Ruby: Implement multipleArgumentCallExclude

Author: hvitved

ruby/ql/consistency-queries/DataFlowConsistency.ql

@@ -37,8 +37,14 @@ private module Input implements InputSig<RubyDataFlow> {
   }
 
   predicate multipleArgumentCallExclude(ArgumentNode arg, DataFlowCall call) {
-    arg.asExpr().getASuccessor(any(SuccessorTypes::ConditionalSuccessor c)).getASuccessor() =
-      call.asCall()
+    // An argument such as `x` in `if not x then ...` has two successors (and hence
+    // two calls); one for each Boolean outcome of `x`.
+    exists(CfgNodes::ExprCfgNode n |
+      arg.argumentOf(call, _) and
+      n = call.asCall() and
+      arg.asExpr().getASuccessor(any(SuccessorTypes::ConditionalSuccessor c)).getASuccessor*() = n and
+      n.getASplit() instanceof Split::ConditionalCompletionSplit
+    )
   }
 }
 

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

@@ -7,7 +7,6 @@ private import codeql.ruby.ast.internal.Constant
 private import codeql.ruby.ast.internal.Literal
 private import ControlFlowGraph
 private import internal.ControlFlowGraphImpl as CfgImpl
-private import internal.Splitting
 
 /** An entry node for a given scope. */
 class EntryNode extends CfgNode, CfgImpl::EntryNode {

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

@@ -4,7 +4,7 @@ private import codeql.ruby.AST
 private import codeql.ruby.controlflow.BasicBlocks
 private import SuccessorTypes
 private import internal.ControlFlowGraphImpl as CfgImpl
-private import internal.Splitting
+private import internal.Splitting as Splitting
 private import internal.Completion
 
 /**
@@ -293,3 +293,10 @@ module SuccessorTypes {
     final override string toString() { result = "exit" }
   }
 }
+
+class Split = Splitting::Split;
+
+/** Provides different kinds of control flow graph splittings. */
+module Split {
+  class ConditionalCompletionSplit = Splitting::ConditionalCompletionSplit;
+}

ruby/ql/lib/codeql/ruby/controlflow/internal/Splitting.qll

@@ -115,6 +115,8 @@ private module ConditionalCompletionSplitting {
   }
 }
 
+class ConditionalCompletionSplit = ConditionalCompletionSplitting::ConditionalCompletionSplit;
+
 module EnsureSplitting {
   /**
    * The type of a split `ensure` node.