Auto merge of #81635 - michaelwoerister:structured_def_path_hash, r=pnkfelix

Let a portion of DefPathHash uniquely identify the DefPath's crate.

This allows to directly map from a `DefPathHash` to the crate it originates from, without constructing side tables to do that mapping -- something that is useful for incremental compilation where we deal with `DefPathHash` instead of `DefId` a lot.

It also allows to reliably and cheaply check for `DefPathHash` collisions which allows the compiler to gracefully abort compilation instead of running into a subsequent ICE at some random place in the code.

The following new piece of documentation describes the most interesting aspects of the changes:

```rust
/// A `DefPathHash` is a fixed-size representation of a `DefPath` that is
/// stable across crate and compilation session boundaries. It consists of two
/// separate 64-bit hashes. The first uniquely identifies the crate this
/// `DefPathHash` originates from (see [StableCrateId]), and the second
/// uniquely identifies the corresponding `DefPath` within that crate. Together
/// they form a unique identifier within an entire crate graph.
///
/// There is a very small chance of hash collisions, which would mean that two
/// different `DefPath`s map to the same `DefPathHash`. Proceeding compilation
/// with such a hash collision would very probably lead to an ICE and, in the
/// worst case, to a silent mis-compilation. The compiler therefore actively
/// and exhaustively checks for such hash collisions and aborts compilation if
/// it finds one.
///
/// `DefPathHash` uses 64-bit hashes for both the crate-id part and the
/// crate-internal part, even though it is likely that there are many more
/// `LocalDefId`s in a single crate than there are individual crates in a crate
/// graph. Since we use the same number of bits in both cases, the collision
/// probability for the crate-local part will be quite a bit higher (though
/// still very small).
///
/// This imbalance is not by accident: A hash collision in the
/// crate-local part of a `DefPathHash` will be detected and reported while
/// compiling the crate in question. Such a collision does not depend on
/// outside factors and can be easily fixed by the crate maintainer (e.g. by
/// renaming the item in question or by bumping the crate version in a harmless
/// way).
///
/// A collision between crate-id hashes on the other hand is harder to fix
/// because it depends on the set of crates in the entire crate graph of a
/// compilation session. Again, using the same crate with a different version
/// number would fix the issue with a high probability -- but that might be
/// easier said then done if the crates in questions are dependencies of
/// third-party crates.
///
/// That being said, given a high quality hash function, the collision
/// probabilities in question are very small. For example, for a big crate like
/// `rustc_middle` (with ~50000 `LocalDefId`s as of the time of writing) there
/// is a probability of roughly 1 in 14,750,000,000 of a crate-internal
/// collision occurring. For a big crate graph with 1000 crates in it, there is
/// a probability of 1 in 36,890,000,000,000 of a `StableCrateId` collision.
```

Given the probabilities involved I hope that no one will ever actually see the error messages. Nonetheless, I'd be glad about some feedback on how to improve them. Should we create a GH issue describing the problem and possible solutions to point to? Or a page in the rustc book?

r? `@pnkfelix` (feel free to re-assign)

15 files changed, 94 insertions, 96 deletions

diff --git a/src/test/ui/single-use-lifetime/one-use-in-fn-argument-in-band.stderr b/src/test/ui/single-use-lifetime/one-use-in-fn-argument-in-band.stderr
index b251e8a438a..723c4a7a1fb 100644
--- a/src/test/ui/single-use-lifetime/one-use-in-fn-argument-in-band.stderr
+++ b/src/test/ui/single-use-lifetime/one-use-in-fn-argument-in-band.stderr
@@ -1,11 +1,11 @@
-error: lifetime parameter `'a` only used once
-  --> $DIR/one-use-in-fn-argument-in-band.rs:11:10
+error: lifetime parameter `'b` only used once
+  --> $DIR/one-use-in-fn-argument-in-band.rs:11:22
    |
 LL | fn a(x: &'a u32, y: &'b u32) {
-   |          ^^-
-   |          |
-   |          this lifetime is only used here
-   |          help: elide the single-use lifetime
+   |                      ^^-
+   |                      |
+   |                      this lifetime is only used here
+   |                      help: elide the single-use lifetime
    |
 note: the lint level is defined here
   --> $DIR/one-use-in-fn-argument-in-band.rs:4:9
@@ -13,14 +13,14 @@ note: the lint level is defined here
 LL | #![deny(single_use_lifetimes)]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: lifetime parameter `'b` only used once
-  --> $DIR/one-use-in-fn-argument-in-band.rs:11:22
+error: lifetime parameter `'a` only used once
+  --> $DIR/one-use-in-fn-argument-in-band.rs:11:10
    |
 LL | fn a(x: &'a u32, y: &'b u32) {
-   |                      ^^-
-   |                      |
-   |                      this lifetime is only used here
-   |                      help: elide the single-use lifetime
+   |          ^^-
+   |          |
+   |          this lifetime is only used here
+   |          help: elide the single-use lifetime
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/symbol-names/basic.legacy.stderr b/src/test/ui/symbol-names/basic.legacy.stderr
index dec57e06ea2..7155d88be96 100644
--- a/src/test/ui/symbol-names/basic.legacy.stderr
+++ b/src/test/ui/symbol-names/basic.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN5basic4main17h4272b3de5e868f5aE)
+error: symbol-name(_ZN5basic4main17hfcf1daab33c43a6aE)
   --> $DIR/basic.rs:8:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(basic::main::h4272b3de5e868f5a)
+error: demangling(basic::main::hfcf1daab33c43a6a)
   --> $DIR/basic.rs:8:1
    |
 LL | #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/basic.rs b/src/test/ui/symbol-names/basic.rs
index ddc349d7f10..bd107c10207 100644
--- a/src/test/ui/symbol-names/basic.rs
+++ b/src/test/ui/symbol-names/basic.rs
@@ -9,8 +9,8 @@
 //[legacy]~^ ERROR symbol-name(_ZN5basic4main
 //[legacy]~| ERROR demangling(basic::main
 //[legacy]~| ERROR demangling-alt(basic::main)
- //[v0]~^^^^ ERROR symbol-name(_RNvCs4fqI2P2rA04_5basic4main)
-    //[v0]~| ERROR demangling(basic[317d481089b8c8fe]::main)
+ //[v0]~^^^^ ERROR symbol-name(_RNvCs21hi0yVfW1J_5basic4main)
+    //[v0]~| ERROR demangling(basic[17891616a171812d]::main)
     //[v0]~| ERROR demangling-alt(basic::main)
 #[rustc_def_path]
 //[legacy]~^ ERROR def-path(main)
diff --git a/src/test/ui/symbol-names/basic.v0.stderr b/src/test/ui/symbol-names/basic.v0.stderr
index 36dba0dfc97..519efc9d7b4 100644
--- a/src/test/ui/symbol-names/basic.v0.stderr
+++ b/src/test/ui/symbol-names/basic.v0.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_RNvCs4fqI2P2rA04_5basic4main)
+error: symbol-name(_RNvCs21hi0yVfW1J_5basic4main)
   --> $DIR/basic.rs:8:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(basic[317d481089b8c8fe]::main)
+error: demangling(basic[17891616a171812d]::main)
   --> $DIR/basic.rs:8:1
    |
 LL | #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/const-generics-demangling.rs b/src/test/ui/symbol-names/const-generics-demangling.rs
index 55ab17fcd5a..bd7e1c0f336 100644
--- a/src/test/ui/symbol-names/const-generics-demangling.rs
+++ b/src/test/ui/symbol-names/const-generics-demangling.rs
@@ -5,32 +5,32 @@
 pub struct Unsigned<const F: u8>;
 
 #[rustc_symbol_name]
-//~^ ERROR symbol-name(_RMCs4fqI2P2rA04_25const_generics_demanglingINtB0_8UnsignedKhb_E)
-//~| ERROR demangling(<const_generics_demangling[317d481089b8c8fe]::Unsigned<11: u8>>)
+//~^ ERROR symbol-name(_RMCs21hi0yVfW1J_25const_generics_demanglingINtB0_8UnsignedKhb_E)
+//~| ERROR demangling(<const_generics_demangling[17891616a171812d]::Unsigned<11: u8>>)
 //~| ERROR demangling-alt(<const_generics_demangling::Unsigned<11>>)
 impl Unsigned<11> {}
 
 pub struct Signed<const F: i16>;
 
 #[rustc_symbol_name]
-//~^ ERROR symbol-name(_RMs_Cs4fqI2P2rA04_25const_generics_demanglingINtB2_6SignedKsn98_E)
-//~| ERROR demangling(<const_generics_demangling[317d481089b8c8fe]::Signed<-152: i16>>)
+//~^ ERROR symbol-name(_RMs_Cs21hi0yVfW1J_25const_generics_demanglingINtB2_6SignedKsn98_E)
+//~| ERROR demangling(<const_generics_demangling[17891616a171812d]::Signed<-152: i16>>)
 //~| ERROR demangling-alt(<const_generics_demangling::Signed<-152>>)
 impl Signed<-152> {}
 
 pub struct Bool<const F: bool>;
 
 #[rustc_symbol_name]
-//~^ ERROR symbol-name(_RMs0_Cs4fqI2P2rA04_25const_generics_demanglingINtB3_4BoolKb1_E)
-//~| ERROR demangling(<const_generics_demangling[317d481089b8c8fe]::Bool<true: bool>>)
+//~^ ERROR symbol-name(_RMs0_Cs21hi0yVfW1J_25const_generics_demanglingINtB3_4BoolKb1_E)
+//~| ERROR demangling(<const_generics_demangling[17891616a171812d]::Bool<true: bool>>)
 //~| ERROR demangling-alt(<const_generics_demangling::Bool<true>>)
 impl Bool<true> {}
 
 pub struct Char<const F: char>;
 
 #[rustc_symbol_name]
-//~^ ERROR symbol-name(_RMs1_Cs4fqI2P2rA04_25const_generics_demanglingINtB3_4CharKc2202_E)
-//~| ERROR demangling(<const_generics_demangling[317d481089b8c8fe]::Char<'∂': char>>)
+//~^ ERROR symbol-name(_RMs1_Cs21hi0yVfW1J_25const_generics_demanglingINtB3_4CharKc2202_E)
+//~| ERROR demangling(<const_generics_demangling[17891616a171812d]::Char<'∂': char>>)
 //~| ERROR demangling-alt(<const_generics_demangling::Char<'∂'>>)
 impl Char<'∂'> {}
 
diff --git a/src/test/ui/symbol-names/const-generics-demangling.stderr b/src/test/ui/symbol-names/const-generics-demangling.stderr
index a9574cacea3..13995403f77 100644
--- a/src/test/ui/symbol-names/const-generics-demangling.stderr
+++ b/src/test/ui/symbol-names/const-generics-demangling.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_RMCs4fqI2P2rA04_25const_generics_demanglingINtB0_8UnsignedKhb_E)
+error: symbol-name(_RMCs21hi0yVfW1J_25const_generics_demanglingINtB0_8UnsignedKhb_E)
   --> $DIR/const-generics-demangling.rs:7:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<const_generics_demangling[317d481089b8c8fe]::Unsigned<11: u8>>)
+error: demangling(<const_generics_demangling[17891616a171812d]::Unsigned<11: u8>>)
   --> $DIR/const-generics-demangling.rs:7:1
    |
 LL | #[rustc_symbol_name]
@@ -16,13 +16,13 @@ error: demangling-alt(<const_generics_demangling::Unsigned<11>>)
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_RMs_Cs4fqI2P2rA04_25const_generics_demanglingINtB2_6SignedKsn98_E)
+error: symbol-name(_RMs_Cs21hi0yVfW1J_25const_generics_demanglingINtB2_6SignedKsn98_E)
   --> $DIR/const-generics-demangling.rs:15:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<const_generics_demangling[317d481089b8c8fe]::Signed<-152: i16>>)
+error: demangling(<const_generics_demangling[17891616a171812d]::Signed<-152: i16>>)
   --> $DIR/const-generics-demangling.rs:15:1
    |
 LL | #[rustc_symbol_name]
@@ -34,13 +34,13 @@ error: demangling-alt(<const_generics_demangling::Signed<-152>>)
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_RMs0_Cs4fqI2P2rA04_25const_generics_demanglingINtB3_4BoolKb1_E)
+error: symbol-name(_RMs0_Cs21hi0yVfW1J_25const_generics_demanglingINtB3_4BoolKb1_E)
   --> $DIR/const-generics-demangling.rs:23:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<const_generics_demangling[317d481089b8c8fe]::Bool<true: bool>>)
+error: demangling(<const_generics_demangling[17891616a171812d]::Bool<true: bool>>)
   --> $DIR/const-generics-demangling.rs:23:1
    |
 LL | #[rustc_symbol_name]
@@ -52,13 +52,13 @@ error: demangling-alt(<const_generics_demangling::Bool<true>>)
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_RMs1_Cs4fqI2P2rA04_25const_generics_demanglingINtB3_4CharKc2202_E)
+error: symbol-name(_RMs1_Cs21hi0yVfW1J_25const_generics_demanglingINtB3_4CharKc2202_E)
   --> $DIR/const-generics-demangling.rs:31:1
    |
 LL | #[rustc_symbol_name]
    | ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<const_generics_demangling[317d481089b8c8fe]::Char<'∂': char>>)
+error: demangling(<const_generics_demangling[17891616a171812d]::Char<'∂': char>>)
   --> $DIR/const-generics-demangling.rs:31:1
    |
 LL | #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/impl1.legacy.stderr b/src/test/ui/symbol-names/impl1.legacy.stderr
index c866f9bd3b7..bd32a39a65c 100644
--- a/src/test/ui/symbol-names/impl1.legacy.stderr
+++ b/src/test/ui/symbol-names/impl1.legacy.stderr
@@ -1,71 +1,71 @@
-error: symbol-name(_ZN5impl13foo3Foo3bar17ha318160f105e638cE)
-  --> $DIR/impl1.rs:16:9
+error: symbol-name(_ZN5impl13foo3Foo3bar17<SYMBOL_HASH>)
+  --> $DIR/impl1.rs:15:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(impl1::foo::Foo::bar::ha318160f105e638c)
-  --> $DIR/impl1.rs:16:9
+error: demangling(impl1::foo::Foo::bar::<SYMBOL_HASH>)
+  --> $DIR/impl1.rs:15:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(impl1::foo::Foo::bar)
-  --> $DIR/impl1.rs:16:9
+  --> $DIR/impl1.rs:15:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: def-path(foo::Foo::bar)
-  --> $DIR/impl1.rs:23:9
+  --> $DIR/impl1.rs:22:9
    |
 LL |         #[rustc_def_path]
    |         ^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_ZN5impl13bar33_$LT$impl$u20$impl1..foo..Foo$GT$3baz17h6c2dbab6e66f9fa3E)
-  --> $DIR/impl1.rs:34:9
+error: symbol-name(_ZN5impl13bar33_$LT$impl$u20$impl1..foo..Foo$GT$3baz17<SYMBOL_HASH>)
+  --> $DIR/impl1.rs:33:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(impl1::bar::<impl impl1::foo::Foo>::baz::h6c2dbab6e66f9fa3)
-  --> $DIR/impl1.rs:34:9
+error: demangling(impl1::bar::<impl impl1::foo::Foo>::baz::<SYMBOL_HASH>)
+  --> $DIR/impl1.rs:33:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(impl1::bar::<impl impl1::foo::Foo>::baz)
-  --> $DIR/impl1.rs:34:9
+  --> $DIR/impl1.rs:33:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: def-path(bar::<impl foo::Foo>::baz)
-  --> $DIR/impl1.rs:41:9
+  --> $DIR/impl1.rs:40:9
    |
 LL |         #[rustc_def_path]
    |         ^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_ZN209_$LT$$u5b$$RF$dyn$u20$impl1..Foo$u2b$Assoc$u20$$u3d$$u20$extern$u20$$u22$C$u22$$u20$fn$LP$$RF$u8$C$$u20$...$RP$$u2b$impl1..AutoTrait$u3b$$u20$3$u5d$$u20$as$u20$impl1..main..$u7b$$u7b$closure$u7d$$u7d$..Bar$GT$6method17SYMBOL_HASHE)
-  --> $DIR/impl1.rs:64:13
+error: symbol-name(_ZN209_$LT$$u5b$$RF$dyn$u20$impl1..Foo$u2b$Assoc$u20$$u3d$$u20$extern$u20$$u22$C$u22$$u20$fn$LP$$RF$u8$C$$u20$...$RP$$u2b$impl1..AutoTrait$u3b$$u20$3$u5d$$u20$as$u20$impl1..main..$u7b$$u7b$closure$u7d$$u7d$..Bar$GT$6method17<SYMBOL_HASH>)
+  --> $DIR/impl1.rs:63:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; 3] as impl1::main::{{closure}}::Bar>::method::SYMBOL_HASH)
-  --> $DIR/impl1.rs:64:13
+error: demangling(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; 3] as impl1::main::{{closure}}::Bar>::method::<SYMBOL_HASH>)
+  --> $DIR/impl1.rs:63:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; 3] as impl1::main::{{closure}}::Bar>::method)
-  --> $DIR/impl1.rs:64:13
+  --> $DIR/impl1.rs:63:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
 error: def-path(<[&dyn Foo<Assoc = for<'r> extern "C" fn(&'r u8, ...)> + AutoTrait; 3] as main::{closure#1}::Bar>::method)
-  --> $DIR/impl1.rs:71:13
+  --> $DIR/impl1.rs:70:13
    |
 LL |             #[rustc_def_path]
    |             ^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/symbol-names/impl1.rs b/src/test/ui/symbol-names/impl1.rs
index 24bdf6d669e..771695330d8 100644
--- a/src/test/ui/symbol-names/impl1.rs
+++ b/src/test/ui/symbol-names/impl1.rs
@@ -3,8 +3,7 @@
 // revisions: legacy v0
 //[legacy]compile-flags: -Z symbol-mangling-version=legacy
     //[v0]compile-flags: -Z symbol-mangling-version=v0
-//[legacy]normalize-stderr-32bit: "hee444285569b39c2" -> "SYMBOL_HASH"
-//[legacy]normalize-stderr-64bit: "h310ea0259fc3d32d" -> "SYMBOL_HASH"
+//[legacy]normalize-stderr-test: "h[\w]{16}E?\)" -> "<SYMBOL_HASH>)"
 
 #![feature(auto_traits, rustc_attrs)]
 #![allow(dead_code)]
@@ -17,8 +16,8 @@ mod foo {
         //[legacy]~^ ERROR symbol-name(_ZN5impl13foo3Foo3bar
         //[legacy]~| ERROR demangling(impl1::foo::Foo::bar
         //[legacy]~| ERROR demangling-alt(impl1::foo::Foo::bar)
-         //[v0]~^^^^ ERROR symbol-name(_RNvMNtCs4fqI2P2rA04_5impl13fooNtB2_3Foo3bar)
-            //[v0]~| ERROR demangling(<impl1[317d481089b8c8fe]::foo::Foo>::bar)
+         //[v0]~^^^^ ERROR symbol-name(_RNvMNtCs21hi0yVfW1J_5impl13fooNtB2_3Foo3bar)
+            //[v0]~| ERROR demangling(<impl1[17891616a171812d]::foo::Foo>::bar)
             //[v0]~| ERROR demangling-alt(<impl1::foo::Foo>::bar)
         #[rustc_def_path]
         //[legacy]~^ ERROR def-path(foo::Foo::bar)
@@ -35,8 +34,8 @@ mod bar {
         //[legacy]~^ ERROR symbol-name(_ZN5impl13bar33_$LT$impl$u20$impl1..foo..Foo$GT$3baz
         //[legacy]~| ERROR demangling(impl1::bar::<impl impl1::foo::Foo>::baz
         //[legacy]~| ERROR demangling-alt(impl1::bar::<impl impl1::foo::Foo>::baz)
-         //[v0]~^^^^ ERROR symbol-name(_RNvMNtCs4fqI2P2rA04_5impl13barNtNtB4_3foo3Foo3baz)
-            //[v0]~| ERROR demangling(<impl1[317d481089b8c8fe]::foo::Foo>::baz)
+         //[v0]~^^^^ ERROR symbol-name(_RNvMNtCs21hi0yVfW1J_5impl13barNtNtB4_3foo3Foo3baz)
+            //[v0]~| ERROR demangling(<impl1[17891616a171812d]::foo::Foo>::baz)
             //[v0]~| ERROR demangling-alt(<impl1::foo::Foo>::baz)
         #[rustc_def_path]
         //[legacy]~^ ERROR def-path(bar::<impl foo::Foo>::baz)
@@ -65,8 +64,8 @@ fn main() {
             //[legacy]~^ ERROR symbol-name(_ZN209_$LT$$u5b$$RF$dyn$u20$impl1..Foo$u2b$Assoc$u20$$u3d$$u20$extern$u20$$u22$C$u22$$u20$fn$LP$$RF$u8$C$$u20$...$RP$$u2b$impl1..AutoTrait$u3b$$u20$3$u5d$$u20$as$u20$impl1..main..$u7b$$u7b$closure$u7d$$u7d$..Bar$GT$6method
             //[legacy]~| ERROR demangling(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; 3] as impl1::main::{{closure}}::Bar>::method
             //[legacy]~| ERROR demangling-alt(<[&dyn impl1::Foo+Assoc = extern "C" fn(&u8, ::.)+impl1::AutoTrait; 3] as impl1::main::{{closure}}::Bar>::method)
-             //[v0]~^^^^ ERROR symbol-name(_RNvXNCNvCs4fqI2P2rA04_5impl14mains_0ARDNtB6_3Foop5AssocFG_KCRL0_hvEuNtB6_9AutoTraitEL_j3_NtB2_3Bar6method)
-                //[v0]~| ERROR demangling(<[&dyn impl1[317d481089b8c8fe]::Foo<Assoc = for<'a> extern "C" fn(&'a u8, ...)> + impl1[317d481089b8c8fe]::AutoTrait; 3: usize] as impl1[317d481089b8c8fe]::main::{closure#1}::Bar>::method)
+             //[v0]~^^^^ ERROR symbol-name(_RNvXNCNvCs21hi0yVfW1J_5impl14mains_0ARDNtB6_3Foop5AssocFG_KCRL0_hvEuNtB6_9AutoTraitEL_j3_NtB2_3Bar6method)
+                //[v0]~| ERROR demangling(<[&dyn impl1[17891616a171812d]::Foo<Assoc = for<'a> extern "C" fn(&'a u8, ...)> + impl1[17891616a171812d]::AutoTrait; 3: usize] as impl1[17891616a171812d]::main::{closure#1}::Bar>::method)
                 //[v0]~| ERROR demangling-alt(<[&dyn impl1::Foo<Assoc = for<'a> extern "C" fn(&'a u8, ...)> + impl1::AutoTrait; 3] as impl1::main::{closure#1}::Bar>::method)
             #[rustc_def_path]
             //[legacy]~^ ERROR def-path(<[&dyn Foo<Assoc = for<'r> extern "C" fn(&'r u8, ...)> + AutoTrait; 3] as main::{closure#1}::Bar>::method)
diff --git a/src/test/ui/symbol-names/impl1.v0.stderr b/src/test/ui/symbol-names/impl1.v0.stderr
index db5eda0db50..3a6610935d6 100644
--- a/src/test/ui/symbol-names/impl1.v0.stderr
+++ b/src/test/ui/symbol-names/impl1.v0.stderr
@@ -1,71 +1,71 @@
-error: symbol-name(_RNvMNtCs4fqI2P2rA04_5impl13fooNtB2_3Foo3bar)
-  --> $DIR/impl1.rs:16:9
+error: symbol-name(_RNvMNtCs21hi0yVfW1J_5impl13fooNtB2_3Foo3bar)
+  --> $DIR/impl1.rs:15:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<impl1[317d481089b8c8fe]::foo::Foo>::bar)
-  --> $DIR/impl1.rs:16:9
+error: demangling(<impl1[17891616a171812d]::foo::Foo>::bar)
+  --> $DIR/impl1.rs:15:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(<impl1::foo::Foo>::bar)
-  --> $DIR/impl1.rs:16:9
+  --> $DIR/impl1.rs:15:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: def-path(foo::Foo::bar)
-  --> $DIR/impl1.rs:23:9
+  --> $DIR/impl1.rs:22:9
    |
 LL |         #[rustc_def_path]
    |         ^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_RNvMNtCs4fqI2P2rA04_5impl13barNtNtB4_3foo3Foo3baz)
-  --> $DIR/impl1.rs:34:9
+error: symbol-name(_RNvMNtCs21hi0yVfW1J_5impl13barNtNtB4_3foo3Foo3baz)
+  --> $DIR/impl1.rs:33:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<impl1[317d481089b8c8fe]::foo::Foo>::baz)
-  --> $DIR/impl1.rs:34:9
+error: demangling(<impl1[17891616a171812d]::foo::Foo>::baz)
+  --> $DIR/impl1.rs:33:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(<impl1::foo::Foo>::baz)
-  --> $DIR/impl1.rs:34:9
+  --> $DIR/impl1.rs:33:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
 error: def-path(bar::<impl foo::Foo>::baz)
-  --> $DIR/impl1.rs:41:9
+  --> $DIR/impl1.rs:40:9
    |
 LL |         #[rustc_def_path]
    |         ^^^^^^^^^^^^^^^^^
 
-error: symbol-name(_RNvXNCNvCs4fqI2P2rA04_5impl14mains_0ARDNtB6_3Foop5AssocFG_KCRL0_hvEuNtB6_9AutoTraitEL_j3_NtB2_3Bar6method)
-  --> $DIR/impl1.rs:64:13
+error: symbol-name(_RNvXNCNvCs21hi0yVfW1J_5impl14mains_0ARDNtB6_3Foop5AssocFG_KCRL0_hvEuNtB6_9AutoTraitEL_j3_NtB2_3Bar6method)
+  --> $DIR/impl1.rs:63:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<[&dyn impl1[317d481089b8c8fe]::Foo<Assoc = for<'a> extern "C" fn(&'a u8, ...)> + impl1[317d481089b8c8fe]::AutoTrait; 3: usize] as impl1[317d481089b8c8fe]::main::{closure#1}::Bar>::method)
-  --> $DIR/impl1.rs:64:13
+error: demangling(<[&dyn impl1[17891616a171812d]::Foo<Assoc = for<'a> extern "C" fn(&'a u8, ...)> + impl1[17891616a171812d]::AutoTrait; 3: usize] as impl1[17891616a171812d]::main::{closure#1}::Bar>::method)
+  --> $DIR/impl1.rs:63:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(<[&dyn impl1::Foo<Assoc = for<'a> extern "C" fn(&'a u8, ...)> + impl1::AutoTrait; 3] as impl1::main::{closure#1}::Bar>::method)
-  --> $DIR/impl1.rs:64:13
+  --> $DIR/impl1.rs:63:13
    |
 LL |             #[rustc_symbol_name]
    |             ^^^^^^^^^^^^^^^^^^^^
 
 error: def-path(<[&dyn Foo<Assoc = for<'r> extern "C" fn(&'r u8, ...)> + AutoTrait; 3] as main::{closure#1}::Bar>::method)
-  --> $DIR/impl1.rs:71:13
+  --> $DIR/impl1.rs:70:13
    |
 LL |             #[rustc_def_path]
    |             ^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/symbol-names/issue-60925.legacy.stderr b/src/test/ui/symbol-names/issue-60925.legacy.stderr
index f5699052795..9575875f5a8 100644
--- a/src/test/ui/symbol-names/issue-60925.legacy.stderr
+++ b/src/test/ui/symbol-names/issue-60925.legacy.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17h79d9aaa05f4b26d6E)
+error: symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17hb8ca3eb2682b1b51E)
   --> $DIR/issue-60925.rs:22:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo::h79d9aaa05f4b26d6)
+error: demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo::hb8ca3eb2682b1b51)
   --> $DIR/issue-60925.rs:22:9
    |
 LL |         #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/issue-60925.rs b/src/test/ui/symbol-names/issue-60925.rs
index 55b7041935c..47c9230c0ed 100644
--- a/src/test/ui/symbol-names/issue-60925.rs
+++ b/src/test/ui/symbol-names/issue-60925.rs
@@ -23,8 +23,8 @@ mod foo {
         //[legacy]~^ ERROR symbol-name(_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo
         //[legacy]~| ERROR demangling(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo
         //[legacy]~| ERROR demangling-alt(issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo)
-         //[v0]~^^^^ ERROR symbol-name(_RNvMNtCs4fqI2P2rA04_11issue_609253fooINtB2_3FooNtNtB4_4llvm3FooE3foo)
-            //[v0]~| ERROR demangling(<issue_60925[317d481089b8c8fe]::foo::Foo<issue_60925[317d481089b8c8fe]::llvm::Foo>>::foo)
+         //[v0]~^^^^ ERROR symbol-name(_RNvMNtCs21hi0yVfW1J_11issue_609253fooINtB2_3FooNtNtB4_4llvm3FooE3foo)
+            //[v0]~| ERROR demangling(<issue_60925[17891616a171812d]::foo::Foo<issue_60925[17891616a171812d]::llvm::Foo>>::foo)
             //[v0]~| ERROR demangling-alt(<issue_60925::foo::Foo<issue_60925::llvm::Foo>>::foo)
         pub(crate) fn foo() {
             for _ in 0..0 {
diff --git a/src/test/ui/symbol-names/issue-60925.v0.stderr b/src/test/ui/symbol-names/issue-60925.v0.stderr
index 78594b88b45..aed60a58af9 100644
--- a/src/test/ui/symbol-names/issue-60925.v0.stderr
+++ b/src/test/ui/symbol-names/issue-60925.v0.stderr
@@ -1,10 +1,10 @@
-error: symbol-name(_RNvMNtCs4fqI2P2rA04_11issue_609253fooINtB2_3FooNtNtB4_4llvm3FooE3foo)
+error: symbol-name(_RNvMNtCs21hi0yVfW1J_11issue_609253fooINtB2_3FooNtNtB4_4llvm3FooE3foo)
   --> $DIR/issue-60925.rs:22:9
    |
 LL |         #[rustc_symbol_name]
    |         ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<issue_60925[317d481089b8c8fe]::foo::Foo<issue_60925[317d481089b8c8fe]::llvm::Foo>>::foo)
+error: demangling(<issue_60925[17891616a171812d]::foo::Foo<issue_60925[17891616a171812d]::llvm::Foo>>::foo)
   --> $DIR/issue-60925.rs:22:9
    |
 LL |         #[rustc_symbol_name]
diff --git a/src/test/ui/symbol-names/issue-75326.legacy.stderr b/src/test/ui/symbol-names/issue-75326.legacy.stderr
index 5f822f6660c..2ad16bdb816 100644
--- a/src/test/ui/symbol-names/issue-75326.legacy.stderr
+++ b/src/test/ui/symbol-names/issue-75326.legacy.stderr
@@ -1,17 +1,17 @@
 error: symbol-name(_ZN72_$LT$issue_75326..Foo$LT$I$C$E$GT$$u20$as$u20$issue_75326..Iterator2$GT$4next17SYMBOL_HASH)
-  --> $DIR/issue-75326.rs:43:5
+  --> $DIR/issue-75326.rs:42:5
    |
 LL |     #[rustc_symbol_name]
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling(<issue_75326::Foo<I,E> as issue_75326::Iterator2>::next::SYMBOL_HASH)
-  --> $DIR/issue-75326.rs:43:5
+  --> $DIR/issue-75326.rs:42:5
    |
 LL |     #[rustc_symbol_name]
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(<issue_75326::Foo<I,E> as issue_75326::Iterator2>::next)
-  --> $DIR/issue-75326.rs:43:5
+  --> $DIR/issue-75326.rs:42:5
    |
 LL |     #[rustc_symbol_name]
    |     ^^^^^^^^^^^^^^^^^^^^
diff --git a/src/test/ui/symbol-names/issue-75326.rs b/src/test/ui/symbol-names/issue-75326.rs
index ce315164cef..faf36715b19 100644
--- a/src/test/ui/symbol-names/issue-75326.rs
+++ b/src/test/ui/symbol-names/issue-75326.rs
@@ -3,8 +3,7 @@
 // revisions: legacy v0
 //[legacy]compile-flags: -Z symbol-mangling-version=legacy
 //[v0]compile-flags: -Z symbol-mangling-version=v0
-//[legacy]normalize-stderr-32bit: "h[\d\w]+" -> "SYMBOL_HASH"
-//[legacy]normalize-stderr-64bit: "h[\d\w]+" -> "SYMBOL_HASH"
+//[legacy]normalize-stderr-test: "h[\w{16}]+" -> "SYMBOL_HASH"
 
 #![feature(rustc_attrs)]
 
@@ -44,8 +43,8 @@ where
     //[legacy]~^ ERROR symbol-name(_ZN72_$LT$issue_75326..Foo$LT$I$C$E$GT$$u20$as$u20$issue_75326..Iterator2$GT$4next
     //[legacy]~| ERROR demangling(<issue_75326::Foo<I,E> as issue_75326::Iterator2>::next
     //[legacy]~| ERROR demangling-alt(<issue_75326::Foo<I,E> as issue_75326::Iterator2>::next)
-    //[v0]~^^^^  ERROR symbol-name(_RNvXINICs4fqI2P2rA04_11issue_75326s_0pppEINtB5_3FooppENtB5_9Iterator24nextB5_)
-    //[v0]~|     ERROR demangling(<issue_75326[317d481089b8c8fe]::Foo<_, _> as issue_75326[317d481089b8c8fe]::Iterator2>::next)
+    //[v0]~^^^^  ERROR symbol-name(_RNvXINICs21hi0yVfW1J_11issue_75326s_0pppEINtB5_3FooppENtB5_9Iterator24nextB5_)
+    //[v0]~|     ERROR demangling(<issue_75326[17891616a171812d]::Foo<_, _> as issue_75326[17891616a171812d]::Iterator2>::next)
     //[v0]~|     ERROR demangling-alt(<issue_75326::Foo<_, _> as issue_75326::Iterator2>::next)
     fn next(&mut self) -> Option<Self::Item> {
         self.find(|_| true)
diff --git a/src/test/ui/symbol-names/issue-75326.v0.stderr b/src/test/ui/symbol-names/issue-75326.v0.stderr
index 59bdfa8ca36..1f57952acd6 100644
--- a/src/test/ui/symbol-names/issue-75326.v0.stderr
+++ b/src/test/ui/symbol-names/issue-75326.v0.stderr
@@ -1,17 +1,17 @@
-error: symbol-name(_RNvXINICs4fqI2P2rA04_11issue_75326s_0pppEINtB5_3FooppENtB5_9Iterator24nextB5_)
-  --> $DIR/issue-75326.rs:43:5
+error: symbol-name(_RNvXINICs21hi0yVfW1J_11issue_75326s_0pppEINtB5_3FooppENtB5_9Iterator24nextB5_)
+  --> $DIR/issue-75326.rs:42:5
    |
 LL |     #[rustc_symbol_name]
    |     ^^^^^^^^^^^^^^^^^^^^
 
-error: demangling(<issue_75326[317d481089b8c8fe]::Foo<_, _> as issue_75326[317d481089b8c8fe]::Iterator2>::next)
-  --> $DIR/issue-75326.rs:43:5
+error: demangling(<issue_75326[17891616a171812d]::Foo<_, _> as issue_75326[17891616a171812d]::Iterator2>::next)
+  --> $DIR/issue-75326.rs:42:5
    |
 LL |     #[rustc_symbol_name]
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: demangling-alt(<issue_75326::Foo<_, _> as issue_75326::Iterator2>::next)
-  --> $DIR/issue-75326.rs:43:5
+  --> $DIR/issue-75326.rs:42:5
    |
 LL |     #[rustc_symbol_name]
    |     ^^^^^^^^^^^^^^^^^^^^