Include arguments to the precondition check in failure messages

[saethlin]

Initial perf run indicates this does not completely tank compile times, so there is hope.

Next problem is that doing this naively makes compiler-builtins call into core's formatting infrastructure for a lot of types, which means we run into the "compiler-builtins cannot call through upstream monomorphizations" error (that I added, yay me). And fixing that is hard. Here are the options I've considered:

Add enough #[inline] to make all of the required formatting infrastructure compile in compiler-builtins.

This is a lot of #[inline], and the process of adding it is infectious. Initially there is just a few calls that need to instantiate a callee, but then adding the attribute there opens up many more functions that are called from the now-annotated functions (I've only pushed this 5 iterations deep or so but I bet eventually it would contaminate all of core::fmt). And the exact call graph of functions that require #[inline] is likely to be very unstable with changes to the standard library; arbitrary library contributors may find confusing CI failures or we may have excessive #[inline].

Make the ub_checks() intrinsic evaluate to false inside compiler-builtins OR Teach cargo and bootstrap to always compile compiler-builtins with -Zub-checks=no.

The checks have already been hit at least once in compiler-builtins, so these options may be rightly unpopular. In addition, we currently have a setup where -Zub-checks agrees with cfg(ub_checks) which agrees with whether UB checks are enabled. If we choose whether UB checks are enabled based on the presence of a crate attribute (there is an attribute that makes a crate the compiler-builtins crate), then we can't have this agreement between a flag and a cfg. One way to resolve that particular problem is to remove cfg(ub_checks) or document that compiler-builtins is weird and sometimes the cfg says checks are on but they aren't.

Codegen the panic call differently in compiler-builtins

Since some of the functions that have assert_unsafe_precondition are const fn so we need to do a const_eval_select anyway, and the const arm doesn't do the problematic formatting. If we could have the MIR for precondition_check remapped inside compiler-builtins in a similar way, we could get panic messages without formatting. The tricky aspect of this is that the code is all written inside core but we need it behave differently when instantiated by compiler-builtins, so any solution involving macros or cfg is out.

[saethlin]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 65e5e12 with merge 3e5570d...

[bors]

☀️ Try build successful - checks-actions
Build commit: 3e5570d (3e5570d97bbdc7ad24c94a33f53de28891b51c2f)

[rust-timer]

Finished benchmarking commit (3e5570d): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.2%, 1.2%]	13
Regressions ❌ (secondary)	0.7%	[0.3%, 1.2%]	5
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.4%, -0.2%]	2
All ❌✅ (primary)	0.6%	[0.2%, 1.2%]	13

Max RSS (memory usage)

Results (primary 0.2%, secondary 2.2%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	3.3%	[1.0%, 6.9%]	5
Regressions ❌ (secondary)	2.2%	[0.7%, 3.7%]	3
Improvements ✅ (primary)	-3.7%	[-6.8%, -1.8%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-6.8%, 6.9%]	9

Cycles

Results (primary 1.5%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.5%	[1.5%, 1.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.5%	[1.5%, 1.5%]	1

Binary size

Results (primary 0.4%, secondary 1.0%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.5%	[0.1%, 4.2%]	67
Regressions ❌ (secondary)	1.5%	[0.3%, 7.0%]	7
Improvements ✅ (primary)	-0.3%	[-0.4%, -0.0%]	9
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	3
All ❌✅ (primary)	0.4%	[-0.4%, 4.2%]	76

Bootstrap: 759.925s -> 762.008s (0.27%)
Artifact size: 325.47 MiB -> 325.53 MiB (0.02%)

[saethlin]

The most-regressed benchmark jumped from 2 CGUs to 4 CGUs. I wonder if that means that the overhead here is coming from having both macros in the codebase.

[saethlin]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 4dc2e6c with merge ab6d099...

[bors]

☀️ Try build successful - checks-actions
Build commit: ab6d099 (ab6d099e757160119c73b5a102cc1bc7a5dae9ca)

[rust-timer]

Finished benchmarking commit (ab6d099): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	0.7%	[0.2%, 2.2%]	26
Regressions ❌ (secondary)	3.1%	[0.1%, 12.0%]	40
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-1.5%, -0.2%]	10
All ❌✅ (primary)	0.7%	[0.2%, 2.2%]	26

Max RSS (memory usage)

Results (primary -2.2%, secondary 2.6%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.8%	[2.0%, 3.2%]	3
Regressions ❌ (secondary)	3.0%	[1.2%, 5.0%]	21
Improvements ✅ (primary)	-4.1%	[-8.1%, -1.0%]	8
Improvements ✅ (secondary)	-1.8%	[-2.4%, -1.3%]	2
All ❌✅ (primary)	-2.2%	[-8.1%, 3.2%]	11

Cycles

Results (primary 1.8%, secondary 4.4%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.8%	[1.2%, 2.4%]	3
Regressions ❌ (secondary)	4.7%	[2.4%, 12.1%]	21
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.6%	[-1.6%, -1.6%]	1
All ❌✅ (primary)	1.8%	[1.2%, 2.4%]	3

Binary size

Results (primary 1.0%, secondary 1.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.1%	[0.0%, 7.1%]	69
Regressions ❌ (secondary)	1.9%	[0.0%, 4.7%]	32
Improvements ✅ (primary)	-0.3%	[-0.6%, -0.2%]	7
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.1%]	3
All ❌✅ (primary)	1.0%	[-0.6%, 7.1%]	76

Bootstrap: 761.022s -> 762.055s (0.14%)
Artifact size: 325.49 MiB -> 325.53 MiB (0.01%)

[bors]

☔ The latest upstream changes (presumably #137231) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #139916) made this pull request unmergeable. Please resolve the merge conflicts.

[rust-log-analyzer]

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

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

   Compiling alloc v0.0.0 (/checkout/library/alloc)
[RUSTC-TIMING] rustc_std_workspace_core test:false 0.045
   Compiling cfg-if v1.0.1
[RUSTC-TIMING] cfg_if test:false 0.046
error: `compiler_builtins` cannot call functions through upstream monomorphizations; encountered invalid call from `core::fmt::num::<impl core::fmt::Debug for usize>::fmt` to `core::fmt::num::imp::<impl core::fmt::Display for usize>::fmt`
   --> /checkout/library/core/src/fmt/num.rs:180:17
    |
174 | / macro_rules! impl_Debug {
175 | |     ($($T:ident)*) => {
176 | |         $(
177 | |             #[stable(feature = "rust1", since = "1.0.0")]
...   |
180 | |                 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
    | |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...   |
191 | |     };
192 | | }
    | |_- in this expansion of `impl_Debug!`
...
526 | / impl_Debug! {
527 | |     i8 i16 i32 i64 i128 isize
528 | |     u8 u16 u32 u64 u128 usize
529 | | }
    | |_- in this macro invocation

error: `compiler_builtins` cannot call functions through upstream monomorphizations; encountered invalid call from `core::fmt::num::<impl core::fmt::Debug for usize>::fmt` to `core::fmt::num::<impl core::fmt::UpperHex for usize>::fmt`
   --> /checkout/library/core/src/fmt/num.rs:180:17
    |
174 | / macro_rules! impl_Debug {
175 | |     ($($T:ident)*) => {
176 | |         $(
177 | |             #[stable(feature = "rust1", since = "1.0.0")]
...   |
180 | |                 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
    | |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...   |
191 | |     };
192 | | }
    | |_- in this expansion of `impl_Debug!`
...
526 | / impl_Debug! {
527 | |     i8 i16 i32 i64 i128 isize
528 | |     u8 u16 u32 u64 u128 usize
529 | | }
    | |_- in this macro invocation

error: `compiler_builtins` cannot call functions through upstream monomorphizations; encountered invalid call from `core::fmt::num::<impl core::fmt::Debug for usize>::fmt` to `core::fmt::num::<impl core::fmt::LowerHex for usize>::fmt`
   --> /checkout/library/core/src/fmt/num.rs:180:17
    |
174 | / macro_rules! impl_Debug {
175 | |     ($($T:ident)*) => {
176 | |         $(
177 | |             #[stable(feature = "rust1", since = "1.0.0")]
...   |
180 | |                 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
    | |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...   |
191 | |     };
192 | | }
    | |_- in this expansion of `impl_Debug!`