Rust-analyzer debugging on VSCode does not jump into function

erenturkm · July 25, 2023, 1:27pm

Hi,

I am relatively new to rust-analyzer+vscode.

When I am debugging rust code in vscode running on Windows 11. My breakpoint is on a line that calls a function and I hit step-into (F11) I expect the IDE to move to the function. However a new window named "Symbol: <alloc::string::String as core::ops::deref::Deref>::deref" opens showing Machine language. I can debug the function only if I set a breakpoint inside the function.

Why am I seeing this instead of the IDE jumping to the function?
Is there a way to configure the default behaviour to jump into the function?

thanks

nerditation · July 26, 2023, 2:54pm

the vscode plugin codelldb tries to set lldb to skip the rust standard libraries in single steps, unfortunately due to the way rustc mangles the symbol name, it is not perfect. see:

github.com/vadimcn/codelldb

Debugger switches to disassembly when stepping into function even though debug information should be available

opened 07:59PM - 16 Jan 20 UTC

bluenote10

priority:Medium

OS: Linux, Ubuntu 18.04 VSCode version: 1.14.1 Extension version: 1.4.5 Pyth…on version: 3.6.9 LLDB version: none I still have problems with dropping into disassembly, although I think I shouldn't. According to the [user manual](https://github.com/vadimcn/vscode-lldb/blob/master/MANUAL.md): > When execution steps into code for which debug info is not available, CodeLLDB will automatically switch to disassembly view. When I step into a function I almost always end up with the disassembly view, only in rare cases the debugger can follow the Rust source, which makes debugging very hard. For instance, I have a module with the structure: ```rust // example function A fn order_events<F>(sorted_events: &[Rc<SweepEvent<F>>]) -> Vec<Rc<SweepEvent<F>>> where F: Float, { // ... } // example function B fn next_pos<F>(pos: i32, result_events: &[Rc<SweepEvent<F>>], processed: &mut HashSet<i32>, orig_index: i32) -> i32 where F: Float, { // ... } // example function C pub fn connect_edges<F>(sorted_events: &[Rc<SweepEvent<F>>], operation: Operation) -> Vec<Polygon<F>> where F: Float, { // <= break point here // somewhere calls A: let result_events = order_events(sorted_events); // later calls B: let pos = next_pos(pos, &result_events, &mut processed, i); } ``` When I set a break point in function C, I can successfully step into the call to A, but stepping into the call to B drops to disassembly. According to manual this suggests that debug info is available for A, but not for B. At first I was wondering according to which patterns debug info is available, but then I noticed that putting a break point into B actually allows to debug it. So I would guess debug info is available. Currently I don't see a pattern when stepping into a function succeeds and when it doesn't, except for maybe that it never works for any function outside the same module. I have tried several ways to define my entries in `launch.json`, but the behavior is the same with both: ```json { "version": "0.2.0", "configurations": [ { "type": "lldb", "request": "launch", "name": "Debug variant 1", "cargo": { "args": [ "build", "--package=geo-booleanop-tests" ] }, "args": [], "cwd": "${workspaceFolder}/tests" }, { "type": "lldb", "request": "launch", "name": "Debug variant 2", "program": "${workspaceRoot}/target/debug/run_single_test", "args": [], "cwd": "${workspaceRoot}/tests", "sourceLanguages": ["rust"] } ] } ``` Any ideas what could be causing this? Currently I don't have a minimal reproducing example, but if it helps I can try to build one.

for now, you'd better using break point on your function entry. if you have to use the step-in debugger command, when it stops at the library function, you can use the step-out command or Shift + F11 to get out of the library function then step-in again, sometimes you might need to repeat this several times before it reaches your own function. this is annoying but it's the current status.

erenturkm · July 27, 2023, 6:45am

Yes I figured that myself. Thanks