Minor cleanup

Author: andrykonchin

doc/user/compatibility.md

@@ -145,6 +145,15 @@ When TruffleRuby is run as part of a polyglot application, any signals that are
 
 TruffleRuby provides similar `GC.stat` statistics to MRI, but not all statistics are available, and some statistics may be approximations. Use `GC.stat.keys` to see which are provided with real or approximate values. Missing values will return `0`.
 
+### Caller locations
+
+Using `Kernel#caller_locations` or `Thread.each_caller_location` might contain engine specific location objects and/or
+paths. This is expected and should be filtered in application code where necessary.
+
+The enumerator returned by `Thread.to_enum(:each_caller_location)` is not supporting iteration with `.next`. In CRuby
+this raises a `StopIteration`, while in TruffleRuby it iterates on an undetermined (related to where and how `.next` is
+called) call stack. It is not recommended to use this in any circumstance (neither CRuby nor TruffleRuby).
+
 ## Features with Very Low Performance
 
 ### `ObjectSpace`
@@ -167,15 +176,6 @@ It is not recommended to use exceptions for control flow on any implementation o
 
 To help alleviate this problem, backtraces are automatically disabled in cases where we can detect that they will not be used.
 
-### Caller locations
-
-Using `Kernel#caller_locations` or `Thread.each_caller_location` might contain engine specific location objects and/or
-paths. This is expected and should be filtered in application code where necessary.
-
-The enumerator returned by `Thread.to_enum(:each_caller_location)` is not supporting iteration with `.next`. In CRuby
-this raises a `StopIteration`, while in TruffleRuby it iterates on an undetermined (related to where and how `.next` is
-called) call stack. It is not recommended to use this in any circumstance (neither CRuby nor TruffleRuby).
-
 ## C Extension Compatibility
 
 ### Identifiers may be macros or functions

src/main/java/org/truffleruby/core/thread/ThreadNodes.java

@@ -50,7 +50,6 @@
 import com.oracle.truffle.api.TruffleSafepoint.Interrupter;
 import com.oracle.truffle.api.dsl.Bind;
 import com.oracle.truffle.api.TruffleStackTraceElement;
-import com.oracle.truffle.api.frame.FrameInstance;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.profiles.InlinedBranchProfile;
 import com.oracle.truffle.api.profiles.InlinedConditionProfile;
@@ -1048,44 +1047,38 @@ protected Object runBlockingSystemCall(Object executable, RubyArray argsArray,
     @CoreMethod(names = "each_caller_location", needsBlock = true, onSingleton = true)
     public abstract static class EachCallerLocationNode extends CoreMethodArrayArgumentsNode {
 
-        private static final Object STOP_ITERATE = new Object();
-
         // Skip the block of `Thread#each_caller_location` + its internal iteration.
         private static final int SKIP = 2;
 
         @Child private CallBlockNode yieldNode = CallBlockNode.create();
 
         @Specialization
         protected Object eachCallerLocation(VirtualFrame frame, RubyProc block) {
-            final List<TruffleStackTraceElement> stackTraceElements = new ArrayList<>();
+            final List<TruffleStackTraceElement> elements = new ArrayList<>();
 
             getContext().getCallStack().iterateFrameBindings(SKIP, frameInstance -> {
                 final Node location = frameInstance.getCallNode();
 
-                final RootCallTarget rootCallTarget = (RootCallTarget) frameInstance.getCallTarget();
-                final TruffleStackTraceElement stackTraceElement = TruffleStackTraceElement.create(
-                        location,
-                        rootCallTarget,
-                        frameInstance.getFrame(FrameInstance.FrameAccess.READ_ONLY));
-                stackTraceElements.add(stackTraceElement);
+                final var rootCallTarget = (RootCallTarget) frameInstance.getCallTarget();
+                final var element = TruffleStackTraceElement.create(location, rootCallTarget, null);
+                elements.add(element);
 
-                final TruffleStackTraceElement[] finalStackTraceElements = stackTraceElements
-                        .toArray(TruffleStackTraceElement[]::new);
-                final boolean readyToYield = BacktraceFormatter.nextAvailableSourceSection(finalStackTraceElements,
+                final var elementsArray = elements.toArray(Backtrace.EMPTY_STACK_TRACE_ELEMENTS_ARRAY);
+                final boolean readyToYield = BacktraceFormatter.nextAvailableSourceSection(elementsArray,
                         0) != null;
 
                 if (readyToYield) {
-                    for (int i = 0; i < finalStackTraceElements.length; i++) {
-                        final Backtrace backtrace = new Backtrace(location, 0, finalStackTraceElements);
-                        RubyBacktraceLocation rubyBacktraceLocation = new RubyBacktraceLocation(
+                    for (int i = 0; i < elementsArray.length; i++) {
+                        final var backtrace = new Backtrace(location, 0, elementsArray);
+                        final var rubyBacktraceLocation = new RubyBacktraceLocation(
                                 getContext().getCoreLibrary().threadBacktraceLocationClass,
                                 getLanguage().threadBacktraceLocationShape,
                                 backtrace,
                                 i);
 
                         yieldNode.yield(block, rubyBacktraceLocation);
                     }
-                    stackTraceElements.clear();
+                    elements.clear();
                 }
 
                 return null;

src/main/java/org/truffleruby/language/backtrace/Backtrace.java

@@ -77,6 +77,8 @@ public final class Backtrace {
     private TruffleStackTraceElement[] stackTrace;
     private int totalUnderlyingElements;
 
+    public static final TruffleStackTraceElement[] EMPTY_STACK_TRACE_ELEMENTS_ARRAY = new TruffleStackTraceElement[0];
+
     // endregion
     // region Constructors
 
@@ -249,8 +251,6 @@ public TruffleStackTraceElement[] getStackTrace() {
         return getStackTrace(this.raiseException);
     }
 
-    private static final TruffleStackTraceElement[] EMPTY_STACK_TRACE_ELEMENTS_ARRAY = new TruffleStackTraceElement[0];
-
     /** Returns a ruby array of {@code Thread::Backtrace::Locations} with maximum length {@code length}, and omitting
      * locations as requested ({@link #getOmitted()}). If more locations are omitted than are available, return a Ruby
      * {@code nil}.