Auto merge of rust-lang#9410 - dswij:issue-9375, r=xFrednet

Use macro callsite when creating `Sugg` helper

Closes rust-lang#9375

changelog: Improvement: [`collapsible_if`]: Suggestions now work with macros, by taking the call site into account.

Author: bors

clippy_utils/src/sugg.rs

@@ -22,7 +22,7 @@ use std::fmt::{Display, Write as _};
 use std::ops::{Add, Neg, Not, Sub};
 
 /// A helper type to build suggestion correctly handling parentheses.
-#[derive(Clone, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum Sugg<'a> {
     /// An expression that never needs parentheses such as `1337` or `[0; 42]`.
     NonParen(Cow<'a, str>),
@@ -177,11 +177,11 @@ impl<'a> Sugg<'a> {
     pub fn ast(cx: &EarlyContext<'_>, expr: &ast::Expr, default: &'a str) -> Self {
         use rustc_ast::ast::RangeLimits;
 
-        let get_whole_snippet = || {
-            if expr.span.from_expansion() {
-                snippet_with_macro_callsite(cx, expr.span, default)
+        let snippet_without_expansion = |cx, span: Span, default| {
+            if span.from_expansion() {
+                snippet_with_macro_callsite(cx, span, default)
             } else {
-                snippet(cx, expr.span, default)
+                snippet(cx, span, default)
             }
         };
 
@@ -192,7 +192,7 @@ impl<'a> Sugg<'a> {
             | ast::ExprKind::If(..)
             | ast::ExprKind::Let(..)
             | ast::ExprKind::Unary(..)
-            | ast::ExprKind::Match(..) => Sugg::MaybeParen(get_whole_snippet()),
+            | ast::ExprKind::Match(..) => Sugg::MaybeParen(snippet_without_expansion(cx, expr.span, default)),
             ast::ExprKind::Async(..)
             | ast::ExprKind::Block(..)
             | ast::ExprKind::Break(..)
@@ -221,41 +221,45 @@ impl<'a> Sugg<'a> {
             | ast::ExprKind::Array(..)
             | ast::ExprKind::While(..)
             | ast::ExprKind::Await(..)
-            | ast::ExprKind::Err => Sugg::NonParen(get_whole_snippet()),
+            | ast::ExprKind::Err => Sugg::NonParen(snippet_without_expansion(cx, expr.span, default)),
             ast::ExprKind::Range(ref lhs, ref rhs, RangeLimits::HalfOpen) => Sugg::BinOp(
                 AssocOp::DotDot,
-                lhs.as_ref().map_or("".into(), |lhs| snippet(cx, lhs.span, default)),
-                rhs.as_ref().map_or("".into(), |rhs| snippet(cx, rhs.span, default)),
+                lhs.as_ref()
+                    .map_or("".into(), |lhs| snippet_without_expansion(cx, lhs.span, default)),
+                rhs.as_ref()
+                    .map_or("".into(), |rhs| snippet_without_expansion(cx, rhs.span, default)),
             ),
             ast::ExprKind::Range(ref lhs, ref rhs, RangeLimits::Closed) => Sugg::BinOp(
                 AssocOp::DotDotEq,
-                lhs.as_ref().map_or("".into(), |lhs| snippet(cx, lhs.span, default)),
-                rhs.as_ref().map_or("".into(), |rhs| snippet(cx, rhs.span, default)),
+                lhs.as_ref()
+                    .map_or("".into(), |lhs| snippet_without_expansion(cx, lhs.span, default)),
+                rhs.as_ref()
+                    .map_or("".into(), |rhs| snippet_without_expansion(cx, rhs.span, default)),
             ),
             ast::ExprKind::Assign(ref lhs, ref rhs, _) => Sugg::BinOp(
                 AssocOp::Assign,
-                snippet(cx, lhs.span, default),
-                snippet(cx, rhs.span, default),
+                snippet_without_expansion(cx, lhs.span, default),
+                snippet_without_expansion(cx, rhs.span, default),
             ),
             ast::ExprKind::AssignOp(op, ref lhs, ref rhs) => Sugg::BinOp(
                 astbinop2assignop(op),
-                snippet(cx, lhs.span, default),
-                snippet(cx, rhs.span, default),
+                snippet_without_expansion(cx, lhs.span, default),
+                snippet_without_expansion(cx, rhs.span, default),
             ),
             ast::ExprKind::Binary(op, ref lhs, ref rhs) => Sugg::BinOp(
                 AssocOp::from_ast_binop(op.node),
-                snippet(cx, lhs.span, default),
-                snippet(cx, rhs.span, default),
+                snippet_without_expansion(cx, lhs.span, default),
+                snippet_without_expansion(cx, rhs.span, default),
             ),
             ast::ExprKind::Cast(ref lhs, ref ty) => Sugg::BinOp(
                 AssocOp::As,
-                snippet(cx, lhs.span, default),
-                snippet(cx, ty.span, default),
+                snippet_without_expansion(cx, lhs.span, default),
+                snippet_without_expansion(cx, ty.span, default),
             ),
             ast::ExprKind::Type(ref lhs, ref ty) => Sugg::BinOp(
                 AssocOp::Colon,
-                snippet(cx, lhs.span, default),
-                snippet(cx, ty.span, default),
+                snippet_without_expansion(cx, lhs.span, default),
+                snippet_without_expansion(cx, ty.span, default),
             ),
         }
     }

tests/ui/collapsible_if.fixed

@@ -139,6 +139,9 @@ fn main() {
     // Fix #5962
     if matches!(true, true) && matches!(true, true) {}
 
+    // Issue #9375
+    if matches!(true, true) && truth() && matches!(true, true) {}
+
     if true {
         #[cfg(not(teehee))]
         if true {

tests/ui/collapsible_if.rs

@@ -155,6 +155,11 @@ fn main() {
         if matches!(true, true) {}
     }
 
+    // Issue #9375
+    if matches!(true, true) && truth() {
+        if matches!(true, true) {}
+    }
+
     if true {
         #[cfg(not(teehee))]
         if true {

tests/ui/collapsible_if.stderr

@@ -126,5 +126,13 @@ 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
+error: this `if` statement can be collapsed
+  --> $DIR/collapsible_if.rs:159:5
+   |
+LL | /     if matches!(true, true) && truth() {
+LL | |         if matches!(true, true) {}
+LL | |     }
+   | |_____^ help: collapse nested if block: `if matches!(true, true) && truth() && matches!(true, true) {}`
+
+error: aborting due to 9 previous errors