Auto merge of rust-lang#6701 - camsteffen:collapsible-if, r=flip1995

Fix collapsible_if with attributes

changelog: Fix collapsible_if FP with attributes

Fixes rust-lang#6593

clippy_lints/src/collapsible_if.rs

@@ -122,6 +122,7 @@ fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) {
         if let ast::ExprKind::Block(ref block, _) = else_.kind;
         if !block_starts_with_comment(cx, block);
         if let Some(else_) = expr_block(block);
+        if else_.attrs.is_empty();
         if !else_.span.from_expansion();
         if let ast::ExprKind::If(..) = else_.kind;
         then {
@@ -143,16 +144,12 @@ fn check_collapsible_no_if_let(cx: &EarlyContext<'_>, expr: &ast::Expr, check: &
     if_chain! {
         if !block_starts_with_comment(cx, then);
         if let Some(inner) = expr_block(then);
+        if inner.attrs.is_empty();
         if let ast::ExprKind::If(ref check_inner, ref content, None) = inner.kind;
+        // Prevent triggering on `if c { if let a = b { .. } }`.
+        if !matches!(check_inner.kind, ast::ExprKind::Let(..));
+        if expr.span.ctxt() == inner.span.ctxt();
         then {
-            if let ast::ExprKind::Let(..) = check_inner.kind {
-                // Prevent triggering on `if c { if let a = b { .. } }`.
-                return;
-            }
-
-            if expr.span.ctxt() != inner.span.ctxt() {
-                return;
-            }
             span_lint_and_then(cx, COLLAPSIBLE_IF, expr.span, "this `if` statement can be collapsed", |diag| {
                 let lhs = Sugg::ast(cx, check, "..");
                 let rhs = Sugg::ast(cx, check_inner, "..");

tests/ui/collapsible_else_if.fixed

@@ -65,4 +65,13 @@ fn main() {
     else {
         println!("!")
     }
+
+    if x == "hello" {
+        print!("Hello ");
+    } else {
+        #[cfg(not(roflol))]
+        if y == "world" {
+            println!("world!")
+        }
+    }
 }

tests/ui/collapsible_else_if.rs

@@ -79,4 +79,13 @@ fn main() {
             println!("!")
         }
     }
+
+    if x == "hello" {
+        print!("Hello ");
+    } else {
+        #[cfg(not(roflol))]
+        if y == "world" {
+            println!("world!")
+        }
+    }
 }

tests/ui/collapsible_if.fixed

@@ -138,4 +138,11 @@ fn main() {
 
     // Fix #5962
     if matches!(true, true) && matches!(true, true) {}
+
+    if true {
+        #[cfg(not(teehee))]
+        if true {
+            println!("Hello world!");
+        }
+    }
 }

tests/ui/collapsible_if.rs

@@ -154,4 +154,11 @@ fn main() {
     if matches!(true, true) {
         if matches!(true, true) {}
     }
+
+    if true {
+        #[cfg(not(teehee))]
+        if true {
+            println!("Hello world!");
+        }
+    }
 }