{borrow,ptr}_as_ptr: don't lint inside proc-macros (#15473)

this could arguably be 2 separate PRs, but both of these were brought up
in the same issue, so..

fixes rust-lang/rust-clippy#15398

- [x] I'm a bit doubtful about the last commit -- see the message for my
reasoning and do let me know whether it's right.

changelog: [`borrow_as_ptr`]: don't lint inside proc-macros
changelog: [`ptr_as_ptr`]: don't lint inside proc-macros

Author: Jarcho

clippy_lints/src/casts/borrow_as_ptr.rs

@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::msrvs::Msrv;
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::sugg::has_enclosing_paren;
-use clippy_utils::{get_parent_expr, is_expr_temporary_value, is_lint_allowed, msrvs, std_or_core};
+use clippy_utils::{get_parent_expr, is_expr_temporary_value, is_from_proc_macro, is_lint_allowed, msrvs, std_or_core};
 use rustc_errors::Applicability;
 use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, Ty, TyKind};
 use rustc_lint::LateContext;
@@ -22,13 +22,12 @@ pub(super) fn check<'tcx>(
         && !matches!(target.ty.kind, TyKind::TraitObject(..))
         && let ExprKind::AddrOf(BorrowKind::Ref, mutability, e) = cast_expr.kind
         && !is_lint_allowed(cx, BORROW_AS_PTR, expr.hir_id)
+        // Fix #9884
+        && !is_expr_temporary_value(cx, e)
+        && !is_from_proc_macro(cx, expr)
     {
         let mut app = Applicability::MachineApplicable;
         let snip = snippet_with_context(cx, e.span, cast_expr.span.ctxt(), "..", &mut app).0;
-        // Fix #9884
-        if is_expr_temporary_value(cx, e) {
-            return false;
-        }
 
         let (suggestion, span) = if msrv.meets(cx, msrvs::RAW_REF_OP) {
             // Make sure that the span to be replaced doesn't include parentheses, that could break the

clippy_lints/src/casts/ptr_as_ptr.rs

@@ -1,4 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_from_proc_macro;
 use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
@@ -25,7 +26,7 @@ impl OmitFollowedCastReason<'_> {
     }
 }
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Msrv) {
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, msrv: Msrv) {
     if let ExprKind::Cast(cast_expr, cast_to_hir_ty) = expr.kind
         && let (cast_from, cast_to) = (cx.typeck_results().expr_ty(cast_expr), cx.typeck_results().expr_ty(expr))
         && let ty::RawPtr(_, from_mutbl) = cast_from.kind()
@@ -36,6 +37,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Msrv) {
         // as explained here: https://github.com/rust-lang/rust/issues/60602.
         && to_pointee_ty.is_sized(cx.tcx, cx.typing_env())
         && msrv.meets(cx, msrvs::POINTER_CAST)
+        && !is_from_proc_macro(cx, expr)
     {
         let mut app = Applicability::MachineApplicable;
         let turbofish = match &cast_to_hir_ty.kind {

tests/ui/borrow_as_ptr.fixed

@@ -1,6 +1,9 @@
+//@aux-build:proc_macros.rs
 #![warn(clippy::borrow_as_ptr)]
 #![allow(clippy::useless_vec)]
 
+extern crate proc_macros;
+
 fn a() -> i32 {
     0
 }
@@ -53,3 +56,12 @@ fn issue_15141() {
     // Don't lint cast to dyn trait pointers
     let b = &a as *const dyn std::any::Any;
 }
+
+fn issue15389() {
+    proc_macros::with_span! {
+        span
+        let var = 0u32;
+        // Don't lint in proc-macros
+        let _ = &var as *const u32;
+    };
+}

tests/ui/borrow_as_ptr.rs

@@ -1,6 +1,9 @@
+//@aux-build:proc_macros.rs
 #![warn(clippy::borrow_as_ptr)]
 #![allow(clippy::useless_vec)]
 
+extern crate proc_macros;
+
 fn a() -> i32 {
     0
 }
@@ -53,3 +56,12 @@ fn issue_15141() {
     // Don't lint cast to dyn trait pointers
     let b = &a as *const dyn std::any::Any;
 }
+
+fn issue15389() {
+    proc_macros::with_span! {
+        span
+        let var = 0u32;
+        // Don't lint in proc-macros
+        let _ = &var as *const u32;
+    };
+}

tests/ui/borrow_as_ptr.stderr

@@ -1,5 +1,5 @@
 error: borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:11:14
+  --> tests/ui/borrow_as_ptr.rs:14:14
    |
 LL |     let _p = &val as *const i32;
    |              ^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::addr_of!(val)`
@@ -8,25 +8,25 @@ LL |     let _p = &val as *const i32;
    = help: to override `-D warnings` add `#[allow(clippy::borrow_as_ptr)]`
 
 error: borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:19:18
+  --> tests/ui/borrow_as_ptr.rs:22:18
    |
 LL |     let _p_mut = &mut val_mut as *mut i32;
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::addr_of_mut!(val_mut)`
 
 error: borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:23:16
+  --> tests/ui/borrow_as_ptr.rs:26:16
    |
 LL |     let _raw = (&mut x[1] as *mut i32).wrapping_offset(-1);
    |                ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::addr_of_mut!(x[1])`
 
 error: borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:29:17
+  --> tests/ui/borrow_as_ptr.rs:32:17
    |
 LL |     let _raw = (&mut x[1] as *mut i32).wrapping_offset(-1);
    |                 ^^^^^^^^^^^^^^^^^^^^^ help: try: `&raw mut x[1]`
 
 error: implicit borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:35:25
+  --> tests/ui/borrow_as_ptr.rs:38:25
    |
 LL |     let p: *const i32 = &val;
    |                         ^^^^
@@ -37,7 +37,7 @@ LL |     let p: *const i32 = &raw const val;
    |                          +++++++++
 
 error: implicit borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:39:23
+  --> tests/ui/borrow_as_ptr.rs:42:23
    |
 LL |     let p: *mut i32 = &mut val;
    |                       ^^^^^^^^
@@ -48,7 +48,7 @@ LL |     let p: *mut i32 = &raw mut val;
    |                        +++
 
 error: implicit borrow as raw pointer
-  --> tests/ui/borrow_as_ptr.rs:44:19
+  --> tests/ui/borrow_as_ptr.rs:47:19
    |
 LL |     core::ptr::eq(&val, &1);
    |                   ^^^^

tests/ui/ptr_as_ptr.fixed

@@ -2,8 +2,8 @@
 
 #![warn(clippy::ptr_as_ptr)]
 
-#[macro_use]
 extern crate proc_macros;
+use proc_macros::{external, inline_macros, with_span};
 
 mod issue_11278_a {
     #[derive(Debug)]
@@ -53,11 +53,13 @@ fn main() {
     //~^ ptr_as_ptr
 
     // Make sure the lint is triggered inside a macro
-    let _ = inline!($ptr.cast::<i32>());
-    //~^ ptr_as_ptr
+    // FIXME: `is_from_proc_macro` incorrectly stops the lint from firing here
+    let _ = inline!($ptr as *const i32);
 
     // Do not lint inside macros from external crates
     let _ = external!($ptr as *const i32);
+
+    let _ = with_span!(expr $ptr as *const i32);
 }
 
 #[clippy::msrv = "1.37"]

tests/ui/ptr_as_ptr.rs

@@ -2,8 +2,8 @@
 
 #![warn(clippy::ptr_as_ptr)]
 
-#[macro_use]
 extern crate proc_macros;
+use proc_macros::{external, inline_macros, with_span};
 
 mod issue_11278_a {
     #[derive(Debug)]
@@ -53,11 +53,13 @@ fn main() {
     //~^ ptr_as_ptr
 
     // Make sure the lint is triggered inside a macro
+    // FIXME: `is_from_proc_macro` incorrectly stops the lint from firing here
     let _ = inline!($ptr as *const i32);
-    //~^ ptr_as_ptr
 
     // Do not lint inside macros from external crates
     let _ = external!($ptr as *const i32);
+
+    let _ = with_span!(expr $ptr as *const i32);
 }
 
 #[clippy::msrv = "1.37"]