Ensure that peeling does not recurse into macros

clippy_lints/src/ptr.rs

@@ -799,8 +799,9 @@ fn check_ptr_eq<'tcx>(
 
     let (left_var, right_var) = (peel_raw_casts(cx, left, left_ty), peel_raw_casts(cx, right, right_ty));
 
-    if let Some(left_snip) = left_var.span.get_source_text(cx)
-        && let Some(right_snip) = right_var.span.get_source_text(cx)
+    let mut app = Applicability::MachineApplicable;
+    let left_snip = Sugg::hir_with_context(cx, left_var, expr.span.ctxt(), "_", &mut app);
+    let right_snip = Sugg::hir_with_context(cx, right_var, expr.span.ctxt(), "_", &mut app);
     {
         let Some(top_crate) = std_or_core(cx) else { return };
         let invert = if op == BinOpKind::Eq { "" } else { "!" };
@@ -811,15 +812,16 @@ fn check_ptr_eq<'tcx>(
             format!("use `{top_crate}::ptr::eq` when comparing raw pointers"),
             "try",
             format!("{invert}{top_crate}::ptr::eq({left_snip}, {right_snip})"),
-            Applicability::MachineApplicable,
+            app,
         );
     }
 }
 
 // If the given expression is a cast to a usize, return the lhs of the cast
 // E.g., `foo as *const _ as usize` returns `foo as *const _`.
 fn expr_as_cast_to_usize<'tcx>(cx: &LateContext<'tcx>, cast_expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
-    if cx.typeck_results().expr_ty(cast_expr) == cx.tcx.types.usize
+    if !cast_expr.span.from_expansion()
+        && cx.typeck_results().expr_ty(cast_expr) == cx.tcx.types.usize
         && let ExprKind::Cast(expr, _) = cast_expr.kind
     {
         Some(expr)
@@ -830,7 +832,8 @@ fn expr_as_cast_to_usize<'tcx>(cx: &LateContext<'tcx>, cast_expr: &'tcx Expr<'_>
 
 // Peel raw casts if the remaining expression can be coerced to it
 fn peel_raw_casts<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, expr_ty: Ty<'tcx>) -> &'tcx Expr<'tcx> {
-    if let ExprKind::Cast(inner, _) = expr.kind
+    if !expr.span.from_expansion()
+        && let ExprKind::Cast(inner, _) = expr.kind
         && let ty::RawPtr(target_ty, _) = expr_ty.kind()
         && let inner_ty = cx.typeck_results().expr_ty(inner)
         && let ty::RawPtr(inner_target_ty, _) | ty::Ref(_, inner_target_ty, _) = inner_ty.kind()

tests/ui/ptr_eq.fixed

@@ -4,6 +4,9 @@ macro_rules! mac {
     ($a:expr, $b:expr) => {
         $a as *const _ as usize == $b as *const _ as usize
     };
+    (cast $a:expr) => {
+        $a as *const [i32; 3]
+    };
 }
 
 macro_rules! another_mac {
@@ -51,4 +54,8 @@ fn main() {
     #[allow(clippy::eq_op)]
     let _issue14337 = std::ptr::eq(main as *const (), main as *const ());
     //~^ ptr_eq
+
+    // Do not peel the content of macros
+    let _ = std::ptr::eq(mac!(cast a), mac!(cast b));
+    //~^ ptr_eq
 }

tests/ui/ptr_eq.rs

@@ -4,6 +4,9 @@ macro_rules! mac {
     ($a:expr, $b:expr) => {
         $a as *const _ as usize == $b as *const _ as usize
     };
+    (cast $a:expr) => {
+        $a as *const [i32; 3]
+    };
 }
 
 macro_rules! another_mac {
@@ -51,4 +54,8 @@ fn main() {
     #[allow(clippy::eq_op)]
     let _issue14337 = main as *const () == main as *const ();
     //~^ ptr_eq
+
+    // Do not peel the content of macros
+    let _ = mac!(cast a) as *const _ == mac!(cast b) as *const _;
+    //~^ ptr_eq
 }

tests/ui/ptr_eq.stderr

@@ -1,5 +1,5 @@
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:19:13
+  --> tests/ui/ptr_eq.rs:22:13
    |
 LL |     let _ = a as *const _ as usize == b as *const _ as usize;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(a, b)`
@@ -8,52 +8,58 @@ LL |     let _ = a as *const _ as usize == b as *const _ as usize;
    = help: to override `-D warnings` add `#[allow(clippy::ptr_eq)]`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:21:13
+  --> tests/ui/ptr_eq.rs:24:13
    |
 LL |     let _ = a as *const _ == b as *const _;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(a, b)`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:23:13
+  --> tests/ui/ptr_eq.rs:26:13
    |
 LL |     let _ = a.as_ptr() == b as *const _;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(a.as_ptr(), b as *const _)`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:25:13
+  --> tests/ui/ptr_eq.rs:28:13
    |
 LL |     let _ = a.as_ptr() == b.as_ptr();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(a.as_ptr(), b.as_ptr())`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:36:13
+  --> tests/ui/ptr_eq.rs:39:13
    |
 LL |     let _ = a.as_mut_ptr() == b as *mut [i32] as *mut _;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(a.as_mut_ptr(), b as *mut [i32] as *mut _)`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:38:13
+  --> tests/ui/ptr_eq.rs:41:13
    |
 LL |     let _ = a.as_mut_ptr() == b.as_mut_ptr();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(a.as_mut_ptr(), b.as_mut_ptr())`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:45:13
+  --> tests/ui/ptr_eq.rs:48:13
    |
 LL |     let _ = x as *const u32 == y as *mut u32 as *const u32;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(x, y)`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:48:13
+  --> tests/ui/ptr_eq.rs:51:13
    |
 LL |     let _ = x as *const u32 != y as *mut u32 as *const u32;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `!std::ptr::eq(x, y)`
 
 error: use `std::ptr::eq` when comparing raw pointers
-  --> tests/ui/ptr_eq.rs:52:23
+  --> tests/ui/ptr_eq.rs:55:23
    |
 LL |     let _issue14337 = main as *const () == main as *const ();
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(main as *const (), main as *const ())`
 
-error: aborting due to 9 previous errors
+error: use `std::ptr::eq` when comparing raw pointers
+  --> tests/ui/ptr_eq.rs:59:13
+   |
+LL |     let _ = mac!(cast a) as *const _ == mac!(cast b) as *const _;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(mac!(cast a), mac!(cast b))`
+
+error: aborting due to 10 previous errors