add tests

Author: ztlpn

src/test/ui/try-block/try-block-bad-type.stderr

@@ -32,18 +32,18 @@ LL |     let res: Result<i32, i32> = try { };
               found type `()`
 
 error[E0277]: the trait bound `(): std::ops::Try` is not satisfied
-  --> $DIR/try-block-bad-type.rs:17:23
+  --> $DIR/try-block-bad-type.rs:17:25
    |
 LL |     let res: () = try { };
-   |                       ^^^ the trait `std::ops::Try` is not implemented for `()`
+   |                         ^ the trait `std::ops::Try` is not implemented for `()`
    |
    = note: required by `std::ops::Try::from_ok`
 
 error[E0277]: the trait bound `i32: std::ops::Try` is not satisfied
-  --> $DIR/try-block-bad-type.rs:19:24
+  --> $DIR/try-block-bad-type.rs:19:26
    |
 LL |     let res: i32 = try { 5 };
-   |                        ^^^^^ the trait `std::ops::Try` is not implemented for `i32`
+   |                          ^ the trait `std::ops::Try` is not implemented for `i32`
    |
    = note: required by `std::ops::Try::from_ok`
 

src/test/ui/try-block/try-block-unreachable-code-lint.rs

@@ -0,0 +1,76 @@
+// Test unreachable_code lint for `try {}` block ok-wrapping. See issues #54165, #63324.
+
+// compile-flags: --edition 2018
+// check-pass
+#![feature(try_blocks)]
+#![warn(unreachable_code)]
+
+fn err() -> Result<u32, ()> {
+    Err(())
+}
+
+// In the following cases unreachable code is autogenerated and should not be reported.
+
+fn test_ok_wrapped_divergent_expr_1() {
+    let res: Result<u32, ()> = try {
+        loop {
+            err()?;
+        }
+    };
+    println!("res: {:?}", res);
+}
+
+fn test_ok_wrapped_divergent_expr_2() {
+    let _: Result<u32, ()> = try {
+        return
+    };
+}
+
+fn test_autogenerated_unit_after_divergent_expr() {
+    let _: Result<(), ()> = try {
+        return;
+    };
+}
+
+// In the following cases unreachable code should be reported.
+
+fn test_try_block_after_divergent_stmt() {
+    let _: Result<u32, ()> = {
+        return;
+
+        try {
+            loop {
+                err()?;
+            }
+        }
+        // ~^^^^^ WARNING unreachable expression
+    };
+}
+
+fn test_wrapped_divergent_expr() {
+    let _: Result<u32, ()> = {
+        Err(return)
+        // ~^ WARNING unreachable call
+    };
+}
+
+fn test_expr_after_divergent_stmt_in_try_block() {
+    let res: Result<u32, ()> = try {
+        loop {
+            err()?;
+        }
+
+        42
+        // ~^ WARNING unreachable expression
+    };
+    println!("res: {:?}", res);
+}
+
+fn main() {
+    test_ok_wrapped_divergent_expr_1();
+    test_ok_wrapped_divergent_expr_2();
+    test_autogenerated_unit_after_divergent_expr();
+    test_try_block_after_divergent_stmt();
+    test_wrapped_divergent_expr();
+    test_expr_after_divergent_stmt_in_try_block();
+}

src/test/ui/try-block/try-block-unreachable-code-lint.stderr

@@ -0,0 +1,28 @@
+warning: unreachable expression
+  --> $DIR/try-block-unreachable-code-lint.rs:41:9
+   |
+LL | /         try {
+LL | |             loop {
+LL | |                 err()?;
+LL | |             }
+LL | |         }
+   | |_________^
+   |
+note: lint level defined here
+  --> $DIR/try-block-unreachable-code-lint.rs:6:9
+   |
+LL | #![warn(unreachable_code)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: unreachable call
+  --> $DIR/try-block-unreachable-code-lint.rs:52:9
+   |
+LL |         Err(return)
+   |         ^^^
+
+warning: unreachable expression
+  --> $DIR/try-block-unreachable-code-lint.rs:63:9
+   |
+LL |         42
+   |         ^^
+