Stabilize #[unix_sigpipe = "sig_dfl"] on fn main()

The attribute is used like this:

    #[unix_sigpipe = "sig_dfl"]
    fn main() {
        // ...
    }

When used, `SIGPIPE` will be set to `SIG_DFL` before `fn main()` is
invoked, rather than being set to `SIG_IGN` which is the default.

This commit does NOT stabilize `#[unix_sigpipe = "sig_ign"]` or
`#[unix_sigpipe = "inherit"]`.

See the PR for more info.

compiler/rustc/src/main.rs

@@ -1,4 +1,4 @@
-#![feature(unix_sigpipe)]
+#![cfg_attr(bootstrap, feature(unix_sigpipe))]
 
 // A note about jemalloc: rustc uses jemalloc when built for CI and
 // distribution. The obvious way to do this is with the `#[global_allocator]`

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -200,6 +200,21 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                 );
             }
         }
+        // Check unstable flavors of the `#[unix_sigpipe]` attribute.
+        if attr.has_name(sym::unix_sigpipe)
+            && let Some(value) = attr.value_str()
+            && (value == sym::sig_ign || value == sym::inherit)
+        {
+            gate!(
+                self,
+                unix_sigpipe,
+                attr.span,
+                format!(
+                    "the `#[unix_sigpipe = \"{}\"]` attribute is an experimental feature",
+                    value.as_str()
+                )
+            );
+        }
         if !attr.is_doc_comment()
             && let [seg, _] = attr.get_normal_item().path.segments.as_slice()
             && seg.ident.name == sym::diagnostic

compiler/rustc_feature/src/builtin_attrs.rs

@@ -364,7 +364,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     ),
 
     // Entry point:
-    gated!(unix_sigpipe, Normal, template!(Word, NameValueStr: "inherit|sig_ign|sig_dfl"), ErrorFollowing, experimental!(unix_sigpipe)),
+    ungated!(unix_sigpipe, Normal, template!(Word, NameValueStr: "inherit|sig_ign|sig_dfl"), ErrorFollowing),
     ungated!(start, Normal, template!(Word), WarnFollowing),
     ungated!(no_start, CrateLevel, template!(Word), WarnFollowing),
     ungated!(no_main, CrateLevel, template!(Word), WarnFollowing),

compiler/rustc_passes/messages.ftl

@@ -692,7 +692,7 @@ passes_undefined_naked_function_abi =
     Rust ABI is unsupported in naked functions
 
 passes_unix_sigpipe_values =
-    valid values for `#[unix_sigpipe = "..."]` are `inherit`, `sig_ign`, or `sig_dfl`
+    the only valid variant of the `unix_sigpipe` attribute is `#[unix_sigpipe = "sig_dfl"]`
 
 passes_unknown_external_lang_item =
     unknown external lang item: `{$lang_item}`

src/tools/rustdoc/main.rs

@@ -1,4 +1,4 @@
-#![feature(unix_sigpipe)]
+#![cfg_attr(bootstrap, feature(unix_sigpipe))]
 
 #[unix_sigpipe = "sig_dfl"]
 fn main() {

tests/ui/attributes/unix_sigpipe/unix_sigpipe-bare.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
 
-#[unix_sigpipe] //~ error: valid values for `#[unix_sigpipe = "..."]` are `inherit`, `sig_ign`, or `sig_dfl`
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
+
+#[unix_sigpipe] //~ error: the only valid variant of the `unix_sigpipe` attribute is `#[unix_sigpipe = "sig_dfl"]
 fn main() {}

tests/ui/attributes/unix_sigpipe/unix_sigpipe-bare.with_feature.stderr

@@ -0,0 +1,8 @@
+error: the only valid variant of the `unix_sigpipe` attribute is `#[unix_sigpipe = "sig_dfl"]`
+  --> $DIR/unix_sigpipe-bare.rs:5:1
+   |
+LL | #[unix_sigpipe]
+   | ^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-bare.without_feature.stderr

@@ -0,0 +1,8 @@
+error: the only valid variant of the `unix_sigpipe` attribute is `#[unix_sigpipe = "sig_dfl"]`
+  --> $DIR/unix_sigpipe-bare.rs:5:1
+   |
+LL | #[unix_sigpipe]
+   | ^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-crate.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 #![unix_sigpipe = "sig_dfl"] //~ error: `unix_sigpipe` attribute cannot be used at crate level
 
 fn main() {}

tests/ui/attributes/unix_sigpipe/unix_sigpipe-crate.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-crate.with_feature.stderr

@@ -1,5 +1,5 @@
 error: `unix_sigpipe` attribute cannot be used at crate level
-  --> $DIR/unix_sigpipe-crate.rs:2:1
+  --> $DIR/unix_sigpipe-crate.rs:4:1
    |
 LL | #![unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-crate.without_feature.stderr

@@ -0,0 +1,17 @@
+error: `unix_sigpipe` attribute cannot be used at crate level
+  --> $DIR/unix_sigpipe-crate.rs:4:1
+   |
+LL | #![unix_sigpipe = "sig_dfl"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |
+LL | fn main() {}
+   |    ---- the inner attribute doesn't annotate this function
+   |
+help: perhaps you meant to use an outer attribute
+   |
+LL - #![unix_sigpipe = "sig_dfl"]
+LL + #[unix_sigpipe = "sig_dfl"]
+   |
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-different-duplicates.rs

@@ -1,5 +1,8 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[unix_sigpipe = "sig_dfl"]
-#[unix_sigpipe = "sig_ign"] //~ error: multiple `unix_sigpipe` attributes
+#[unix_sigpipe = "sig_ign"] //[without_feature]~ the `#[unix_sigpipe = "sig_ign"]` attribute is an experimental feature
+//~^ error: multiple `unix_sigpipe` attributes
 fn main() {}

tests/ui/attributes/unix_sigpipe/unix_sigpipe-different-duplicates.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-different-duplicates.with_feature.stderr

@@ -1,11 +1,11 @@
 error: multiple `unix_sigpipe` attributes
-  --> $DIR/unix_sigpipe-different-duplicates.rs:4:1
+  --> $DIR/unix_sigpipe-different-duplicates.rs:6:1
    |
 LL | #[unix_sigpipe = "sig_ign"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/unix_sigpipe-different-duplicates.rs:3:1
+  --> $DIR/unix_sigpipe-different-duplicates.rs:5:1
    |
 LL | #[unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-different-duplicates.without_feature.stderr

@@ -0,0 +1,25 @@
+error[E0658]: the `#[unix_sigpipe = "sig_ign"]` attribute is an experimental feature
+  --> $DIR/unix_sigpipe-different-duplicates.rs:6:1
+   |
+LL | #[unix_sigpipe = "sig_ign"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #97889 <https://github.com/rust-lang/rust/issues/97889> for more information
+   = help: add `#![feature(unix_sigpipe)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: multiple `unix_sigpipe` attributes
+  --> $DIR/unix_sigpipe-different-duplicates.rs:6:1
+   |
+LL | #[unix_sigpipe = "sig_ign"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
+   |
+note: attribute also specified here
+  --> $DIR/unix_sigpipe-different-duplicates.rs:5:1
+   |
+LL | #[unix_sigpipe = "sig_dfl"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0658`.

tests/ui/attributes/unix_sigpipe/unix_sigpipe-duplicates.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[unix_sigpipe = "sig_dfl"]
 #[unix_sigpipe = "sig_dfl"] //~ error: multiple `unix_sigpipe` attributes

tests/ui/attributes/unix_sigpipe/unix_sigpipe-duplicates.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-duplicates.with_feature.stderr

@@ -1,11 +1,11 @@
 error: multiple `unix_sigpipe` attributes
-  --> $DIR/unix_sigpipe-duplicates.rs:4:1
+  --> $DIR/unix_sigpipe-duplicates.rs:6:1
    |
 LL | #[unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
    |
 note: attribute also specified here
-  --> $DIR/unix_sigpipe-duplicates.rs:3:1
+  --> $DIR/unix_sigpipe-duplicates.rs:5:1
    |
 LL | #[unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-duplicates.without_feature.stderr

@@ -0,0 +1,14 @@
+error: multiple `unix_sigpipe` attributes
+  --> $DIR/unix_sigpipe-duplicates.rs:6:1
+   |
+LL | #[unix_sigpipe = "sig_dfl"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
+   |
+note: attribute also specified here
+  --> $DIR/unix_sigpipe-duplicates.rs:5:1
+   |
+LL | #[unix_sigpipe = "sig_dfl"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-inherit.rs

@@ -1,9 +1,11 @@
-// run-pass
+// revisions: with_feature without_feature
+// [with_feature]run-pass
+// [without_feature]check-fail
 // aux-build:sigpipe-utils.rs
 
-#![feature(unix_sigpipe)]
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
-#[unix_sigpipe = "inherit"]
+#[unix_sigpipe = "inherit"] //[without_feature]~ ERROR the `#[unix_sigpipe = "inherit"]` attribute is an experimental feature
 fn main() {
     extern crate sigpipe_utils;
 

tests/ui/feature-gates/feature-gate-unix_sigpipe.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-inherit.without_feature.stderr

@@ -1,5 +1,5 @@
-error[E0658]: the `#[unix_sigpipe]` attribute is an experimental feature
-  --> $DIR/feature-gate-unix_sigpipe.rs:3:1
+error[E0658]: the `#[unix_sigpipe = "inherit"]` attribute is an experimental feature
+  --> $DIR/unix_sigpipe-inherit.rs:8:1
    |
 LL | #[unix_sigpipe = "inherit"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-list.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[unix_sigpipe(sig_dfl)] //~ error: malformed `unix_sigpipe` attribute input
 fn main() {}

tests/ui/attributes/unix_sigpipe/unix_sigpipe-list.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-list.with_feature.stderr

@@ -1,5 +1,5 @@
 error: malformed `unix_sigpipe` attribute input
-  --> $DIR/unix_sigpipe-list.rs:3:1
+  --> $DIR/unix_sigpipe-list.rs:5:1
    |
 LL | #[unix_sigpipe(sig_dfl)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-list.without_feature.stderr

@@ -0,0 +1,15 @@
+error: malformed `unix_sigpipe` attribute input
+  --> $DIR/unix_sigpipe-list.rs:5:1
+   |
+LL | #[unix_sigpipe(sig_dfl)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: the following are the possible correct uses
+   |
+LL | #[unix_sigpipe = "inherit|sig_ign|sig_dfl"]
+   | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+LL | #[unix_sigpipe]
+   | ~~~~~~~~~~~~~~~
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-main-fn.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[unix_sigpipe = "sig_dfl"] //~ error: `unix_sigpipe` attribute can only be used on `fn main()`
 fn f() {}

tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-main-fn.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-main-fn.with_feature.stderr

@@ -1,5 +1,5 @@
 error: `unix_sigpipe` attribute can only be used on `fn main()`
-  --> $DIR/unix_sigpipe-non-main-fn.rs:3:1
+  --> $DIR/unix_sigpipe-non-main-fn.rs:5:1
    |
 LL | #[unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-main-fn.without_feature.stderr

@@ -0,0 +1,8 @@
+error: `unix_sigpipe` attribute can only be used on `fn main()`
+  --> $DIR/unix_sigpipe-non-main-fn.rs:5:1
+   |
+LL | #[unix_sigpipe = "sig_dfl"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-root-main.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 mod m {
     #[unix_sigpipe = "sig_dfl"] //~ error: `unix_sigpipe` attribute can only be used on root `fn main()`

tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-root-main.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-root-main.with_feature.stderr

@@ -1,5 +1,5 @@
 error: `unix_sigpipe` attribute can only be used on root `fn main()`
-  --> $DIR/unix_sigpipe-non-root-main.rs:4:5
+  --> $DIR/unix_sigpipe-non-root-main.rs:6:5
    |
 LL |     #[unix_sigpipe = "sig_dfl"]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-non-root-main.without_feature.stderr

@@ -0,0 +1,8 @@
+error: `unix_sigpipe` attribute can only be used on root `fn main()`
+  --> $DIR/unix_sigpipe-non-root-main.rs:6:5
+   |
+LL |     #[unix_sigpipe = "sig_dfl"]
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/attributes/unix_sigpipe/unix_sigpipe-rustc_main.rs

@@ -1,7 +1,8 @@
+// revisions: with_feature without_feature
 // run-pass
 // aux-build:sigpipe-utils.rs
 
-#![feature(unix_sigpipe)]
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 #![feature(rustc_attrs)]
 
 #[unix_sigpipe = "sig_dfl"]

tests/ui/attributes/unix_sigpipe/unix_sigpipe-sig_dfl.rs

@@ -1,7 +1,8 @@
+// revisions: with_feature without_feature
 // run-pass
 // aux-build:sigpipe-utils.rs
 
-#![feature(unix_sigpipe)]
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[unix_sigpipe = "sig_dfl"]
 fn main() {

tests/ui/attributes/unix_sigpipe/unix_sigpipe-sig_ign.rs

@@ -1,9 +1,11 @@
-// run-pass
+// revisions: with_feature without_feature
+// [with_feature]run-pass
+// [without_feature]check-fail
 // aux-build:sigpipe-utils.rs
 
-#![feature(unix_sigpipe)]
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
-#[unix_sigpipe = "sig_ign"]
+#[unix_sigpipe = "sig_ign"] //[without_feature]~ the `#[unix_sigpipe = "sig_ign"]` attribute is an experimental feature
 fn main() {
     extern crate sigpipe_utils;
 

tests/ui/attributes/unix_sigpipe/unix_sigpipe-sig_ign.without_feature.stderr

@@ -0,0 +1,13 @@
+error[E0658]: the `#[unix_sigpipe = "sig_ign"]` attribute is an experimental feature
+  --> $DIR/unix_sigpipe-sig_ign.rs:8:1
+   |
+LL | #[unix_sigpipe = "sig_ign"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #97889 <https://github.com/rust-lang/rust/issues/97889> for more information
+   = help: add `#![feature(unix_sigpipe)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0658`.

tests/ui/attributes/unix_sigpipe/unix_sigpipe-start.rs

@@ -1,5 +1,7 @@
+// revisions: with_feature without_feature
+
 #![feature(start)]
-#![feature(unix_sigpipe)]
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[start]
 #[unix_sigpipe = "sig_dfl"] //~ error: `unix_sigpipe` attribute can only be used on `fn main()`

tests/ui/attributes/unix_sigpipe/unix_sigpipe-start.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-start.with_feature.stderr

@@ -1,5 +1,5 @@
 error: `unix_sigpipe` attribute can only be used on `fn main()`
-  --> $DIR/unix_sigpipe-start.rs:5:1
+  --> $DIR/unix_sigpipe-start.rs:7:1
    |
 LL | #[unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-struct.stderr → tests/ui/attributes/unix_sigpipe/unix_sigpipe-start.without_feature.stderr

@@ -1,5 +1,5 @@
 error: `unix_sigpipe` attribute can only be used on `fn main()`
-  --> $DIR/unix_sigpipe-struct.rs:3:1
+  --> $DIR/unix_sigpipe-start.rs:7:1
    |
 LL | #[unix_sigpipe = "sig_dfl"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/attributes/unix_sigpipe/unix_sigpipe-struct.rs

@@ -1,4 +1,6 @@
-#![feature(unix_sigpipe)]
+// revisions: with_feature without_feature
+
+#![cfg_attr(with_feature, feature(unix_sigpipe))]
 
 #[unix_sigpipe = "sig_dfl"] //~ error: `unix_sigpipe` attribute can only be used on `fn main()`
 struct S;

tests/ui/attributes/unix_sigpipe/unix_sigpipe-struct.with_feature.stderr

@@ -0,0 +1,8 @@
+error: `unix_sigpipe` attribute can only be used on `fn main()`
+  --> $DIR/unix_sigpipe-struct.rs:5:1
+   |
+LL | #[unix_sigpipe = "sig_dfl"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+