rustup https://github.com/rust-lang/rust/pull/67455

[rust.git] / clippy_lints / src / collapsible_if.rs

diff --git a/clippy_lints/src/collapsible_if.rs b/clippy_lints/src/collapsible_if.rs
index c1d39716083e8878b4e277a35743f95f6aed39e2..0fd0abdc39d2326d5087aa875580cf21f4e134c6 100644 (file)
--- a/clippy_lints/src/collapsible_if.rs
+++ b/clippy_lints/src/collapsible_if.rs
@@ -13,12 +13,13 @@
 //! This lint is **warn** by default
 
 use if_chain::if_chain;
+use rustc::declare_lint_pass;
 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_session::declare_tool_lint;
 use syntax::ast;
 
 use crate::utils::sugg::Sugg;
-use crate::utils::{in_macro, snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then};
+use crate::utils::{snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then};
 use rustc_errors::Applicability;
 
 declare_clippy_lint! {
@@ -75,25 +76,21 @@
 
 impl EarlyLintPass for CollapsibleIf {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
-        if !in_macro(expr.span) {
+        if !expr.span.from_expansion() {
             check_if(cx, expr)
         }
     }
 }
 
 fn check_if(cx: &EarlyContext<'_>, expr: &ast::Expr) {
-    match expr.node {
-        ast::ExprKind::If(ref check, ref then, ref else_) => {
-            if let Some(ref else_) = *else_ {
-                check_collapsible_maybe_if_let(cx, else_);
-            } else {
-                check_collapsible_no_if_let(cx, expr, check, then);
-            }
-        },
-        ast::ExprKind::IfLet(_, _, _, Some(ref else_)) => {
+    if let ast::ExprKind::If(check, then, else_) = &expr.kind {
+        if let Some(else_) = else_ {
             check_collapsible_maybe_if_let(cx, else_);
-        },
-        _ => (),
+        } else if let ast::ExprKind::Let(..) = check.kind {
+            // Prevent triggering on `if let a = b { if c { .. } }`.
+        } else {
+            check_collapsible_no_if_let(cx, expr, check, then);
+        }
     }
 }
 
@@ -107,26 +104,22 @@ fn block_starts_with_comment(cx: &EarlyContext<'_>, expr: &ast::Block) -> bool {
 
 fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) {
     if_chain! {
-        if let ast::ExprKind::Block(ref block, _) = else_.node;
+        if let ast::ExprKind::Block(ref block, _) = else_.kind;
         if !block_starts_with_comment(cx, block);
         if let Some(else_) = expr_block(block);
-        if !in_macro(else_.span);
+        if !else_.span.from_expansion();
+        if let ast::ExprKind::If(..) = else_.kind;
         then {
-            match else_.node {
-                ast::ExprKind::If(..) | ast::ExprKind::IfLet(..) => {
-                    let mut applicability = Applicability::MachineApplicable;
-                    span_lint_and_sugg(
-                        cx,
-                        COLLAPSIBLE_IF,
-                        block.span,
-                        "this `else { if .. }` block can be collapsed",
-                        "try",
-                        snippet_block_with_applicability(cx, else_.span, "..", &mut applicability).into_owned(),
-                        applicability,
-                    );
-                }
-                _ => (),
-            }
+            let mut applicability = Applicability::MachineApplicable;
+            span_lint_and_sugg(
+                cx,
+                COLLAPSIBLE_IF,
+                block.span,
+                "this `else { if .. }` block can be collapsed",
+                "try",
+                snippet_block_with_applicability(cx, else_.span, "..", &mut applicability).into_owned(),
+                applicability,
+            );
         }
     }
 }
@@ -135,8 +128,13 @@ 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 let ast::ExprKind::If(ref check_inner, ref content, None) = inner.node;
+        if let ast::ExprKind::If(ref check_inner, ref content, None) = inner.kind;
         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;
             }
@@ -163,7 +161,7 @@ fn expr_block(block: &ast::Block) -> Option<&ast::Expr> {
     let mut it = block.stmts.iter();
 
     if let (Some(stmt), None) = (it.next(), it.next()) {
-        match stmt.node {
+        match stmt.kind {
             ast::StmtKind::Expr(ref expr) | ast::StmtKind::Semi(ref expr) => Some(expr),
             _ => None,
         }