rustdoc search: prefer stable items in search results

[lolbinarycat]

fixes https://github.com/rust-lang/rust/issues/138067

this does add a new field to the search index, but since we're only listing unstable items instead of adding a boolean flag to every item, it should only increase the search index size of sysroot crates, since those are the only ones using the staged_api feature, at least as far as the rust project is concerned.

[rustbot]

r? @GuillaumeGomez

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[rustbot]

Some changes occurred in HTML/CSS/JS.

cc @GuillaumeGomez, @jsha, @lolbinarycat

[rust-log-analyzer]

The job x86_64-gnu-llvm-19 failed! Check out the build log: (web) (plain)

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

#18 exporting to docker image format
#18 sending tarball 20.4s done
#18 DONE 26.7s
##[endgroup]
Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
[CI_JOB_NAME=x86_64-gnu-llvm-19]
[CI_JOB_NAME=x86_64-gnu-llvm-19]
debug: `DISABLE_CI_RUSTC_IF_INCOMPATIBLE` configured.
---
sccache: Listening on address 127.0.0.1:4226
##[group]Configure the build
configure: processing command line
configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-19', '--enable-llvm-link-shared', '--set', 'rust.randomize-layout=true', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'build.print-step-timings', '--enable-verbose-tests', '--set', 'build.metrics', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--set', 'rust.lld=false', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--set', 'gcc.download-ci-gcc=true', '--enable-new-symbol-mangling']
configure: build.build          := x86_64-unknown-linux-gnu
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-19/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.randomize-layout := True
configure: rust.thin-lto-import-instr-limit := 10
---
[RUSTC-TIMING] proc_macro test:false 5.558
[RUSTC-TIMING] test test:false 9.538
    Finished `release` profile [optimized] target(s) in 1m 20s
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[TIMING] core::build_steps::compile::Std { target: x86_64-unknown-linux-gnu, compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: true }, crates: [], force_recompile: false, extra_rust_args: ["-Csymbol-mangling-version=v0", "-Cpanic=abort"], is_for_mir_opt_tests: false } -- 80.198
Testing GCC stage1 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
 Downloading crates ...
  Downloaded boml v0.3.1
   Compiling boml v0.3.1
[RUSTC-TIMING] boml test:false 0.771
   Compiling y v0.1.0 (/checkout/compiler/rustc_codegen_gcc/build_system)
[RUSTC-TIMING] y test:false 2.957
    Finished `release` profile [optimized] target(s) in 4.09s
     Running `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-codegen/x86_64-unknown-linux-gnu/release/y test --use-backend gcc --gcc-path /checkout/obj/build/x86_64-unknown-linux-gnu/ci-gcc/lib --out-dir /checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_gcc --release --mini-tests --std-tests`
`--gcc-path` was provided, ignoring config file. Using `/checkout/obj/build/x86_64-unknown-linux-gnu/ci-gcc/lib` as path for libgccjit
[BUILD] mini_core
[RUSTC-TIMING] mini_core test:false 0.207
[BUILD] example
[AOT] mini_core_hello_world
[RUSTC-TIMING] mini_core_hello_world test:false 0.182
---
Testing basic.js ... OK
Testing bufread-fill-buf.js ... OK
Testing const-is-nullary-func.js ... OK
Testing core-transmute.js ... FAILED
[ query `generic:T -> generic:U`]==> '{"path":"core::mem","name":"transmute"}' was supposed to be before '{"type":{"inputs":[{"id":-1,"name":"","ty":26,"path":null,"exactPath":null,"generics":[],"bindings":{},"unboxFlag":true}],"output":[{"id":-2,"name":"","ty":26,"path":null,"exactPath":null,"generics":[],"bindings":{},"unboxFlag":true}],"where_clause":[[],[]]},"dist":2,"path_dist":0,"index":0,"desc":"Numerically casts a vector, elementwise.","item":{"crate":"core","ty":7,"name":"simd_cast","path":"core::intrinsics::simd","descShard":{"crate":"core","shard":11,"start":25145,"len":2283,"promise":{}},"descIndex":713,"exactPath":"core::intrinsics::simd","type":{"inputs":[{"id":-1,"name":"","ty":26,"path":null,"exactPath":null,"generics":[],"bindings":{},"unboxFlag":true}],"output":[{"id":-2,"name":"","ty":26,"path":null,"exactPath":null,"generics":[],"bindings":{},"unboxFlag":true}],"where_clause":[[],[]]},"paramNames":["T","U"],"id":37540,"word":"simd_cast","normalizedName":"simdcast","bitIndex":33486,"implDisambiguator":null},"displayPath":"<span>core::</span><span>intrinsics::</span><span>simd::</span>","fullPath":"core::intrinsics::simd::simd_cast|7","href":"../core/intrinsics/simd/fn.simd_cast.html","displayTypeSignature":{},"crate":"core","ty":7,"name":"simd_cast","path":"core::intrinsics::simd","descShard":{"crate":"core","shard":11,"start":25145,"len":2283,"promise":{}},"descIndex":713,"exactPath":"core::intrinsics::simd","paramNames":["T","U"],"id":37540,"word":"simd_cast","normalizedName":"simdcast","bitIndex":33486,"implDisambiguator":null,"displayType":"`T` -> `U`","displayMappedNames":"T = T, U = U","displayWhereClause":""}'
Testing deduplication.js ... OK
Testing enum-option.js ... OK
Testing exact-case.js ... OK
Testing field-is-unary-func.js ... OK
Testing filter-crate.js ... OK
---
Testing unbox-type-result.js ... OK
Testing vec-new.js ... OK
Testing vec-type-signatures.js ... OK
Testing write.js ... OK
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:40:48
  local time: Tue May 27 18:32:10 UTC 2025
  network time: Tue, 27 May 2025 18:32:11 GMT
##[error]Process completed with exit code 1.
Post job cleanup.

[GuillaumeGomez]

I'm concerned here about the search index size increase. In particular for very big crates like windows. Do you have some before/after numbers?

Nevermind, the only difference is a new array in the search index, so should be very limited, and only an impact on std/core/alloc crates.

[lolbinarycat]

@GuillaumeGomez the windows crate will not see any size increase (beyond the 6 bytes of the empty u field), as it does not use thr staged_api feature, and we only store a list of unstable items.

i should look at how much bigger the standard library index is, thought.

[GuillaumeGomez]

@GuillaumeGomez the windows crate will not see any size increase (beyond the 6 bytes of the empty u field), as it does not use thr staged_api feature, and we only store a list of unstable items.

i should look at how much bigger the standard library index is, thought.

Yeah, after re-reading, I realized I was wrong. So yeah, only impact should be in std/core/alloc crates. Would be nice to have some numbers for them. Although I don't expect the impact to be that big.

So seems like a very good start, just a few nits and it should be ready for merge.

[lolbinarycat]

Based on my limited testing, this adds 8KiB to the std search index, which is currently at 1.3MiB, meaning this is an increase in size of 0.6%.

It's a bit worse in terms of compressed size, 0.8%, but it's still not super significant, but it's also only 1.8KB compressed.

[GuillaumeGomez]

It's acceptable, but now we have numbers.

[lolbinarycat]

@GuillaumeGomez would it be acceptable to merge this as-is, then do followup perf testing about the best way to handle unstable, deprecated, and empty description items is? I have a hunch that the short circuiting nature of search result sorting might mean this is a situation where worst case algorithmic complexity is not the factor that matters in practice.

[rustbot]

:warning: Warning :warning:

• This PR is based on an upstream commit that is 63 days old.

  It's recommended to update your branch according to the rustc-dev-guide.

[GuillaumeGomez]

Thanks!

@bors r+ rollup

[bors]

:pushpin: Commit fdbc8d08a63a3d34b7aebabb2f18a768462a98c4 has been approved by GuillaumeGomez

It is now in the queue for this repository.

[jieyouxu]

Hi bors this already merged @bors r-

[jieyouxu]

I am bors @rustbot label: -S-waiting-on-author +S-waiting-on-bors +merged-by-bors