Ruby: wip fixes

Author: aschackmull

ruby/ql/lib/codeql/ruby/ast/internal/Synthesis.qll

@@ -833,6 +833,10 @@ private module AssignOperationDesugar {
         )
       )
     }
+
+    final override predicate excludeFromControlFlowTree(AstNode n) {
+      n = any(ScopeResolutionAssignOperation sao).getLeftOperand()
+    }
   }
 
   /** An assignment operation where the left-hand side is a method call. */

ruby/ql/lib/codeql/ruby/controlflow/CfgNodes.qll

@@ -93,9 +93,8 @@ abstract private class ChildMapping extends AstNode {
    */
   abstract predicate relevantChild(AstNode child);
 
-  pragma[nomagic]
-  abstract predicate reachesBasicBlock(AstNode child, CfgNode cfn, BasicBlock bb);
-
+  // pragma[nomagic]
+  // abstract predicate reachesBasicBlock(AstNode child, CfgNode cfn, BasicBlock bb);
   /**
    * Holds if there is a control-flow path from `cfn` to `cfnChild`, where `cfn`
    * is a control-flow node for this expression, and `cfnChild` is a control-flow
@@ -105,7 +104,9 @@ abstract private class ChildMapping extends AstNode {
    */
   cached
   predicate hasCfgChild(AstNode child, CfgNode cfn, CfgNode cfnChild) {
-    this.reachesBasicBlock(child, cfn, cfnChild.getBasicBlock()) and
+    this.relevantChild(child) and
+    cfn.injects(this) and
+    // this.reachesBasicBlock(child, cfn, cfnChild.getBasicBlock()) and
     cfnChild.injects(desugar(child))
   }
 }
@@ -114,38 +115,37 @@ abstract private class ChildMapping extends AstNode {
  * A class for mapping parent-child AST nodes to parent-child CFG nodes.
  */
 abstract private class ExprChildMapping extends Expr, ChildMapping {
-  pragma[nomagic]
-  override predicate reachesBasicBlock(AstNode child, CfgNode cfn, BasicBlock bb) {
-    this.relevantChild(child) and
-    cfn = this.getAControlFlowNode() and
-    bb.getANode() = cfn
-    or
-    exists(BasicBlock mid |
-      this.reachesBasicBlock(child, cfn, mid) and
-      bb = mid.getAPredecessor() and
-      not mid.getANode().getAstNode() = child
-    )
-  }
+  // pragma[nomagic]
+  // override predicate reachesBasicBlock(AstNode child, CfgNode cfn, BasicBlock bb) {
+  //   this.relevantChild(child) and
+  //   cfn = this.getAControlFlowNode() and
+  //   bb.getANode() = cfn
+  //   or
+  //   exists(BasicBlock mid |
+  //     this.reachesBasicBlock(child, cfn, mid) and
+  //     bb = mid.getAPredecessor() and
+  //     not mid.getANode().getAstNode() = child
+  //   )
+  // }
 }
 
 /**
  * A class for mapping parent-child AST nodes to parent-child CFG nodes.
  */
 abstract private class NonExprChildMapping extends ChildMapping {
   NonExprChildMapping() { not this instanceof Expr }
-
-  pragma[nomagic]
-  override predicate reachesBasicBlock(AstNode child, CfgNode cfn, BasicBlock bb) {
-    this.relevantChild(child) and
-    cfn.injects(this) and
-    bb.getANode() = cfn
-    or
-    exists(BasicBlock mid |
-      this.reachesBasicBlock(child, cfn, mid) and
-      bb = mid.getASuccessor() and
-      not mid.getANode().getAstNode() = child
-    )
-  }
+  // pragma[nomagic]
+  // override predicate reachesBasicBlock(AstNode child, CfgNode cfn, BasicBlock bb) {
+  //   this.relevantChild(child) and
+  //   cfn.injects(this) and
+  //   bb.getANode() = cfn
+  //   or
+  //   exists(BasicBlock mid |
+  //     this.reachesBasicBlock(child, cfn, mid) and
+  //     bb = mid.getASuccessor() and
+  //     not mid.getANode().getAstNode() = child
+  //   )
+  // }
 }
 
 /** Provides classes for control-flow nodes that wrap AST expressions. */

ruby/ql/lib/codeql/ruby/controlflow/ControlFlowGraph2.qll

@@ -89,6 +89,29 @@ private module Ast implements AstSig<Location> {
       index = 1 and pair.getValue() = result
     )
     or
+    exists(R::Ast::ArrayPattern arraypattern | parent = arraypattern |
+      index = -1 and arraypattern.getClass() = result
+      or
+      arraypattern.getPrefixElement(index) = result
+      or
+      exists(int restix | restix = count(arraypattern.getPrefixElement(_)) |
+        restix = index and arraypattern.getRestVariableAccess() = result
+        or
+        arraypattern.getSuffixElement(index - restix - 1) = result
+      )
+    )
+    or
+    exists(R::Ast::FindPattern findpattern | parent = findpattern |
+      index = -2 and findpattern.getClass() = result
+      or
+      index = -1 and findpattern.getPrefixVariableAccess() = result
+      or
+      findpattern.getElement(index) = result
+      or
+      index = 1 + max(int i | exists(findpattern.getElement(i))) and
+      findpattern.getSuffixVariableAccess() = result
+    )
+    or
     exists(R::Ast::HashPattern hashpattern | parent = hashpattern |
       index = -1 and hashpattern.getClass() = result
       or