Rust: fix multiplePositions consistency check

Author: redsun82

rust/ql/lib/codeql/rust/elements/internal/ArrayRepeatExprImpl.qll

@@ -27,8 +27,10 @@ module Impl {
           this.getRepeatLength().toAbbreviatedString() + "]"
     }
 
-    override Expr getRepeatOperand() { result = this.getExpr(0) }
+    override Expr getExpr(int index) { none() }
 
-    override Expr getRepeatLength() { result = this.getExpr(1) }
+    override Expr getRepeatOperand() { result = super.getExpr(0) }
+
+    override Expr getRepeatLength() { result = super.getExpr(1) }
   }
 }

rust/ql/lib/codeql/rust/internal/AstConsistency.qll

@@ -60,17 +60,12 @@ query predicate multipleChildren(Element parent, int index, Element child1, Elem
 }
 
 /**
- * Holds if `child` has multiple positions amongst the `accessor` children
- * of `parent`.
- *
- * Children are allowed to have multiple positions for _different_ accessors,
- * for example in an array repeat expression `[1; 10]`, `1` has positions for
- * both `getRepeatOperand()` and `getExpr()`.
+ * Holds if `child` has multiple positions amongst the children of `parent`.
  */
-query predicate multiplePositions(Element parent, int pos1, int pos2, string accessor, Element child) {
-  child = getChildAndAccessor(parent, pos1, accessor) and
-  child = getChildAndAccessor(parent, pos2, accessor) and
-  pos1 != pos2
+query predicate multiplePositions(Element parent, int pos1, int pos2, Element child) {
+  child = getChildAndAccessor(parent, pos1, _) and
+  child = getChildAndAccessor(parent, pos2, _) and
+  pos1 < pos2
 }
 
 /**
@@ -97,5 +92,5 @@ int getAstInconsistencyCounts(string type) {
   result = count(Element e | multipleChildren(_, _, e, _) | e)
   or
   type = "Multiple positions" and
-  result = count(Element e | multiplePositions(_, _, _, _, e) | e)
+  result = count(Element e | multiplePositions(_, _, _, e) | e)
 }

rust/ql/test/extractor-tests/generated/ArrayRepeatExpr/ArrayRepeatExpr.expected

@@ -1 +1 @@
-| gen_array_repeat_expr.rs:5:5:5:11 | [1; 10] | getNumberOfExprs: | 2 | getNumberOfAttrs: | 0 | getRepeatOperand: | gen_array_repeat_expr.rs:5:6:5:6 | 1 | getRepeatLength: | gen_array_repeat_expr.rs:5:9:5:10 | 10 |
+| gen_array_repeat_expr.rs:5:5:5:11 | [1; 10] | getNumberOfExprs: | 0 | getNumberOfAttrs: | 0 | getRepeatOperand: | gen_array_repeat_expr.rs:5:6:5:6 | 1 | getRepeatLength: | gen_array_repeat_expr.rs:5:9:5:10 | 10 |

rust/ql/test/extractor-tests/generated/ArrayRepeatExpr/ArrayRepeatExpr_getExpr.expected

@@ -1,2 +0,0 @@
-| gen_array_repeat_expr.rs:5:5:5:11 | [1; 10] | 0 | gen_array_repeat_expr.rs:5:6:5:6 | 1 |
-| gen_array_repeat_expr.rs:5:5:5:11 | [1; 10] | 1 | gen_array_repeat_expr.rs:5:9:5:10 | 10 |