From 058b74fce4f34f4ace7d7b02fb938c6b1dc9c531 Mon Sep 17 00:00:00 2001
From: StackOverflowExcept1on
 <109800286+StackOverflowExcept1on@users.noreply.github.com>
Date: Fri, 15 Dec 2023 22:52:38 +0300
Subject: [PATCH 1/2] Do not lint `assertions_on_constants` for `const _: () =
 assert!(expr)`

---
 clippy_lints/src/assertions_on_constants.rs | 15 ++++++++++++---
 tests/ui/assertions_on_constants.rs         |  7 +++++++
 tests/ui/assertions_on_constants.stderr     | 10 +++++++++-
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/clippy_lints/src/assertions_on_constants.rs b/clippy_lints/src/assertions_on_constants.rs
index a15ec199a28..11d614afaf8 100644
--- a/clippy_lints/src/assertions_on_constants.rs
+++ b/clippy_lints/src/assertions_on_constants.rs
@@ -1,7 +1,7 @@
-use clippy_utils::consts::{constant, Constant};
+use clippy_utils::consts::{constant_with_source, Constant, ConstantSource};
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::macros::{find_assert_args, root_macro_call_first_node, PanicExpn};
-use rustc_hir::Expr;
+use rustc_hir::{Expr, Item, ItemKind, Node};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
@@ -42,9 +42,18 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         let Some((condition, panic_expn)) = find_assert_args(cx, e, macro_call.expn) else {
             return;
         };
-        let Some(Constant::Bool(val)) = constant(cx, cx.typeck_results(), condition) else {
+        let Some((Constant::Bool(val), source)) = constant_with_source(cx, cx.typeck_results(), condition) else {
             return;
         };
+        if let ConstantSource::Constant = source
+            && let Some(node) = cx.tcx.hir().find_parent(e.hir_id)
+            && let Node::Item(Item {
+                kind: ItemKind::Const(.., _body_id),
+                ..
+            }) = node
+        {
+            return;
+        }
         if val {
             span_lint_and_help(
                 cx,
diff --git a/tests/ui/assertions_on_constants.rs b/tests/ui/assertions_on_constants.rs
index 10809a6d247..1309ae45d0a 100644
--- a/tests/ui/assertions_on_constants.rs
+++ b/tests/ui/assertions_on_constants.rs
@@ -45,4 +45,11 @@ fn main() {
 
     const CFG_FLAG: &bool = &cfg!(feature = "hey");
     assert!(!CFG_FLAG);
+
+    const _: () = assert!(true);
+    //~^ ERROR: `assert!(true)` will be optimized out by the compiler
+
+    // Don't lint if the value is dependent on a defined constant:
+    const N: usize = 1024;
+    const _: () = assert!(N.is_power_of_two());
 }
diff --git a/tests/ui/assertions_on_constants.stderr b/tests/ui/assertions_on_constants.stderr
index 780d1fe1c8a..099be4ed355 100644
--- a/tests/ui/assertions_on_constants.stderr
+++ b/tests/ui/assertions_on_constants.stderr
@@ -72,5 +72,13 @@ LL |     debug_assert!(true);
    |
    = help: remove it
 
-error: aborting due to 9 previous errors
+error: `assert!(true)` will be optimized out by the compiler
+  --> $DIR/assertions_on_constants.rs:49:19
+   |
+LL |     const _: () = assert!(true);
+   |                   ^^^^^^^^^^^^^
+   |
+   = help: remove it
+
+error: aborting due to 10 previous errors
 

From 90ece568d3ec1fb0273db452ce4b65c6bbc9c055 Mon Sep 17 00:00:00 2001
From: StackOverflowExcept1on
 <109800286+StackOverflowExcept1on@users.noreply.github.com>
Date: Fri, 15 Dec 2023 23:02:13 +0300
Subject: [PATCH 2/2] simplify pattern

---
 clippy_lints/src/assertions_on_constants.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_lints/src/assertions_on_constants.rs b/clippy_lints/src/assertions_on_constants.rs
index 11d614afaf8..1e327f7a6df 100644
--- a/clippy_lints/src/assertions_on_constants.rs
+++ b/clippy_lints/src/assertions_on_constants.rs
@@ -48,7 +48,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         if let ConstantSource::Constant = source
             && let Some(node) = cx.tcx.hir().find_parent(e.hir_id)
             && let Node::Item(Item {
-                kind: ItemKind::Const(.., _body_id),
+                kind: ItemKind::Const(..),
                 ..
             }) = node
         {