Revert of IDL: Support optional argument default value syntax (https:…

…//codereview.chromium.org/312683005/)

Reason for revert:
This patch is the most likely candidate for browser test failures: http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests%20%28dbg%29/builds/2905

BrowserTestBase signal handler received SIGTERM. Backtrace:
#0 0x7f2c2a201a1d base::debug::StackTrace::StackTrace()
#1 0x00000460caf2 content::(anonymous namespace)::DumpStackTraceSignalHandler()
#2 0x7f2c232cd4a0 \u003Cunknown>
#3 0x7f2c2337f313 __poll
#4 0x7f2c240b6036 \u003Cunknown>
#5 0x7f2c240b6164 g_main_context_iteration
#6 0x7f2c2a1c9b45 base::MessagePumpGlib::Run()
#7 0x7f2c2a29eed7 base::MessageLoop::RunHandler()
#8 0x7f2c2a2f69d8 base::RunLoop::Run()
#9 0x00000466bd59 content::RunThisRunLoop()
#10 0x00000466c1b8 content::MessageLoopRunner::Run()
#11 0x000004610946 content::TitleWatcher::WaitAndGetTitle()
#12 0x0000011fdf00 MediaBrowserTest::RunTest()
#13 0x0000011fdc00 MediaBrowserTest::RunMediaTestPage()
#14 0x0000011ec98b EncryptedMediaTestBase::RunEncryptedMediaTestPage()
#15 0x0000011ee5fa EncryptedMediaTest::TestConfigChange()
#16 0x0000011eb73a EncryptedMediaTest_ConfigChangeVideo_Test::RunTestOnMainThread()
...

Please look into it. An alterate possible candidate is  https://codereview.chromium.org/327553002 but I think that's less likely.

Original issue's description:
> IDL: Support optional argument default value syntax
> 
> Adds support for parsing default values of different types, but
> only handles null default values when generating code.
> 
> Replaces existing
> 
>   [Default=Null] optional SomeInterface arg
>   [Default=NullString] optional DOMString arg
> 
> with the now equivalent
> 
>   optional SomeInterface arg = null
>   optional DOMString arg = null
> 
> in IDL files, and drops support for those [Default] attributes.
> 
> No changes to generated code.
> 
> BUG=258153
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=176200

[email protected],[email protected],[email protected],[email protected],[email protected]
NOTREECHECKS=true
NOTRY=true
BUG=258153

Review URL: https://codereview.chromium.org/339683002

git-svn-id: svn://svn.chromium.org/blink/trunk@176220 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Source/bindings/IDLExtendedAttributes.txt

@@ -46,7 +46,7 @@ ConstructorCallWith=ExecutionContext|Document
 Custom=|Getter|Setter|LegacyCallAsFunction|ToV8|VisitDOMWrapper|Wrap|PropertyGetter|PropertyEnumerator|PropertyQuery
 CustomConstructor
 CustomElementCallbacks
-Default=Undefined
+Default=Null|NullString|Undefined
 DependentLifetime
 DeprecateAs=*
 DoNotCheckConstants

Source/bindings/scripts/idl_definitions.py

@@ -393,59 +393,6 @@ def __init__(self, node):
             self.extended_attributes = {}
 
 
-################################################################################
-# Literals
-################################################################################
-
-class IdlLiteral(object):
-    def __init__(self, idl_type, value):
-        self.idl_type = idl_type
-        self.value = value
-        self.is_null = False
-
-    def __str__(self):
-        if self.idl_type == 'DOMString':
-            return 'String("%s")' % self.value
-        if self.idl_type == 'integer':
-            return '%d' % self.value
-        if self.idl_type == 'float':
-            return '%g' % self.value
-        if self.idl_type == 'boolean':
-            return 'true' if self.value else 'false'
-        raise ValueError('Unsupported literal type: %s' % self.idl_type)
-
-
-class IdlLiteralNull(IdlLiteral):
-    def __init__(self):
-        self.idl_type = 'NULL'
-        self.value = None
-        self.is_null = True
-
-    def __str__(self):
-        return 'nullptr'
-
-
-def default_node_to_idl_literal(node):
-    # FIXME: This code is unnecessarily complicated due to the rather
-    # inconsistent way the upstream IDL parser outputs default values.
-    # http://crbug.com/374178
-    idl_type = node.GetProperty('TYPE')
-    if idl_type == 'DOMString':
-        value = node.GetProperty('NAME')
-        if '"' in value or '\\' in value:
-            raise ValueError('Unsupported string value: %r' % value)
-        return IdlLiteral(idl_type, value)
-    if idl_type == 'integer':
-        return IdlLiteral(idl_type, int(node.GetProperty('NAME')))
-    if idl_type == 'float':
-        return IdlLiteral(idl_type, float(node.GetProperty('VALUE')))
-    if idl_type == 'boolean':
-        return IdlLiteral(idl_type, node.GetProperty('VALUE'))
-    if idl_type == 'NULL':
-        return IdlLiteralNull()
-    raise ValueError('Unrecognized default value type: %s' % idl_type)
-
-
 ################################################################################
 # Operations
 ################################################################################
@@ -528,7 +475,6 @@ def __init__(self, node):
         self.is_optional = node.GetProperty('OPTIONAL')  # syntax: (optional T)
         self.is_variadic = False  # syntax: (T...)
         self.name = node.GetName()
-        self.default_value = None
 
         children = node.GetChildren()
         for child in children:
@@ -542,8 +488,6 @@ def __init__(self, node):
                 if child_name != '...':
                     raise ValueError('Unrecognized Argument node; expected "...", got "%s"' % child_name)
                 self.is_variadic = child.GetProperty('ELLIPSIS') or False
-            elif child_class == 'Default':
-                self.default_value = default_node_to_idl_literal(child)
             else:
                 raise ValueError('Unrecognized node class: %s' % child_class)
 

Source/bindings/scripts/v8_methods.py

@@ -181,11 +181,8 @@ def generate_argument(interface, method, argument, index):
                                            used_as_argument=True,
                                            used_as_variadic_argument=argument.is_variadic),
         'cpp_value': this_cpp_value,
-        # FIXME: check that the default value's type is compatible with the argument's
-        'default_value': str(argument.default_value) if argument.default_value else None,
         'enum_validation_expression': idl_type.enum_validation_expression,
-        # FIXME: remove once [Default] removed and just use argument.default_value
-        'has_default': 'Default' in extended_attributes or argument.default_value,
+        'has_default': 'Default' in extended_attributes,
         'has_event_listener_argument': any(
             argument_so_far for argument_so_far in method.arguments[:index]
             if argument_so_far.idl_type.name == 'EventListener'),
@@ -301,10 +298,9 @@ def v8_value_to_local_cpp_value(argument, index):
     name = argument.name
     if argument.is_variadic:
         return v8_value_to_local_cpp_variadic_value(argument, index)
-    # FIXME: This special way of handling string arguments with null defaults
-    # can go away once we fully support default values.
+    # [Default=NullString]
     if (argument.is_optional and idl_type.name in ('String', 'ByteString') and
-        argument.default_value and argument.default_value.is_null):
+        extended_attributes.get('Default') == 'NullString'):
         v8_value = 'argumentOrNull(info, %s)' % index
     else:
         v8_value = 'info[%s]' % index

Source/bindings/tests/idls/TestInterfaceConstructor2.idl

@@ -44,7 +44,7 @@
         TestInterfaceEmpty testInterfaceEmptyArg,
         long longArg,
         [Default=Undefined] optional DOMString defaultUndefinedOptionalStringArg,
-        optional DOMString defaultNullStringOptionalStringArg = null,
+        [Default=NullString] optional DOMString defaultNullStringOptionalStringArg,
         [Default=Undefined] optional Dictionary defaultUndefinedOptionalDictionaryArg,
         optional DOMString optionalStringArg),
 ] interface TestInterfaceConstructor2 {

Source/bindings/tests/idls/TestInterfaceNamedConstructor.idl

@@ -33,7 +33,7 @@
         [Default=Undefined] optional boolean defaultUndefinedOptionalBooleanArg,
         [Default=Undefined] optional long defaultUndefinedOptionalLongArg,
         [Default=Undefined] optional DOMString defaultUndefinedOptionalStringArg,
-        optional DOMString defaultNullStringOptionalstringArg = null,
+        [Default=NullString] optional DOMString defaultNullStringOptionalstringArg,
         optional DOMString optionalStringArg),
     RaisesException=Constructor,
 ] interface TestInterfaceNamedConstructor {

Source/bindings/tests/idls/TestObject.idl

@@ -379,16 +379,6 @@ interface TestObject {
     // Optional arguments: exceptional case
     void voidMethodOptionalDictionaryArg(optional Dictionary optionalDictionaryArg);
 
-    // Optional arguments with defaults
-    void voidMethodDefaultStringArg(optional DOMString defaultStringArg = "foo");
-    void voidMethodDefaultNullStringArg(optional DOMString defaultStringArg = null);
-    void voidMethodDefaultLongArg(optional long defaultLongArg = 10);
-    void voidMethodDefaultDoubleArg(optional double defaultDoubleArg = 0.5);
-    void voidMethodDefaultTrueBooleanArg(optional boolean defaultBooleanArg = true);
-    void voidMethodDefaultFalseBooleanArg(optional boolean defaultBooleanArg = false);
-    void voidMethodDefaultNullableStringArg(optional DOMString? defaultStringArg = null);
-    void voidMethodDefaultNullableTestInterfaceArg(optional TestInterface? defaultTestInterfaceArg = null);
-
     // Variadic operations
     void voidMethodVariadicStringArg(DOMString... variadicStringArgs);
     void voidMethodStringArgVariadicStringArg(DOMString stringArg, DOMString... variadicStringArgs);
@@ -411,7 +401,7 @@ interface TestObject {
     void overloadedMethodF(optional DOMString stringArg);
     void overloadedMethodF(double doubleArg);
     void overloadedMethodG(long longArg);
-    void overloadedMethodG(optional TestInterfaceEmpty? testInterfaceEmptyOrNullArg = null);
+    void overloadedMethodG([Default=Null] TestInterfaceEmpty? testInterfaceEmptyOrNullArg);
     void overloadedMethodH(TestInterface testInterfaceArg);
     void overloadedMethodH(TestInterfaceEmpty testInterfaceEmptyArg);
     void overloadedMethodI(DOMString stringArg);
@@ -432,6 +422,7 @@ interface TestObject {
     void voidMethodDefaultUndefinedTestInterfaceEmptyArg([Default=Undefined] optional TestInterfaceEmpty defaultUndefinedTestInterfaceEmptyArg);
     void voidMethodDefaultUndefinedLongArg([Default=Undefined] optional long defaultUndefinedLongArg);
     void voidMethodDefaultUndefinedStringArg([Default=Undefined] optional DOMString defaultUndefinedStringArg);
+    void voidMethodDefaultNullStringStringArg([Default=NullString] optional DOMString defaultNullStringStringArg);
     // [EnforceRange]
     void voidMethodEnforceRangeLongArg([EnforceRange] long enforceRangeLongArg);
     // [TreatNullAs], [TreatUndefinedAs]