Don't encode doc comments cross-crate

[JonathanBrouwer]

No description provided.

[JonathanBrouwer]

@bors try @rust-timer queue

[rust-log-analyzer]

The job aarch64-gnu-llvm-21-2 failed! Check out the build log: (web) (plain enhanced) (plain)

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

##[endgroup]
Executing "/scripts/stage_2_test_set2.sh"
+ /scripts/stage_2_test_set2.sh
+ '[' 1 == 1 ']'
+ echo 'PR_CI_JOB set; skipping tidy'
+ SKIP_TIDY='--skip tidy'
+ ../x.py --stage 2 test --skip tidy --skip tests --skip coverage-map --skip coverage-run --skip library --skip tidyselftest
PR_CI_JOB set; skipping tidy
##[group]Building bootstrap
    Finished `dev` profile [unoptimized] target(s) in 0.04s
##[endgroup]
---
##[endgroup]
[TIMING:end] tool::ToolBuild { build_compiler: Compiler { stage: 0, host: aarch64-unknown-linux-gnu, forced_compiler: false }, target: aarch64-unknown-linux-gnu, tool: "linkchecker", path: "src/tools/linkchecker", mode: ToolBootstrap, source_type: InTree, extra_features: [], allow_features: "", cargo_args: [], artifact_kind: Binary } -- 0.165
[TIMING:end] tool::Linkchecker { compiler: Compiler { stage: 0, host: aarch64-unknown-linux-gnu, forced_compiler: false }, target: aarch64-unknown-linux-gnu } -- 0.000
##[group]Testing stage1 Linkcheck (aarch64-unknown-linux-gnu)
std/primitive.fn.html:6: broken link fragment `#options-and-pointers-nullable-pointers` pointing to `std/option/index.html`
std/primitive.fn.html:137: broken link fragment `#representation` pointing to `std/option/index.html`
std/error/index.html:27: broken link fragment `#the-question-mark-operator-` pointing to `std/result/index.html`
std/primitive.pointer.html:5: broken link fragment `#safety` pointing to `std/ptr/index.html`
std/os/fd/constant.STDERR.html:6: broken link fragment `#re-entrance` pointing to `std/alloc/trait.GlobalAlloc.html`
std/process/struct.Command.html:389: broken link fragment `#sign0` pointing to `std/fmt/index.html`
std/alloc/index.html:47: broken link fragment `#re-entrance` pointing to `std/alloc/trait.GlobalAlloc.html`
std/primitive.reference.html:104: broken link fragment `#allocation` pointing to `std/ptr/index.html`
core/fmt/enum.DebugAsHex.html:6: broken link fragment `#formatting-traits` pointing to `std/fmt/index.html`
core/fmt/enum.DebugAsHex.html:7: broken link fragment `#formatting-traits` pointing to `std/fmt/index.html`
core/fmt/trait.Display.html:31: broken link fragment `#formatting-traits` pointing to `std/fmt/index.html`
core/error/index.html:27: broken link fragment `#the-question-mark-operator-` pointing to `std/result/index.html`
alloc/vec/struct.Vec.html:593: broken link fragment `#currently-allocated-memory` pointing to `alloc/alloc/trait.Allocator.html`
alloc/vec/struct.Vec.html:603: broken link fragment `#memory-fitting` pointing to `alloc/alloc/trait.Allocator.html`
alloc/vec/struct.Vec.html:680: broken link fragment `#currently-allocated-memory` pointing to `alloc/alloc/trait.Allocator.html`
alloc/vec/struct.Vec.html:690: broken link fragment `#memory-fitting` pointing to `alloc/alloc/trait.Allocator.html`
nomicon/dot-operator.html:273: broken link fragment `#derivable` pointing to `std/clone/trait.Clone.html`
nomicon/print.html:3001: broken link fragment `#derivable` pointing to `std/clone/trait.Clone.html`
cargo/reference/semver.html:434: broken link fragment `#memory-layout` pointing to `std/cell/struct.UnsafeCell.html`
cargo/print.html:9240: broken link fragment `#memory-layout` pointing to `std/cell/struct.UnsafeCell.html`
checked links in: 22.4s
number of HTML files scanned: 49035
number of HTML redirects found: 15651
number of links checked: 2606322
number of links ignored due to external: 123545
---
   2: <std::backtrace::Backtrace>::create
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/backtrace.rs:331:13
   3: <bootstrap::utils::exec::DeferredCommand>::finish_process
             at /checkout/src/bootstrap/src/utils/exec.rs:939:17
   4: <bootstrap::utils::exec::DeferredCommand>::wait_for_output::<&bootstrap::utils::exec::ExecutionContext>
             at /checkout/src/bootstrap/src/utils/exec.rs:831:21
   5: <bootstrap::utils::exec::ExecutionContext>::run
             at /checkout/src/bootstrap/src/utils/exec.rs:741:45
   6: <bootstrap::utils::exec::BootstrapCommand>::run::<&bootstrap::core::builder::Builder>
             at /checkout/src/bootstrap/src/utils/exec.rs:339:27
   7: <bootstrap::core::build_steps::test::Linkcheck as bootstrap::core::builder::Step>::run
             at /checkout/src/bootstrap/src/core/build_steps/test.rs:191:77
   8: <bootstrap::core::builder::Builder>::ensure::<bootstrap::core::build_steps::test::Linkcheck>
             at /checkout/src/bootstrap/src/core/builder/mod.rs:1579:36
   9: <bootstrap::core::build_steps::test::Linkcheck as bootstrap::core::builder::Step>::make_run
             at /checkout/src/bootstrap/src/core/build_steps/test.rs:137:21
  10: <bootstrap::core::builder::StepDescription>::maybe_run
             at /checkout/src/bootstrap/src/core/builder/mod.rs:476:13
  11: bootstrap::core::builder::cli_paths::match_paths_to_steps_and_run
             at /checkout/src/bootstrap/src/core/builder/cli_paths.rs:141:22
  12: <bootstrap::core::builder::Builder>::run_step_descriptions
             at /checkout/src/bootstrap/src/core/builder/mod.rs:1122:9
  13: <bootstrap::core::builder::Builder>::execute_cli
             at /checkout/src/bootstrap/src/core/builder/mod.rs:1101:14
  14: <bootstrap::Build>::build
             at /checkout/src/bootstrap/src/lib.rs:799:25
  15: bootstrap::main
             at /checkout/src/bootstrap/src/bin/main.rs:130:11
  16: <fn() as core::ops::function::FnOnce<()>>::call_once
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/core/src/ops/function.rs:250:5
  17: std::sys::backtrace::__rust_begin_short_backtrace::<fn(), ()>
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/sys/backtrace.rs:166:18
  18: std::rt::lang_start::<()>::{closure#0}
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/rt.rs:206:18
  19: <&dyn core::ops::function::Fn<(), Output = i32> + core::panic::unwind_safe::RefUnwindSafe + core::marker::Sync as core::ops::function::FnOnce<()>>::call_once
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/core/src/ops/function.rs:287:21
  20: std::panicking::catch_unwind::do_call::<&dyn core::ops::function::Fn<(), Output = i32> + core::panic::unwind_safe::RefUnwindSafe + core::marker::Sync, i32>
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/panicking.rs:581:40
  21: std::panicking::catch_unwind::<i32, &dyn core::ops::function::Fn<(), Output = i32> + core::panic::unwind_safe::RefUnwindSafe + core::marker::Sync>
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/panicking.rs:544:19
  22: std::panic::catch_unwind::<&dyn core::ops::function::Fn<(), Output = i32> + core::panic::unwind_safe::RefUnwindSafe + core::marker::Sync, i32>
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/panic.rs:359:14
  23: std::rt::lang_start_internal::{closure#0}
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/rt.rs:175:24
  24: std::panicking::catch_unwind::do_call::<std::rt::lang_start_internal::{closure#0}, isize>
             at /rustc/ad726b5063362ec9897ef3d67452fc5606ee70fa/library/std/src/panicking.rs:581:40
---
  31: __libc_start_main
  32: _start


Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:36:14
  local time: Wed Apr  8 18:48:31 UTC 2026
  network time: Wed, 08 Apr 2026 18:48:32 GMT
##[error]Process completed with exit code 1.
##[group]Run echo "disk usage:"

[lqd]

This is a good idea (just look at the size of the docs in the stdlib rmeta), and we’ve discussed something like this in the past. The prototype broke the doc(inline) feature at the time unfortunately, and was thus delayed to the future. Maybe that future is now. It would be good to check that feature still works with this PR, as well as when inlining docs from the stdlib.

[JonathanBrouwer]

That feature definitely doesn't work with this PR, looking at the CI failure :c
I tried only cross-crate encoding if sess.opts.actually_rustdoc is set locally to fix that, but dependencies are still compiled with sess.opts.actually_rustdoc set to false during a rustdoc run so that doesn't fix it
Therefore I think this PR is pretty hopeless, still interested in the perf tho

[lqd]

Perf was good when I tried, reducing stdlib metadata makes every crate load it faster, in rustc and rustdoc, even more so for the benchmarks only using libcore, with its numerous stdarch intrinsics doc comments.

[rust-bors]

☀️ Try build successful (CI)
Build commit: 99dc17f (99dc17f85ea04858877e47c9d71a81f7a143c245, parent: c771f6ee804969b5c046393c4110c22720e56114)

[rust-timer]

Finished benchmarking commit (99dc17f): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

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

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.1%, 0.1%]	1
Regressions ❌ (secondary)	0.5%	[0.3%, 0.5%]	5
Improvements ✅ (primary)	-2.3%	[-15.4%, -0.2%]	61
Improvements ✅ (secondary)	-4.1%	[-18.2%, -0.2%]	60
All ❌✅ (primary)	-2.2%	[-15.4%, 0.1%]	62

Max RSS (memory usage)

Results (primary -2.8%, secondary -3.7%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.8%	[-11.9%, -0.6%]	187
Improvements ✅ (secondary)	-3.7%	[-14.0%, -0.7%]	117
All ❌✅ (primary)	-2.8%	[-11.9%, -0.6%]	187

Cycles

Results (primary -7.3%, secondary -10.3%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-7.3%	[-13.4%, -2.4%]	19
Improvements ✅ (secondary)	-10.3%	[-20.8%, -1.4%]	24
All ❌✅ (primary)	-7.3%	[-13.4%, -2.4%]	19

Binary size

Results (primary -2.4%, secondary -1.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.4%	[-11.8%, -0.1%]	114
Improvements ✅ (secondary)	-1.6%	[-4.1%, -0.2%]	23
All ❌✅ (primary)	-2.4%	[-11.8%, -0.1%]	114

Bootstrap: 490.389s -> 491.393s (0.20%)
Artifact size: 395.39 MiB -> 395.34 MiB (-0.01%)