From 446e2ecfb72cf91c8389a42357a168de77dd414b Mon Sep 17 00:00:00 2001
From: flip1995 <hello@philkrones.com>
Date: Tue, 5 Feb 2019 19:05:42 +0100
Subject: [PATCH 1/2] Don't warn about const assertions when assert is in a
 macro itself

---
 clippy_lints/src/assertions_on_constants.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/assertions_on_constants.rs b/clippy_lints/src/assertions_on_constants.rs
index d420de3a4db..92ee9d1bc66 100644
--- a/clippy_lints/src/assertions_on_constants.rs
+++ b/clippy_lints/src/assertions_on_constants.rs
@@ -3,7 +3,7 @@ use crate::rustc::hir::{Expr, ExprKind};
 use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
 use crate::rustc::{declare_tool_lint, lint_array};
 use crate::syntax::ast::LitKind;
-use crate::utils::{is_direct_expn_of, span_help_and_lint};
+use crate::utils::{in_macro, is_direct_expn_of, span_help_and_lint};
 use if_chain::if_chain;
 
 /// **What it does:** Check to call assert!(true/false)
@@ -43,7 +43,9 @@ impl LintPass for AssertionsOnConstants {
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssertionsOnConstants {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         if_chain! {
-            if is_direct_expn_of(e.span, "assert").is_some();
+            if let Some(assert_span) = is_direct_expn_of(e.span, "assert");
+            if !in_macro(assert_span)
+                || is_direct_expn_of(assert_span, "debug_assert").map_or(false, |span| !in_macro(span));
             if let ExprKind::Unary(_, ref lit) = e.node;
             then {
                 if let ExprKind::Lit(ref inner) = lit.node {

From cb2d987ed4d4074e67ec307cbf5bfe289e876a3b Mon Sep 17 00:00:00 2001
From: flip1995 <hello@philkrones.com>
Date: Tue, 5 Feb 2019 19:06:08 +0100
Subject: [PATCH 2/2] Add tests for assertion_on_constants macro check

---
 tests/ui/assertions_on_constants.rs     | 11 +++++++++++
 tests/ui/assertions_on_constants.stderr | 23 ++++++++++++++++-------
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/tests/ui/assertions_on_constants.rs b/tests/ui/assertions_on_constants.rs
index daeceebd3a2..0d2953c7ed8 100644
--- a/tests/ui/assertions_on_constants.rs
+++ b/tests/ui/assertions_on_constants.rs
@@ -1,3 +1,10 @@
+macro_rules! assert_const {
+    ($len:expr) => {
+        assert!($len > 0);
+        debug_assert!($len < 0);
+    };
+}
+
 fn main() {
     assert!(true);
     assert!(false);
@@ -9,4 +16,8 @@ fn main() {
 
     const C: bool = false;
     assert!(C);
+
+    debug_assert!(true);
+    assert_const!(3);
+    assert_const!(-1);
 }
diff --git a/tests/ui/assertions_on_constants.stderr b/tests/ui/assertions_on_constants.stderr
index e8001acceb1..adfa326abac 100644
--- a/tests/ui/assertions_on_constants.stderr
+++ b/tests/ui/assertions_on_constants.stderr
@@ -1,5 +1,5 @@
 error: assert!(true) will be optimized out by the compiler
-  --> $DIR/assertions_on_constants.rs:2:5
+  --> $DIR/assertions_on_constants.rs:9:5
    |
 LL |     assert!(true);
    |     ^^^^^^^^^^^^^^
@@ -8,7 +8,7 @@ LL |     assert!(true);
    = help: remove it
 
 error: assert!(false) should probably be replaced
-  --> $DIR/assertions_on_constants.rs:3:5
+  --> $DIR/assertions_on_constants.rs:10:5
    |
 LL |     assert!(false);
    |     ^^^^^^^^^^^^^^^
@@ -16,7 +16,7 @@ LL |     assert!(false);
    = help: use panic!() or unreachable!()
 
 error: assert!(true) will be optimized out by the compiler
-  --> $DIR/assertions_on_constants.rs:4:5
+  --> $DIR/assertions_on_constants.rs:11:5
    |
 LL |     assert!(true, "true message");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -24,7 +24,7 @@ LL |     assert!(true, "true message");
    = help: remove it
 
 error: assert!(false) should probably be replaced
-  --> $DIR/assertions_on_constants.rs:5:5
+  --> $DIR/assertions_on_constants.rs:12:5
    |
 LL |     assert!(false, "false message");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -32,7 +32,7 @@ LL |     assert!(false, "false message");
    = help: use panic!() or unreachable!()
 
 error: assert!(const: true) will be optimized out by the compiler
-  --> $DIR/assertions_on_constants.rs:8:5
+  --> $DIR/assertions_on_constants.rs:15:5
    |
 LL |     assert!(B);
    |     ^^^^^^^^^^^
@@ -40,12 +40,21 @@ LL |     assert!(B);
    = help: remove it
 
 error: assert!(const: false) should probably be replaced
-  --> $DIR/assertions_on_constants.rs:11:5
+  --> $DIR/assertions_on_constants.rs:18:5
    |
 LL |     assert!(C);
    |     ^^^^^^^^^^^
    |
    = help: use panic!() or unreachable!()
 
-error: aborting due to 6 previous errors
+error: assert!(true) will be optimized out by the compiler
+  --> $DIR/assertions_on_constants.rs:20:5
+   |
+LL |     debug_assert!(true);
+   |     ^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: remove it
+   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
+
+error: aborting due to 7 previous errors