From d0257dda36d7b99c7b2e7e6e774dbc5f251834d8 Mon Sep 17 00:00:00 2001
From: Tom Hvitved <hvitved@github.com>
Date: Mon, 23 Nov 2020 12:21:47 +0100
Subject: [PATCH 1/2] Add `unique` wrapper to `AstNode::getParent()`

---
 generator/src/ql.rs        | 20 ++++++++++++++++++++
 generator/src/ql_gen.rs    | 21 ++++++++++++++++-----
 ql/src/codeql_ruby/ast.qll |  4 +++-
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/generator/src/ql.rs b/generator/src/ql.rs
index daa261f099d..f25412c5b98 100644
--- a/generator/src/ql.rs
+++ b/generator/src/ql.rs
@@ -97,6 +97,12 @@ pub enum Expression<'a> {
     Or(Vec<Expression<'a>>),
     Equals(Box<Expression<'a>>, Box<Expression<'a>>),
     Dot(Box<Expression<'a>>, &'a str, Vec<Expression<'a>>),
+    Aggregate(
+        &'a str,
+        Vec<FormalParameter<'a>>,
+        Box<Expression<'a>>,
+        Box<Expression<'a>>,
+    ),
 }
 
 impl<'a> fmt::Display for Expression<'a> {
@@ -138,6 +144,20 @@ impl<'a> fmt::Display for Expression<'a> {
                 }
                 write!(f, ")")
             }
+            Expression::Aggregate(n, vars, range, term) => {
+                write!(f, "{}(", n)?;
+                for (index, var) in vars.iter().enumerate() {
+                    if index > 0 {
+                        write!(f, ", ")?;
+                    }
+                    write!(f, "{}", var)?;
+                }
+                write!(f, " | ")?;
+                write!(f, "{}", range)?;
+                write!(f, " | ")?;
+                write!(f, "{}", term)?;
+                write!(f, ")")
+            }
         }
     }
 }
diff --git a/generator/src/ql_gen.rs b/generator/src/ql_gen.rs
index b8ec8ec5cb9..443a009abf9 100644
--- a/generator/src/ql_gen.rs
+++ b/generator/src/ql_gen.rs
@@ -52,11 +52,22 @@ fn create_ast_node_class<'a>() -> ql::Class<'a> {
         return_type: Some(ql::Type::Normal("AstNode")),
         formal_parameters: vec![],
         body: ql::Expression::Equals(
-            Box::new(ql::Expression::Var("this")),
-            Box::new(ql::Expression::Dot(
-                Box::new(ql::Expression::Var("result")),
-                "getAFieldOrChild",
-                vec![],
+            Box::new(ql::Expression::Var("result")),
+            Box::new(ql::Expression::Aggregate(
+                "unique",
+                vec![ql::FormalParameter {
+                    name: "parent",
+                    param_type: ql::Type::Normal("AstNode"),
+                }],
+                Box::new(ql::Expression::Equals(
+                    Box::new(ql::Expression::Var("this")),
+                    Box::new(ql::Expression::Dot(
+                        Box::new(ql::Expression::Var("parent")),
+                        "getAFieldOrChild",
+                        vec![],
+                    )),
+                )),
+                Box::new(ql::Expression::Var("parent")),
             )),
         ),
     };
diff --git a/ql/src/codeql_ruby/ast.qll b/ql/src/codeql_ruby/ast.qll
index 6275a8811a8..96ca104eccc 100644
--- a/ql/src/codeql_ruby/ast.qll
+++ b/ql/src/codeql_ruby/ast.qll
@@ -11,7 +11,9 @@ class AstNode extends @ast_node {
 
   Location getLocation() { none() }
 
-  AstNode getParent() { this = result.getAFieldOrChild() }
+  AstNode getParent() {
+    result = unique(AstNode parent | this = parent.getAFieldOrChild() | parent)
+  }
 
   AstNode getAFieldOrChild() { none() }
 

From 8132c4cafbaf3f0e8882cf511b4b23afaf60d401 Mon Sep 17 00:00:00 2001
From: Tom Hvitved <hvitved@github.com>
Date: Mon, 23 Nov 2020 16:12:31 +0100
Subject: [PATCH 2/2] Update generator/src/ql.rs

Co-authored-by: Arthur Baars <aibaars@github.com>
---
 generator/src/ql.rs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/generator/src/ql.rs b/generator/src/ql.rs
index f25412c5b98..29381cd581c 100644
--- a/generator/src/ql.rs
+++ b/generator/src/ql.rs
@@ -152,11 +152,7 @@ impl<'a> fmt::Display for Expression<'a> {
                     }
                     write!(f, "{}", var)?;
                 }
-                write!(f, " | ")?;
-                write!(f, "{}", range)?;
-                write!(f, " | ")?;
-                write!(f, "{}", term)?;
-                write!(f, ")")
+                write!(f, " | {} | {})", range, term)
             }
         }
     }