Refactor rb_lastline to use new fast path and remove old primitive.

Author: aardvark179

CHANGELOG.md

@@ -36,7 +36,7 @@ Performance:
 * Improved `String#gsub` performance by adding a fast path for the `string_byte_index` primitive (#2380, @nirvdrum).
 * Improved `String#index` performance by adding a fast path for the `string_character_index` primitive (#2383, @LillianZ).
 * Optimized conversion of strings to integers if the string contained a numeric value (#2401, @nirvdrum).
-* Provide a new fast path for get and setting backrefs from C extensions.
+* Provide a new fast path for `rb_backref*` and `rb_lastline*`functions from C extensions.
 
 Changes:
 

lib/truffle/truffle/cext.rb

@@ -1733,16 +1733,18 @@ def rb_class_inherited_p(ruby_module, object)
     end
   end
 
-  def rb_backref_get
+  def rb_get_special_vars
     vars = Primitive.cext_special_variables_from_stack
     vars = Truffle::ThreadOperations.ruby_caller_special_variables([Truffle::CExt, Truffle::Interop.singleton_class]) if vars.nil?
-    Primitive.regexp_last_match_get(vars)
+    vars
+  end
+
+  def rb_backref_get
+    Primitive.regexp_last_match_get(rb_get_special_vars())
   end
 
   def rb_backref_set(value)
-    vars = Primitive.cext_special_variables_from_stack
-    vars = Truffle::ThreadOperations.ruby_caller_special_variables([Truffle::CExt, Truffle::Interop.singleton_class]) if vars.nil?
-    Truffle::RegexpOperations::LAST_MATCH_SET.call(value, vars)
+    Truffle::RegexpOperations::LAST_MATCH_SET.call(value, rb_get_special_vars())
   end
 
   def rb_gv_set(name, value)
@@ -1760,7 +1762,7 @@ def rb_gv_get(name)
 
   def rb_reg_match(re, str)
     result = str ? Truffle::RegexpOperations.match(re, str, 0) : nil
-    Primitive.regexp_last_match_set(Truffle::ThreadOperations.ruby_caller_special_variables([Truffle::CExt, Truffle::Interop.singleton_class]), result)
+    Primitive.regexp_last_match_set(rb_get_special_vars(), result)
 
     result.begin(0) if result
   end
@@ -1882,13 +1884,11 @@ def rb_syserr_new(errno, mesg)
   end
 
   def rb_lastline_set(str)
-    storage = Primitive.ruby_caller_special_variables
-    Primitive.io_last_line_set(storage, str)
+    Primitive.io_last_line_set(rb_get_special_vars(), str)
   end
 
   def rb_lastline_get
-    storage = Primitive.ruby_caller_special_variables
-    Primitive.io_last_line_get(storage)
+    Primitive.io_last_line_get(rb_get_special_vars())
   end
 
   def rb_cFiber

src/main/java/org/truffleruby/core/kernel/TruffleKernelNodes.java

@@ -37,7 +37,6 @@
 import org.truffleruby.language.ReadOwnFrameAndVariablesNode;
 import org.truffleruby.language.RubyBaseNode;
 import org.truffleruby.language.RubyNode;
-import org.truffleruby.language.RubyRootNode;
 import org.truffleruby.language.arguments.MaybeReadCallerVariablesNode;
 import org.truffleruby.language.arguments.ReadCallerVariablesNode;
 import org.truffleruby.language.arguments.RubyArguments;
@@ -62,17 +61,13 @@
 import com.oracle.truffle.api.dsl.NodeChild;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.FrameDescriptor;
-import com.oracle.truffle.api.frame.FrameInstance.FrameAccess;
 import com.oracle.truffle.api.frame.FrameSlot;
 import com.oracle.truffle.api.frame.FrameSlotKind;
 import com.oracle.truffle.api.frame.FrameUtil;
 import com.oracle.truffle.api.frame.MaterializedFrame;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.IndirectCallNode;
-import com.oracle.truffle.api.nodes.Node;
-import com.oracle.truffle.api.nodes.RootNode;
 import com.oracle.truffle.api.profiles.ConditionProfile;
-import com.oracle.truffle.api.Truffle;
 
 @CoreModule("Truffle::KernelOperations")
 public abstract class TruffleKernelNodes {
@@ -364,36 +359,6 @@ protected Object storage(VirtualFrame frame,
         }
     }
 
-    /* When getting special variables from the wrong side of a C call we know it's going to be slow. */
-    @Primitive(name = "ruby_caller_special_variables")
-    public abstract static class GetSlowCallerSpecialVariableStorage extends PrimitiveArrayArgumentsNode {
-
-        @Child GetSpecialVariableStorage getStorageNode = GetSpecialVariableStorage.create();
-
-        @Specialization
-        @TruffleBoundary
-        protected Object storage() {
-            return getStorageNode.execute(Truffle.getRuntime().iterateFrames(frameInstance -> {
-                final Node callNode = frameInstance.getCallNode();
-
-                if (callNode != null) {
-                    final RootNode rootNode = callNode.getRootNode();
-                    // Skip Ruby frames in cext.rb file since they are implementing methods which are implemented
-                    // with C in MRI, and therefore are also implicitly skipped when when looking up the block passed
-                    // to a C API function.
-                    if (rootNode instanceof RubyRootNode &&
-                            rootNode.getSourceSection().isAvailable() &&
-                            !rootNode.getSourceSection().getSource().getName().endsWith("cext.rb") &&
-                            !rootNode.getSourceSection().getSource().getName().endsWith("cext_ruby.rb")) {
-                        return frameInstance.getFrame(FrameAccess.MATERIALIZE).materialize();
-                    }
-                }
-
-                return null;
-            }));
-        }
-    }
-
     @Primitive(name = "proc_special_variables")
     public abstract static class GetProcSpecialVariableStorage extends PrimitiveArrayArgumentsNode {