Inline the core::arch documentation into std

[jfrimmel]

This PR removes the #[doc(no_inline)]-attribute from the pub use statement of the core::arch-module. This has the effect, that the module is not listed under the re-exported section in the documentation (it is the only item in a re-exports-section in the std), but as a normal module.

This also removes the only mention of the core-crate in the std crate, which is desirable, as only a subset of Rust users know core and its relationship with the std.

The git history did not reveal, why this was added in the first place. If there is a reason, I can close this PR 😉

[rust-highfive]

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[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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---
Suite("src/test/assembly") not skipped for "bootstrap::test::Assembly" -- not in ["src/tools/tidy"]
Check compiletest suite=assembly mode=assembly (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)

running 29 tests
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 finished in 0.051 seconds
Suite("src/test/incremental") not skipped for "bootstrap::test::Incremental" -- not in ["src/tools/tidy"]
Check compiletest suite=incremental mode=incremental (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
---
Suite("src/test/debuginfo") not skipped for "bootstrap::test::Debuginfo" -- not in ["src/tools/tidy"]
Check compiletest suite=debuginfo mode=debuginfo (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)

running 116 tests
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test result: ok. 78 passed; 0 failed; 38 ignored; 0 measured; 0 filtered out; finished in 1.85s

Suite("src/test/ui-fulldeps") not skipped for "bootstrap::test::UiFullDeps" -- not in ["src/tools/tidy"]
 finished in 1.907 seconds
---
Building stage0 tool linkchecker (x86_64-unknown-linux-gnu)
   Compiling once_cell v1.4.1
   Compiling linkchecker v0.1.0 (/checkout/src/tools/linkchecker)
    Finished release [optimized] target(s) in 1.38s
std/arch/index.html:154: broken link - std/arch/x86/index.html
std/arch/index.html:156: broken link - std/arch/arm/index.html
std/arch/index.html:157: broken link - std/arch/aarch64/index.html
std/arch/index.html:158: broken link - std/arch/mips/index.html
std/arch/index.html:159: broken link - std/arch/mips64/index.html
std/arch/index.html:160: broken link - std/arch/powerpc/index.html
std/arch/index.html:161: broken link - std/arch/powerpc64/index.html
std/arch/index.html:162: broken link - std/arch/nvptx/index.html
std/arch/index.html:163: broken link - std/arch/wasm32/index.html
thread 'main' panicked at 'found some broken links', src/tools/linkchecker/main.rs:102:9


command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/linkchecker" "/checkout/obj/build/x86_64-unknown-linux-gnu/doc"
expected success, got: exit code: 101

[jfrimmel]

Hm, I'm unsure about this test failure. Maybe this is the cause for the re-export in the first place...

[jyn514]

The git history did not reveal, why this was added in the first place. If there is a reason, I can close this PR wink
Hm, I'm unsure about this test failure. Maybe this is the cause for the re-export in the first place...

#57808 (comment):

I chatted with @gnzlbg on Discord and realized what was going on. When rustdoc is generating docs for libstd, it needs to link against a compiled version of libcore. Since only rustdoc sets cfg(rustdoc), the compiled version of libcore that libstd links against only has the core::arch information for the target's arch. This is why the std::arch page is missing most of its submodules - even though it's re-exporting the module directly from libcore, the libcore that it sees is the one that only has the target's arch available. The version with all the arches specified only exists while rustdoc is running, and it doesn't generate anything that libstd can use to create its own docs.

So this won't work without substantial changes to rustdoc or how core is compiled.

[jyn514]

If you want to add a comment saying why doc(no_inline) is there, that would be helpful, though :)

[jfrimmel]

I could not re-open this PR, so I opened a new one for the comment: #82870.

[jyn514]

I could not re-open this PR, so I opened a new one for the comment: #82870.

Thanks. Sorry, I didn't realize github doesn't let you reopen your own PR.