Rollup merge of #99784 - est31:deny_cfg_attr_crate_type_name, r=Mark-Simulacrum

Make forward compatibility lint deprecated_cfg_attr_crate_type_name deny by default

Turns the forward compatibility lint added by #83744 to deprecate `cfg_attr` usage with `#![crate_type]` and `#![crate_name]` attributes into deny by default. Copying the example from #83744:

```Rust
#![crate_type = "lib"] // remains working
#![cfg_attr(foo, crate_type = "bin")] // will stop working
```

Over 8 months have passed since #83744 was merged so I'd say this gives ample time for people to have been warned, so we can make the warning stronger. No usage was found via grep.app except for one, which was in an unmaintained code base that didn't seem to be used in the open source eco system. The crater run conducted in #83744 also didn't show up anything.

cc #91632 - tracking issue for the lint

4 files changed, 9 insertions, 16 deletions

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 95e34da734d..2dca6acdd6d 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -3094,7 +3094,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust
+    /// ```rust,compile_fail
     /// #![cfg_attr(debug_assertions, crate_type = "lib")]
     /// ```
     ///
@@ -3114,7 +3114,7 @@ declare_lint! {
     /// rustc instead of `#![cfg_attr(..., crate_type = "...")]` and
     /// `--crate-name` instead of `#![cfg_attr(..., crate_name = "...")]`.
     pub DEPRECATED_CFG_ATTR_CRATE_TYPE_NAME,
-    Warn,
+    Deny,
     "detects usage of `#![cfg_attr(..., crate_type/crate_name = \"...\")]`",
     @future_incompatible = FutureIncompatibleInfo {
         reference: "issue #91632 <https://github.com/rust-lang/rust/issues/91632>",
diff --git a/src/test/codegen/external-no-mangle-statics.rs b/src/test/codegen/external-no-mangle-statics.rs
index 6274434cd8f..c6ecb7aa96a 100644
--- a/src/test/codegen/external-no-mangle-statics.rs
+++ b/src/test/codegen/external-no-mangle-statics.rs
@@ -1,12 +1,11 @@
 // revisions: lib staticlib
 // ignore-emscripten default visibility is hidden
 // compile-flags: -O
+// [lib] compile-flags: --crate-type lib
+// [staticlib] compile-flags: --crate-type staticlib
 // `#[no_mangle]`d static variables always have external linkage, i.e., no `internal` in their
 // definitions
 
-#![cfg_attr(lib, crate_type = "lib")]
-#![cfg_attr(staticlib, crate_type = "staticlib")]
-
 // CHECK: @A = local_unnamed_addr constant
 #[no_mangle]
 static A: u8 = 0;
diff --git a/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.rs b/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.rs
index 6cb2ff9d813..1f23dadc432 100644
--- a/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.rs
+++ b/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.rs
@@ -1,7 +1,6 @@
 // check-fail
 // compile-flags:--cfg foo
 
-#![deny(warnings)]
 #![cfg_attr(foo, crate_type="bin")]
 //~^ERROR `crate_type` within
 //~| WARN this was previously accepted
diff --git a/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.stderr b/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.stderr
index 5609f8e9d9f..b52535ffdba 100644
--- a/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.stderr
+++ b/src/test/ui/cfg/future-compat-crate-attributes-using-cfg_attr.stderr
@@ -1,20 +1,15 @@
 error: `crate_type` within an `#![cfg_attr] attribute is deprecated`
-  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:5:18
+  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:4:18
    |
 LL | #![cfg_attr(foo, crate_type="bin")]
    |                  ^^^^^^^^^^^^^^^^
    |
-note: the lint level is defined here
-  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:4:9
-   |
-LL | #![deny(warnings)]
-   |         ^^^^^^^^
-   = note: `#[deny(deprecated_cfg_attr_crate_type_name)]` implied by `#[deny(warnings)]`
+   = note: `#[deny(deprecated_cfg_attr_crate_type_name)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #91632 <https://github.com/rust-lang/rust/issues/91632>
 
 error: `crate_name` within an `#![cfg_attr] attribute is deprecated`
-  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:10:18
+  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:9:18
    |
 LL | #![cfg_attr(foo, crate_name="bar")]
    |                  ^^^^^^^^^^^^^^^^
@@ -23,7 +18,7 @@ LL | #![cfg_attr(foo, crate_name="bar")]
    = note: for more information, see issue #91632 <https://github.com/rust-lang/rust/issues/91632>
 
 error: `crate_type` within an `#![cfg_attr] attribute is deprecated`
-  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:5:18
+  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:4:18
    |
 LL | #![cfg_attr(foo, crate_type="bin")]
    |                  ^^^^^^^^^^^^^^^^
@@ -32,7 +27,7 @@ LL | #![cfg_attr(foo, crate_type="bin")]
    = note: for more information, see issue #91632 <https://github.com/rust-lang/rust/issues/91632>
 
 error: `crate_name` within an `#![cfg_attr] attribute is deprecated`
-  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:10:18
+  --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:9:18
    |
 LL | #![cfg_attr(foo, crate_name="bar")]
    |                  ^^^^^^^^^^^^^^^^