Rollup merge of #103468 - chenyukang:yukang/fix-103435-extra-parentheses, r=estebank

Fix unused lint and parser caring about spaces to won't produce invalid code

Fixes #103435

src/test/ui/lint/issue-103435-extra-parentheses.fixed

@@ -0,0 +1,18 @@
+// run-rustfix
+#![deny(unused_parens)]
+
+fn main() {
+    if let Some(_) = Some(1) {}
+    //~^ ERROR unnecessary parentheses around pattern
+
+    for _x in 1..10 {}
+    //~^ ERROR unnecessary parentheses around pattern
+
+    if 2 == 1 {}
+    //~^ ERROR unnecessary parentheses around `if` condition
+
+    // reported by parser
+    for _x in 1..10 {}
+    //~^ ERROR expected one of
+    //~| ERROR unexpected parentheses surrounding
+}

src/test/ui/lint/issue-103435-extra-parentheses.rs

@@ -0,0 +1,18 @@
+// run-rustfix
+#![deny(unused_parens)]
+
+fn main() {
+    if let(Some(_))= Some(1) {}
+    //~^ ERROR unnecessary parentheses around pattern
+
+    for(_x)in 1..10 {}
+    //~^ ERROR unnecessary parentheses around pattern
+
+    if(2 == 1){}
+    //~^ ERROR unnecessary parentheses around `if` condition
+
+    // reported by parser
+    for(_x in 1..10){}
+    //~^ ERROR expected one of
+    //~| ERROR unexpected parentheses surrounding
+}

src/test/ui/lint/issue-103435-extra-parentheses.stderr

@@ -0,0 +1,61 @@
+error: expected one of `)`, `,`, `@`, or `|`, found keyword `in`
+  --> $DIR/issue-103435-extra-parentheses.rs:15:12
+   |
+LL |     for(_x in 1..10){}
+   |            ^^ expected one of `)`, `,`, `@`, or `|`
+
+error: unexpected parentheses surrounding `for` loop head
+  --> $DIR/issue-103435-extra-parentheses.rs:15:8
+   |
+LL |     for(_x in 1..10){}
+   |        ^           ^
+   |
+help: remove parentheses in `for` loop
+   |
+LL -     for(_x in 1..10){}
+LL +     for _x in 1..10 {}
+   |
+
+error: unnecessary parentheses around pattern
+  --> $DIR/issue-103435-extra-parentheses.rs:5:11
+   |
+LL |     if let(Some(_))= Some(1) {}
+   |           ^       ^
+   |
+note: the lint level is defined here
+  --> $DIR/issue-103435-extra-parentheses.rs:2:9
+   |
+LL | #![deny(unused_parens)]
+   |         ^^^^^^^^^^^^^
+help: remove these parentheses
+   |
+LL -     if let(Some(_))= Some(1) {}
+LL +     if let Some(_) = Some(1) {}
+   |
+
+error: unnecessary parentheses around pattern
+  --> $DIR/issue-103435-extra-parentheses.rs:8:8
+   |
+LL |     for(_x)in 1..10 {}
+   |        ^  ^
+   |
+help: remove these parentheses
+   |
+LL -     for(_x)in 1..10 {}
+LL +     for _x in 1..10 {}
+   |
+
+error: unnecessary parentheses around `if` condition
+  --> $DIR/issue-103435-extra-parentheses.rs:11:7
+   |
+LL |     if(2 == 1){}
+   |       ^      ^
+   |
+help: remove these parentheses
+   |
+LL -     if(2 == 1){}
+LL +     if 2 == 1 {}
+   |
+
+error: aborting due to 5 previous errors
+