Rust: Add tests for chained let expressions

Author: hvitved

rust/ql/test/library-tests/dataflow/local/CONSISTENCY/CfgConsistency.expected

@@ -0,0 +1,3 @@
+deadEnd
+| main.rs:30:12:30:12 | x |
+| main.rs:255:17:255:17 | n |

rust/ql/test/library-tests/dataflow/local/CONSISTENCY/PathResolutionConsistency.expected

@@ -1,2 +1,2 @@
 multipleCallTargets
-| main.rs:445:18:445:24 | n.len() |
+| main.rs:471:18:471:24 | n.len() |

rust/ql/test/library-tests/dataflow/local/DataFlowStep.expected

@@ -1,3 +1,4 @@
+#![feature(let_chains)]
 // Tests for intraprocedural data flow.
 
 fn source(i: i64) -> i64 {
@@ -21,6 +22,19 @@ fn direct() {
 fn variable_usage() {
     let s = source(2);
     sink(s); // $ hasValueFlow=2
+
+    if let x = s {
+        sink(x); // $ MISSING: hasValueFlow=2
+    };
+
+    if let x = s
+        && {
+            sink(x); // $ MISSING: hasValueFlow=2
+            true
+        }
+    {
+        sink(x); // $ MISSING: hasValueFlow=2
+    };
 }
 
 fn if_expression(cond: bool) {
@@ -236,6 +250,18 @@ fn option_pattern_match_unqualified() {
     }
 }
 
+fn option_chained_let() {
+    let s1 = Some(source(45));
+    if let Some(n) = s1
+        && {
+            sink(n); // $ MISSING: hasValueFlow=45
+            true
+        }
+    {
+        sink(n); // $ MISSING: hasValueFlow=45
+    }
+}
+
 fn option_unwrap() {
     let s1 = Some(source(19));
     sink(s1.unwrap()); // $ hasValueFlow=19
@@ -558,6 +584,7 @@ fn main() {
     struct_nested_match();
     option_pattern_match_qualified();
     option_pattern_match_unqualified();
+    option_chained_let();
     option_unwrap();
     option_unwrap_or();
     option_questionmark();

rust/ql/test/library-tests/dataflow/local/inline-flow.expected

@@ -0,0 +1 @@
+qltest_use_nightly: true

rust/ql/test/library-tests/dataflow/local/main.rs

@@ -0,0 +1,5 @@
+deadEnd
+| main.rs:280:17:280:17 | x |
+| main.rs:296:17:296:17 | x |
+| main.rs:315:20:315:20 | x |
+| main.rs:335:20:335:20 | x |

rust/ql/test/library-tests/dataflow/local/options.yml

@@ -1,3 +1,3 @@
 multipleCallTargets
-| main.rs:87:19:87:40 | ...::from(...) |
-| main.rs:106:19:106:40 | ...::from(...) |
+| main.rs:89:19:89:40 | ...::from(...) |
+| main.rs:111:19:111:40 | ...::from(...) |