[js] Support throwing and handling control exceptions.

Author: pmurias

src/vm/js/Operations.nqp

@@ -753,27 +753,19 @@ class QAST::OperationsJS {
             my str $try_ret := '';
             my $set_try_ret := '';
 
-            my $handle := '';
+
+            my @handlers;
+
             for @children -> $type, $handler {
-                if $type eq 'CATCH' {  
-                    my $catch_body := $comp.as_js($handler, :want($T_OBJ));
-                    $handle := Chunk.void(
-                        "$unwind_marker = \{\};\n",
-                        "$handler_ctx.\$\$CATCH = function() \{\n",
-                        $catch_body,
-                        "return {$catch_body.expr};\n",
-                        "\};\n",
-                        "$handler_ctx.unwind = $unwind_marker;\n"
-                    );
-                }
-                elsif $type eq 'CONTROL' {
-                    # STUB - we are nooping this, needs to be implemented
-                }
-                else {
-                    return $comp.NYI("Not implemented type with handle: $type");
-                }
+                my $catch_body := $comp.as_js($handler, :want($T_OBJ));
+                @handlers.push("$handler_ctx.\$\${$type} = function() \{\n");
+                @handlers.push($catch_body);
+                @handlers.push( "return {$catch_body.expr};\n" ~ "\};\n");
             }
 
+            @handlers.push("$unwind_marker = \{\};\n");
+            @handlers.push("$handler_ctx.unwind = $unwind_marker;\n");
+
             {
                 my $*CTX := $handler_ctx;
                 my $body := $comp.as_js($protected, :$want);
@@ -801,7 +793,7 @@ class QAST::OperationsJS {
 
                 return Chunk.new($want, $try_ret, [
                     "var $handler_ctx = new nqp.Ctx($outer_ctx, $outer_ctx, $outer_ctx.\$\$callThis, $outer_ctx.\$\$codeRefAttr);\n",
-                    $handle,
+                    Chunk.void(|@handlers),
                     "try \{",
                     $body,
                     # HACK we need to check $body.type if we handle something like return
@@ -831,7 +823,12 @@ class QAST::OperationsJS {
     add_simple_op('setpayload', $T_OBJ, [$T_OBJ, $T_OBJ], :side_effects);
     add_simple_op('getpayload', $T_OBJ, [$T_OBJ, $T_OBJ]);
 
-    add_simple_op('setmessage', $T_OBJ, [$T_OBJ, $T_OBJ], :side_effects);
+    add_simple_op('setmessage', $T_STR, [$T_OBJ, $T_STR], :side_effects);
+    add_simple_op('getmessage', $T_STR, [$T_OBJ]);
+
+    add_simple_op('setextype', $T_INT, [$T_OBJ, $T_INT], :side_effects);
+    add_simple_op('getextype', $T_INT, [$T_OBJ]);
+
     add_simple_op('getmessage', $T_STR, [$T_OBJ]);
 
     add_simple_op('newexception', $T_OBJ, [], :side_effects);

src/vm/js/const_map.nqp

@@ -22,14 +22,18 @@ my %const_map := nqp::hash(
     'HLL_ROLE_HASH',        5,
     'HLL_ROLE_CODE',        6,
 
-    'CONTROL_TAKE',         32,
-    'CONTROL_LAST',         16,
     'CONTROL_NEXT',         4,
     'CONTROL_REDO',         8,
+    'CONTROL_LAST',         16,
     'CONTROL_RETURN',       32,
-    'CONTROL_SUCCEED',      128,
-    'CONTROL_PROCEED',      256,
-    'CONTROL_WARN',         64,
+    'CONTROL_TAKE',         128,
+    'CONTROL_WARN',         256,
+    'CONTROL_SUCCEED',      512,
+    'CONTROL_PROCEED',      1024,
+    'CONTROL_LABELED',      4096,
+    'CONTROL_AWAIT',        8192,
+    'CONTROL_EMIT',         16384,
+    'CONTROL_DONE',         32768,
 
     'STAT_EXISTS',             0,
     'STAT_FILESIZE',           1,

src/vm/js/nqp-runtime/core.js

@@ -1147,3 +1147,16 @@ op.split = function(hllName, separator, string) {
 op.exception = function() {
   return exceptionsStack[exceptionsStack.length - 1];
 };
+
+op.setextype = function(exception, category) {
+  exception.$$category = category;
+  return exception;
+};
+
+op.getextype = function(exception) {
+  if (exception.$$category === undefined) {
+    return 0;
+  } else {
+    return exception.$$category;
+  }
+};

src/vm/js/nqp-runtime/ctx.js

@@ -6,6 +6,21 @@ var NQPObject = require('./nqp-object.js');
 var Null = require('./null.js');
 var exceptionsStack = require('./exceptions-stack.js');
 
+var categoryToName = {
+  4: 'NEXT',
+  8: 'REDO',
+  16: 'LAST',
+  32: 'RETURN',
+  128: 'TAKE',
+  256: 'WARN',
+  512: 'SUCCEED',
+  1024: 'PROCEED',
+  4096: 'LABELED',
+  8192: 'AWAIT',
+  16384: 'EMIT',
+  32768: 'DONE'
+};
+
 class Ctx extends NQPObject {
   constructor(callerCtx, outerCtx, callThis, codeRefAttr) {
     super();
@@ -19,8 +34,45 @@ class Ctx extends NQPObject {
     return (this.$$callThis instanceof CodeRef ? this.$$callThis : this.$$callThis[this.$$codeRefAttr]);
   }
 
+  propagateControlException(exception) {
+    var handler = '$$' + categoryToName[exception.$$category];
+
+    var ctx = this;
+
+    while (ctx) {
+      if (ctx[handler] || ctx.$$CONTROL) {
+        exception.caught = ctx;
+        exception.resume = false;
+        ctx.exception = exception;
+
+        exceptionsStack.push(exception);
+        try {
+          if (ctx[handler]) {
+            ctx.unwind.ret = ctx[handler]();
+          } else {
+            ctx.unwind.ret = ctx.$$CONTROL();
+          }
+        } finally {
+          exceptionsStack.pop();
+        }
+
+        if (exception.resume) {
+          return;
+        } else {
+          throw ctx.unwind;
+        }
+      }
+      ctx = ctx.$$caller;
+    }
+
+    throw exception;
+  }
+
   propagateException(exception) {
+    if (exception.$$category) this.propagateControlException(exception);
+
     var ctx = this;
+
     while (ctx) {
       if (ctx.$$CATCH) {
         exception.caught = ctx;