Merge branch 'main' into dcreager/legacy-class

* main:
  [red-knot] Use 'full' salsa backtrace output that includes durability and revisions (#17735)
  [red-knot] Initial support for protocol types (#17682)
  [red-knot] Computing a type ordering for two non-normalized types is meaningless (#17734)
  [red-knot] Include salsa backtrace in check and mdtest panic messages (#17732)
  [red-knot] Fix control flow for `assert` statements (#17702)
  [red-knot] Fix recording of negative visibility constraints (#17731)
  [red-knot] Update salsa (#17730)
  [red-knot] Support overloads for callable equivalence (#17698)
  [red-knot] Run py-fuzzer in CI to check for new panics (#17719)
  Upload red-knot binaries in CI on completion of linux tests (#17720)
  [`flake8-use-pathlib`] Fix `PTH123` false positive when `open` is passed a file descriptor from a function call (#17705)

Author: dcreager

.github/workflows/ci.yaml

@@ -276,6 +276,10 @@ jobs:
         with:
           name: ruff
           path: target/debug/ruff
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: red_knot
+          path: target/debug/red_knot
 
   cargo-test-linux-release:
     name: "cargo test (linux, release)"
@@ -632,6 +636,53 @@ jobs:
           name: ecosystem-result
           path: ecosystem-result
 
+  fuzz-redknot:
+    name: "Fuzz for new red-knot panics"
+    runs-on: depot-ubuntu-22.04-16
+    needs:
+      - cargo-test-linux
+      - determine_changes
+    # Only runs on pull requests, since that is the only we way we can find the base version for comparison.
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.red_knot == 'true' }}
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        name: Download new red-knot binary
+        id: redknot-new
+        with:
+          name: red_knot
+          path: target/debug
+      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+        name: Download baseline red-knot binary
+        with:
+          name: red_knot
+          branch: ${{ github.event.pull_request.base.ref }}
+          workflow: "ci.yaml"
+          check_artifacts: true
+      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - name: Fuzz
+        env:
+          FORCE_COLOR: 1
+          NEW_REDKNOT: ${{ steps.redknot-new.outputs.download-path }}
+        run: |
+          # Make executable, since artifact download doesn't preserve this
+          chmod +x "${PWD}/red_knot" "${NEW_REDKNOT}/red_knot"
+
+          (
+            uvx \
+            --python="${PYTHON_VERSION}" \
+            --from=./python/py-fuzzer \
+            fuzz \
+            --test-executable="${NEW_REDKNOT}/red_knot" \
+            --baseline-executable="${PWD}/red_knot" \
+            --only-new-bugs \
+            --bin=red_knot \
+            0-500
+          )
+
   cargo-shear:
     name: "cargo shear"
     runs-on: ubuntu-latest

Cargo.lock

@@ -124,7 +124,7 @@ rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "c75b0161aba55965ab6ad8cc9aaee7dc177967f1" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "79afd59ed5a5edb4dac63cf5b6cf4a6aa9514bdf" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }

Cargo.toml

@@ -20,6 +20,7 @@ use ruff_db::system::{SystemPath, SystemPathBuf};
 use rustc_hash::FxHashSet;
 use salsa::Durability;
 use salsa::Setter;
+use std::backtrace::BacktraceStatus;
 use std::panic::{AssertUnwindSafe, UnwindSafe};
 use std::sync::Arc;
 use thiserror::Error;
@@ -626,10 +627,27 @@ where
             ));
 
             if let Some(backtrace) = error.backtrace {
-                diagnostic.sub(SubDiagnostic::new(
-                    Severity::Info,
-                    format!("Backtrace:\n{backtrace}"),
-                ));
+                match backtrace.status() {
+                    BacktraceStatus::Disabled => {
+                        diagnostic.sub(SubDiagnostic::new(
+                            Severity::Info,
+                            "run with `RUST_BACKTRACE=1` environment variable to show the full backtrace information",
+                        ));
+                    }
+                    BacktraceStatus::Captured => {
+                        diagnostic.sub(SubDiagnostic::new(
+                            Severity::Info,
+                            format!("Backtrace:\n{backtrace}"),
+                        ));
+                    }
+                    _ => {}
+                }
+            }
+
+            if let Some(backtrace) = error.salsa_backtrace {
+                salsa::attach(db, || {
+                    diagnostic.sub(SubDiagnostic::new(Severity::Info, backtrace.to_string()));
+                });
             }
 
             Err(diagnostic)

crates/red_knot_project/src/lib.rs

@@ -7,15 +7,15 @@ Builtin symbols can be explicitly imported:
 ```py
 import builtins
 
-reveal_type(builtins.chr)  # revealed: def chr(i: int | SupportsIndex, /) -> str
+reveal_type(builtins.chr)  # revealed: def chr(i: SupportsIndex, /) -> str
 ```
 
 ## Implicit use of builtin
 
 Or used implicitly:
 
 ```py
-reveal_type(chr)  # revealed: def chr(i: int | SupportsIndex, /) -> str
+reveal_type(chr)  # revealed: def chr(i: SupportsIndex, /) -> str
 reveal_type(str)  # revealed: Literal[str]
 ```
 

crates/red_knot_python_semantic/resources/mdtest/import/builtins.md

@@ -51,3 +51,64 @@ def _(x: Literal[1, 2, 3], y: Literal[1, 2, 3]):
     assert y not in (1, 2)
     reveal_type(y)  # revealed: Literal[3]
 ```
+
+## Assertions with messages
+
+```py
+def _(x: int | None, y: int | None):
+    reveal_type(x)  # revealed: int | None
+    assert x is None, reveal_type(x)  # revealed: int
+    reveal_type(x)  # revealed: None
+
+    reveal_type(y)  # revealed: int | None
+    assert isinstance(y, int), reveal_type(y)  # revealed: None
+    reveal_type(y)  # revealed: int
+```
+
+## Assertions with definitions inside the message
+
+```py
+def one(x: int | None):
+    assert x is None, (y := x * 42) * reveal_type(y)  # revealed: int
+
+    # error: [unresolved-reference]
+    reveal_type(y)  # revealed: Unknown
+
+def two(x: int | None, y: int | None):
+    assert x is None, (y := 42) * reveal_type(y)  # revealed: Literal[42]
+    reveal_type(y)  # revealed: int | None
+```
+
+## Assertions with `test` predicates that are statically known to always be `True`
+
+```py
+assert True, (x := 1)
+
+# error: [unresolved-reference]
+reveal_type(x)  # revealed: Unknown
+
+assert False, (y := 1)
+
+# The `assert` statement is terminal if `test` resolves to `False`,
+# so even though we know the `msg` branch will have been taken here
+# (we know what the truthiness of `False is!), we also know that the
+# `y` definition is not visible from this point in control flow
+# (because this point in control flow is unreachable).
+# We make sure that this does not emit an `[unresolved-reference]`
+# diagnostic by adding a reachability constraint,
+# but the inferred type is `Unknown`.
+#
+reveal_type(y)  # revealed: Unknown
+```
+
+## Assertions with messages that reference definitions from the `test`
+
+```py
+def one(x: int | None):
+    assert (y := x), reveal_type(y)  # revealed: (int & ~AlwaysTruthy) | None
+    reveal_type(y)  # revealed: int & ~AlwaysFalsy
+
+def two(x: int | None):
+    assert isinstance((y := x), int), reveal_type(y)  # revealed: None
+    reveal_type(y)  # revealed: int
+```