From 79bb20b31f56d0b731ccf7cd11fc592e58cd67d2 Mon Sep 17 00:00:00 2001
From: Arthur Baars <aibaars@github.com>
Date: Mon, 22 Feb 2021 12:31:11 +0100
Subject: [PATCH] AST: add MethodCall as a subclass of Call

---
 ql/src/codeql_ruby/ast/Call.qll               | 66 +++++++++++--------
 ql/src/codeql_ruby/ast/internal/Call.qll      | 36 +++++-----
 ql/src/codeql_ruby/controlflow/CfgNodes.qll   |  6 +-
 .../codeql_ruby/dataflow/internal/SsaImpl.qll |  4 +-
 .../queries/variables/UninitializedLocal.ql   |  2 +-
 .../library-tests/ast/calls/calls.expected    | 10 +--
 ql/test/library-tests/ast/calls/calls.ql      | 12 ++--
 .../ast/literals/literals.expected            |  8 +--
 .../ast/modules/classes.expected              |  2 +-
 .../ast/modules/modules.expected              | 10 +--
 .../ast/modules/singleton_classes.expected    |  2 +-
 .../controlflow/graph/Cfg.expected            |  4 +-
 12 files changed, 89 insertions(+), 73 deletions(-)

diff --git a/ql/src/codeql_ruby/ast/Call.qll b/ql/src/codeql_ruby/ast/Call.qll
index c360677c065..522b19aa8e9 100644
--- a/ql/src/codeql_ruby/ast/Call.qll
+++ b/ql/src/codeql_ruby/ast/Call.qll
@@ -9,32 +9,6 @@ class Call extends Expr {
 
   override string getAPrimaryQlClass() { result = "Call" }
 
-  /**
-   * Gets the receiver of this call, if any. For example:
-   *
-   * ```rb
-   * foo.bar
-   * Baz::qux
-   * corge()
-   * ```
-   *
-   * The result for the call to `bar` is the `Expr` for `foo`; the result for
-   * the call to `qux` is the `Expr` for `Baz`; for the call to `corge` there
-   * is no result.
-   */
-  final Expr getReceiver() { result = range.getReceiver() }
-
-  /**
-   * Gets the name of the method being called. For example, in:
-   *
-   * ```rb
-   * foo.bar x, y
-   * ```
-   *
-   * the result is `"bar"`.
-   */
-  final string getMethodName() { result = range.getMethodName() }
-
   /**
    * Gets the `n`th argument of this method call. In the following example, the
    * result for n=0 is the `IntegerLiteral` 0, while for n=1 the result is a
@@ -44,6 +18,7 @@ class Call extends Expr {
    * `getKeywordArgument(string keyword)` predicate.
    * ```rb
    * foo(0, bar: 1)
+   * yield 0, bar: 1
    * ```
    */
   final Expr getArgument(int n) { result = range.getArgument(n) }
@@ -73,6 +48,41 @@ class Call extends Expr {
    * Gets the number of arguments of this method call.
    */
   final int getNumberOfArguments() { result = count(this.getAnArgument()) }
+}
+
+/**
+ * A method call.
+ */
+class MethodCall extends Call {
+  override MethodCall::Range range;
+
+  override string getAPrimaryQlClass() { result = "MethodCall" }
+
+  /**
+   * Gets the receiver of this call, if any. For example:
+   *
+   * ```rb
+   * foo.bar
+   * Baz::qux
+   * corge()
+   * ```
+   *
+   * The result for the call to `bar` is the `Expr` for `foo`; the result for
+   * the call to `qux` is the `Expr` for `Baz`; for the call to `corge` there
+   * is no result.
+   */
+  final Expr getReceiver() { result = range.getReceiver() }
+
+  /**
+   * Gets the name of the method being called. For example, in:
+   *
+   * ```rb
+   * foo.bar x, y
+   * ```
+   *
+   * the result is `"bar"`.
+   */
+  final string getMethodName() { result = range.getMethodName() }
 
   /**
    * Gets the block of this method call, if any.
@@ -89,7 +99,7 @@ class Call extends Expr {
  * a[0]
  * ```
  */
-class ElementReference extends Call, @element_reference {
+class ElementReference extends MethodCall, @element_reference {
   final override ElementReference::Range range;
 
   final override string getAPrimaryQlClass() { result = "ElementReference" }
@@ -117,7 +127,7 @@ class YieldCall extends Call, @yield {
  * end
  * ```
  */
-class SuperCall extends Call {
+class SuperCall extends MethodCall {
   final override SuperCall::Range range;
 
   final override string getAPrimaryQlClass() { result = "SuperCall" }
diff --git a/ql/src/codeql_ruby/ast/internal/Call.qll b/ql/src/codeql_ruby/ast/internal/Call.qll
index 595d25f5944..dc95bdaeea9 100644
--- a/ql/src/codeql_ruby/ast/internal/Call.qll
+++ b/ql/src/codeql_ruby/ast/internal/Call.qll
@@ -6,26 +6,34 @@ private import codeql_ruby.ast.internal.Variable
 
 module Call {
   abstract class Range extends Expr::Range {
+    abstract Expr getArgument(int n);
+
+    override predicate child(string label, AstNode::Range child) {
+      label = "getArgument" and child = getArgument(_)
+    }
+  }
+}
+
+module MethodCall {
+  abstract class Range extends Call::Range {
+    abstract Block getBlock();
+
     abstract Expr getReceiver();
 
     abstract string getMethodName();
 
-    abstract Expr getArgument(int n);
-
-    abstract Block getBlock();
-
     override string toString() { result = "call to " + this.getMethodName() }
 
     final override predicate child(string label, AstNode::Range child) {
-      label = "getReceiver" and child = getReceiver()
+      super.child(label, child)
       or
-      label = "getArgument" and child = getArgument(_)
+      label = "getReceiver" and child = getReceiver()
       or
       label = "getBlock" and child = getBlock()
     }
   }
 
-  private class IdentifierCallRange extends Call::Range, @token_identifier {
+  private class IdentifierCallRange extends MethodCall::Range, @token_identifier {
     final override Generated::Identifier generated;
 
     IdentifierCallRange() { vcall(this) and not access(this, _) }
@@ -39,7 +47,7 @@ module Call {
     final override Block getBlock() { none() }
   }
 
-  private class ScopeResolutionIdentifierCallRange extends Call::Range, @scope_resolution {
+  private class ScopeResolutionIdentifierCallRange extends MethodCall::Range, @scope_resolution {
     final override Generated::ScopeResolution generated;
     Generated::Identifier identifier;
 
@@ -57,7 +65,7 @@ module Call {
     final override Block getBlock() { none() }
   }
 
-  private class RegularCallRange extends Call::Range, @call {
+  private class RegularCallRange extends MethodCall::Range, @call {
     final override Generated::Call generated;
 
     final override Expr getReceiver() {
@@ -88,7 +96,7 @@ module Call {
 }
 
 module ElementReference {
-  class Range extends Call::Range, @element_reference {
+  class Range extends MethodCall::Range, @element_reference {
     final override Generated::ElementReference generated;
 
     final override Expr getReceiver() { result = generated.getObject() }
@@ -107,18 +115,14 @@ module YieldCall {
   class Range extends Call::Range, @yield {
     final override Generated::Yield generated;
 
-    final override Expr getReceiver() { none() }
-
-    final override string getMethodName() { result = "yield" }
-
     final override Expr getArgument(int n) { result = generated.getChild().getChild(n) }
 
-    final override Block getBlock() { none() }
+    final override string toString() { result = "yield ..." }
   }
 }
 
 module SuperCall {
-  abstract class Range extends Call::Range { }
+  abstract class Range extends MethodCall::Range { }
 
   private class SuperTokenCallRange extends SuperCall::Range, @token_super {
     final override Generated::Super generated;
diff --git a/ql/src/codeql_ruby/controlflow/CfgNodes.qll b/ql/src/codeql_ruby/controlflow/CfgNodes.qll
index 2258f02c28b..7f310b86bb1 100644
--- a/ql/src/codeql_ruby/controlflow/CfgNodes.qll
+++ b/ql/src/codeql_ruby/controlflow/CfgNodes.qll
@@ -247,7 +247,9 @@ module ExprNodes {
   }
 
   private class CallExprChildMapping extends ExprChildMapping, Call {
-    override predicate relevantChild(Expr e) { e = [this.getAnArgument(), this.getReceiver()] }
+    override predicate relevantChild(Expr e) {
+      e = [this.getAnArgument(), this.(MethodCall).getReceiver()]
+    }
   }
 
   /** A control-flow node that wraps a `Call` AST expression. */
@@ -260,7 +262,7 @@ module ExprNodes {
     final ExprCfgNode getArgument(int n) { e.hasCfgChild(e.getArgument(n), this, result) }
 
     /** Gets the receiver of this call. */
-    final ExprCfgNode getReceiver() { e.hasCfgChild(e.getReceiver(), this, result) }
+    final ExprCfgNode getReceiver() { e.hasCfgChild(e.(MethodCall).getReceiver(), this, result) }
   }
 
   private class CaseExprChildMapping extends ExprChildMapping, CaseExpr {
diff --git a/ql/src/codeql_ruby/dataflow/internal/SsaImpl.qll b/ql/src/codeql_ruby/dataflow/internal/SsaImpl.qll
index 3f7d066ad83..f8d4671e563 100644
--- a/ql/src/codeql_ruby/dataflow/internal/SsaImpl.qll
+++ b/ql/src/codeql_ruby/dataflow/internal/SsaImpl.qll
@@ -89,7 +89,7 @@ private predicate capturedCallRead(BasicBlock bb, int i, LocalVariable v) {
     or
     // If the read happens inside a block, we restrict to the call that
     // contains the block
-    scope = any(Call c | bb.getNode(i) = c.getAControlFlowNode()).getBlock()
+    scope = any(MethodCall c | bb.getNode(i) = c.getAControlFlowNode()).getBlock()
   )
 }
 
@@ -146,7 +146,7 @@ private module Cached {
       or
       // If the write happens inside a block, we restrict to the call that
       // contains the block
-      scope = any(Call c | bb.getNode(i) = c.getAControlFlowNode()).getBlock()
+      scope = any(MethodCall c | bb.getNode(i) = c.getAControlFlowNode()).getBlock()
     )
   }
 
diff --git a/ql/src/queries/variables/UninitializedLocal.ql b/ql/src/queries/variables/UninitializedLocal.ql
index 081ab771b7b..2b4f4511a10 100644
--- a/ql/src/queries/variables/UninitializedLocal.ql
+++ b/ql/src/queries/variables/UninitializedLocal.ql
@@ -15,7 +15,7 @@ import codeql_ruby.dataflow.SSA
 
 class RelevantLocalVariableReadAccess extends LocalVariableReadAccess {
   RelevantLocalVariableReadAccess() {
-    not exists(Call c |
+    not exists(MethodCall c |
       c.getReceiver() = this and
       c.getMethodName() = "nil?"
     )
diff --git a/ql/test/library-tests/ast/calls/calls.expected b/ql/test/library-tests/ast/calls/calls.expected
index 6ba250f77dc..48d1a4389cd 100644
--- a/ql/test/library-tests/ast/calls/calls.expected
+++ b/ql/test/library-tests/ast/calls/calls.expected
@@ -1,7 +1,7 @@
 callsWithNoReceiverArgumentsOrBlock
 | calls.rb:2:1:2:5 | call to foo | foo |
 | calls.rb:8:1:8:7 | call to bar | bar |
-| calls.rb:31:3:31:7 | call to yield | yield |
+| calls.rb:31:3:31:7 | yield ... | (none) |
 | calls.rb:46:1:46:3 | call to foo | foo |
 | calls.rb:50:2:50:4 | call to foo | foo |
 | calls.rb:54:11:54:13 | call to foo | foo |
@@ -82,8 +82,8 @@ callsWithArguments
 | calls.rb:14:1:14:11 | call to foo | foo | 1 | calls.rb:14:8:14:8 | 1 |
 | calls.rb:14:1:14:11 | call to foo | foo | 2 | calls.rb:14:11:14:11 | 2 |
 | calls.rb:25:1:27:3 | call to bar | bar | 0 | calls.rb:25:9:25:13 | "foo" |
-| calls.rb:36:3:36:16 | call to yield | yield | 0 | calls.rb:36:9:36:11 | 100 |
-| calls.rb:36:3:36:16 | call to yield | yield | 1 | calls.rb:36:14:36:16 | 200 |
+| calls.rb:36:3:36:16 | yield ... | (none) | 0 | calls.rb:36:9:36:11 | 100 |
+| calls.rb:36:3:36:16 | yield ... | (none) | 1 | calls.rb:36:14:36:16 | 200 |
 | calls.rb:54:1:54:14 | call to some_func | some_func | 0 | calls.rb:54:11:54:13 | call to foo |
 | calls.rb:55:1:55:17 | call to some_func | some_func | 0 | calls.rb:55:11:55:16 | call to foo |
 | calls.rb:234:1:234:8 | ...[...] | [] | 0 | calls.rb:234:5:234:7 | call to bar |
@@ -195,8 +195,8 @@ callsWithBlock
 | calls.rb:292:5:292:30 | call to super | calls.rb:292:16:292:30 | { ... } |
 | calls.rb:293:5:293:33 | call to super | calls.rb:293:16:293:33 | do ... end |
 yieldCalls
-| calls.rb:31:3:31:7 | call to yield |
-| calls.rb:36:3:36:16 | call to yield |
+| calls.rb:31:3:31:7 | yield ... |
+| calls.rb:36:3:36:16 | yield ... |
 superCalls
 | calls.rb:286:5:286:9 | call to super |
 | calls.rb:287:5:287:11 | call to super |
diff --git a/ql/test/library-tests/ast/calls/calls.ql b/ql/test/library-tests/ast/calls/calls.ql
index f49874f8ed0..fa771eb3e32 100644
--- a/ql/test/library-tests/ast/calls/calls.ql
+++ b/ql/test/library-tests/ast/calls/calls.ql
@@ -2,16 +2,16 @@ import ruby
 import codeql_ruby.ast.internal.TreeSitter
 
 private string getMethodName(Call c) {
-  result = c.getMethodName()
+  result = c.(MethodCall).getMethodName()
   or
-  not exists(c.getMethodName()) and result = "(none)"
+  not c instanceof MethodCall and result = "(none)"
 }
 
 query predicate callsWithNoReceiverArgumentsOrBlock(Call c, string name) {
   name = getMethodName(c) and
-  not exists(c.getReceiver()) and
+  not exists(c.(MethodCall).getReceiver()) and
   not exists(c.getAnArgument()) and
-  not exists(c.getBlock())
+  not exists(c.(MethodCall).getBlock())
 }
 
 query predicate callsWithArguments(Call c, string name, int n, Expr argN) {
@@ -19,9 +19,9 @@ query predicate callsWithArguments(Call c, string name, int n, Expr argN) {
   argN = c.getArgument(n)
 }
 
-query predicate callsWithReceiver(Call c, Expr rcv) { rcv = c.getReceiver() }
+query predicate callsWithReceiver(MethodCall c, Expr rcv) { rcv = c.getReceiver() }
 
-query predicate callsWithBlock(Call c, Block b) { b = c.getBlock() }
+query predicate callsWithBlock(MethodCall c, Block b) { b = c.getBlock() }
 
 query predicate yieldCalls(YieldCall c) { any() }
 
diff --git a/ql/test/library-tests/ast/literals/literals.expected b/ql/test/library-tests/ast/literals/literals.expected
index 522bdb32ab5..94252726bef 100644
--- a/ql/test/library-tests/ast/literals/literals.expected
+++ b/ql/test/library-tests/ast/literals/literals.expected
@@ -534,7 +534,7 @@ stringInterpolations
 | literals.rb:64:11:64:20 | #{...} | 0 | literals.rb:64:14:64:18 | ... * ... | MulExpr |
 | literals.rb:65:6:65:30 | #{...} | 0 | literals.rb:65:9:65:28 | "bar #{...} baz" | StringLiteral |
 | literals.rb:65:14:65:23 | #{...} | 0 | literals.rb:65:17:65:21 | ... + ... | AddExpr |
-| literals.rb:66:6:66:21 | #{...} | 0 | literals.rb:66:9:66:14 | call to blah | Call |
+| literals.rb:66:6:66:21 | #{...} | 0 | literals.rb:66:9:66:14 | call to blah | MethodCall |
 | literals.rb:66:6:66:21 | #{...} | 1 | literals.rb:66:17:66:19 | ... + ... | AddExpr |
 | literals.rb:87:7:87:15 | #{...} | 0 | literals.rb:87:10:87:14 | ... + ... | AddExpr |
 | literals.rb:101:11:101:16 | #{...} | 0 | literals.rb:101:13:101:15 | ... + ... | AddExpr |
@@ -543,9 +543,9 @@ stringInterpolations
 | literals.rb:129:10:129:19 | #{...} | 0 | literals.rb:129:13:129:17 | ... - ... | SubExpr |
 | literals.rb:136:5:136:14 | #{...} | 0 | literals.rb:136:8:136:12 | ... + ... | AddExpr |
 | literals.rb:142:7:142:16 | #{...} | 0 | literals.rb:142:10:142:14 | ... + ... | AddExpr |
-| literals.rb:154:14:154:22 | #{...} | 0 | literals.rb:154:17:154:20 | call to name | Call |
-| literals.rb:168:12:168:29 | #{...} | 0 | literals.rb:168:15:168:27 | call to interpolation | Call |
-| literals.rb:173:15:173:32 | #{...} | 0 | literals.rb:173:18:173:30 | call to interpolation | Call |
+| literals.rb:154:14:154:22 | #{...} | 0 | literals.rb:154:17:154:20 | call to name | MethodCall |
+| literals.rb:168:12:168:29 | #{...} | 0 | literals.rb:168:15:168:27 | call to interpolation | MethodCall |
+| literals.rb:173:15:173:32 | #{...} | 0 | literals.rb:173:18:173:30 | call to interpolation | MethodCall |
 concatenatedStrings
 | literals.rb:62:1:62:17 | "..." "..." | foobarbaz | 0 | literals.rb:62:1:62:5 | "foo" |
 | literals.rb:62:1:62:17 | "..." "..." | foobarbaz | 1 | literals.rb:62:7:62:11 | "bar" |
diff --git a/ql/test/library-tests/ast/modules/classes.expected b/ql/test/library-tests/ast/modules/classes.expected
index 49afd7ee415..9eb7604f0df 100644
--- a/ql/test/library-tests/ast/modules/classes.expected
+++ b/ql/test/library-tests/ast/modules/classes.expected
@@ -17,7 +17,7 @@ classesWithGlobalNameScopeExprs
 exprsInClasses
 | classes.rb:20:1:37:3 | Wibble | 0 | classes.rb:21:3:23:5 | method_a | Method |
 | classes.rb:20:1:37:3 | Wibble | 1 | classes.rb:25:3:27:5 | method_b | Method |
-| classes.rb:20:1:37:3 | Wibble | 2 | classes.rb:29:3:29:20 | call to some_method_call | Call |
+| classes.rb:20:1:37:3 | Wibble | 2 | classes.rb:29:3:29:20 | call to some_method_call | MethodCall |
 | classes.rb:20:1:37:3 | Wibble | 3 | classes.rb:30:3:30:19 | ... = ... | AssignExpr |
 | classes.rb:20:1:37:3 | Wibble | 4 | classes.rb:32:3:33:5 | ClassInWibble | Class |
 | classes.rb:20:1:37:3 | Wibble | 5 | classes.rb:35:3:36:5 | ModuleInWibble | Module |
diff --git a/ql/test/library-tests/ast/modules/modules.expected b/ql/test/library-tests/ast/modules/modules.expected
index 14569cf827c..b21ae05c813 100644
--- a/ql/test/library-tests/ast/modules/modules.expected
+++ b/ql/test/library-tests/ast/modules/modules.expected
@@ -16,23 +16,23 @@ exprsInModules
 | modules.rb:4:1:24:3 | Foo | 0 | modules.rb:5:3:14:5 | Bar | Module |
 | modules.rb:4:1:24:3 | Foo | 1 | modules.rb:16:3:17:5 | method_in_foo | Method |
 | modules.rb:4:1:24:3 | Foo | 2 | modules.rb:19:3:20:5 | ClassInFoo | Class |
-| modules.rb:4:1:24:3 | Foo | 3 | modules.rb:22:3:22:19 | call to puts | Call |
+| modules.rb:4:1:24:3 | Foo | 3 | modules.rb:22:3:22:19 | call to puts | MethodCall |
 | modules.rb:4:1:24:3 | Foo | 4 | modules.rb:23:3:23:17 | ... = ... | AssignExpr |
 | modules.rb:5:3:14:5 | Bar | 0 | modules.rb:6:5:7:7 | ClassInFooBar | Class |
 | modules.rb:5:3:14:5 | Bar | 1 | modules.rb:9:5:10:7 | method_in_foo_bar | Method |
-| modules.rb:5:3:14:5 | Bar | 2 | modules.rb:12:5:12:26 | call to puts | Call |
+| modules.rb:5:3:14:5 | Bar | 2 | modules.rb:12:5:12:26 | call to puts | MethodCall |
 | modules.rb:5:3:14:5 | Bar | 3 | modules.rb:13:5:13:19 | ... = ... | AssignExpr |
 | modules.rb:26:1:35:3 | Foo | 0 | modules.rb:27:3:28:5 | method_in_another_definition_of_foo | Method |
 | modules.rb:26:1:35:3 | Foo | 1 | modules.rb:30:3:31:5 | ClassInAnotherDefinitionOfFoo | Class |
-| modules.rb:26:1:35:3 | Foo | 2 | modules.rb:33:3:33:25 | call to puts | Call |
+| modules.rb:26:1:35:3 | Foo | 2 | modules.rb:33:3:33:25 | call to puts | MethodCall |
 | modules.rb:26:1:35:3 | Foo | 3 | modules.rb:34:3:34:17 | ... = ... | AssignExpr |
 | modules.rb:37:1:46:3 | Bar | 0 | modules.rb:38:3:39:5 | method_a | Method |
 | modules.rb:37:1:46:3 | Bar | 1 | modules.rb:41:3:42:5 | method_b | Method |
-| modules.rb:37:1:46:3 | Bar | 2 | modules.rb:44:3:44:19 | call to puts | Call |
+| modules.rb:37:1:46:3 | Bar | 2 | modules.rb:44:3:44:19 | call to puts | MethodCall |
 | modules.rb:37:1:46:3 | Bar | 3 | modules.rb:45:3:45:17 | ... = ... | AssignExpr |
 | modules.rb:48:1:57:3 | Bar | 0 | modules.rb:49:3:50:5 | ClassInAnotherDefinitionOfFooBar | Class |
 | modules.rb:48:1:57:3 | Bar | 1 | modules.rb:52:3:53:5 | method_in_another_definition_of_foo_bar | Method |
-| modules.rb:48:1:57:3 | Bar | 2 | modules.rb:55:3:55:30 | call to puts | Call |
+| modules.rb:48:1:57:3 | Bar | 2 | modules.rb:55:3:55:30 | call to puts | MethodCall |
 | modules.rb:48:1:57:3 | Bar | 3 | modules.rb:56:3:56:17 | ... = ... | AssignExpr |
 methodsInModules
 | modules.rb:4:1:24:3 | Foo | modules.rb:16:3:17:5 | method_in_foo | method_in_foo |
diff --git a/ql/test/library-tests/ast/modules/singleton_classes.expected b/ql/test/library-tests/ast/modules/singleton_classes.expected
index b7b9ab29966..845afe551e7 100644
--- a/ql/test/library-tests/ast/modules/singleton_classes.expected
+++ b/ql/test/library-tests/ast/modules/singleton_classes.expected
@@ -3,7 +3,7 @@ singletonClasses
 exprsInSingletonClasses
 | classes.rb:41:1:52:3 | class << ... | 0 | classes.rb:42:3:44:5 | length | Method |
 | classes.rb:41:1:52:3 | class << ... | 1 | classes.rb:46:3:48:5 | wibble | Method |
-| classes.rb:41:1:52:3 | class << ... | 2 | classes.rb:50:3:50:21 | call to another_method_call | Call |
+| classes.rb:41:1:52:3 | class << ... | 2 | classes.rb:50:3:50:21 | call to another_method_call | MethodCall |
 | classes.rb:41:1:52:3 | class << ... | 3 | classes.rb:51:3:51:20 | ... = ... | AssignExpr |
 methodsInSingletonClasses
 | classes.rb:41:1:52:3 | class << ... | classes.rb:42:3:44:5 | length |
diff --git a/ql/test/library-tests/controlflow/graph/Cfg.expected b/ql/test/library-tests/controlflow/graph/Cfg.expected
index 8e3167bc71d..2857ce80056 100644
--- a/ql/test/library-tests/controlflow/graph/Cfg.expected
+++ b/ql/test/library-tests/controlflow/graph/Cfg.expected
@@ -59,7 +59,7 @@ cfg.rb:
 #-----|  -> a
 
 #  187| enter run_block
-#-----|  -> call to yield
+#-----|  -> yield ...
 
 #  191| enter { ... }
 #-----|  -> x
@@ -2030,7 +2030,7 @@ cfg.rb:
 #  187| run_block
 #-----|  -> run_block
 
-#  188| call to yield
+#  188| yield ...
 #-----|  -> 42
 
 #  188| 42