Sort bounds by DefPathHash during astconv

[Aaron1011]

cc #82920

The value of a DefId is not stable across compilation sessions. If we
sort by DefIds, and then include the sorted list as part of a query
result, then the query will no longer be a pure function of its input
(e.g. the DefId can change while the DefPathHash remains the same).

For reasons that are not yet clear, this issue lead to segfaults and
garbage slice index values when the project in the linked issue was
built with a particular incremental cache.

[rust-highfive]

r? @lcnr

(rust-highfive has picked a reviewer for you, use r? to override)

[lcnr]

r=me after blessing the ui tests

i've already had a similar bug in the past iirc, not sure if there's a way to prevent bugs like this from happening 🤔
maybe removing the Ord impl from DefId and adding a DefId::fast_ord method or something?

[Aaron1011]

I had opened #83006 to track removing the Ord impls

[Aaron1011]

@bors r=lcnr

[bors]

📌 Commit 9339982 has been approved by lcnr

[Aaron1011]

This most general fix for this kind of issue is something like #83007. However, benchmarks currently show that the cost is extremely high.

[Aaron1011]

It looks like I'm getting different output locally. Did this somehow make the order less stable?

[Aaron1011]

@michaelwoerister You worked on DefPathHash recently - do you know what could cause this apparent difference between my machine and CI (both are Linux)?

[Aaron1011]

@bors r-

[michaelwoerister]

Let me take a look ...

[michaelwoerister]

This is probably the reason for the test failures: dedup_by_key assumes that the Vec is sorted by the given key. So this should be auto_traits.dedup_by_key(|i| self.tcx().def_path_hash(i.trait_ref().def_id()));

Maybe it would make sense to use a rustc_data_structures::sorted_map::SortedMap here.

[Aaron1011]

Since def path hash equality implies that the DefIds are equal, I thought that deduplicating by DefId would still work, since equal DefIds should still be adjacent to each other.

[Aaron1011]

Also, the failure appears to be caused be re-ordered errors, not duplicated errors.

[rust-log-analyzer]

The job x86_64-gnu-llvm-9 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

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---- [ui] ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs stdout ----
diff of stderr:

10 LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Iterator {
12 
12 
- error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
-   --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:93
+ error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
15    |
15    |
16 LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
-    |                                                                                             ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
+    |                                    ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
18    | 
19   ::: $SRC_DIR/core/src/marker.rs:LL:COL

- LL | pub unsafe auto trait Sync {
- LL | pub unsafe auto trait Sync {
-    | -------------------------- required by this bound in `Sync`
+ LL | pub unsafe auto trait Send {
+    | -------------------------- required by this bound in `Send`
23    |
-    = help: the trait `Sync` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
+    = help: the trait `Send` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=x86_64-unknown-linux-gnu
26    |
26    |
- LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Sync {
+ LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Send {
29 
29 
- error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
-   --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:36
+ error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
32    |
32    |
33 LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
-    |                                    ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
+    |                                                                                             ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
35    | 
36   ::: $SRC_DIR/core/src/marker.rs:LL:COL

- LL | pub unsafe auto trait Send {
- LL | pub unsafe auto trait Send {
-    | -------------------------- required by this bound in `Send`
+ LL | pub unsafe auto trait Sync {
+    | -------------------------- required by this bound in `Sync`
40    |
-    = help: the trait `Send` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
+    = help: the trait `Sync` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
43    |
43    |
- LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Send {
+ LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Sync {
46 
47 error: aborting due to 3 previous errors



The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait/bad-bounds-on-assoc-in-trait.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args associated-type-bounds/bad-bounds-on-assoc-in-trait.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0277]: `<<Self as Case1>::C as Iterator>::Item` is not an iterator
   |
   |
LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<<Self as Case1>::C as Iterator>::Item` is not an iterator
   |
   = help: the trait `Iterator` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
   |
   |
LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Iterator {


error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
   |
   |
LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
   |                                    ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
  ::: /checkout/library/core/src/marker.rs:38:1
   |
LL | pub unsafe auto trait Send {
LL | pub unsafe auto trait Send {
   | -------------------------- required by this bound in `Send`
   |
   = help: the trait `Send` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
   |
   |
LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Send {


error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
   |
   |
LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
   |                                                                                             ^^^^ `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
  ::: /checkout/library/core/src/marker.rs:469:1
   |
LL | pub unsafe auto trait Sync {
LL | pub unsafe auto trait Sync {
   | -------------------------- required by this bound in `Sync`
   |
   = help: the trait `Sync` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
   |
   |
LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Sync {

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0277`.
For more information about this error, try `rustc --explain E0277`.

------------------------------------------


---- [ui] ui/associated-types/defaults-unsound-62211-1.rs stdout ----
diff of stderr:

- error[E0277]: the trait bound `Self: Copy` is not satisfied
-   --> $DIR/defaults-unsound-62211-1.rs:20:5
-    |
- LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
-    |     |            |
-    |     |            |
-    |     |            required by this bound in `UncheckedCopy::Output`
-    |     the trait `Copy` is not implemented for `Self`
- help: consider further restricting `Self`
-    |
-    |
- LL | trait UncheckedCopy: Sized + Copy {
- 
15 error[E0277]: the trait bound `Self: Deref` is not satisfied
16   --> $DIR/defaults-unsound-62211-1.rs:20:5
17    |
17    |

39    |
40 LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {
+ 
+ 
+ error[E0277]: the trait bound `Self: Copy` is not satisfied
+    |
+    |
+ LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
+    |     |            |
+    |     |            |
+    |     |            required by this bound in `UncheckedCopy::Output`
+    |     the trait `Copy` is not implemented for `Self`
+ help: consider further restricting `Self`
+    |
+    |
+ LL | trait UncheckedCopy: Sized + Copy {
42 
42 
43 error[E0277]: `Self` doesn't implement `std::fmt::Display`


The actual stderr differed from the expected stderr.
The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/defaults-unsound-62211-1/defaults-unsound-62211-1.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args associated-types/defaults-unsound-62211-1.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/associated-types/defaults-unsound-62211-1.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/defaults-unsound-62211-1" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/defaults-unsound-62211-1/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0277]: the trait bound `Self: Deref` is not satisfied
  --> /checkout/src/test/ui/associated-types/defaults-unsound-62211-1.rs:20:5
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |                   |
   |     |                   |
   |     |                   required by this bound in `UncheckedCopy::Output`
   |     the trait `Deref` is not implemented for `Self`
help: consider further restricting `Self`
   |
   |
LL | trait UncheckedCopy: Sized + Deref {


error[E0277]: cannot add-assign `&'static str` to `Self`
   |
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |                                         |
   |     |                                         |
   |     |                                         required by this bound in `UncheckedCopy::Output`
   |     no implementation for `Self += &'static str`
help: consider further restricting `Self`
   |
   |
LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {


error[E0277]: the trait bound `Self: Copy` is not satisfied
   |
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |            |
   |     |            |
   |     |            required by this bound in `UncheckedCopy::Output`
   |     the trait `Copy` is not implemented for `Self`
help: consider further restricting `Self`
   |
   |
LL | trait UncheckedCopy: Sized + Copy {


error[E0277]: `Self` doesn't implement `std::fmt::Display`
   |
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |                                                                                |
   |     |                                                                                |
   |     |                                                                                required by this bound in `UncheckedCopy::Output`
   |     `Self` cannot be formatted with the default formatter
   |
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
help: consider further restricting `Self`
   |
LL | trait UncheckedCopy: Sized + std::fmt::Display {

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0277`.
For more information about this error, try `rustc --explain E0277`.

------------------------------------------


---- [ui] ui/associated-types/defaults-unsound-62211-2.rs stdout ----
diff of stderr:

- error[E0277]: the trait bound `Self: Copy` is not satisfied
-   --> $DIR/defaults-unsound-62211-2.rs:20:5
-    |
- LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
-    |     |            |
-    |     |            |
-    |     |            required by this bound in `UncheckedCopy::Output`
-    |     the trait `Copy` is not implemented for `Self`
- help: consider further restricting `Self`
-    |
-    |
- LL | trait UncheckedCopy: Sized + Copy {
- 
15 error[E0277]: the trait bound `Self: Deref` is not satisfied
16   --> $DIR/defaults-unsound-62211-2.rs:20:5
17    |
17    |

39    |
40 LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {
+ 
+ 
+ error[E0277]: the trait bound `Self: Copy` is not satisfied
+    |
+    |
+ LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
+    |     |            |
+    |     |            |
+    |     |            required by this bound in `UncheckedCopy::Output`
+    |     the trait `Copy` is not implemented for `Self`
+ help: consider further restricting `Self`
+    |
+    |
+ LL | trait UncheckedCopy: Sized + Copy {
42 
42 
43 error[E0277]: `Self` doesn't implement `std::fmt::Display`


The actual stderr differed from the expected stderr.
The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/defaults-unsound-62211-2/defaults-unsound-62211-2.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args associated-types/defaults-unsound-62211-2.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/associated-types/defaults-unsound-62211-2.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/defaults-unsound-62211-2" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/defaults-unsound-62211-2/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0277]: the trait bound `Self: Deref` is not satisfied
  --> /checkout/src/test/ui/associated-types/defaults-unsound-62211-2.rs:20:5
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |                   |
   |     |                   |
   |     |                   required by this bound in `UncheckedCopy::Output`
   |     the trait `Deref` is not implemented for `Self`
help: consider further restricting `Self`
   |
   |
LL | trait UncheckedCopy: Sized + Deref {


error[E0277]: cannot add-assign `&'static str` to `Self`
   |
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |                                         |
   |     |                                         |
   |     |                                         required by this bound in `UncheckedCopy::Output`
   |     no implementation for `Self += &'static str`
help: consider further restricting `Self`
   |
   |
LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {


error[E0277]: the trait bound `Self: Copy` is not satisfied
   |
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |            |
   |     |            |
   |     |            required by this bound in `UncheckedCopy::Output`
   |     the trait `Copy` is not implemented for `Self`
help: consider further restricting `Self`
   |
   |
LL | trait UncheckedCopy: Sized + Copy {


error[E0277]: `Self` doesn't implement `std::fmt::Display`
   |
   |
LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
   |     |                                                                                |
   |     |                                                                                |
   |     |                                                                                required by this bound in `UncheckedCopy::Output`
   |     `Self` cannot be formatted with the default formatter
   |
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
help: consider further restricting `Self`
   |
LL | trait UncheckedCopy: Sized + std::fmt::Display {

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0277`.
For more information about this error, try `rustc --explain E0277`.

------------------------------------------


---- [ui] ui/associated-types/trait-with-supertraits-needing-sized-self.rs stdout ----
diff of stderr:

1 error[E0277]: the size for values of type `Self` cannot be known at compilation time
-   --> $DIR/trait-with-supertraits-needing-sized-self.rs:3:22
3    |
3    |
4 LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self> + Div<Output=Self> {}
-    |                      ^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+    |                                         ^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
6    | 
7   ::: $SRC_DIR/core/src/ops/arith.rs:LL:COL


- LL | pub trait Add<Rhs = Self> {
-    |               --- required by this bound in `Add`
+ LL | pub trait Sub<Rhs = Self> {
+    |               --- required by this bound in `Sub`
12 help: consider further restricting `Self`
13    |



The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/trait-with-supertraits-needing-sized-self/trait-with-supertraits-needing-sized-self.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args associated-types/trait-with-supertraits-needing-sized-self.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/associated-types/trait-with-supertraits-needing-sized-self.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/trait-with-supertraits-needing-sized-self" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/associated-types/trait-with-supertraits-needing-sized-self/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0277]: the size for values of type `Self` cannot be known at compilation time
   |
   |
LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self> + Div<Output=Self> {}
   |                                         ^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
  ::: /checkout/library/core/src/ops/arith.rs:181:15
   |
   |
LL | pub trait Sub<Rhs = Self> {
   |               --- required by this bound in `Sub`
help: consider further restricting `Self`
   |
   |
LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self> + Div<Output=Self> + Sized {}

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.
---
diff of stderr:

13   --> $DIR/E0225.rs:8:20
14    |
15 LL | trait Foo = std::io::Read + std::io::Write;
-    |             -------------   -------------- first non-auto trait
+    |             -------------   -------------- additional non-auto trait
-    |             additional non-auto trait
+    |             first non-auto trait
19 ...
19 ...
20 LL |     let _: Box<dyn Foo>;


23    |                    trait alias used in trait object type (additional use)
24    |                    trait alias used in trait object type (first use)
25    |
-    = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: std::io::Write + std::io::Read {}`
+    = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
27    = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
29 error: aborting due to 2 previous errors


The actual stderr differed from the expected stderr.
The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/error-codes/E0225/E0225.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args error-codes/E0225.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/error-codes/E0225.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/error-codes/E0225" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/error-codes/E0225/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0225]: only auto traits can be used as additional traits in a trait object
   |
   |
LL |     let _: Box<dyn std::io::Read + std::io::Write>;
   |                    -------------   ^^^^^^^^^^^^^^ additional non-auto trait
   |                    first non-auto trait
   |
   |
   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
   = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>

error[E0225]: only auto traits can be used as additional traits in a trait object
   |
   |
LL | trait Foo = std::io::Read + std::io::Write;
   |             -------------   -------------- additional non-auto trait
   |             first non-auto trait
...
...
LL |     let _: Box<dyn Foo>;
   |                    |
   |                    |
   |                    trait alias used in trait object type (additional use)
   |                    trait alias used in trait object type (first use)
   |
   = help: consider creating a new trait with all of these as super-traits and using that trait here instead: `trait NewTrait: std::io::Read + std::io::Write {}`
   = note: auto-traits like `Send` and `Sync` are traits that have special properties; for more information on them, visit <https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits>
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0225`.


------------------------------------------


---- [ui] ui/issues/issue-40827.rs stdout ----
diff of stderr:

- error[E0277]: `Rc<Foo>` cannot be shared between threads safely
+ error[E0277]: `Rc<Foo>` cannot be sent between threads safely
3    |
3    |
4 LL | fn f<T: Send>(_: T) {}

5    |         ---- required by this bound in `f`
6 ...
7 LL |     f(Foo(Arc::new(Bar::B(None))));
-    |     ^ `Rc<Foo>` cannot be shared between threads safely
+    |     ^ `Rc<Foo>` cannot be sent between threads safely
9    |
-    = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
+    = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
11    = note: required because it appears within the type `Bar`
12    = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
13    = note: required because it appears within the type `Foo`
14 
14 
- error[E0277]: `Rc<Foo>` cannot be sent between threads safely
+ error[E0277]: `Rc<Foo>` cannot be shared between threads safely
17    |
17    |
18 LL | fn f<T: Send>(_: T) {}

19    |         ---- required by this bound in `f`
20 ...
21 LL |     f(Foo(Arc::new(Bar::B(None))));
-    |     ^ `Rc<Foo>` cannot be sent between threads safely
+    |     ^ `Rc<Foo>` cannot be shared between threads safely
23    |
-    = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
+    = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
25    = note: required because it appears within the type `Bar`
26    = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
27    = note: required because it appears within the type `Foo`

The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/issues/issue-40827/issue-40827.stderr
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/issues/issue-40827/issue-40827.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args issues/issue-40827.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/issues/issue-40827.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/issues/issue-40827" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/issues/issue-40827/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0277]: `Rc<Foo>` cannot be sent between threads safely
   |
   |
LL | fn f<T: Send>(_: T) {}
   |         ---- required by this bound in `f`
...
LL |     f(Foo(Arc::new(Bar::B(None))));
   |     ^ `Rc<Foo>` cannot be sent between threads safely
   |
   = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
   = note: required because it appears within the type `Bar`
   = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
   = note: required because it appears within the type `Foo`

error[E0277]: `Rc<Foo>` cannot be shared between threads safely
   |
   |
LL | fn f<T: Send>(_: T) {}
   |         ---- required by this bound in `f`
...
LL |     f(Foo(Arc::new(Bar::B(None))));
   |     ^ `Rc<Foo>` cannot be shared between threads safely
   |
   = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
   = note: required because it appears within the type `Bar`
   = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
   = note: required because it appears within the type `Foo`
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.


------------------------------------------


---- [ui] ui/traits/alias/cross-crate.rs stdout ----
diff of stderr:

- error[E0277]: `Rc<u32>` cannot be shared between threads safely
+ error[E0277]: `Rc<u32>` cannot be sent between threads safely
3    |
3    |
4 LL | fn use_alias<T: SendSync>() {}

5    |                 -------- required by this bound in `use_alias`
6 ...
7 LL |     use_alias::<Rc<u32>>();
-    |                 ^^^^^^^ `Rc<u32>` cannot be shared between threads safely
+    |                 ^^^^^^^ `Rc<u32>` cannot be sent between threads safely
9    |
-    = help: the trait `Sync` is not implemented for `Rc<u32>`
+    = help: the trait `Send` is not implemented for `Rc<u32>`
11 
- error[E0277]: `Rc<u32>` cannot be sent between threads safely
+ error[E0277]: `Rc<u32>` cannot be shared between threads safely
14    |
14    |
15 LL | fn use_alias<T: SendSync>() {}

16    |                 -------- required by this bound in `use_alias`
17 ...
18 LL |     use_alias::<Rc<u32>>();
-    |                 ^^^^^^^ `Rc<u32>` cannot be sent between threads safely
+    |                 ^^^^^^^ `Rc<u32>` cannot be shared between threads safely
20    |
-    = help: the trait `Send` is not implemented for `Rc<u32>`
+    = help: the trait `Sync` is not implemented for `Rc<u32>`
23 error: aborting due to 2 previous errors
24 



The actual stderr differed from the expected stderr.
Actual stderr saved to /checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/traits/alias/cross-crate/cross-crate.stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args traits/alias/cross-crate.rs`
error: 1 errors occurred comparing output.
status: exit code: 1
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/traits/alias/cross-crate.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zemit-future-incompat-report" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/traits/alias/cross-crate" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/traits/alias/cross-crate/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0277]: `Rc<u32>` cannot be sent between threads safely
   |
   |
LL | fn use_alias<T: SendSync>() {}
   |                 -------- required by this bound in `use_alias`
...
LL |     use_alias::<Rc<u32>>();
   |                 ^^^^^^^ `Rc<u32>` cannot be sent between threads safely
   |
   = help: the trait `Send` is not implemented for `Rc<u32>`

error[E0277]: `Rc<u32>` cannot be shared between threads safely
   |
   |
LL | fn use_alias<T: SendSync>() {}
   |                 -------- required by this bound in `use_alias`
...
LL |     use_alias::<Rc<u32>>();
   |                 ^^^^^^^ `Rc<u32>` cannot be shared between threads safely
   |
   = help: the trait `Sync` is not implemented for `Rc<u32>`
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.

---
test result: FAILED. 11445 passed; 7 failed; 93 ignored; 0 measured; 0 filtered out; finished in 139.16s



command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--suite" "ui" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-9/bin/FileCheck" "--nodejs" "/usr/bin/node" "--host-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--target-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python3" "--lldb-python" "/usr/bin/python3" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "9.0.0" "--llvm-components" "aarch64 aarch64asmparser aarch64codegen aarch64desc aarch64disassembler aarch64info aarch64utils aggressiveinstcombine all all-targets amdgpu amdgpuasmparser amdgpucodegen amdgpudesc amdgpudisassembler amdgpuinfo amdgpuutils analysis arm armasmparser armcodegen armdesc armdisassembler arminfo armutils asmparser asmprinter avr avrasmparser avrcodegen avrdesc avrdisassembler avrinfo binaryformat bitreader bitstreamreader bitwriter bpf bpfasmparser bpfcodegen bpfdesc bpfdisassembler bpfinfo codegen core coroutines coverage debuginfocodeview debuginfodwarf debuginfogsym debuginfomsf debuginfopdb demangle dlltooldriver engine executionengine fuzzmutate globalisel hexagon hexagonasmparser hexagoncodegen hexagondesc hexagondisassembler hexagoninfo instcombine instrumentation interpreter ipo irreader jitlink lanai lanaiasmparser lanaicodegen lanaidesc lanaidisassembler lanaiinfo libdriver lineeditor linker lto mc mca mcdisassembler mcjit mcparser mips mipsasmparser mipscodegen mipsdesc mipsdisassembler mipsinfo mirparser msp430 msp430asmparser msp430codegen msp430desc msp430disassembler msp430info native nativecodegen nvptx nvptxcodegen nvptxdesc nvptxinfo objcarcopts object objectyaml option orcjit passes perfjitevents powerpc powerpcasmparser powerpccodegen powerpcdesc powerpcdisassembler powerpcinfo profiledata remarks riscv riscvasmparser riscvcodegen riscvdesc riscvdisassembler riscvinfo riscvutils runtimedyld scalaropts selectiondag sparc sparcasmparser sparccodegen sparcdesc sparcdisassembler sparcinfo support symbolize systemz systemzasmparser systemzcodegen systemzdesc systemzdisassembler systemzinfo tablegen target textapi transformutils vectorize webassembly webassemblyasmparser webassemblycodegen webassemblydesc webassemblydisassembler webassemblyinfo windowsmanifest x86 x86asmparser x86codegen x86desc x86disassembler x86info x86utils xcore xcorecodegen xcoredesc xcoredisassembler xcoreinfo xray" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"


failed to run: /checkout/obj/build/bootstrap/debug/bootstrap --stage 2 test --exclude src/tools/tidy
Build completed unsuccessfully in 0:14:05

[Aaron1011]

After some further consideration, I don't think sorting by DefPathHash is the right approach. Regardless of what's causing the difference between my machine and the PR builder, I'm pretty sure that a DefPathHash is not the same across platforms, in general. The crate-id part of a DefPathHash is computed using the -C metadata arguments:

rust/compiler/rustc_interface/src/util.rs

Lines 500 to 503 in b3e19a2

	let mut metadata = session.opts.cg.metadata.clone();
	// We don't want the crate_disambiguator to dependent on the order
	// -C metadata arguments, so sort them:
	metadata.sort();

This is generated by Cargo from a large amount of information: https://github.com/rust-lang/cargo/blob/c4adfd553b7210d1aeb462d6d4b1dabfd2d0910e/src/cargo/core/compiler/context/compilation_files.rs#L489-L565

In particular, the name of the host platform is included: https://github.com/rust-lang/cargo/blob/c4adfd553b7210d1aeb462d6d4b1dabfd2d0910e/src/cargo/core/compiler/context/compilation_files.rs#L582-L585

This means that we'll get different DefPathHash values across different platforms, and across different config options (debuginfo vs no debuginfo).

This means that sorting by DefPathHash should give us a stable result for a fixed set of compilation settings, but will differ across platforms, making it impossible to directly compare the compiler stdout.

Instead, I think we should avoid sorting by both DefId and DefPathHash, since both depend on global state. In the places where we currently sort, we should instead sort by the stringified path, or avoid sorting at all (e.g. de-duplicate by inserting into a HashMap).

[Aaron1011]

It turns out that the difference in ordering between my machine and the PR builder was caused by my local config.toml (I suspect that it was one of the debuginfo settings). Restoring my local config.toml to config.toml.example gave me the same ordering that are present on CI.

[cjgillot]

The fact that we sort the vectors by DefId should mean the relative order of the elements is irrelevant. As a consequence, I am not sure that sorting the vectors inside the query is relevant. The change would be better in the HashStable impl for the query's result, wouldn't it?

[Aaron1011]

The fact that we sort the vectors by DefId should mean the relative order of the elements is irrelevant.

The problem is that the value of a DefId can be changed when other items are inserted/deleted in the crate. If all of the query's inputs have the same DefPathHash as in a previous session, then the result of the query should have the same DefPathHash as before. If we sort by DefId, then we might end up with a differently ordered result even if all of the inputs have the same DefPathHashes.

The change would be better in the HashStable impl for the query's result, wouldn't it?

The relevant query result is ty::GenericPredicates, so we would have to make its HashStable implementation independent of the order of the predicates it stores. That makes me really uncomfortable - we'd be basically assuming that any code that iterates over predicates is completely order-insensitive, which seems like a really dangerous assumption to make.

[Aaron1011]

Closing in favor of #83074, which avoids the sorting alogether.