impl causes RA to crash repeatedly overflowing stack

[KerfuffleV2]

rust-analyzer version: rust-analyzer version: 5a6918f1c 2022-04-05 nightly

rustc version: rustc 1.60.0-beta.6 (7bccde197 2022-03-22)

relevant settings:

VS Codium 1.66.0 (using VS Code marketplace)

Preferences:

{
  "rust-analyzer.checkOnSave.command": "clippy",
  "rust-analyzer.highlighting.strings": true,
  "rust-analyzer.lens.methodReferences": true,
  "rust-analyzer.lens.references": true,
  "rust-analyzer.procMacro.enable": true,
  "rust-analyzer.server.extraEnv": {
    "CHALK_OVERFLOW_DEPTH": "3000",
    "CHALK_SOLVER_MAX_SIZE": "1500"
  },
  "rust-analyzer.cache.warmup": false,
  "rust-analyzer.experimental.procAttrMacros": false,
  "rust-analyzer.diagnostics.enableExperimental": false,
  "rust-analyzer.inlayHints.reborrowHints": true,
  "rust-analyzer.inlayHints.closureReturnTypeHints": true,
  "rust-analyzer.inlayHints.lifetimeElisionHints.useParameterNames": true,
  "rust-analyzer.inlayHints.lifetimeElisionHints": "always",
  "rust-analyzer.inlayHints.hideNamedConstructorHints": true,
  "rust-analyzer.checkOnSave.extraArgs": ["--no-deps"],
  "rust-analyzer.inlayHints.lifetimeElisionHints.enable": "skip_trivial"
}

This small code fragment causes RA to repeatedly crash until it disables itself:

[package]
name = "testaes"
version = "0.1.0"
edition = "2021"

[dependencies]
aes = "=0.8.1"

use aes::cipher::{generic_array::GenericArray, BlockCipher, KeySizeUser};

struct Testy<CI>(CI);

impl<CI: BlockCipher + KeySizeUser> Testy<CI> {
    pub fn new(_key: GenericArray<u8, <CI as KeySizeUser>::KeySize>) {}
}

fn main() {}

Example output from a crash:

thread '<unknown>' has overflowed its stack
fatal runtime error: stack overflow
[Error - 2:44:59 AM] The Rust Analyzer Language Server server crashed 5 times in the last 3 minutes. The server will not be restarted. See the output for more information.
[Error - 2:44:59 AM] Request textDocument/semanticTokens/full failed.
Error: Connection got disposed.
	at Object.dispose (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:32:4437)
	at Object.dispose (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:37:12019)
	at Rg.handleConnectionClosed (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:39:9883)
	at Rg.handleConnectionClosed (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:39:80621)
	at t (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:39:9591)
	at zd.invoke (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:5:14370)
	at Ri.fire (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:5:15139)
	at qt (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:6:6354)
	at zd.invoke (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:5:14370)
	at Ri.fire (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:5:15139)
	at ca.fireClose (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:5:17394)
	at Socket.<anonymous> (/home/some_user/.vscode-oss/extensions/matklad.rust-analyzer-0.3.1003-linux-x64/out/main.js:5:18924)
	at Socket.emit (node:events:402:35)
	at Pipe.<anonymous> (node:net:687:12)

Please let me know if any further details would be helpful.

[flodiebold]

This would usually be a Chalk overflow; it's probably not helpful to set CHALK_OVERFLOW_DEPTH that high.

[flodiebold]

Presumably a duplicate of #11370.

[KerfuffleV2]

Thanks for the response. I disabled setting those environment variables and it just panics due to hitting the maximum depth.

Is there any other information that would be helpful?

Output (note - some repetition elided):

Panic context:
> 
version: 134dbc610 2022-04-07 nightly
request: textDocument/semanticTokens/full/delta SemanticTokensDeltaParams {
    work_done_progress_params: WorkDoneProgressParams {
        work_done_token: None,
    },
    partial_result_params: PartialResultParams {
        partial_result_token: None,
    },
    text_document: TextDocumentIdentifier {
        uri: Url {
            scheme: "file",
            cannot_be_a_base: false,
            username: "",
            password: None,
            host: None,
            port: None,
            path: "/home/some_user/personal/testaes/src/main.rs",
            query: None,
            fragment: None,
        },
    },
    previous_result_id: "1",
}

thread '<unnamed>' panicked at 'overflow depth reached', /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/chalk-recursive-0.81.0/src/fixed_point/stack.rs:51:13
stack backtrace:
   0: std::panicking::begin_panic
   1: chalk_recursive::fixed_point::RecursiveContext<K,V>::solve_goal
   2: chalk_recursive::fulfill::Fulfill<I,Solver>::prove
   3: chalk_recursive::fulfill::Fulfill<I,Solver>::solve
   4: chalk_recursive::solve::SolveIteration::solve_iteration
   5: chalk_recursive::fixed_point::RecursiveContext<K,V>::solve_goal
   6: chalk_recursive::fulfill::Fulfill<I,Solver>::prove
   7: chalk_recursive::fulfill::Fulfill<I,Solver>::solve
   8: chalk_recursive::solve::SolveIteration::solve_iteration
   9: chalk_recursive::fixed_point::RecursiveContext<K,V>::solve_goal
[...]
  88: chalk_recursive::solve::SolveIteration::solve_iteration
  89: chalk_recursive::fixed_point::RecursiveContext<K,V>::solve_goal
  90: chalk_recursive::fulfill::Fulfill<I,Solver>::prove
  91: chalk_recursive::fulfill::Fulfill<I,Solver>::solve
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
[Error - 4:38:57 AM] Request textDocument/semanticTokens/full/delta failed.
  Message: server panicked: overflow depth reached
  Code: -32603 
Panic context:
> 
version: 134dbc610 2022-04-07 nightly
request: experimental/inlayHints InlayHintsParams {
    text_document: TextDocumentIdentifier {
        uri: Url {
            scheme: "file",
            cannot_be_a_base: false,
            username: "",
            password: None,
            host: None,
            port: None,
            path: "/home/some_user/personal/testaes/src/main.rs",
            query: None,
            fragment: None,
        },
    },
    range: Some(
        Range {
            start: Position {
                line: 0,
                character: 0,
            },
            end: Position {
                line: 9,
                character: 0,
            },
        },
    ),
}

[KerfuffleV2]

Regarding #11370, setting CHALK_SOLVER_MAX_SIZE to 100 does seem to fix the problem. I guess I don't understand how those settings work, I'd think increasing the maximum size would make it more likely to work instead of less!

[flodiebold]

Having a lower max size makes it short-circuit the calculation earlier, so it doesn't get as deep. It still means the result might be wrong though.

[lnicola]

This works for me with CHALK_OVERFLOW_DEPTH set to 350 or above. #12281 will probably bump it slightly, but at this point we probably can't avoid the need to tweak these at times.