[DO NOT MERGE] Remove #[no_link] attribute

[bjorn3]

This is a pre-1.0 attribute that accidentally got stabilized. It was meant for compiler plugins, not regular crates. #152854 (comment) It is also rather fragile. If you use any function defined inside a crate you import using #[no_link] it might or might not work depending on if another crate has a normal dependency on it, if the function is codegened cross-crate and if the call site is optimized out or not. As such I think it should be deprecated and eventually removed.

Fixes #152854

This PR is probably not something we can merge immediately, but should be enough for a crater run.

[rustbot]

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Some changes occurred in compiler/rustc_passes/src/check_attr.rs

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rust-analyzer is developed in its own repository. If possible, consider making this change to rust-lang/rust-analyzer instead.

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[rustbot]

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[bjorn3]

Should have done r? @ghost

[bjorn3]

Reference changes

diff --git a/src/attributes.md b/src/attributes.md
index 696e6184..5b75095a 100644
--- a/src/attributes.md
+++ b/src/attributes.md
@@ -240,7 +240,6 @@ The following is an index of all built-in attributes.
   - [`link`] --- Specifies a native library to link with an `extern` block.
   - [`link_name`] --- Specifies the name of the symbol for functions or statics in an `extern` block.
   - [`link_ordinal`] --- Specifies the ordinal of the symbol for functions or statics in an `extern` block.
-  - [`no_link`] --- Prevents linking an extern crate.
   - [`repr`] --- Controls type layout.
   - [`crate_type`] --- Specifies the type of crate (library, executable, etc.).
   - [`no_main`] --- Disables emitting the `main` symbol.
@@ -323,7 +322,6 @@ The following is an index of all built-in attributes.
 [`naked`]: attributes/codegen.md#the-naked-attribute
 [`no_builtins`]: attributes/codegen.md#the-no_builtins-attribute
 [`no_implicit_prelude`]: names/preludes.md#the-no_implicit_prelude-attribute
-[`no_link`]: items/extern-crates.md#the-no_link-attribute
 [`no_main`]: crates-and-source-files.md#the-no_main-attribute
 [`no_mangle`]: abi.md#the-no_mangle-attribute
 [`no_std`]: names/preludes.md#the-no_std-attribute
diff --git a/src/items/extern-crates.md b/src/items/extern-crates.md
index ffad1d98..feb55409 100644
--- a/src/items/extern-crates.md
+++ b/src/items/extern-crates.md
@@ -59,40 +59,6 @@ An external crate dependency can be declared without binding its name in scope b
 r[items.extern-crate.underscore.macro_use]
 The [`macro_use` attribute] works as usual and imports the macro names into the [`macro_use` prelude].
 
-<!-- template:attributes -->
-r[items.extern-crate.no_link]
-## The `no_link` attribute
-
-r[items.extern-crate.no_link.intro]
-The *`no_link` [attribute][attributes]* may be applied to an `extern crate` item to prevent linking the crate.
-
-> [!NOTE]
-> This is helpful, e.g., when only the macros of a crate are needed.
-
-> [!EXAMPLE]
-> <!-- ignore: requires external crates -->
-> ```rust,ignore
-> #[no_link]
-> extern crate other_crate;
->
-> other_crate::some_macro!();
-> ```
-
-r[items.extern-crate.no_link.syntax]
-The `no_link` attribute uses the [MetaWord] syntax.
-
-r[items.extern-crate.no_link.allowed-positions]
-The `no_link` attribute may only be applied to an `extern crate` declaration.
-
-> [!NOTE]
-> `rustc` ignores use in other positions but lints against it. This may become an error in the future.
-
-r[items.extern-crate.no_link.duplicates]
-Only the first use of `no_link` on an `extern crate` declaration has effect.
-
-> [!NOTE]
-> `rustc` lints against any use following the first. This may become an error in the future.
-
 [identifier]: ../identifiers.md
 [RFC 940]: https://github.com/rust-lang/rfcs/blob/master/text/0940-hyphens-considered-harmful.md
 [`macro_use` attribute]: ../macros-by-example.md#the-macro_use-attribute

[apiraino]

@bjorn3 mostly for my understanding - would this change need an MCP?

[bjorn3]

I think it would need a lang FCP as this affects the language. It definitively needs a crater run if we want to go through with removing it.