Merge pull request #7394 from aibaars/ruby-cfg-expr-post

Ruby: CFG: make all expressions "post-order" nodes
2026-04-30 11:15:13 +02:00 · 2021-12-21 16:36:42 +01:00
parent c138a2796f a86ba3b14e
commit a7aff11140
15 changed files with 327 additions and 262 deletions
--- a/ruby/ql/consistency-queries/CfgConsistency.ql
+++ b/ruby/ql/consistency-queries/CfgConsistency.ql
@@ -1 +1,20 @@
 import codeql.ruby.controlflow.internal.ControlFlowGraphImplShared::Consistency
+import codeql.ruby.AST
+import codeql.ruby.controlflow.internal.Completion
+import codeql.ruby.controlflow.internal.ControlFlowGraphImpl
+
+/**
+ * All `Expr` nodes are `PostOrderTree`s
+ */
+query predicate nonPostOrderExpr(Expr e, string cls) {
+  cls = e.getPrimaryQlClasses() and
+  not exists(e.getDesugared()) and
+  not e instanceof BeginExpr and
+  not e instanceof Namespace and
+  not e instanceof Toplevel and
+  exists(AstNode last, Completion c |
+    last(e, last, c) and
+    last != e and
+    c instanceof NormalCompletion
+  )
+}
--- a/ruby/ql/lib/codeql/ruby/ast/Control.qll
+++ b/ruby/ql/lib/codeql/ruby/ast/Control.qll
@@ -361,22 +361,22 @@ class CaseExpr extends ControlExpr instanceof CaseExprImpl {
  final Expr getValue() { result = super.getValue() }

  /**
-   * Gets the `n`th branch of this case expression, either a `WhenExpr`, an
+   * Gets the `n`th branch of this case expression, either a `WhenClause`, an
   * `InClause`, or a `StmtSequence`.
   */
-  final Expr getBranch(int n) { result = super.getBranch(n) }
+  final AstNode getBranch(int n) { result = super.getBranch(n) }

  /**
-   * Gets a branch of this case expression, either a `WhenExpr`, an
+   * Gets a branch of this case expression, either a `WhenClause`, an
   * `InClause`, or a `StmtSequence`.
   */
-  final Expr getABranch() { result = this.getBranch(_) }
+  final AstNode getABranch() { result = this.getBranch(_) }

  /** Gets the `n`th `when` branch of this case expression. */
-  deprecated final WhenExpr getWhenBranch(int n) { result = this.getBranch(n) }
+  deprecated final WhenClause getWhenBranch(int n) { result = this.getBranch(n) }

  /** Gets a `when` branch of this case expression. */
-  deprecated final WhenExpr getAWhenBranch() { result = this.getABranch() }
+  deprecated final WhenClause getAWhenBranch() { result = this.getABranch() }

  /** Gets the `else` branch of this case expression, if any. */
  final StmtSequence getElseBranch() { result = this.getABranch() }
@@ -401,6 +401,11 @@ class CaseExpr extends ControlExpr instanceof CaseExprImpl {
  }
 }

+/**
+ * DEPRECATED: Use `WhenClause` instead.
+ */
+deprecated class WhenExpr = WhenClause;
+
 /**
 * A `when` branch of a `case` expression.
 * ```rb
@@ -409,12 +414,12 @@ class CaseExpr extends ControlExpr instanceof CaseExprImpl {
 * end
 * ```
 */
-class WhenExpr extends Expr, TWhenExpr {
+class WhenClause extends AstNode, TWhenClause {
  private Ruby::When g;

-  WhenExpr() { this = TWhenExpr(g) }
+  WhenClause() { this = TWhenClause(g) }

-  final override string getAPrimaryQlClass() { result = "WhenExpr" }
+  final override string getAPrimaryQlClass() { result = "WhenClause" }

  /** Gets the body of this case-when expression. */
  final Stmt getBody() { toGenerated(result) = g.getBody() }
@@ -461,7 +466,7 @@ class WhenExpr extends Expr, TWhenExpr {
 * end
 * ```
 */
-class InClause extends Expr, TInClause {
+class InClause extends AstNode, TInClause {
  private Ruby::InClause g;

  InClause() { this = TInClause(g) }
--- a/ruby/ql/lib/codeql/ruby/ast/internal/AST.qll
+++ b/ruby/ql/lib/codeql/ruby/ast/internal/AST.qll
@@ -305,7 +305,7 @@ private module Cached {
    TUntilExpr(Ruby::Until g) or
    TUntilModifierExpr(Ruby::UntilModifier g) or
    TVariableReferencePattern(Ruby::VariableReferencePattern g) or
-    TWhenExpr(Ruby::When g) or
+    TWhenClause(Ruby::When g) or
    TWhileExpr(Ruby::While g) or
    TWhileModifierExpr(Ruby::WhileModifier g) or
    TYieldCall(Ruby::Yield g)
@@ -344,7 +344,7 @@ private module Cached {
        TTernaryIfExpr or TThen or TTokenConstantAccess or TTokenMethodName or TTokenSuperCall or
        TToplevel or TTrueLiteral or TUnaryMinusExpr or TUnaryPlusExpr or TUndefStmt or
        TUnlessExpr or TUnlessModifierExpr or TUntilExpr or TUntilModifierExpr or
-        TVariableReferencePattern or TWhenExpr or TWhileExpr or TWhileModifierExpr or TYieldCall;
+        TVariableReferencePattern or TWhenClause or TWhileExpr or TWhileModifierExpr or TYieldCall;

  class TAstNodeSynth =
    TAddExprSynth or TAssignExprSynth or TBitwiseAndExprSynth or TBitwiseOrExprSynth or
@@ -511,7 +511,7 @@ private module Cached {
    n = TUntilExpr(result) or
    n = TUntilModifierExpr(result) or
    n = TVariableReferencePattern(result) or
-    n = TWhenExpr(result) or
+    n = TWhenClause(result) or
    n = TWhileExpr(result) or
    n = TWhileModifierExpr(result) or
    n = TYieldCall(result)
@@ -657,10 +657,9 @@ class TSelf = TSelfReal or TSelfSynth;
 class TDestructuredLhsExpr = TDestructuredLeftAssignment or TLeftAssignmentList;

 class TExpr =
-  TSelf or TArgumentList or TInClause or TRescueClause or TRescueModifierExpr or TPair or
-      TStringConcatenation or TCall or TBlockArgument or TConstantAccess or TControlExpr or
-      TWhenExpr or TLiteral or TCallable or TVariableAccess or TStmtSequence or TOperation or
-      TForwardArgument or TDestructuredLhsExpr;
+  TSelf or TArgumentList or TRescueClause or TRescueModifierExpr or TPair or TStringConcatenation or
+      TCall or TBlockArgument or TConstantAccess or TControlExpr or TLiteral or TCallable or
+      TVariableAccess or TStmtSequence or TOperation or TForwardArgument or TDestructuredLhsExpr;

 class TSplatExpr = TSplatExprReal or TSplatExprSynth;

--- a/ruby/ql/lib/codeql/ruby/ast/internal/Control.qll
+++ b/ruby/ql/lib/codeql/ruby/ast/internal/Control.qll
@@ -5,17 +5,17 @@ private import codeql.ruby.ast.internal.AST
 abstract class CaseExprImpl extends ControlExpr, TCase {
  abstract Expr getValue();

-  abstract Expr getBranch(int n);
+  abstract AstNode getBranch(int n);
 }

-class CaseWhenExpr extends CaseExprImpl, TCaseExpr {
+class CaseWhenClause extends CaseExprImpl, TCaseExpr {
  private Ruby::Case g;

-  CaseWhenExpr() { this = TCaseExpr(g) }
+  CaseWhenClause() { this = TCaseExpr(g) }

  final override Expr getValue() { toGenerated(result) = g.getValue() }

-  final override Expr getBranch(int n) {
+  final override AstNode getBranch(int n) {
    toGenerated(result) = g.getChild(n) or
    toGenerated(result) = g.getChild(n)
  }
@@ -28,7 +28,7 @@ class CaseMatch extends CaseExprImpl, TCaseMatch {

  final override Expr getValue() { toGenerated(result) = g.getValue() }

-  final override Expr getBranch(int n) {
+  final override AstNode getBranch(int n) {
    toGenerated(result) = g.getClauses(n)
    or
    n = count(g.getClauses(_)) and toGenerated(result) = g.getElse()
--- a/ruby/ql/lib/codeql/ruby/controlflow/CfgNodes.qll
+++ b/ruby/ql/lib/codeql/ruby/controlflow/CfgNodes.qll
@@ -338,7 +338,7 @@ module ExprNodes {
  }

  private class CaseExprChildMapping extends ExprChildMapping, CaseExpr {
-    override predicate relevantChild(Expr e) { e = this.getValue() or e = this.getBranch(_) }
+    override predicate relevantChild(Expr e) { e = this.getValue() }
  }

  /** A control-flow node that wraps a `MethodCall` AST expression. */
@@ -356,11 +356,6 @@ module ExprNodes {

    /** Gets the expression being compared, if any. */
    final ExprCfgNode getValue() { e.hasCfgChild(e.getValue(), this, result) }
-
-    /**
-     * Gets the `n`th branch of this case expression.
-     */
-    final ExprCfgNode getBranch(int n) { e.hasCfgChild(e.getBranch(n), this, result) }
  }

  private class ConditionalExprChildMapping extends ExprChildMapping, ConditionalExpr {
--- a/ruby/ql/lib/codeql/ruby/controlflow/internal/Completion.qll
+++ b/ruby/ql/lib/codeql/ruby/controlflow/internal/Completion.qll
@@ -107,11 +107,7 @@ abstract class Completion extends TCompletion {
    n = any(RescueModifierExpr parent).getBody() and
    this = [TSimpleCompletion().(TCompletion), TRaiseCompletion()]
    or
-    (
-      mayRaise(n)
-      or
-      n instanceof CaseMatch and not exists(n.(CaseExpr).getElseBranch())
-    ) and
+    mayRaise(n) and
    (
      this = TRaiseCompletion()
      or
@@ -209,7 +205,7 @@ private predicate inBooleanContext(AstNode n) {
  or
  n = any(StmtSequence parent | inBooleanContext(parent)).getLastStmt()
  or
-  exists(CaseExpr c, WhenExpr w |
+  exists(CaseExpr c, WhenClause w |
    not exists(c.getValue()) and
    c.getABranch() = w and
    w.getPattern(_) = n
@@ -231,7 +227,7 @@ private predicate mustHaveMatchingCompletion(AstNode n) {
 private predicate inMatchingContext(AstNode n) {
  n = any(RescueClause r).getException(_)
  or
-  exists(CaseExpr c, WhenExpr w |
+  exists(CaseExpr c, WhenClause w |
    exists(c.getValue()) and
    c.getABranch() = w and
    w.getPattern(_) = n
--- a/ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImpl.qll
+++ b/ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImpl.qll
@@ -107,14 +107,8 @@ module Trees {
    }
  }

-  private class ArgumentListTree extends StandardTree, ArgumentList {
+  private class ArgumentListTree extends StandardPostOrderTree, ArgumentList {
    final override ControlFlowTree getChildElement(int i) { result = this.getElement(i) }
-
-    final override predicate first(AstNode first) { first(this.getFirstChildElement(), first) }
-
-    final override predicate last(AstNode last, Completion c) {
-      last(this.getLastChildElement(), last, c)
-    }
  }

  private class AssignExprTree extends StandardPostOrderTree, AssignExpr {
@@ -252,7 +246,7 @@ module Trees {
      )
      or
      // Last element from any matching `rescue` block continues to the `ensure` block
-      this.getRescue(_).(RescueTree).lastMatch(result, c) and
+      last(this.getRescue(_), result, c) and
      ensurable = true
      or
      // If the last `rescue` block does not match, continue to the `ensure` block
@@ -378,35 +372,18 @@ module Trees {
    override ControlFlowTree getChildElement(int i) { result = this.getArgument(i) }
  }

-  private class CaseTree extends PreOrderTree, CaseExpr, ASTInternal::TCaseExpr {
+  private class CaseTree extends PostOrderTree, CaseExpr, ASTInternal::TCaseExpr {
    final override predicate propagatesAbnormal(AstNode child) {
      child = this.getValue() or child = this.getABranch()
    }

-    final override predicate last(AstNode last, Completion c) {
-      last(this.getValue(), last, c) and not exists(this.getABranch())
+    final override predicate first(AstNode first) {
+      first(this.getValue(), first)
      or
-      last(this.getABranch().(WhenExpr).getBody(), last, c)
-      or
-      exists(int i, ControlFlowTree lastBranch |
-        lastBranch = this.getBranch(i) and
-        not exists(this.getBranch(i + 1)) and
-        last(lastBranch, last, c)
-      )
+      not exists(this.getValue()) and first(this.getBranch(0), first)
    }

    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
-      exists(AstNode next |
-        pred = this and
-        first(next, succ) and
-        c instanceof SimpleCompletion
-      |
-        next = this.getValue()
-        or
-        not exists(this.getValue()) and
-        next = this.getBranch(0)
-      )
-      or
      last(this.getValue(), pred, c) and
      first(this.getBranch(0), succ) and
      c instanceof SimpleCompletion
@@ -416,20 +393,35 @@ module Trees {
        first(this.getBranch(i + 1), succ) and
        c.(ConditionalCompletion).getValue() = false
      )
+      or
+      succ = this and
+      c instanceof NormalCompletion and
+      (
+        last(this.getValue(), pred, c) and not exists(this.getABranch())
+        or
+        last(this.getABranch().(WhenClause).getBody(), pred, c)
+        or
+        exists(int i, ControlFlowTree lastBranch |
+          lastBranch = this.getBranch(i) and
+          not exists(this.getBranch(i + 1)) and
+          last(lastBranch, pred, c)
+        )
+      )
    }
  }

-  private class CaseMatchTree extends PreOrderTree, CaseExpr, ASTInternal::TCaseMatch {
+  private class CaseMatchTree extends PostOrderTree, CaseExpr, ASTInternal::TCaseMatch {
    final override predicate propagatesAbnormal(AstNode child) {
      child = this.getValue() or child = this.getABranch()
    }

+    final override predicate first(AstNode first) { first(this.getValue(), first) }
+
    final override predicate last(AstNode last, Completion c) {
-      last(this.getABranch(), last, c) and
-      not c.(MatchingCompletion).getValue() = false
+      super.last(last, c)
      or
      not exists(this.getElseBranch()) and
-      exists(MatchingCompletion lc, Expr lastBranch |
+      exists(MatchingCompletion lc, AstNode lastBranch |
        lastBranch = max(int i | | this.getBranch(i) order by i) and
        lc.getValue() = false and
        last(lastBranch, last, lc) and
@@ -439,19 +431,24 @@ module Trees {
    }

    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
-      pred = this and
-      first(this.getValue(), succ) and
-      c instanceof SimpleCompletion
-      or
      last(this.getValue(), pred, c) and
      first(this.getBranch(0), succ) and
      c instanceof SimpleCompletion
      or
-      exists(int i, Expr branch | branch = this.getBranch(i) |
+      exists(int i, AstNode branch | branch = this.getBranch(i) |
        last(branch, pred, c) and
        first(this.getBranch(i + 1), succ) and
        c.(MatchingCompletion).getValue() = false
      )
+      or
+      succ = this and
+      c instanceof NormalCompletion and
+      (
+        last(this.getABranch(), pred, c) and
+        not c.(MatchingCompletion).getValue() = false
+        or
+        last(this.getElseBranch(), pred, c)
+      )
    }
  }

@@ -981,6 +978,8 @@ module Trees {
    }
  }

+  private class ForwardedArgumentsTree extends LeafTree, ForwardedArguments { }
+
  private class ForwardParameterTree extends LeafTree, ForwardParameter { }

  private class GlobalVariableTree extends LeafTree, GlobalVariableAccess { }
@@ -993,7 +992,7 @@ module Trees {

  private class HashSplatParameterTree extends NonDefaultValueParameterTree, HashSplatParameter { }

-  private class HereDocTree extends StandardPreOrderTree, HereDoc {
+  private class HereDocTree extends StandardPostOrderTree, HereDoc {
    final override ControlFlowTree getChildElement(int i) { result = this.getComponent(i) }
  }

@@ -1155,90 +1154,70 @@ module Trees {

  private class RedoStmtTree extends LeafTree, RedoStmt { }

-  private class RescueModifierTree extends PreOrderTree, RescueModifierExpr {
+  private class RescueModifierTree extends PostOrderTree, RescueModifierExpr {
    final override predicate propagatesAbnormal(AstNode child) { child = this.getHandler() }

-    final override predicate last(AstNode last, Completion c) {
-      last(this.getBody(), last, c) and
-      not c instanceof RaiseCompletion
-      or
-      last(this.getHandler(), last, c)
-    }
+    final override predicate first(AstNode first) { first(this.getBody(), first) }

    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
-      pred = this and
-      first(this.getBody(), succ) and
-      c instanceof SimpleCompletion
-      or
      last(this.getBody(), pred, c) and
-      c instanceof RaiseCompletion and
-      first(this.getHandler(), succ)
+      (
+        c instanceof RaiseCompletion and
+        first(this.getHandler(), succ)
+        or
+        not c instanceof RaiseCompletion and
+        succ = this
+      )
+      or
+      last(this.getHandler(), pred, c) and
+      c instanceof NormalCompletion and
+      succ = this
    }
  }

-  private class RescueTree extends PreOrderTree, RescueClause {
-    final override predicate propagatesAbnormal(AstNode child) { child = this.getAnException() }
-
-    private Expr getLastException() {
-      exists(int i | result = this.getException(i) and not exists(this.getException(i + 1)))
+  private class RescueTree extends PostOrderTree, RescueClause {
+    final override predicate propagatesAbnormal(AstNode child) {
+      child = this.getAnException() or
+      child = this.getBody()
    }

-    predicate lastMatch(AstNode last, Completion c) {
-      last(this.getBody(), last, c)
+    final override predicate first(AstNode first) {
+      first(this.getException(0), first)
      or
-      not exists(this.getBody()) and
+      not exists(this.getException(0)) and
      (
-        last(this.getVariableExpr(), last, c)
+        first(this.getVariableExpr(), first)
        or
        not exists(this.getVariableExpr()) and
        (
-          last(this.getAnException(), last, c) and
-          c.(MatchingCompletion).getValue() = true
+          first(this.getBody(), first)
          or
-          not exists(this.getAnException()) and
-          last = this and
-          c.isValidFor(this)
+          not exists(this.getBody()) and first = this
        )
      )
    }

+    private Expr getLastException() {
+      exists(int i | result = this.getException(i) and not exists(this.getException(i + 1)))
+    }
+
    predicate lastNoMatch(AstNode last, Completion c) {
      last(this.getLastException(), last, c) and
      c.(MatchingCompletion).getValue() = false
    }

-    final override predicate last(AstNode last, Completion c) {
-      this.lastNoMatch(last, c)
-      or
-      this.lastMatch(last, c)
-    }
-
    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
-      exists(AstNode next |
-        pred = this and
-        first(next, succ) and
-        c instanceof SimpleCompletion
-      |
-        next = this.getException(0)
-        or
-        not exists(this.getException(0)) and
-        (
-          next = this.getVariableExpr()
-          or
-          not exists(this.getVariableExpr()) and
-          next = this.getBody()
-        )
-      )
-      or
-      exists(AstNode next |
-        last(this.getAnException(), pred, c) and
-        first(next, succ) and
-        c.(MatchingCompletion).getValue() = true
-      |
-        next = this.getVariableExpr()
+      last(this.getAnException(), pred, c) and
+      c.(MatchingCompletion).getValue() = true and
+      (
+        first(this.getVariableExpr(), succ)
        or
        not exists(this.getVariableExpr()) and
-        next = this.getBody()
+        (
+          first(this.getBody(), succ)
+          or
+          not exists(this.getBody()) and succ = this
+        )
      )
      or
      exists(int i |
@@ -1248,8 +1227,16 @@ module Trees {
      )
      or
      last(this.getVariableExpr(), pred, c) and
-      first(this.getBody(), succ) and
-      c instanceof NormalCompletion
+      c instanceof NormalCompletion and
+      (
+        first(this.getBody(), succ)
+        or
+        not exists(this.getBody()) and succ = this
+      )
+      or
+      last(this.getBody(), pred, c) and
+      c instanceof NormalCompletion and
+      succ = this
    }
  }

@@ -1353,14 +1340,8 @@ module Trees {
    }
  }

-  private class StringConcatenationTree extends StandardTree, StringConcatenation {
+  private class StringConcatenationTree extends StandardPostOrderTree, StringConcatenation {
    final override ControlFlowTree getChildElement(int i) { result = this.getString(i) }
-
-    final override predicate first(AstNode first) { first(this.getFirstChildElement(), first) }
-
-    final override predicate last(AstNode last, Completion c) {
-      last(this.getLastChildElement(), last, c)
-    }
  }

  private class StringlikeLiteralTree extends StandardPostOrderTree, StringlikeLiteral {
@@ -1389,7 +1370,7 @@ module Trees {
    final override ControlFlowTree getChildElement(int i) { result = this.getMethodName(i) }
  }

-  private class WhenTree extends PreOrderTree, WhenExpr {
+  private class WhenTree extends PreOrderTree, WhenClause {
    final override predicate propagatesAbnormal(AstNode child) { child = this.getAPattern() }

    final Expr getLastPattern() {
--- a/ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll
+++ b/ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll
@@ -126,7 +126,16 @@ module LocalFlow {
    or
    nodeFrom.asExpr() = nodeTo.asExpr().(CfgNodes::ExprNodes::ConditionalExprCfgNode).getBranch(_)
    or
-    nodeFrom.asExpr() = nodeTo.asExpr().(CfgNodes::ExprNodes::CaseExprCfgNode).getBranch(_)
+    exists(CfgNode n, Stmt stmt, CaseExpr c |
+      c = nodeTo.asExpr().getExpr() and
+      n = nodeFrom.asExpr() and
+      n = nodeTo.asExpr().getAPredecessor() and
+      stmt = n.getNode()
+    |
+      stmt = c.getElseBranch() or
+      stmt = c.getABranch().(InClause).getBody() or
+      stmt = c.getABranch().(WhenClause).getBody()
+    )
    or
    exists(CfgNodes::ExprCfgNode exprTo, ReturningStatementNode n |
      nodeFrom = n and
--- a/ruby/ql/test/library-tests/ast/Ast.expected
+++ b/ruby/ql/test/library-tests/ast/Ast.expected
@@ -170,7 +170,7 @@ calls/calls.rb:
 #  106|   getStmt: [CaseExpr] case ...
 #  106|     getValue: [MethodCall] call to foo
 #  106|       getReceiver: [Self, SelfVariableAccess] self
-#  107|     getBranch: [WhenExpr] when ...
+#  107|     getBranch: [WhenClause] when ...
 #  107|       getPattern: [MethodCall] call to bar
 #  107|         getReceiver: [Self, SelfVariableAccess] self
 #  107|       getBody: [StmtSequence] then ...
@@ -179,7 +179,7 @@ calls/calls.rb:
 #  110|   getStmt: [CaseExpr] case ...
 #  110|     getValue: [MethodCall] call to foo
 #  110|       getReceiver: [ConstantReadAccess] X
-#  111|     getBranch: [WhenExpr] when ...
+#  111|     getBranch: [WhenClause] when ...
 #  111|       getPattern: [MethodCall] call to bar
 #  111|         getReceiver: [ConstantReadAccess] X
 #  111|       getBody: [StmtSequence] then ...
@@ -689,11 +689,11 @@ control/cases.rb:
 #    5|     getAnOperand/getRightOperand: [IntegerLiteral] 0
 #    8|   getStmt: [CaseExpr] case ...
 #    8|     getValue: [LocalVariableAccess] a
-#    9|     getBranch: [WhenExpr] when ...
+#    9|     getBranch: [WhenClause] when ...
 #    9|       getPattern: [LocalVariableAccess] b
 #    9|       getBody: [StmtSequence] then ...
 #   10|         getStmt: [IntegerLiteral] 100
-#   11|     getBranch: [WhenExpr] when ...
+#   11|     getBranch: [WhenClause] when ...
 #   11|       getPattern: [LocalVariableAccess] c
 #   11|       getPattern: [LocalVariableAccess] d
 #   11|       getBody: [StmtSequence] then ...
@@ -701,19 +701,19 @@ control/cases.rb:
 #   13|     getBranch/getElseBranch: [StmtSequence] else ...
 #   14|       getStmt: [IntegerLiteral] 300
 #   18|   getStmt: [CaseExpr] case ...
-#   19|     getBranch: [WhenExpr] when ...
+#   19|     getBranch: [WhenClause] when ...
 #   19|       getPattern: [GTExpr] ... > ...
 #   19|         getAnOperand/getGreaterOperand/getLeftOperand/getReceiver: [LocalVariableAccess] a
 #   19|         getAnOperand/getArgument/getLesserOperand/getRightOperand: [LocalVariableAccess] b
 #   19|       getBody: [StmtSequence] then ...
 #   19|         getStmt: [IntegerLiteral] 10
-#   20|     getBranch: [WhenExpr] when ...
+#   20|     getBranch: [WhenClause] when ...
 #   20|       getPattern: [EqExpr] ... == ...
 #   20|         getAnOperand/getLeftOperand/getReceiver: [LocalVariableAccess] a
 #   20|         getAnOperand/getArgument/getRightOperand: [LocalVariableAccess] b
 #   20|       getBody: [StmtSequence] then ...
 #   20|         getStmt: [IntegerLiteral] 20
-#   21|     getBranch: [WhenExpr] when ...
+#   21|     getBranch: [WhenClause] when ...
 #   21|       getPattern: [LTExpr] ... < ...
 #   21|         getAnOperand/getLeftOperand/getLesserOperand/getReceiver: [LocalVariableAccess] a
 #   21|         getAnOperand/getArgument/getGreaterOperand/getRightOperand: [LocalVariableAccess] b
--- a/ruby/ql/test/library-tests/ast/control/CaseExpr.ql
+++ b/ruby/ql/test/library-tests/ast/control/CaseExpr.ql
@@ -10,10 +10,10 @@ query predicate caseElseBranches(CaseExpr c, StmtSequence elseBranch) {

 query predicate caseNoElseBranches(CaseExpr c) { not exists(c.getElseBranch()) }

-query predicate caseWhenBranches(CaseExpr c, WhenExpr when, int pIndex, Expr p, StmtSequence body) {
+query predicate caseWhenBranches(CaseExpr c, WhenClause when, int pIndex, Expr p, StmtSequence body) {
  when = c.getABranch() and
  p = when.getPattern(pIndex) and
  body = when.getBody()
 }

-query predicate caseAllBranches(CaseExpr c, int n, Expr branch) { branch = c.getBranch(n) }
+query predicate caseAllBranches(CaseExpr c, int n, AstNode branch) { branch = c.getBranch(n) }
--- a/ruby/ql/test/library-tests/controlflow/graph/Cfg.expected
+++ b/ruby/ql/test/library-tests/controlflow/graph/Cfg.expected
@@ -486,7 +486,7 @@ break_ensure.rb:

 case.rb:
 #    1| enter if_in_case
-#-----|  -> case ...
+#-----|  -> self

 #    1| enter case.rb
 #-----|  -> if_in_case
@@ -505,7 +505,7 @@ case.rb:
 #-----|  -> exit case.rb

 #    2| case ...
-#-----|  -> self
+#-----|  -> exit if_in_case (normal)

 #    2| call to x1
 #-----|  -> when ...
@@ -521,7 +521,7 @@ case.rb:
 #-----| match -> self

 #    3| then ...
-#-----|  -> exit if_in_case (normal)
+#-----|  -> case ...

 #    3| ( ... )
 #-----|  -> then ...
@@ -552,11 +552,11 @@ case.rb:
 #-----|  -> 2

 #    4| 2
+#-----| no-match -> case ...
 #-----| match -> self
-#-----| no-match -> exit if_in_case (normal)

 #    4| then ...
-#-----|  -> exit if_in_case (normal)
+#-----|  -> case ...

 #    4| call to puts
 #-----|  -> then ...
@@ -579,10 +579,10 @@ case.rb:
 #-----|  -> exit case_match

 #    8| value
-#-----|  -> case ...
+#-----|  -> value

 #    9| case ...
-#-----|  -> value
+#-----|  -> exit case_match (normal)

 #    9| value
 #-----|  -> in ... then ...
@@ -591,8 +591,8 @@ case.rb:
 #-----|  -> 0

 #   10| 0
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match (normal)

 #   11| in ... then ...
 #-----|  -> 1
@@ -602,7 +602,7 @@ case.rb:
 #-----| match -> 3

 #   11| then ...
-#-----|  -> exit case_match (normal)
+#-----|  -> case ...

 #   11| 3
 #-----|  -> then ...
@@ -615,7 +615,7 @@ case.rb:
 #-----| match -> 4

 #   12| then ...
-#-----|  -> exit case_match (normal)
+#-----|  -> case ...

 #   13| 4
 #-----|  -> then ...
@@ -637,7 +637,7 @@ case.rb:
 #-----|  -> ... == ...

 #   14| then ...
-#-----|  -> exit case_match (normal)
+#-----|  -> case ...

 #   14| 6
 #-----|  -> then ...
@@ -659,13 +659,13 @@ case.rb:
 #-----|  -> ... < ...

 #   15| then ...
-#-----|  -> exit case_match (normal)
+#-----|  -> case ...

 #   15| 7
 #-----|  -> then ...

 #   16| else ...
-#-----|  -> exit case_match (normal)
+#-----|  -> case ...

 #   16| 8
 #-----|  -> else ...
@@ -685,10 +685,10 @@ case.rb:
 #-----|  -> exit case_match_no_match

 #   20| value
-#-----|  -> case ...
+#-----|  -> value

 #   21| case ...
-#-----|  -> value
+#-----|  -> exit case_match_no_match (normal)

 #   21| value
 #-----|  -> in ... then ...
@@ -697,8 +697,8 @@ case.rb:
 #-----|  -> 1

 #   22| 1
+#-----| match -> case ...
 #-----| raise -> exit case_match_no_match (abnormal)
-#-----| match -> exit case_match_no_match (normal)

 #   26| enter case_match_raise
 #-----|  -> value
@@ -715,10 +715,10 @@ case.rb:
 #-----|  -> exit case_match_raise

 #   26| value
-#-----|  -> case ...
+#-----|  -> value

 #   27| case ...
-#-----|  -> value
+#-----|  -> exit case_match_raise (normal)

 #   27| value
 #-----|  -> in ... then ...
@@ -730,8 +730,8 @@ case.rb:
 #-----|  -> x

 #   28| -> { ... }
+#-----| match -> case ...
 #-----| raise -> exit case_match_raise (abnormal)
-#-----| match -> exit case_match_raise (normal)

 #   28| exit -> { ... }

@@ -765,10 +765,10 @@ case.rb:
 #-----|  -> exit case_match_array

 #   32| value
-#-----|  -> case ...
+#-----|  -> value

 #   33| case ...
-#-----|  -> value
+#-----|  -> exit case_match_array (normal)

 #   33| value
 #-----|  -> in ... then ...
@@ -777,8 +777,8 @@ case.rb:
 #-----|  -> [ ..., * ]

 #   34| [ ..., * ]
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_array (normal)

 #   35| in ... then ...
 #-----|  -> [ ..., * ]
@@ -788,7 +788,7 @@ case.rb:
 #-----| match -> x

 #   35| x
-#-----| match -> exit case_match_array (normal)
+#-----| match -> case ...

 #   36| in ... then ...
 #-----|  -> [ ..., * ]
@@ -798,7 +798,7 @@ case.rb:
 #-----| match -> x

 #   36| x
-#-----| match -> exit case_match_array (normal)
+#-----| match -> case ...

 #   37| in ... then ...
 #-----|  -> Bar
@@ -824,7 +824,7 @@ case.rb:
 #-----| match -> e

 #   37| e
-#-----| match -> exit case_match_array (normal)
+#-----| match -> case ...

 #   41| enter case_match_find
 #-----|  -> value
@@ -841,10 +841,10 @@ case.rb:
 #-----|  -> exit case_match_find

 #   41| value
-#-----|  -> case ...
+#-----|  -> value

 #   42| case ...
-#-----|  -> value
+#-----|  -> exit case_match_find (normal)

 #   42| value
 #-----|  -> in ... then ...
@@ -868,7 +868,7 @@ case.rb:
 #-----| raise -> exit case_match_find (abnormal)

 #   43| y
-#-----|  -> exit case_match_find (normal)
+#-----|  -> case ...

 #   47| enter case_match_hash
 #-----|  -> value
@@ -885,10 +885,10 @@ case.rb:
 #-----|  -> exit case_match_hash

 #   47| value
-#-----|  -> case ...
+#-----|  -> value

 #   48| case ...
-#-----|  -> value
+#-----|  -> exit case_match_hash (normal)

 #   48| value
 #-----|  -> in ... then ...
@@ -912,7 +912,7 @@ case.rb:
 #-----| match -> rest

 #   49| rest
-#-----|  -> exit case_match_hash (normal)
+#-----|  -> case ...

 #   50| in ... then ...
 #-----|  -> Bar
@@ -926,15 +926,15 @@ case.rb:
 #-----| no-match -> in ... then ...

 #   50| 1
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_hash (normal)

 #   51| in ... then ...
 #-----|  -> Bar

 #   51| { ..., ** }
+#-----| match -> case ...
 #-----| raise -> exit case_match_hash (abnormal)
-#-----| match -> exit case_match_hash (normal)

 #   51| Bar
 #-----| match -> { ..., ** }
@@ -952,10 +952,10 @@ case.rb:
 #-----|  -> exit case_match_variable

 #   55| value
-#-----|  -> case ...
+#-----|  -> value

 #   56| case ...
-#-----|  -> value
+#-----|  -> exit case_match_variable (normal)

 #   56| value
 #-----|  -> in ... then ...
@@ -964,14 +964,14 @@ case.rb:
 #-----|  -> 5

 #   57| 5
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_variable (normal)

 #   58| in ... then ...
 #-----|  -> var

 #   58| var
-#-----| match -> exit case_match_variable (normal)
+#-----| match -> case ...

 #   63| enter case_match_underscore
 #-----|  -> value
@@ -985,10 +985,10 @@ case.rb:
 #-----|  -> exit case_match_underscore

 #   63| value
-#-----|  -> case ...
+#-----|  -> value

 #   64| case ...
-#-----|  -> value
+#-----|  -> exit case_match_underscore (normal)

 #   64| value
 #-----|  -> in ... then ...
@@ -1000,11 +1000,11 @@ case.rb:
 #-----|  -> 5

 #   65| 5
+#-----| match -> case ...
 #-----| no-match -> _
-#-----| match -> exit case_match_underscore (normal)

 #   65| _
-#-----| match -> exit case_match_underscore (normal)
+#-----| match -> case ...

 #   69| enter case_match_various
 #-----|  -> value
@@ -1024,7 +1024,7 @@ case.rb:
 #-----|  -> foo

 #   70| ... = ...
-#-----|  -> case ...
+#-----|  -> value

 #   70| foo
 #-----|  -> 42
@@ -1033,7 +1033,7 @@ case.rb:
 #-----|  -> ... = ...

 #   72| case ...
-#-----|  -> value
+#-----|  -> exit case_match_various (normal)

 #   72| value
 #-----|  -> in ... then ...
@@ -1042,8 +1042,8 @@ case.rb:
 #-----|  -> 5

 #   73| 5
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   74| in ... then ...
 #-----|  -> ^...
@@ -1052,22 +1052,22 @@ case.rb:
 #-----|  -> foo

 #   74| foo
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   75| in ... then ...
 #-----|  -> "string"

 #   75| "string"
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   76| in ... then ...
 #-----|  -> Array

 #   76| call to []
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   76| Array
 #-----|  -> "foo"
@@ -1082,8 +1082,8 @@ case.rb:
 #-----|  -> Array

 #   77| call to []
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   77| Array
 #-----|  -> :"foo"
@@ -1098,8 +1098,8 @@ case.rb:
 #-----|  -> /.*abc[0-9]/

 #   78| /.*abc[0-9]/
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   79| in ... then ...
 #-----|  -> 5
@@ -1108,8 +1108,8 @@ case.rb:
 #-----|  -> 10

 #   79| _ .. _
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   79| 10
 #-----|  -> _ .. _
@@ -1118,8 +1118,8 @@ case.rb:
 #-----|  -> 10

 #   80| _ .. _
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   80| 10
 #-----|  -> _ .. _
@@ -1131,8 +1131,8 @@ case.rb:
 #-----|  -> _ .. _

 #   81| _ .. _
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   82| in ... then ...
 #-----|  -> ... => ...
@@ -1145,7 +1145,7 @@ case.rb:
 #-----| match -> x

 #   82| x
-#-----|  -> exit case_match_various (normal)
+#-----|  -> case ...

 #   83| in ... then ...
 #-----|  -> ... | ...
@@ -1154,26 +1154,26 @@ case.rb:
 #-----|  -> 5

 #   83| 5
+#-----| match -> case ...
 #-----| no-match -> ^...
-#-----| match -> exit case_match_various (normal)

 #   83| ^...
 #-----|  -> foo

 #   83| foo
+#-----| match -> case ...
 #-----| no-match -> "string"
-#-----| match -> exit case_match_various (normal)

 #   83| "string"
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   84| in ... then ...
 #-----|  -> Foo

 #   84| Bar
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   84| Foo
 #-----|  -> Bar
@@ -1185,8 +1185,8 @@ case.rb:
 #-----|  -> x

 #   85| -> { ... }
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   85| exit -> { ... }

@@ -1209,15 +1209,15 @@ case.rb:
 #-----|  -> :foo

 #   86| :foo
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   87| in ... then ...
 #-----|  -> :"foo bar"

 #   87| :"foo bar"
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   88| in ... then ...
 #-----|  -> ... | ...
@@ -1226,15 +1226,15 @@ case.rb:
 #-----|  -> 5

 #   88| - ...
+#-----| match -> case ...
 #-----| no-match -> 10
-#-----| match -> exit case_match_various (normal)

 #   88| 5
 #-----|  -> - ...

 #   88| + ...
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   88| 10
 #-----|  -> + ...
@@ -1246,32 +1246,32 @@ case.rb:
 #-----|  -> nil

 #   89| nil
+#-----| match -> case ...
 #-----| no-match -> self
-#-----| match -> exit case_match_various (normal)

 #   89| self
+#-----| match -> case ...
 #-----| no-match -> true
-#-----| match -> exit case_match_various (normal)

 #   89| true
+#-----| match -> case ...
 #-----| no-match -> false
-#-----| match -> exit case_match_various (normal)

 #   89| false
+#-----| match -> case ...
 #-----| no-match -> __LINE__
-#-----| match -> exit case_match_various (normal)

 #   89| __LINE__
+#-----| match -> case ...
 #-----| no-match -> __FILE__
-#-----| match -> exit case_match_various (normal)

 #   89| __FILE__
+#-----| match -> case ...
 #-----| no-match -> __ENCODING__
-#-----| match -> exit case_match_various (normal)

 #   89| __ENCODING__
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   90| in ... then ...
 #-----|  -> ( ... )
@@ -1283,8 +1283,8 @@ case.rb:
 #-----|  -> _ .. _

 #   90| _ .. _
+#-----| match -> case ...
 #-----| no-match -> in ... then ...
-#-----| match -> exit case_match_various (normal)

 #   91| in ... then ...
 #-----|  -> ( ... )
@@ -1296,20 +1296,20 @@ case.rb:
 #-----|  -> 0

 #   91| 0
+#-----| match -> case ...
 #-----| no-match -> ""
-#-----| match -> exit case_match_various (normal)

 #   91| ""
 #-----| no-match -> [ ..., * ]
-#-----| match -> exit case_match_various (normal)
+#-----| match -> case ...

 #   91| [ ..., * ]
+#-----| match -> case ...
 #-----| no-match -> { ..., ** }
-#-----| match -> exit case_match_various (normal)

 #   91| { ..., ** }
+#-----| match -> case ...
 #-----| raise -> exit case_match_various (abnormal)
-#-----| match -> exit case_match_various (normal)

 #   95| enter case_match_guard_no_else
 #-----|  -> value
@@ -1326,10 +1326,10 @@ case.rb:
 #-----|  -> exit case_match_guard_no_else

 #   95| value
-#-----|  -> case ...
+#-----|  -> value

 #   96| case ...
-#-----|  -> value
+#-----|  -> exit case_match_guard_no_else (normal)

 #   96| value
 #-----|  -> in ... then ...
@@ -1351,7 +1351,7 @@ case.rb:
 #-----|  -> ... == ...

 #   97| then ...
-#-----|  -> exit case_match_guard_no_else (normal)
+#-----|  -> case ...

 #   97| 6
 #-----|  -> then ...
@@ -1703,7 +1703,7 @@ cfg.rb:
 #-----| false -> if ...

 #   39| call to puts
-#-----|  -> case ...
+#-----|  -> 10

 #   39| self
 #-----|  -> 42
@@ -1712,7 +1712,7 @@ cfg.rb:
 #-----|  -> call to puts

 #   41| case ...
-#-----|  -> 10
+#-----|  -> when ...

 #   41| 10
 #-----|  -> when ...
@@ -1776,7 +1776,7 @@ cfg.rb:
 #-----|  -> call to puts

 #   47| case ...
-#-----|  -> when ...
+#-----|  -> chained

 #   48| when ...
 #-----|  -> b
@@ -1792,7 +1792,7 @@ cfg.rb:
 #-----|  -> ... == ...

 #   48| then ...
-#-----|  -> chained
+#-----|  -> case ...

 #   48| call to puts
 #-----|  -> then ...
@@ -1817,7 +1817,7 @@ cfg.rb:
 #-----|  -> ... == ...

 #   49| ... > ...
-#-----| false -> chained
+#-----| false -> case ...
 #-----| true -> self

 #   49| b
@@ -1827,7 +1827,7 @@ cfg.rb:
 #-----|  -> ... > ...

 #   49| then ...
-#-----|  -> chained
+#-----|  -> case ...

 #   49| call to puts
 #-----|  -> then ...
@@ -1847,6 +1847,9 @@ cfg.rb:
 #   52| "a"
 #-----|  -> chained

+#   52| "..." "..."
+#-----|  -> ... = ...
+
 #   52| "#{...}"
 #-----|  -> "string"

@@ -1857,7 +1860,7 @@ cfg.rb:
 #-----|  -> #{...}

 #   52| "string"
-#-----|  -> ... = ...
+#-----|  -> "..." "..."

 #   54| ... = ...
 #-----|  -> Silly
@@ -2416,13 +2419,13 @@ cfg.rb:
 #-----|  -> b

 #  108| self
-#-----|  -> <<SQL
+#-----|  -> table

 #  108| ( ... )
 #-----|  -> call to puts

 #  108| <<SQL
-#-----|  -> table
+#-----|  -> ( ... )

 #  109| #{...}
 #-----|  -> type
@@ -2431,7 +2434,7 @@ cfg.rb:
 #-----|  -> #{...}

 #  110| #{...}
-#-----|  -> ( ... )
+#-----|  -> <<SQL

 #  110| type
 #-----|  -> #{...}
@@ -2641,23 +2644,23 @@ cfg.rb:
 #-----|  -> EmptyModule

 #  134| EmptyModule
-#-----|  -> ... rescue ...
+#-----|  -> 1

 #  136| ... / ...
+#-----|  -> ... rescue ...
 #-----| raise -> self
-#-----|  -> __synth__0

 #  136| 1
 #-----|  -> 0

 #  136| ... rescue ...
-#-----|  -> 1
+#-----|  -> __synth__0

 #  136| 0
 #-----|  -> ... / ...

 #  136| call to puts
-#-----|  -> __synth__0
+#-----|  -> ... rescue ...

 #  136| self
 #-----|  -> "div by zero"
@@ -2704,6 +2707,9 @@ cfg.rb:
 #  138| __synth__0
 #-----|  -> -1

+#  138| ..., ...
+#-----|  -> * ...
+
 #  138| 1
 #-----|  -> 2

@@ -2720,7 +2726,7 @@ cfg.rb:
 #-----|  -> 3

 #  138| 3
-#-----|  -> * ...
+#-----|  -> ..., ...

 #  140| M
 #-----|  -> Constant
@@ -3270,6 +3276,9 @@ cfg.rb:
 #-----|  -> b

 #  197| b
+#-----|  -> ...
+
+#  197| ...
 #-----|  -> call to bar

 desugar.rb:
@@ -4905,7 +4914,7 @@ raise.rb:
 #-----| true -> self

 #   17| call to raise
-#-----| raise -> rescue ...
+#-----| raise -> ExceptionA

 #   17| self
 #-----|  -> ExceptionA
@@ -4914,14 +4923,14 @@ raise.rb:
 #-----|  -> call to raise

 #   19| rescue ...
-#-----|  -> ExceptionA
+#-----|  -> self

 #   19| ExceptionA
 #-----| match -> self
 #-----| raise -> exit m2 (abnormal)

 #   19| then ...
-#-----|  -> self
+#-----|  -> rescue ...

 #   20| call to puts
 #-----|  -> then ...
@@ -4963,7 +4972,7 @@ raise.rb:
 #-----| true -> self

 #   28| call to raise
-#-----| raise -> rescue ...
+#-----| raise -> self

 #   28| self
 #-----|  -> ExceptionA
@@ -4975,7 +4984,7 @@ raise.rb:
 #-----|  -> self

 #   30| then ...
-#-----|  -> self
+#-----|  -> rescue ...

 #   31| call to puts
 #-----|  -> then ...
@@ -5017,7 +5026,7 @@ raise.rb:
 #-----| true -> self

 #   39| call to raise
-#-----| raise -> rescue ...
+#-----| raise -> e

 #   39| self
 #-----|  -> ExceptionA
@@ -5026,13 +5035,13 @@ raise.rb:
 #-----|  -> call to raise

 #   41| rescue ...
-#-----|  -> e
+#-----|  -> self

 #   41| e
 #-----|  -> self

 #   41| then ...
-#-----|  -> self
+#-----|  -> rescue ...

 #   42| call to puts
 #-----|  -> then ...
@@ -5074,7 +5083,7 @@ raise.rb:
 #-----| true -> self

 #   50| call to raise
-#-----| raise -> rescue ...
+#-----| raise -> e

 #   50| self
 #-----|  -> ExceptionA
@@ -5083,10 +5092,10 @@ raise.rb:
 #-----|  -> call to raise

 #   52| rescue ...
-#-----|  -> e
+#-----|  -> self

 #   52| e
-#-----|  -> self
+#-----|  -> rescue ...

 #   54| call to puts
 #-----|  -> exit m5 (normal)
@@ -5122,7 +5131,7 @@ raise.rb:
 #-----| true -> self

 #   60| call to raise
-#-----| raise -> rescue ...
+#-----| raise -> ExceptionA

 #   60| self
 #-----|  -> ExceptionA
@@ -5131,7 +5140,7 @@ raise.rb:
 #-----|  -> call to raise

 #   62| rescue ...
-#-----|  -> ExceptionA
+#-----|  -> self

 #   62| ExceptionA
 #-----| no-match -> ExceptionB
@@ -5145,7 +5154,7 @@ raise.rb:
 #-----|  -> self

 #   62| then ...
-#-----|  -> self
+#-----|  -> rescue ...

 #   63| call to puts
 #-----|  -> then ...
@@ -5804,7 +5813,7 @@ raise.rb:
 #-----| true -> self

 #  131| call to raise
-#-----| raise -> rescue ...
+#-----| raise -> ExceptionA

 #  131| self
 #-----|  -> ExceptionA
@@ -5813,21 +5822,21 @@ raise.rb:
 #-----|  -> call to raise

 #  133| rescue ...
-#-----|  -> ExceptionA
+#-----|  -> self

 #  133| ExceptionA
-#-----| no-match -> rescue ...
-#-----| match -> self
+#-----| match -> rescue ...
+#-----| no-match -> ExceptionB

 #  134| rescue ...
-#-----|  -> ExceptionB
+#-----|  -> self

 #  134| ExceptionB
 #-----| match -> self
 #-----| raise -> [ensure: raise] self

 #  134| then ...
-#-----|  -> self
+#-----|  -> rescue ...

 #  135| call to puts
 #-----|  -> then ...
--- a/ruby/ql/test/library-tests/controlflow/graph/Nodes.expected
+++ b/ruby/ql/test/library-tests/controlflow/graph/Nodes.expected
@@ -191,6 +191,7 @@ positionalArguments
 | cfg.rb:191:3:191:10 | yield ... | cfg.rb:191:9:191:10 | 42 |
 | cfg.rb:194:16:194:21 | call to puts | cfg.rb:194:21:194:21 | x |
 | cfg.rb:197:3:197:13 | call to bar | cfg.rb:197:7:197:7 | b |
+| cfg.rb:197:3:197:13 | call to bar | cfg.rb:197:10:197:12 | ... |
 | desugar.rb:2:5:2:6 | ... + ... | desugar.rb:2:8:2:8 | 1 |
 | desugar.rb:6:3:6:13 | call to count= | desugar.rb:6:3:6:13 | ... = ... |
 | desugar.rb:10:3:10:10 | call to []= | desugar.rb:10:3:10:10 | ... = ... |
--- a/ruby/ql/test/library-tests/dataflow/local/DataflowStep.expected
+++ b/ruby/ql/test/library-tests/dataflow/local/DataflowStep.expected
@@ -70,3 +70,33 @@
 | local_dataflow.rb:50:18:50:18 | [post] x | local_dataflow.rb:51:20:51:20 | x |
 | local_dataflow.rb:50:18:50:18 | x | local_dataflow.rb:51:20:51:20 | x |
 | local_dataflow.rb:51:9:51:15 | "break" | local_dataflow.rb:51:3:51:15 | break |
+| local_dataflow.rb:60:15:60:15 | x | local_dataflow.rb:60:15:60:15 | x |
+| local_dataflow.rb:60:15:60:15 | x | local_dataflow.rb:61:12:61:12 | x |
+| local_dataflow.rb:61:7:68:5 | case ... | local_dataflow.rb:61:3:68:5 | ... = ... |
+| local_dataflow.rb:61:12:61:12 | x | local_dataflow.rb:63:15:63:15 | x |
+| local_dataflow.rb:61:12:61:12 | x | local_dataflow.rb:65:6:65:6 | x |
+| local_dataflow.rb:61:12:61:12 | x | local_dataflow.rb:67:5:67:5 | x |
+| local_dataflow.rb:61:12:61:12 | x | local_dataflow.rb:69:12:69:12 | x |
+| local_dataflow.rb:62:10:62:15 | then ... | local_dataflow.rb:61:7:68:5 | case ... |
+| local_dataflow.rb:62:15:62:15 | 3 | local_dataflow.rb:62:10:62:15 | then ... |
+| local_dataflow.rb:63:10:63:15 | then ... | local_dataflow.rb:61:7:68:5 | case ... |
+| local_dataflow.rb:63:15:63:15 | x | local_dataflow.rb:63:10:63:15 | then ... |
+| local_dataflow.rb:63:15:63:15 | x | local_dataflow.rb:69:12:69:12 | x |
+| local_dataflow.rb:64:9:65:6 | then ... | local_dataflow.rb:61:7:68:5 | case ... |
+| local_dataflow.rb:65:6:65:6 | x | local_dataflow.rb:64:9:65:6 | then ... |
+| local_dataflow.rb:65:6:65:6 | x | local_dataflow.rb:69:12:69:12 | x |
+| local_dataflow.rb:66:3:67:5 | else ... | local_dataflow.rb:61:7:68:5 | case ... |
+| local_dataflow.rb:67:5:67:5 | x | local_dataflow.rb:66:3:67:5 | else ... |
+| local_dataflow.rb:67:5:67:5 | x | local_dataflow.rb:69:12:69:12 | x |
+| local_dataflow.rb:69:7:76:5 | case ... | local_dataflow.rb:69:3:76:5 | ... = ... |
+| local_dataflow.rb:69:12:69:12 | x | local_dataflow.rb:71:13:71:13 | x |
+| local_dataflow.rb:69:12:69:12 | x | local_dataflow.rb:73:7:73:7 | x |
+| local_dataflow.rb:69:12:69:12 | x | local_dataflow.rb:75:6:75:6 | x |
+| local_dataflow.rb:70:8:70:13 | then ... | local_dataflow.rb:69:7:76:5 | case ... |
+| local_dataflow.rb:70:13:70:13 | 4 | local_dataflow.rb:70:8:70:13 | then ... |
+| local_dataflow.rb:71:8:71:13 | then ... | local_dataflow.rb:69:7:76:5 | case ... |
+| local_dataflow.rb:71:13:71:13 | x | local_dataflow.rb:71:8:71:13 | then ... |
+| local_dataflow.rb:72:7:73:7 | then ... | local_dataflow.rb:69:7:76:5 | case ... |
+| local_dataflow.rb:73:7:73:7 | x | local_dataflow.rb:72:7:73:7 | then ... |
+| local_dataflow.rb:74:3:75:6 | else ... | local_dataflow.rb:69:7:76:5 | case ... |
+| local_dataflow.rb:75:6:75:6 | x | local_dataflow.rb:74:3:75:6 | else ... |
--- a/ruby/ql/test/library-tests/dataflow/local/Nodes.expected
+++ b/ruby/ql/test/library-tests/dataflow/local/Nodes.expected
@@ -12,6 +12,7 @@ ret
 | local_dataflow.rb:50:3:50:13 | next |
 | local_dataflow.rb:51:3:51:15 | break |
 | local_dataflow.rb:52:3:52:10 | "normal" |
+| local_dataflow.rb:69:3:76:5 | ... = ... |
 arg
 | local_dataflow.rb:3:8:3:10 | self | local_dataflow.rb:3:8:3:10 | call to p | -1 |
 | local_dataflow.rb:3:10:3:10 | a | local_dataflow.rb:3:8:3:10 | call to p | 0 |
--- a/ruby/ql/test/library-tests/dataflow/local/local_dataflow.rb
+++ b/ruby/ql/test/library-tests/dataflow/local/local_dataflow.rb
@@ -56,3 +56,23 @@ foo([1, 2, 3])

 def foo x
 end
+
+def test_case x
+  y = case x
+  when 1 then 3
+  when 2 then x
+  when 3
+     x
+  else
+    x
+  end
+  z = case x
+  in 1 then 4
+  in 2 then x
+  in 3
+      x
+  else
+     x
+  end
+end
+