Check MSRV for any entity, not just function and method calls

New Rust releases also stabilize enum variants, constants, and so on.
Lint them as well.

Author: samueltardieu

clippy_lints/src/incompatible_msrv.rs

@@ -174,14 +174,12 @@ impl<'tcx> LateLintPass<'tcx> for IncompatibleMsrv {
                     self.emit_lint_if_under_msrv(cx, method_did, expr.hir_id, span);
                 }
             },
-            ExprKind::Call(call, _) => {
-                // Desugaring into function calls by the compiler will use `QPath::LangItem` variants. Those should
-                // not be linted as they will not be generated in older compilers if the function is not available,
-                // and the compiler is allowed to call unstable functions.
-                if let ExprKind::Path(qpath @ (QPath::Resolved(..) | QPath::TypeRelative(..))) = call.kind
-                    && let Some(path_def_id) = cx.qpath_res(&qpath, call.hir_id).opt_def_id()
-                {
-                    self.emit_lint_if_under_msrv(cx, path_def_id, expr.hir_id, call.span);
+            // Desugaring into function calls by the compiler will use `QPath::LangItem` variants. Those should
+            // not be linted as they will not be generated in older compilers if the function is not available,
+            // and the compiler is allowed to call unstable functions.
+            ExprKind::Path(qpath @ (QPath::Resolved(..) | QPath::TypeRelative(..))) => {
+                if let Some(path_def_id) = cx.qpath_res(&qpath, expr.hir_id).opt_def_id() {
+                    self.emit_lint_if_under_msrv(cx, path_def_id, expr.hir_id, expr.span);
                 }
             },
             _ => {},

tests/ui/checked_conversions.fixed

@@ -95,7 +95,7 @@ pub const fn issue_8898(i: u32) -> bool {
 #[clippy::msrv = "1.33"]
 fn msrv_1_33() {
     let value: i64 = 33;
-    let _ = value <= (u32::MAX as i64) && value >= 0;
+    let _ = value <= (u32::max_value() as i64) && value >= 0;
 }
 
 #[clippy::msrv = "1.34"]

tests/ui/checked_conversions.rs

@@ -95,13 +95,13 @@ pub const fn issue_8898(i: u32) -> bool {
 #[clippy::msrv = "1.33"]
 fn msrv_1_33() {
     let value: i64 = 33;
-    let _ = value <= (u32::MAX as i64) && value >= 0;
+    let _ = value <= (u32::max_value() as i64) && value >= 0;
 }
 
 #[clippy::msrv = "1.34"]
 fn msrv_1_34() {
     let value: i64 = 34;
-    let _ = value <= (u32::MAX as i64) && value >= 0;
+    let _ = value <= (u32::max_value() as i64) && value >= 0;
     //~^ checked_conversions
 }
 

tests/ui/checked_conversions.stderr

@@ -100,8 +100,8 @@ LL |     let _ = value <= u16::MAX as u32 && value as i32 == 5;
 error: checked cast can be simplified
   --> tests/ui/checked_conversions.rs:104:13
    |
-LL |     let _ = value <= (u32::MAX as i64) && value >= 0;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `u32::try_from(value).is_ok()`
+LL |     let _ = value <= (u32::max_value() as i64) && value >= 0;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `u32::try_from(value).is_ok()`
 
 error: aborting due to 17 previous errors
 

tests/ui/incompatible_msrv.rs

@@ -105,4 +105,9 @@ fn feature_enable_14425(ptr: *const u8) -> usize {
     //~^ incompatible_msrv
 }
 
+fn non_fn_items() {
+    let _ = std::io::ErrorKind::CrossesDevices;
+    //~^ incompatible_msrv
+}
+
 fn main() {}

tests/ui/incompatible_msrv.stderr

@@ -74,5 +74,11 @@ error: current MSRV (Minimum Supported Rust Version) is `1.78.0` but this item i
 LL |     r.isqrt()
    |       ^^^^^^^
 
-error: aborting due to 11 previous errors
+error: current MSRV (Minimum Supported Rust Version) is `1.3.0` but this item is stable since `1.85.0`
+  --> tests/ui/incompatible_msrv.rs:109:13
+   |
+LL |     let _ = std::io::ErrorKind::CrossesDevices;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 12 previous errors