Auto merge of rust-lang#5992 - giraffate:fix_wrong_seggestion_in_collapsible_if, r=yaahc

Fix the wrong suggestion when using macro in `collapsible_if`

Fix rust-lang#5962

changelog: Fix the wrong suggestion when using macro in `collapsible_if`

Author: bors

clippy_lints/src/utils/sugg.rs

@@ -132,7 +132,11 @@ impl<'a> Sugg<'a> {
     pub fn ast(cx: &EarlyContext<'_>, expr: &ast::Expr, default: &'a str) -> Self {
         use rustc_ast::ast::RangeLimits;
 
-        let snippet = snippet(cx, expr.span, default);
+        let snippet = if expr.span.from_expansion() {
+            snippet_with_macro_callsite(cx, expr.span, default)
+        } else {
+            snippet(cx, expr.span, default)
+        };
 
         match expr.kind {
             ast::ExprKind::AddrOf(..)

tests/ui/collapsible_if.fixed

@@ -135,4 +135,7 @@ fn main() {
             if truth() {}
         }
     }
+
+    // Fix #5962
+    if matches!(true, true) && matches!(true, true) {}
 }

tests/ui/collapsible_if.rs

@@ -149,4 +149,9 @@ fn main() {
             if truth() {}
         }
     }
+
+    // Fix #5962
+    if matches!(true, true) {
+        if matches!(true, true) {}
+    }
 }

tests/ui/collapsible_if.stderr

@@ -118,5 +118,13 @@ LL |         println!("Hello world!");
 LL |     }
    |
 
-error: aborting due to 7 previous errors
+error: this `if` statement can be collapsed
+  --> $DIR/collapsible_if.rs:154:5
+   |
+LL | /     if matches!(true, true) {
+LL | |         if matches!(true, true) {}
+LL | |     }
+   | |_____^ help: collapse nested if block: `if matches!(true, true) && matches!(true, true) {}`
+
+error: aborting due to 8 previous errors