compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary #128097

iduanyingjie · 2024-07-23T13:42:16Z

Code

trait Cut {
    fn floor(&mut self) -> (Option<TransDataType>, Bson)
    where
        Self: Serialize,
    {
        match serde_json::to_string(&self) {
            Ok(json) => match json.len() {
                len if len > MAX_VARCHAR_SIZE => {
                    (Some(TransDataType::Varchar(MAX_VARCHAR_SIZE)), self.cut())
                }
                len => (
                    Some(TransDataType::Varchar(varchar_size(len))),
                    Bson::String(json),
                ),
            },
            Err(e) => {
                tracing::error!(?e);
                (None, Bson::Null)
            }
        }
    }
    fn cut(&mut self) -> Bson;
}

impl Cut for Vec<Bson> {
    /// When the size of the JSON array string exceeds 65535, it needs to be trimmed so that the length is less than 65535;<br>
    /// Discard the largest element in the array, and then recursively repeat the judgment
    fn cut(&mut self) -> Bson {
        let remove_index = self
            .iter()
            .enumerate()
            .map(|(idx, value)| {
                (
                    idx,
                    serde_json::to_string(value)
                        .map(|s| s.len())
                        .unwrap_or(usize::MAX),
                )
            })
            .max_by(|a, b| a.1.cmp(&b.1))
            .map(|(idx, _)| idx);

        if let Some(remove_index) = remove_index {
            let remove_value = self.remove(remove_index);
            tracing::warn!(?remove_index, ?remove_value, "Cut the BSON array length");
        }

        match serde_json::to_string(&self) {
            Ok(json) if json.len() > MAX_VARCHAR_SIZE => become self.cut(),
            Ok(json) => Bson::String(json),
            Err(e) => {
                tracing::error!(?e);
                Bson::Null
            }
        }
    }
}

impl Cut for Document {
    /// When the size of the JSON object string exceeds 65535, it needs to be trimmed so that the length is less than 65535;<br>
    /// Discard the largest element in the array, and then recursively repeat the judgment
    fn cut(&mut self) -> Bson {
        let replace_key = self
            .iter()
            .map(|(key, value)| {
                (
                    key,
                    serde_json::to_string(value)
                        .map(|s| s.len())
                        .unwrap_or(usize::MAX),
                )
            })
            .max_by(|a, b| a.1.cmp(&b.1))
            .map(|(k, _)| k.to_string());

        if let Some(replace_key) = replace_key {
            tracing::warn!(
                "Replace the value of the largest field: {} in the BSON object as ...",
                replace_key
            );
            let _ = self.insert(replace_key, Bson::String("...".to_string()));
        }

        match serde_json::to_string(&self) {
            Ok(json) if json.len() > MAX_VARCHAR_SIZE => become self.cut(),
            Ok(json) => Bson::String(json),
            Err(e) => {
                tracing::error!(?e);
                Bson::Null
            }
        }
    }
}

Error output

internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary _179: bb204[0] and bb205[0]

Backtrace

warning: the feature `explicit_tail_calls` is incomplete and may not be safe to use and/or cause compiler crashes
 --> src/lib.rs:8:12
  |
8 | #![feature(explicit_tail_calls)]
  |            ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #112788 <https://github.com/rust-lang/rust/issues/112788> for more information
  = note: `#[warn(incomplete_features)]` on by default

error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary _234: bb210[0] and bb211[0]
   --> src/trans/bson.rs:142:58
    |
142 |             Ok(json) if json.len() > MAX_VARCHAR_SIZE => become self.cut(),
    |                                                          ^^^^^^^^^^^^^^^^^

thread 'rustc' panicked at compiler/rustc_borrowck/src/borrow_set.rs:250:17:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   3: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   5: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: <rustc_borrowck::borrow_set::BorrowSet>::build
   8: rustc_borrowck::do_mir_borrowck
      [... omitted 1 frame ...]
   9: rustc_interface::passes::analysis
      [... omitted 1 frame ...]
  10: rustc_interface::interface::run_compiler::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: please attach the file at `/home/iduanyingjie/Projects/rust/data-mongodb2redshift/rustc-ice-2024-07-23T13_38_17-80983.txt` to your bug report

note: compiler flags: --crate-type lib -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED]

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [mir_borrowck] borrow-checking `trans::bson::<impl at src/trans/bson.rs:118:1: 118:23>::cut`
#1 [analysis] running analysis passes on this crate
end of query stack
error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary _179: bb204[0] and bb205[0]
   --> src/trans/bson.rs:178:58
    |
178 |             Ok(json) if json.len() > MAX_VARCHAR_SIZE => become self.cut(),
    |                                                          ^^^^^^^^^^^^^^^^^

thread 'rustc' panicked at compiler/rustc_borrowck/src/borrow_set.rs:250:17:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   3: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   5: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: <rustc_borrowck::borrow_set::BorrowSet>::build
   8: rustc_borrowck::do_mir_borrowck
      [... omitted 1 frame ...]
   9: rustc_interface::passes::analysis
      [... omitted 1 frame ...]
  10: rustc_interface::interface::run_compiler::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: please make sure that you have updated to the latest nightly

note: please attach the file at `/home/iduanyingjie/Projects/rust/data-mongodb2redshift/rustc-ice-2024-07-23T13_38_17-80983.txt` to your bug report

note: compiler flags: --crate-type lib -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED]

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [mir_borrowck] borrow-checking `trans::bson::<impl at src/trans/bson.rs:152:1: 152:22>::cut`
#1 [analysis] running analysis passes on this crate
end of query stack
warning: `mongodb2redshift` (lib) generated 1 warning
error: could not compile `mongodb2redshift` (lib); 1 warning emitted

The text was updated successfully, but these errors were encountered:

theemathas · 2024-07-23T15:03:27Z

Could you provide enough code that would be needed to compile and reproduce the issue?

@rustbot labels +S-needs-repro

WaffleLapkin · 2024-07-25T08:09:37Z

@iduanyingjie note that explicit_tail_calls is an incomplete feature and not ready yet for a real use. I'd recommend you do not use it until it is properly implemented.

still, it would be nice to see a reproducible example, as this is not an error I'd expect to see.

cyrgani · 2024-07-31T20:07:14Z

Reduced example:

#![feature(explicit_tail_calls)]
fn cut(x: &mut ()) {
    if let Some(_) = Some(Box::new(())) {
        become cut(x);
    }
}

lqd · 2024-07-31T20:11:23Z

The repro ICEs on beta even without a feature gate.

WaffleLapkin · 2024-08-01T07:16:47Z

@lqd the ICEs without a feature gate is more a general but that we continue complication even if the gate is not enabled, not necessarily specific to explicit tail calls

WaffleLapkin · 2024-08-01T07:23:26Z

Minimized a little bit more:

#![feature(explicit_tail_calls)]
fn f(x: &mut ()) {
    let _y = String::new();
    become f(x);
}

add crashtests for several old unfixed ICEs Adds several new crashtests for some older ICEs that did not yet have any. Tests were added for rust-lang#128097, rust-lang#119095, rust-lang#117460 and rust-lang#126443.

Rollup merge of rust-lang#129780 - cyrgani:master, r=compiler-errors add crashtests for several old unfixed ICEs Adds several new crashtests for some older ICEs that did not yet have any. Tests were added for rust-lang#128097, rust-lang#119095, rust-lang#117460 and rust-lang#126443.

Rollup merge of rust-lang#135976 - WaffleLapkin:tailcall-nodrop, r=oli-obk Don't drop types with no drop glue when building drops for tailcalls this is required as otherwise drops of `&mut` refs count as a usage of a 'two-phase temporary' causing an ICE. fixes rust-lang#128097 The underlying issue is that the current code generates drops for `&mut` which are later counted as a second use of a two-phase temporary: `bat t.rs -p` ```rust #![expect(incomplete_features)] #![feature(explicit_tail_calls)] fn f(x: &mut ()) { let _y = String::new(); become f(x); } fn main() {} ``` `rustc t.rs -Zdump_mir=f` ```text error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:298:17: found two uses for 2-phase borrow temporary _4: bb2[1] and bb3[0] --> t.rs:6:5 | 6 | become f(x); | ^^^^^^^^^^^ thread 'rustc' panicked at compiler/rustc_borrowck/src/borrow_set.rs:298:17: Box<dyn Any> stack backtrace: [REDACTED] error: aborting due to 1 previous error ``` `bat ./mir_dump/t.f.-------.renumber.0.mir -p -lrust` ```rust // MIR for `f` 0 renumber fn f(_1: &mut ()) -> () { debug x => _1; let mut _0: (); let mut _2: !; let _3: std::string::String; let mut _4: &mut (); scope 1 { debug _y => _3; } bb0: { StorageLive(_3); _3 = String::new() -> [return: bb1, unwind: bb4]; } bb1: { FakeRead(ForLet(None), _3); StorageLive(_4); _4 = &mut (*_1); drop(_3) -> [return: bb2, unwind: bb3]; } bb2: { StorageDead(_3); tailcall f(Spanned { node: move _4, span: t.rs:6:14: 6:15 (#0) }); } bb3 (cleanup): { drop(_4) -> [return: bb4, unwind terminate(cleanup)]; } bb4 (cleanup): { resume; } } ``` Note how `_4 is moved into the tail call in `bb2` and dropped in `bb3`. This PR adds a check that the locals we drop need dropping. r? `@oli-obk` (feel free to reassign, I'm not sure who would be a good reviewer, but thought you might have an idea) cc `@beepster4096,` since you wrote the original drop implementation.

iduanyingjie added C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jul 23, 2024

rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Jul 23, 2024

rustbot added the S-needs-repro Status: This issue has no reproduction and needs a reproduction to make progress. label Jul 23, 2024

tgross35 added A-borrow-checker Area: The borrow checker E-needs-mcve Call for participation: This issue has a repro, but needs a Minimal Complete and Verifiable Example and removed needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. labels Jul 23, 2024

matthiaskrgr added the F-explicit_tail_calls `#![feature(explicit_tail_calls)]` label Jul 24, 2024

lqd removed E-needs-mcve Call for participation: This issue has a repro, but needs a Minimal Complete and Verifiable Example S-needs-repro Status: This issue has no reproduction and needs a reproduction to make progress. labels Jul 31, 2024

cyrgani mentioned this issue Aug 30, 2024

add crashtests for several old unfixed ICEs #129780

Merged

matthiaskrgr added the S-bug-has-test Status: This bug is tracked inside the repo by a `known-bug` test. label Sep 1, 2024

WaffleLapkin mentioned this issue Jan 24, 2025

Don't drop types with no drop glue when building drops for tailcalls #135976

Merged

bors closed this as completed in 99e34a4 Jan 25, 2025

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compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary #128097

compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary #128097

iduanyingjie commented Jul 23, 2024

theemathas commented Jul 23, 2024

WaffleLapkin commented Jul 25, 2024

cyrgani commented Jul 31, 2024 •

edited

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lqd commented Jul 31, 2024

WaffleLapkin commented Aug 1, 2024

WaffleLapkin commented Aug 1, 2024 •

edited

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compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary #128097

compiler/rustc_borrowck/src/borrow_set.rs:250:17: found two uses for 2-phase borrow temporary #128097

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iduanyingjie commented Jul 23, 2024

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theemathas commented Jul 23, 2024

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cyrgani commented Jul 31, 2024 • edited Loading

lqd commented Jul 31, 2024

WaffleLapkin commented Aug 1, 2024

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cyrgani commented Jul 31, 2024 •

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WaffleLapkin commented Aug 1, 2024 •

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