Rust: Additional test cases for rust/dead-code.

rust/ql/test/query-tests/unusedentities/UnreachableCode.expected

@@ -5,12 +5,19 @@
 | unreachable.rs:67:5:67:19 | ExprStmt | This code is never reached. |
 | unreachable.rs:134:13:134:20 | MacroExpr | This code is never reached. |
 | unreachable.rs:143:13:143:20 | MacroExpr | This code is never reached. |
-| unreachable.rs:169:5:169:19 | ExprStmt | This code is never reached. |
-| unreachable.rs:177:13:177:27 | ExprStmt | This code is never reached. |
-| unreachable.rs:187:13:187:27 | ExprStmt | This code is never reached. |
-| unreachable.rs:193:9:193:23 | ExprStmt | This code is never reached. |
-| unreachable.rs:200:17:200:31 | ExprStmt | This code is never reached. |
-| unreachable.rs:210:17:210:31 | ExprStmt | This code is never reached. |
-| unreachable.rs:213:9:213:23 | ExprStmt | This code is never reached. |
-| unreachable.rs:238:9:238:23 | ExprStmt | This code is never reached. |
-| unreachable.rs:254:9:254:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:166:9:166:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:171:9:171:17 | MacroExpr | This code is never reached. |
+| unreachable.rs:177:9:177:26 | MacroExpr | This code is never reached. |
+| unreachable.rs:206:9:206:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:231:13:231:27 | ExprStmt | This code is never reached. |
+| unreachable.rs:241:13:241:27 | ExprStmt | This code is never reached. |
+| unreachable.rs:247:9:247:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:254:17:254:31 | ExprStmt | This code is never reached. |
+| unreachable.rs:264:17:264:31 | ExprStmt | This code is never reached. |
+| unreachable.rs:267:9:267:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:303:9:303:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:332:9:332:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:348:9:348:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:370:9:370:23 | ExprStmt | This code is never reached. |
+| unreachable.rs:375:5:375:10 | ExprStmt | This code is never reached. |
+| unreachable.rs:382:5:382:10 | ExprStmt | This code is never reached. |

rust/ql/test/query-tests/unusedentities/UnusedValue.expected

@@ -18,3 +18,5 @@
 | more.rs:44:9:44:14 | a_ptr4 | Variable $@ is assigned a value that is never used. | more.rs:44:9:44:14 | a_ptr4 | a_ptr4 |
 | more.rs:59:9:59:13 | d_ptr | Variable $@ is assigned a value that is never used. | more.rs:59:9:59:13 | d_ptr | d_ptr |
 | more.rs:65:9:65:17 | f_ptr | Variable $@ is assigned a value that is never used. | more.rs:65:13:65:17 | f_ptr | f_ptr |
+| unreachable.rs:292:9:292:15 | for_ten | Variable $@ is assigned a value that is never used. | unreachable.rs:292:9:292:15 | for_ten | for_ten |
+| unreachable.rs:299:9:299:16 | for_ever | Variable $@ is assigned a value that is never used. | unreachable.rs:299:9:299:16 | for_ever | for_ever |

rust/ql/test/query-tests/unusedentities/main.rs

@@ -484,11 +484,14 @@ fn main() {
     unreachable_if_2();
     unreachable_if_3();
     unreachable_panic();
+    _ = unreachable_bail();
     unreachable_match();
     unreachable_loop();
+    unreachable_loop_async();
     unreachable_paren();
     unreachable_let_1();
     unreachable_let_2();
+    unreachable_attributes();
 
     macros();
 }

rust/ql/test/query-tests/unusedentities/unreachable.rs

@@ -147,26 +147,80 @@ pub fn unreachable_panic() {
     }
 }
 
-pub fn unreachable_match() {
-    match get_a_number() {
-        1 => {
-            return;
-        }
-        _ => {
-            do_something();
-        }
+macro_rules! bail_1 {
+    () => {
+        return Err(String::from("message"))
+    };
+}
+
+macro_rules! bail_2 {
+    ($message:literal) => {
+        return Err(String::from($message))
+    };
+}
+
+pub fn unreachable_bail() -> Result<i32, String> {
+    if cond() {
+        do_something();
+        return Err(String::from("message"));
+        do_something(); // $ Alert[rust/dead-code]
+    }
+
+    if cond() {
+        do_something();
+        bail_1!(); // $ SPURIOUS: Alert[rust/dead-code]
+        do_something(); // $ MISSING: Alert[rust/dead-code]
+    }
+
+    if cond() {
+        do_something();
+        bail_2!("message"); // $ SPURIOUS: Alert[rust/dead-code]
     }
     do_something();
 
-    match get_a_number() {
-        1 => {
-            return;
-        }
-        _ => {
-            return;
+    Ok(1)
+}
+
+pub fn unreachable_match() {
+    if cond() {
+        match get_a_number() {
+            1 => {
+                return;
+            }
+            _ => {
+                do_something();
+            }
         }
+        do_something();
+    }
+
+    if cond() {
+        match get_a_number() {
+            1 => {
+                return;
+            }
+            _ => {
+                return;
+            }
+        }
+        do_something(); // $ Alert[rust/dead-code]
+    }
+
+    if cond() {
+        _ = match get_a_number() {
+            1 => "One",
+            _ => "Some"
+        };
+        do_something();
+    }
+
+    if cond() {
+        _ = Some(match get_a_number() {
+            1 => "One",
+            _ => "Some"
+        });
+        do_something();
     }
-    do_something(); // $ Alert[rust/dead-code]
 }
 
 pub fn unreachable_loop() {
@@ -214,6 +268,46 @@ pub fn unreachable_loop() {
         do_something();
         do_something();
     }
+
+    if cond() {
+        fn do_nothing() { };
+        fn loop_forever() { loop {} };
+        fn take_a_fn(_: fn() -> ()) {
+        };
+        fn call_a_fn(f: fn() -> ()) {
+            f();
+        };
+
+        take_a_fn( do_nothing );
+        call_a_fn( do_nothing );
+        take_a_fn( loop_forever );
+        call_a_fn( loop_forever );
+        do_something(); // $ MISSING: Alert[rust/dead-code]
+    }
+}
+
+async fn do_something_async() {}
+
+pub async fn unreachable_loop_async() {
+    let for_ten = async { // $ SPURIOUS: Alert[rust/unused-value]
+        for _ in 1..10 {
+            do_something_async().await;
+        }
+        do_something();
+    };
+
+    let for_ever = async { // $ SPURIOUS: Alert[rust/unused-value]
+        loop {
+            do_something_async().await;
+        }
+        do_something(); // $ Alert[rust/dead-code]
+    };
+
+    do_something();
+    for_ten.await;
+    do_something();
+    for_ever.await;
+    do_something(); // $ MISSING: Alert[rust/dead-code]
 }
 
 pub fn unreachable_paren() {
@@ -257,3 +351,33 @@ pub fn unreachable_let_2() {
 
     do_something();
 }
+
+#[cfg(not(foo))]
+pub fn unreachable_attributes() {
+    // `#[cfg` and `cfg!` checks can go either way, we should not assume this
+    // function or either branch below is unreachable.
+    if cfg!(bar) {
+        do_something();
+    } else {
+        do_something();
+    }
+
+    #[doc="This is a doc comment declared through an attribute."]
+
+    if (true) {
+        do_something();
+    } else {
+        do_something(); // $ Alert[rust/dead-code]
+    }
+}
+
+const _: () = {
+    _ = 1; // $ SPURIOUS: Alert[rust/dead-code]
+};
+
+const _: () = {
+    const fn foo() {
+        _ = 1;
+    };
+    foo(); // $ SPURIOUS: Alert[rust/dead-code]
+};