add support for retrieving the JavaScript stack trace from Ruby via Context#stack.

ext/v8/v8_exception.cpp

@@ -69,21 +69,27 @@ namespace {
      return V8_Ref_Get<StackFrame>(value);
     }
     VALUE GetLineNumber(VALUE self) {
+      HandleScope scope;
       return rr_v82rb(frame(self)->GetLineNumber());
     }
     VALUE GetColumn(VALUE self) {
+      HandleScope scope;
       return rr_v82rb(frame(self)->GetColumn());
     }
     VALUE GetScriptName(VALUE self) {
+      HandleScope scope;
       return rr_v82rb(frame(self)->GetScriptName());
     }
     VALUE GetFunctionName(VALUE self) {
+      HandleScope scope;
       return rr_v82rb(frame(self)->GetFunctionName());
     }
     VALUE IsEval(VALUE self) {
+      HandleScope scope;
       return rr_v82rb(frame(self)->IsEval());
     }
     VALUE IsConstructor(VALUE self) {
+      HandleScope scope;
       return rr_v82rb(frame(self)->IsConstructor());
     }
   }
@@ -102,7 +108,7 @@ void rr_init_v8_exception() {
   rr_define_singleton_method(ExceptionClass, "Error", Error, 1);
 
   StackTraceClass = rr_define_class("StackTrace");
-  rr_define_singleton_method(StackTraceClass, "CurrentStackTrace", Trace::CurrentStackTrace, 0);
+  rr_define_singleton_method(StackTraceClass, "CurrentStackTrace", Trace::CurrentStackTrace, 1);
   rr_define_method(StackTraceClass, "GetFrame", Trace::GetFrame, 1);
   rr_define_method(StackTraceClass, "GetFrameCount", Trace::GetFrameCount, 0);
   rr_define_method(StackTraceClass, "AsArray", Trace::AsArray, 0);
@@ -123,6 +129,6 @@ void rr_init_v8_exception() {
 VALUE rr_reflect_v8_stacktrace(Handle<StackTrace> value) {
   return rr_v8_ref_create(StackTraceClass, value);
 }
-VALUE rr_reflect_v8_stackframe(Handle<StackTrace> value) {
+VALUE rr_reflect_v8_stackframe(Handle<StackFrame> value) {
   return rr_v8_ref_create(StackFrameClass, value);
 }

lib/v8.rb

@@ -13,4 +13,5 @@ module V8
   require 'v8/tap'
   require 'v8/access'
   require 'v8/error'
+  require 'v8/stack'
 end

lib/v8/context.rb

@@ -1,8 +1,9 @@
 require 'stringio'
 
 module V8
-  class Context    
+  class Context
     attr_reader :native, :scope, :access
+
     def initialize(opts = {})
       @access = Access.new
       @to = Portal.new(self, @access)
@@ -11,10 +12,11 @@ module V8
         @global = @native.Global()
         @scope = @to.rb(@global)
         @global.SetHiddenValue(C::String::New("TheRubyRacer::RubyObject"), C::External::New(opts[:with])) if opts[:with]
+        @global.SetHiddenValue(C::String::NewSymbol("TheRubyRacer::RubyContext"), C::External::New(self))
       end
       yield(self) if block_given?
     end
-    
+
     def eval(javascript, filename = "<eval>", line = 1)
       if IO === javascript || StringIO === javascript
         javascript = javascript.read()
@@ -43,16 +45,26 @@ module V8
     def load(filename)
       File.open(filename) do |file|
         evaluate file, filename, 1
-      end      
+      end
     end
-    
+
     def [](key)
       @scope[key]
     end
-    
+
     def []=(key, value)
       @scope[key] = value
     end
+
+    def self.stack(limit = 99)
+      if native = C::Context::GetEntered()
+        global = native.Global().instance_eval {@native}
+        cxt = global.GetHiddenValue(C::String::NewSymbol("TheRubyRacer::RubyContext")).Value()
+        cxt.instance_eval {@to.rb(C::StackTrace::CurrentStackTrace(limit))}
+      else
+        []
+      end
+    end
   end
 
   module C

lib/v8/portal.rb

@@ -78,12 +78,13 @@ module V8
 
     def rb(value)
       case value
-      when V8::C::Function  then peer(value) {V8::Function}
-      when V8::C::Array     then peer(value) {V8::Array}
-      when V8::C::Object    then peer(value) {V8::Object}
-      when V8::C::String    then value.Utf8Value.tap {|s| return s.respond_to?(:force_encoding) ? s.force_encoding("UTF-8") : s}
-      when V8::C::Date      then Time.at(value.NumberValue() / 1000)
-      when V8::C::Value     then nil if value.IsEmpty()
+      when V8::C::Function    then peer(value) {V8::Function}
+      when V8::C::Array       then peer(value) {V8::Array}
+      when V8::C::Object      then peer(value) {V8::Object}
+      when V8::C::String      then value.Utf8Value.tap {|s| return s.respond_to?(:force_encoding) ? s.force_encoding("UTF-8") : s}
+      when V8::C::Date        then Time.at(value.NumberValue() / 1000)
+      when V8::C::StackTrace  then V8::StackTrace.new(self, value)
+      when V8::C::Value       then nil if value.IsEmpty()
       else
         value
       end

lib/v8/stack.rb

@@ -0,0 +1,66 @@
+
+module V8
+
+  class StackTrace
+    include Enumerable
+
+    def initialize(to, native)
+      @to = to
+      @native = native
+    end
+
+    def length
+      @native.GetFrameCount()
+    end
+
+    def each
+      for i in 0..length - 1
+        yield V8::StackFrame.new(@to, @native.GetFrame(i))
+      end
+    end
+
+    def to_s
+      map {|f|"at #{f}"}.join("\n")
+    end
+  end
+
+  class StackFrame
+
+    def initialize(portal, native)
+      @to = portal
+      @native = native
+    end
+
+    def script_name
+      @to.rb(@native.GetScriptName())
+    end
+
+    def function_name
+      @to.rb(@native.GetFunctionName())
+    end
+
+    def line_number
+      @native.GetLineNumber()
+    end
+
+    def column
+      @native.GetColumn()
+    end
+
+    def eval?
+      @native.IsEval()
+    end
+
+    def constructor?
+      @native.IsConstructor()
+    end
+
+    def to_s
+      if @native.GetFunctionName()
+        "#{function_name} (#{script_name}:#{line_number}:#{column})"
+      else
+        "#{script_name}:#{line_number}:#{column}"
+      end
+    end
+  end
+end

spec/ext/cxt_spec.rb

@@ -4,9 +4,44 @@ require "#{File.dirname(__FILE__)}/../spec_helper.rb"
 include V8
 
 describe C::Context do  
-  
+
   it "should not have a current context if no context is open" do
     C::Context::GetEntered().should be_nil
   end
 
+  it "can get the current javascript execution stack" do
+    V8::Context.new do |cxt|
+      cxt['getTrace'] = lambda do
+        V8::Context.stack
+      end
+      trace = cxt.eval(<<-JS, 'trace.js')
+      function one() {
+        return two();
+      }
+      
+      function two() {
+        return three();
+      }
+      
+      function three() {
+        return getTrace()
+      }
+      one();
+JS
+
+      trace.length.should be(4)
+      trace.first.tap do |frame|
+        frame.line_number.should == 10
+        frame.column.should == 16
+        frame.script_name.should == 'trace.js'
+        frame.function_name.should == 'three'
+        frame.should_not be_eval
+        frame.should_not be_constructor
+      end
+    end
+  end
+
+  it "has an empty stack if there is no enterned context" do
+    V8::Context.stack.should be_empty
+  end
 end

spec/redjs

@@ -1 +1 @@
-Subproject commit 222bf1b12fe6b58293668d8d8bed9a0dd968a9e8
+Subproject commit 7914da03e60cde3cde9d0aba83d36ddd49fe8b28