Keep track and initialize to nil used gvars

fixes #489
opal · Mar 1, 2014 · adc35ea · adc35ea
1 parent 8c56856
commit adc35ea
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Showing 5 changed files with 44 additions and 16 deletions.
diff --git a/lib/opal/nodes/base.rb b/lib/opal/nodes/base.rb
@@ -123,6 +123,10 @@ def add_ivar(name)
         scope.add_scope_ivar name
       end
 
+      def add_gvar(name)
+        scope.add_scope_gvar name
+      end
+
       def add_temp(temp)
         scope.add_scope_temp temp
       end

diff --git a/lib/opal/nodes/helpers.rb b/lib/opal/nodes/helpers.rb
@@ -3,31 +3,40 @@ module Nodes
     module Helpers
 
       # Reserved javascript keywords - we cannot create variables with the
-      # same name
-      RESERVED = %w[
-        arguments break case catch char class const continue debugger default
-        delete do else enum export extends false finally for function if import
-        in instanceof let native new return static switch super this throw try
-        true typeof var void while with undefined
-      ]
+      # same name (ref: http://stackoverflow.com/a/9337272/601782)
+      ES51_RESERVED_WORD = /^(?:do|if|in|for|let|new|try|var|case|else|enum|eval|false|null|this|true|void|with|break|catch|class|const|super|throw|while|yield|delete|export|import|public|return|static|switch|typeof|default|extends|finally|package|private|continue|debugger|function|arguments|interface|protected|implements|instanceof)$/
+
+      # ES3 reserved words that aren’t ES5.1 reserved words
+      ES3_RESERVED_WORD_EXCLUSIVE = /^(?:int|byte|char|goto|long|final|float|short|double|native|throws|boolean|abstract|volatile|transient|synchronized)$/
+
+      # Immutable properties of the global object
+      IMMUTABLE_PROPS = /^(?:NaN|Infinity|undefined)$/
+
+      # Doesn't take in account utf8
+      BASIC_IDENTIFIER_RULES = /^[$_a-z][$_a-z\d]*$/i
+
 
       def property(name)
-        reserved?(name) ? "['#{name}']" : ".#{name}"
+        valid_name?(name) ? ".#{name}" : "[#{name.inspect}]"
       end
 
-      def reserved?(name)
-        RESERVED.include? name
+      def valid_name?(name)
+        BASIC_IDENTIFIER_RULES =~ name and not(
+          ES51_RESERVED_WORD          =~ name or
+          ES3_RESERVED_WORD_EXCLUSIVE =~ name or
+          IMMUTABLE_PROPS             =~ name
+        )
       end
 
       def variable(name)
-        reserved?(name.to_s) ? "#{name}$" : name
+        valid_name?(name.to_s) ? name : "#{name}$"
       end
 
       # Converts a ruby lvar/arg name to a js identifier. Not all ruby names
       # are valid in javascript. A $ suffix is added to non-valid names.
       # varibales
       def lvar_to_js(var)
-        var = "#{var}$" if RESERVED.include? var.to_s
+        var = "#{var}$" unless valid_name? var.to_s
         var.to_sym
       end
 

diff --git a/lib/opal/nodes/scope.rb b/lib/opal/nodes/scope.rb
@@ -15,6 +15,7 @@ class ScopeNode < Base
 
       attr_reader :scope_name
       attr_reader :ivars
+      attr_reader :gvars
 
       attr_accessor :mid
 
@@ -37,6 +38,7 @@ def initialize(*)
         @temps    = []
         @args     = []
         @ivars    = []
+        @gvars    = []
         @parent   = nil
         @queue    = []
         @unique   = 'a'
@@ -124,9 +126,14 @@ def to_vars
           "if (self#{ivar} == null) self#{ivar} = nil;\n"
         end
 
+        gv = gvars.map do |gvar|
+          "if ($gvars#{gvar} == null) $gvars#{gvar} = nil;\n"
+        end
+
         indent = @compiler.parser_indent
-        res = vars.empty? ? '' : "var #{vars.join ', '};"
-        str = ivars.empty? ? res : "#{res}\n#{indent}#{iv.join indent}"
+        str  = vars.empty? ? '' : "var #{vars.join ', '};\n"
+        str += "#{indent}#{iv.join indent}" unless ivars.empty?
+        str += "#{indent}#{gv.join indent}" unless gvars.empty?
 
         if class? and !@proto_ivars.empty?
           #raise "FIXME to_vars"
@@ -156,6 +163,10 @@ def add_scope_ivar(ivar)
         end
       end
 
+      def add_scope_gvar(gvar)
+        @gvars << gvar unless @gvars.include? gvar
+      end
+
       def add_proto_ivar(ivar)
         @proto_ivars << ivar unless @proto_ivars.include? ivar
       end

diff --git a/lib/opal/nodes/variables.rb b/lib/opal/nodes/variables.rb
@@ -88,7 +88,9 @@ def var_name
 
       def compile
         helper :gvars
-        push "$gvars[#{var_name.inspect}]"
+        name = property var_name
+        add_gvar name
+        push "$gvars#{name}"
       end
     end
 
@@ -103,7 +105,8 @@ def var_name
 
       def compile
         helper :gvars
-        push "$gvars[#{var_name.inspect}] = "
+        name = property var_name
+        push "$gvars#{name} = "
         push expr(value)
       end
     end

diff --git a/spec/opal/filters/bugs/language.rb b/spec/opal/filters/bugs/language.rb
@@ -155,6 +155,7 @@
   fails "The defined? keyword for an expression with logical connectives returns nil for an expression with '!' and an unset global variable"
   fails "The defined? keyword for an expression with logical connectives returns nil for an expression with 'not' and an unset class variable"
   fails "The defined? keyword for an expression with logical connectives returns nil for an expression with '!' and an unset class variable"
+  fails "The defined? keyword for variables returns nil for a global variable that has been read but not assigned to"
 
   fails "An ensure block inside a begin block is executed even when a symbol is thrown in it's corresponding begin block"
   fails "An ensure block inside a method is executed even when a symbol is thrown in the method"