Rust: Add local data flow edge for SSA nodes

rust/ql/lib/codeql/rust/dataflow/internal/DataFlowImpl.qll

@@ -145,7 +145,7 @@ module Node {
 
     PatNode() { this = TPatNode(n) }
 
-    /** Gets the Pat in the AST that this node corresponds to. */
+    /** Gets the `Pat` in the AST that this node corresponds to. */
     Pat getPat() { result = n.getPat() }
   }
 
@@ -282,6 +282,10 @@ module LocalFlow {
       nodeFrom.getCfgNode().getAstNode() = s.getInitializer() and
       nodeTo.getCfgNode().getAstNode() = s.getPat()
     )
+    or
+    // An edge from a pattern to its corresponding SSA definition.
+    nodeFrom.(Node::PatNode).getPat() =
+      nodeTo.(Node::SsaNode).getDefinitionExt().getSourceVariable().getPat()
   }
 }
 
@@ -395,7 +399,14 @@ module RustDataFlow implements InputSig<Location> {
    * Holds if there is a simple local flow step from `node1` to `node2`. These
    * are the value-preserving intra-callable flow steps.
    */
-  predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo, string model) { none() }
+  predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo, string model) {
+    (
+      LocalFlow::localFlowStepCommon(nodeFrom, nodeTo)
+      or
+      SsaFlow::localFlowStep(_, nodeFrom, nodeTo, _)
+    ) and
+    model = ""
+  }
 
   /**
    * Holds if data can flow from `node1` to `node2` through a non-local step

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

@@ -1,10 +1,16 @@
 models
 edges
+| main.rs:21:13:21:21 | CallExpr : unit | main.rs:22:10:22:10 | s | provenance |  |
+| main.rs:32:13:32:21 | CallExpr : unit | main.rs:33:10:33:10 | s | provenance |  |
 nodes
 | main.rs:17:10:17:18 | CallExpr | semmle.label | CallExpr |
+| main.rs:21:13:21:21 | CallExpr : unit | semmle.label | CallExpr : unit |
+| main.rs:22:10:22:10 | s | semmle.label | s |
+| main.rs:32:13:32:21 | CallExpr : unit | semmle.label | CallExpr : unit |
+| main.rs:33:10:33:10 | s | semmle.label | s |
 subpaths
 testFailures
-| main.rs:22:14:22:32 | Comment | Missing result: hasValueFlow=1 |
-| main.rs:33:14:33:32 | Comment | Missing result: hasValueFlow=1 |
 #select
 | main.rs:17:10:17:18 | CallExpr | main.rs:17:10:17:18 | CallExpr | main.rs:17:10:17:18 | CallExpr | $@ | main.rs:17:10:17:18 | CallExpr | CallExpr |
+| main.rs:22:10:22:10 | s | main.rs:21:13:21:21 | CallExpr : unit | main.rs:22:10:22:10 | s | $@ | main.rs:21:13:21:21 | CallExpr : unit | CallExpr : unit |
+| main.rs:33:10:33:10 | s | main.rs:32:13:32:21 | CallExpr : unit | main.rs:33:10:33:10 | s | $@ | main.rs:32:13:32:21 | CallExpr : unit | CallExpr : unit |

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

@@ -1,31 +1,86 @@
-| main.rs:2:9:2:9 | [SSA] s | main.rs:3:33:3:33 | s |
-| main.rs:2:13:2:19 | "Hello" | main.rs:2:9:2:9 | s |
-| main.rs:6:18:6:21 | [SSA] cond | main.rs:9:16:9:19 | cond |
-| main.rs:7:9:7:9 | [SSA] a | main.rs:10:9:10:9 | a |
-| main.rs:7:13:7:13 | 1 | main.rs:7:9:7:9 | a |
-| main.rs:8:9:8:9 | [SSA] b | main.rs:12:9:12:9 | b |
-| main.rs:8:13:8:13 | 2 | main.rs:8:9:8:9 | b |
-| main.rs:9:9:9:9 | [SSA] c | main.rs:14:5:14:5 | c |
-| main.rs:9:13:13:5 | IfExpr | main.rs:9:9:9:9 | c |
-| main.rs:9:21:11:5 | BlockExpr | main.rs:9:13:13:5 | IfExpr |
-| main.rs:10:9:10:9 | a | main.rs:9:21:11:5 | BlockExpr |
-| main.rs:11:12:13:5 | BlockExpr | main.rs:9:13:13:5 | IfExpr |
-| main.rs:12:9:12:9 | b | main.rs:11:12:13:5 | BlockExpr |
-| main.rs:14:5:14:5 | c | main.rs:6:37:15:1 | BlockExpr |
-| main.rs:18:9:18:9 | [SSA] a | main.rs:20:15:20:15 | a |
-| main.rs:18:13:18:13 | 1 | main.rs:18:9:18:9 | a |
-| main.rs:19:9:19:9 | [SSA] b | main.rs:22:5:22:5 | b |
-| main.rs:19:13:21:5 | LoopExpr | main.rs:19:9:19:9 | b |
-| main.rs:20:9:20:15 | BreakExpr | main.rs:19:13:21:5 | LoopExpr |
-| main.rs:20:15:20:15 | a | main.rs:20:9:20:15 | BreakExpr |
-| main.rs:22:5:22:5 | b | main.rs:17:29:23:1 | BlockExpr |
-| main.rs:26:17:26:17 | 1 | main.rs:26:9:26:13 | i |
-| main.rs:27:5:27:5 | [SSA] i | main.rs:28:5:28:5 | i |
-| main.rs:27:5:27:5 | i | main.rs:27:5:27:5 | [SSA] i |
-| main.rs:28:5:28:5 | i | main.rs:25:24:29:1 | BlockExpr |
-| main.rs:31:21:31:21 | [SSA] a | main.rs:33:20:33:20 | a |
-| main.rs:31:29:31:29 | [SSA] b | main.rs:34:17:34:17 | b |
-| main.rs:31:37:31:37 | [SSA] c | main.rs:32:11:32:11 | c |
-| main.rs:32:5:35:5 | MatchExpr | main.rs:31:60:36:1 | BlockExpr |
-| main.rs:33:20:33:20 | a | main.rs:32:5:35:5 | MatchExpr |
-| main.rs:34:17:34:17 | b | main.rs:32:5:35:5 | MatchExpr |
+| main.rs:3:11:3:11 | [SSA] i | main.rs:4:12:4:12 | i |
+| main.rs:3:11:3:11 | i | main.rs:3:11:3:11 | [SSA] i |
+| main.rs:4:5:4:12 | ... + ... | main.rs:3:26:5:1 | BlockExpr |
+| main.rs:7:9:7:9 | [SSA] s | main.rs:8:20:8:20 | s |
+| main.rs:7:9:7:9 | s | main.rs:7:9:7:9 | [SSA] s |
+| main.rs:19:9:19:9 | [SSA] s | main.rs:20:10:20:10 | s |
+| main.rs:19:9:19:9 | s | main.rs:19:9:19:9 | [SSA] s |
+| main.rs:19:13:19:21 | CallExpr | main.rs:19:9:19:9 | s |
+| main.rs:23:18:23:21 | [SSA] cond | main.rs:26:16:26:19 | cond |
+| main.rs:23:18:23:21 | cond | main.rs:23:18:23:21 | [SSA] cond |
+| main.rs:24:9:24:9 | [SSA] a | main.rs:26:23:26:23 | a |
+| main.rs:24:9:24:9 | a | main.rs:24:9:24:9 | [SSA] a |
+| main.rs:24:13:24:21 | CallExpr | main.rs:24:9:24:9 | a |
+| main.rs:25:9:25:9 | [SSA] b | main.rs:26:34:26:34 | b |
+| main.rs:25:9:25:9 | b | main.rs:25:9:25:9 | [SSA] b |
+| main.rs:25:13:25:13 | 2 | main.rs:25:9:25:9 | b |
+| main.rs:26:9:26:9 | [SSA] c | main.rs:27:10:27:10 | c |
+| main.rs:26:9:26:9 | c | main.rs:26:9:26:9 | [SSA] c |
+| main.rs:26:13:26:36 | IfExpr | main.rs:26:9:26:9 | c |
+| main.rs:26:21:26:25 | BlockExpr | main.rs:26:13:26:36 | IfExpr |
+| main.rs:26:23:26:23 | a | main.rs:26:21:26:25 | BlockExpr |
+| main.rs:26:32:26:36 | BlockExpr | main.rs:26:13:26:36 | IfExpr |
+| main.rs:26:34:26:34 | b | main.rs:26:32:26:36 | BlockExpr |
+| main.rs:30:21:30:21 | [SSA] m | main.rs:32:19:32:19 | m |
+| main.rs:30:21:30:21 | m | main.rs:30:21:30:21 | [SSA] m |
+| main.rs:31:9:31:9 | [SSA] a | main.rs:33:20:33:20 | a |
+| main.rs:31:9:31:9 | a | main.rs:31:9:31:9 | [SSA] a |
+| main.rs:31:13:31:21 | CallExpr | main.rs:31:9:31:9 | a |
+| main.rs:32:9:32:9 | [SSA] b | main.rs:36:10:36:10 | b |
+| main.rs:32:9:32:9 | b | main.rs:32:9:32:9 | [SSA] b |
+| main.rs:32:13:35:5 | MatchExpr | main.rs:32:9:32:9 | b |
+| main.rs:33:20:33:20 | a | main.rs:32:13:35:5 | MatchExpr |
+| main.rs:34:17:34:17 | 0 | main.rs:32:13:35:5 | MatchExpr |
+| main.rs:40:9:40:9 | [SSA] a | main.rs:43:10:43:10 | a |
+| main.rs:40:9:40:9 | a | main.rs:40:9:40:9 | [SSA] a |
+| main.rs:40:13:42:5 | LoopExpr | main.rs:40:9:40:9 | a |
+| main.rs:41:9:41:15 | BreakExpr | main.rs:40:13:42:5 | LoopExpr |
+| main.rs:41:15:41:15 | 1 | main.rs:41:9:41:15 | BreakExpr |
+| main.rs:44:9:44:9 | [SSA] b | main.rs:47:10:47:10 | b |
+| main.rs:44:9:44:9 | b | main.rs:44:9:44:9 | [SSA] b |
+| main.rs:44:13:46:5 | LoopExpr | main.rs:44:9:44:9 | b |
+| main.rs:45:9:45:23 | BreakExpr | main.rs:44:13:46:5 | LoopExpr |
+| main.rs:45:15:45:23 | CallExpr | main.rs:45:9:45:23 | BreakExpr |
+| main.rs:51:9:51:13 | [SSA] i | main.rs:52:10:52:10 | i |
+| main.rs:51:9:51:13 | i | main.rs:51:9:51:13 | [SSA] i |
+| main.rs:51:9:51:13 | i | main.rs:53:5:53:5 | [SSA] i |
+| main.rs:51:17:51:17 | 1 | main.rs:51:9:51:13 | i |
+| main.rs:53:5:53:5 | [SSA] i | main.rs:54:10:54:10 | i |
+| main.rs:53:5:53:5 | i | main.rs:53:5:53:5 | [SSA] i |
+| main.rs:61:9:61:9 | [SSA] i | main.rs:62:11:62:11 | i |
+| main.rs:61:9:61:9 | i | main.rs:61:9:61:9 | [SSA] i |
+| main.rs:61:13:61:31 | CallExpr | main.rs:61:9:61:9 | i |
+| main.rs:66:9:66:9 | [SSA] a | main.rs:67:10:67:10 | a |
+| main.rs:66:9:66:9 | a | main.rs:66:9:66:9 | [SSA] a |
+| main.rs:66:13:66:26 | TupleExpr | main.rs:66:9:66:9 | a |
+| main.rs:67:10:67:10 | a | main.rs:68:10:68:10 | a |
+| main.rs:78:9:78:9 | [SSA] p | main.rs:83:10:83:10 | p |
+| main.rs:78:9:78:9 | p | main.rs:78:9:78:9 | [SSA] p |
+| main.rs:78:13:82:5 | RecordExpr | main.rs:78:9:78:9 | p |
+| main.rs:83:10:83:10 | p | main.rs:84:10:84:10 | p |
+| main.rs:84:10:84:10 | p | main.rs:85:10:85:10 | p |
+| main.rs:92:9:92:9 | [SSA] p | main.rs:97:38:97:38 | p |
+| main.rs:92:9:92:9 | p | main.rs:92:9:92:9 | [SSA] p |
+| main.rs:92:13:96:5 | RecordExpr | main.rs:92:9:92:9 | p |
+| main.rs:97:20:97:20 | [SSA] a | main.rs:98:10:98:10 | a |
+| main.rs:97:20:97:20 | a | main.rs:97:20:97:20 | [SSA] a |
+| main.rs:97:26:97:26 | [SSA] b | main.rs:99:10:99:10 | b |
+| main.rs:97:26:97:26 | b | main.rs:97:26:97:26 | [SSA] b |
+| main.rs:97:32:97:32 | [SSA] c | main.rs:100:10:100:10 | c |
+| main.rs:97:32:97:32 | c | main.rs:97:32:97:32 | [SSA] c |
+| main.rs:97:38:97:38 | p | main.rs:97:9:97:34 | RecordPat |
+| main.rs:104:9:104:10 | [SSA] s1 | main.rs:106:11:106:12 | s1 |
+| main.rs:104:9:104:10 | s1 | main.rs:104:9:104:10 | [SSA] s1 |
+| main.rs:104:14:104:28 | CallExpr | main.rs:104:9:104:10 | s1 |
+| main.rs:105:9:105:10 | [SSA] s2 | main.rs:110:11:110:12 | s2 |
+| main.rs:105:9:105:10 | s2 | main.rs:105:9:105:10 | [SSA] s2 |
+| main.rs:105:14:105:20 | CallExpr | main.rs:105:9:105:10 | s2 |
+| main.rs:107:14:107:14 | [SSA] n | main.rs:107:25:107:25 | n |
+| main.rs:107:14:107:14 | n | main.rs:107:14:107:14 | [SSA] n |
+| main.rs:107:20:107:26 | CallExpr | main.rs:106:5:109:5 | MatchExpr |
+| main.rs:108:17:108:23 | CallExpr | main.rs:106:5:109:5 | MatchExpr |
+| main.rs:110:5:113:5 | MatchExpr | main.rs:103:27:114:1 | BlockExpr |
+| main.rs:111:14:111:14 | [SSA] n | main.rs:111:25:111:25 | n |
+| main.rs:111:14:111:14 | n | main.rs:111:14:111:14 | [SSA] n |
+| main.rs:111:20:111:26 | CallExpr | main.rs:110:5:113:5 | MatchExpr |
+| main.rs:112:17:112:23 | CallExpr | main.rs:110:5:113:5 | MatchExpr |

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

@@ -0,0 +1,24 @@
+models
+edges
+| main.rs:19:13:19:21 | CallExpr : unit | main.rs:20:10:20:10 | s | provenance |  |
+| main.rs:24:13:24:21 | CallExpr : unit | main.rs:27:10:27:10 | c | provenance |  |
+| main.rs:31:13:31:21 | CallExpr : unit | main.rs:36:10:36:10 | b | provenance |  |
+| main.rs:45:15:45:23 | CallExpr : unit | main.rs:47:10:47:10 | b | provenance |  |
+nodes
+| main.rs:15:10:15:18 | CallExpr | semmle.label | CallExpr |
+| main.rs:19:13:19:21 | CallExpr : unit | semmle.label | CallExpr : unit |
+| main.rs:20:10:20:10 | s | semmle.label | s |
+| main.rs:24:13:24:21 | CallExpr : unit | semmle.label | CallExpr : unit |
+| main.rs:27:10:27:10 | c | semmle.label | c |
+| main.rs:31:13:31:21 | CallExpr : unit | semmle.label | CallExpr : unit |
+| main.rs:36:10:36:10 | b | semmle.label | b |
+| main.rs:45:15:45:23 | CallExpr : unit | semmle.label | CallExpr : unit |
+| main.rs:47:10:47:10 | b | semmle.label | b |
+subpaths
+testFailures
+#select
+| main.rs:15:10:15:18 | CallExpr | main.rs:15:10:15:18 | CallExpr | main.rs:15:10:15:18 | CallExpr | $@ | main.rs:15:10:15:18 | CallExpr | CallExpr |
+| main.rs:20:10:20:10 | s | main.rs:19:13:19:21 | CallExpr : unit | main.rs:20:10:20:10 | s | $@ | main.rs:19:13:19:21 | CallExpr : unit | CallExpr : unit |
+| main.rs:27:10:27:10 | c | main.rs:24:13:24:21 | CallExpr : unit | main.rs:27:10:27:10 | c | $@ | main.rs:24:13:24:21 | CallExpr : unit | CallExpr : unit |
+| main.rs:36:10:36:10 | b | main.rs:31:13:31:21 | CallExpr : unit | main.rs:36:10:36:10 | b | $@ | main.rs:31:13:31:21 | CallExpr : unit | CallExpr : unit |
+| main.rs:47:10:47:10 | b | main.rs:45:15:45:23 | CallExpr : unit | main.rs:47:10:47:10 | b | $@ | main.rs:45:15:45:23 | CallExpr : unit | CallExpr : unit |

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

@@ -0,0 +1,12 @@
+/**
+ * @kind path-problem
+ */
+
+import rust
+import utils.InlineFlowTest
+import DefaultFlowTest
+import ValueFlow::PathGraph
+
+from ValueFlow::PathNode source, ValueFlow::PathNode sink
+where ValueFlow::flowPath(source, sink)
+select sink, source, sink, "$@", source, source.toString()

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

@@ -1,41 +1,128 @@
-fn variable() {
-    let s = "Hello";
-    println!("{:?} data flow!", s);
+// Tests for intraprocedural data flow.
+
+fn source(i: i64) -> i64 {
+    1000 + i
+}
+
+fn sink(s: i64) {
+    println!("{}", s);
+}
+
+// -----------------------------------------------------------------------------
+// Simple data flow through expressions and assignments
+
+fn direct() {
+    sink(source(1)); // $ hasValueFlow=1
+}
+
+fn variable_usage() {
+    let s = source(1);
+    sink(s); // $ hasValueFlow=1
 }
 
-fn if_expression(cond: bool) -> i64 {
-    let a = 1;
+fn if_expression(cond: bool) {
+    let a = source(1);
     let b = 2;
-    let c = if cond {
-        a
-    } else {
-        b
+    let c = if cond { a } else { b };
+    sink(c); // $ hasValueFlow=1
+}
+
+fn match_expression(m: Option<i64>) {
+    let a = source(1);
+    let b = match m {
+        Some(_) => a,
+        None => 0,
     };
-    c
+    sink(b); // $ hasValueFlow=1
 }
 
-fn loop_expression() -> i64 {
-    let a = 1;
+fn loop_with_break() {
+    let a = loop {
+        break 1;
+    };
+    sink(a);
     let b = loop {
-        break a;
+        break source(1);
     };
-    b
+    sink(b); // $ hasValueFlow=1
 }
 
-fn assignment() -> i64 {
+fn assignment() {
     let mut i = 1;
-    i = 2;
-    i
+    sink(i);
+    i = source(2);
+    sink(i); // $ MISSING: hasValueFlow=2
 }
 
-fn match_expression(a: i64, b: i64, c: Option<i64>) -> i64 {
-    match c {
-        Some(_) => a,
-        None => b,
+// -----------------------------------------------------------------------------
+// Data flow through data structures by writing and reading
+
+fn box_deref() {
+    let i = Box::new(source(1));
+    sink(*i); // $ MISSING: hasValueFlow=1
+}
+
+fn tuple() {
+    let a = (source(1), 2);
+    sink(a.0); // $ MISSING: hasValueFlow=1
+    sink(a.1);
+}
+
+struct Point {
+    x: i64,
+    y: i64,
+    z: i64,
+}
+
+fn struct_field() {
+    let p = Point {
+        x: source(1),
+        y: 2,
+        z: source(3),
+    };
+    sink(p.x); // MISSING: hasValueFlow=1
+    sink(p.y);
+    sink(p.z); // MISSING: hasValueFlow=3
+}
+
+// -----------------------------------------------------------------------------
+// Data flow through data structures by pattern matching
+
+fn struct_pattern_match() {
+    let p = Point {
+        x: source(1),
+        y: 2,
+        z: source(3),
+    };
+    let Point { x: a, y: b, z: c } = p;
+    sink(a); // MISSING: hasValueFlow=1
+    sink(b);
+    sink(c); // MISSING: hasValueFlow=3
+}
+
+fn option_pattern_match() {
+    let s1 = Some(source(1));
+    let s2 = Some(2);
+    match s1 {
+        Some(n) => sink(n), // MISSING: hasValueFlow=3
+        None => sink(0),
+    }
+    match s2 {
+        Some(n) => sink(n),
+        None => sink(0),
     }
 }
 
 fn main() {
-    variable();
+    direct();
+    variable_usage();
     if_expression(true);
+    match_expression(Some(0));
+    loop_with_break();
+    assignment();
+    box_deref();
+    tuple();
+    struct_field();
+    struct_pattern_match();
+    option_pattern_match();
 }

rust/ql/test/library-tests/definitions/CONSISTENCY/DataFlowConsistency.expected

@@ -0,0 +1,4 @@
+uniqueEnclosingCallable
+| main.rs:5:29:5:33 | width | Node should have one enclosing callable but has 0. |
+| main.rs:5:36:5:44 | precision | Node should have one enclosing callable but has 0. |
+| main.rs:9:22:9:27 | people | Node should have one enclosing callable but has 0. |

rust/ql/test/library-tests/formatstrings/CONSISTENCY/DataFlowConsistency.expected

@@ -0,0 +1,5 @@
+uniqueEnclosingCallable
+| main.rs:5:29:5:33 | width | Node should have one enclosing callable but has 0. |
+| main.rs:5:36:5:44 | precision | Node should have one enclosing callable but has 0. |
+| main.rs:16:22:16:27 | people | Node should have one enclosing callable but has 0. |
+| main.rs:27:23:27:27 | width | Node should have one enclosing callable but has 0. |

rust/ql/test/library-tests/variables/CONSISTENCY/DataFlowConsistency.expected

@@ -0,0 +1,5 @@
+localFlowIsLocal
+| variables.rs:400:9:400:9 | x | variables.rs:402:15:404:5 | [SSA] <captured entry> x | Local flow step does not preserve enclosing callable. |
+| variables.rs:410:9:410:13 | x | variables.rs:412:20:414:5 | [SSA] <captured entry> x | Local flow step does not preserve enclosing callable. |
+| variables.rs:418:9:418:13 | y | variables.rs:421:9:421:9 | [SSA] y | Local flow step does not preserve enclosing callable. |
+| variables.rs:436:9:436:13 | i | variables.rs:438:9:438:9 | [SSA] i | Local flow step does not preserve enclosing callable. |

rust/ql/test/query-tests/unusedentities/CONSISTENCY/DataFlowConsistency.expected

@@ -0,0 +1,7 @@
+uniqueEnclosingCallable
+| main.rs:194:25:194:25 | x | Node should have one enclosing callable but has 0. |
+| main.rs:198:28:198:28 | x | Node should have one enclosing callable but has 0. |
+| main.rs:202:28:202:28 | x | Node should have one enclosing callable but has 0. |
+| main.rs:206:28:206:28 | x | Node should have one enclosing callable but has 0. |
+localFlowIsLocal
+| main.rs:432:9:432:10 | i6 | main.rs:434:20:434:44 | [SSA] <captured entry> i6 | Local flow step does not preserve enclosing callable. |