembly view supports single-stepping of assembler instructions.



Big improvements in the Watch View. The list now has icons for each type of member. Drill down has been improved, for example big arrays are now split in 'ranges' which makes easier to locate elements.

The Watch View now supports expressions. The expression evaluator is based on NRefactory, and although not all C# expressions are supported, many of them are (for example, arithmetic operations, method calls, array access, conditional expressions, etc). Expressions can be used both to select what to show in the view, and to assign values to variables or members. For GDB, the GDB expression evaluator is used. The screenshot below shows some examples. In one of the examples, the value of an expression will be assigned to the variable 'n':



The Watch View can also be used to inspect types. The view will show all static members of a type. Namespaces are also supported. For example, you can enter the namespace 'System' and drill down through all types and inspect their static members (not supported in GDB):



The Watch View also supports code completion (both for entering expressions and values). Code completion is based on data from the debugger backend, not on the MonoDevelop parser database, so it works for MDB and GDB, and even when debugging an application for which there isn't a MonoDevelop project:



Another nice feature is the support for debug tooltips in the editor. When moving the mouse over a variable or member, a tooltip will show its value. The tooltip is interactive and allows drilling down and modifying values just like the watch window:



It is also possible to use tooltips to inspect the value of expressions:



And works for GDB too! This final screenshot shows a Mono process attached with GDB, a debug tooltip for a MonoMethod, and a member of that struct being modified using code completion:



That's all for now. If you want to try it you'll have to get everything from SVN (see my last post).