Infrastructure to support LEAVE and friends.

Author: jnthn

src/QAST/Block.nqp

@@ -2,6 +2,7 @@ class QAST::Block is QAST::Node {
     has str $!name;
     has str $!blocktype;
     has int $!custom_args;
+    has int $!has_exit_handler;
     has str $!cuid;
     has %!symbol;
 
@@ -14,6 +15,7 @@ class QAST::Block is QAST::Node {
         nqp::isnull_s($!blocktype) ?? "" !! $!blocktype
     }
     method custom_args(*@value) { $!custom_args := @value[0] if @value; $!custom_args }
+    method has_exit_handler(*@value) { $!has_exit_handler := @value[0] if @value; $!has_exit_handler }
 
     my $cur_cuid := 0;
     my $cuid_suffix := ~nqp::time_n();

src/vm/jvm/QAST/Compiler.nqp

@@ -3484,6 +3484,11 @@ class QAST::CompilerJAST {
                 $*JMETH.append($resume);
             }
 
+            # Set exit handler flag if needed.
+            if $node.has_exit_handler {
+                $*JMETH.has_exit_handler(1);
+            }
+            
             # Finalize method and add it to the class.
             $*JCLASS.add_method($*JMETH);
         }

src/vm/jvm/QAST/JASTNodes.nqp

@@ -113,6 +113,7 @@ class JAST::Method is JAST::Node {
     has @!cr_nlex;
     has @!cr_slex;
     has @!cr_handlers;
+    has int $!has_exit_handler;
 
     method BUILD(:$name!, :$returns!, :$static = 1) {
         $!name := $name;
@@ -159,6 +160,7 @@ class JAST::Method is JAST::Node {
     method cr_nlex(*@value) { @value ?? (@!cr_nlex := @value[0]) !! @!cr_nlex }
     method cr_slex(*@value) { @value ?? (@!cr_slex := @value[0]) !! @!cr_slex }
     method cr_handlers(*@value) { @value ?? (@!cr_handlers := @value[0]) !! @!cr_handlers }
+    method has_exit_handler(*@value) { $!has_exit_handler := @value[0] if @value; $!has_exit_handler }
 
     method dump(@dumped) {
         nqp::push(@dumped, "+ method");
@@ -181,6 +183,9 @@ class JAST::Method is JAST::Node {
         for @!cr_nlex { nqp::push(@dumped, "++ nlex $_"); }
         for @!cr_slex { nqp::push(@dumped, "++ slex $_"); }
         nqp::push(@dumped, "++ handlers " ~ join(' ', @!cr_handlers));
+        if $!has_exit_handler {
+            nqp::push(@dumped, "++ has_exit_handler");
+        }
         for @!instructions {
             $_.dump(@dumped);
         }

src/vm/jvm/runtime/org/perl6/nqp/jast2bc/JASTToJVMBytecode.java

@@ -200,6 +200,7 @@ private static boolean processMethod(JavaClass jcout, BufferedReader in, ClassWr
         Label endAll = new Label();
         long[] crHandlers = null;
         int curArgIndex = 1;
+        boolean hasExitHandler = false;
 
         MethodVisitor m = null;
         boolean contAfter = false;
@@ -262,6 +263,8 @@ else if (curLine.startsWith("++ handlers ")) {
                         crHandlers = new long[0];
                     }
                 }
+                else if (curLine.startsWith("++ has_exit_handler"))
+                    hasExitHandler = true;
                 else
                     throw new Exception("Cannot understand '" + curLine + "'");
                 continue;
@@ -316,6 +319,7 @@ else if (curLine.startsWith("++ handlers ")) {
                     }
 
                     if (crHandlers.length != 1 || crHandlers[0] != 0) av.visit("handlers", crHandlers);
+                    if (hasExitHandler) av.visit("hasExitHandler", hasExitHandler);
                     av.visitEnd();
                  }
 

src/vm/jvm/runtime/org/perl6/nqp/runtime/CallFrame.java

@@ -222,8 +222,16 @@ public void autoClose(StaticCodeInfo wanted) {
     }
 
     // Does work needed to leave this callframe.
+    private static final CallSiteDescriptor exitHandlerCallSite = new CallSiteDescriptor(
+        new byte[] { CallSiteDescriptor.ARG_OBJ, CallSiteDescriptor.ARG_OBJ }, null);
     public void leave() {
-        this.codeRef.staticInfo.priorInvocation = this;
+        StaticCodeInfo sci = this.codeRef.staticInfo;
+        sci.priorInvocation = this;
+        if (sci.hasExitHandler) {
+            HLLConfig hll = sci.compUnit.hllConfig;
+            Ops.invokeDirect(tc, hll.exitHandler, exitHandlerCallSite,
+                new Object[] { this.codeRef, Ops.result_o(this.caller) });
+        }
         this.tc.curFrame = this.caller;
     }
 

src/vm/jvm/runtime/org/perl6/nqp/runtime/CodeRefAnnotation.java

@@ -14,4 +14,5 @@
     String[] nLexicalNames() default {};
     String[] sLexicalNames() default {};
     long[] handlers() default {0};
+    boolean hasExitHandler() default false;
 }

src/vm/jvm/runtime/org/perl6/nqp/runtime/CompilationUnit.java

@@ -94,6 +94,7 @@ public void initializeCompilationUnit(ThreadContext tc) {
                 ann.nLexicalNames(), ann.sLexicalNames(),
                 m.handlers);
             cr.staticInfo.methodName = m.methodName;
+            cr.staticInfo.hasExitHandler = ann.hasExitHandler();
             cr.st = BOOTCodeSTable;
             codeRefList.add(cr);
 

src/vm/jvm/runtime/org/perl6/nqp/runtime/HLLConfig.java

@@ -85,4 +85,9 @@ public class HLLConfig {
     public SixModelObject foreignTransformHash;
     public SixModelObject foreignTransformCode;
     public SixModelObject foreignTransformAny;
+    
+    /**
+     * Block exit handler, for those that need it.
+     */
+    public SixModelObject exitHandler;
 }

src/vm/jvm/runtime/org/perl6/nqp/runtime/Ops.java

@@ -3920,6 +3920,8 @@ public static SixModelObject sethllconfig(String language, SixModelObject config
             config.foreignTransformAny = configHash.at_key_boxed(tc, "foreign_transform_any");
         if (configHash.exists_key(tc, "null_value") != 0)
             config.nullValue = configHash.at_key_boxed(tc, "null_value");
+        if (configHash.exists_key(tc, "exit_handler") != 0)
+            config.exitHandler = configHash.at_key_boxed(tc, "exit_handler");
         return configHash;
     }
     public static SixModelObject getcomp(String name, ThreadContext tc) {

src/vm/jvm/runtime/org/perl6/nqp/runtime/StaticCodeInfo.java

@@ -80,6 +80,11 @@ public class StaticCodeInfo implements Cloneable {
     public HashMap<String, Integer> nLexicalMap;
     public HashMap<String, Integer> sLexicalMap;
 
+    /**
+     * Does this code object have a block exit handler?
+     */
+    public boolean hasExitHandler;
+    
     public Integer oTryGetLexicalIdx(String name) {
         if (oLexicalMap == null) {
             HashMap<String, Integer> map = new HashMap<String, Integer>();