[wasm] Disassemble wasm code from script

src/objects-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 60 matching lines @@
   const type* type::cast(const Object* object) {  \
     SLOW_DCHECK(object->Is##type());              \
     return reinterpret_cast<const type*>(object); \
   }
 
 
 #define INT_ACCESSORS(holder, name, offset)                                   \
   int holder::name() const { return READ_INT_FIELD(this, offset); }           \
   void holder::set_##name(int value) { WRITE_INT_FIELD(this, offset, value); }
 
-
-#define ACCESSORS(holder, name, type, offset)                                 \
-  type* holder::name() const { return type::cast(READ_FIELD(this, offset)); } \
-  void holder::set_##name(type* value, WriteBarrierMode mode) {               \
-    WRITE_FIELD(this, offset, value);                                         \
-    CONDITIONAL_WRITE_BARRIER(GetHeap(), this, offset, value, mode);          \
+#define ACCESSORS_CHECKED(holder, name, type, offset, condition)     \
+  type* holder::name() const {                                       \
+    DCHECK(condition);                                               \
+    return type::cast(READ_FIELD(this, offset));                     \
+  }                                                                  \
+  void holder::set_##name(type* value, WriteBarrierMode mode) {      \
+    DCHECK(condition);                                               \
+    WRITE_FIELD(this, offset, value);                                \
+    CONDITIONAL_WRITE_BARRIER(GetHeap(), this, offset, value, mode); \
   }
 
+#define ACCESSORS(holder, name, type, offset) \
+  ACCESSORS_CHECKED(holder, name, type, offset, true)
 
 // Getter that returns a Smi as an int and writes an int as a Smi.
-#define SMI_ACCESSORS(holder, name, offset)             \
-  int holder::name() const {                            \
-    Object* value = READ_FIELD(this, offset);           \
-    return Smi::cast(value)->value();                   \
-  }                                                     \
-  void holder::set_##name(int value) {                  \
-    WRITE_FIELD(this, offset, Smi::FromInt(value));     \
+#define SMI_ACCESSORS_CHECKED(holder, name, offset, condition) \
+  int holder::name() const {                                   \
+    DCHECK(condition);                                         \
+    Object* value = READ_FIELD(this, offset);                  \
+    return Smi::cast(value)->value();                          \
+  }                                                            \
+  void holder::set_##name(int value) {                         \
+    DCHECK(condition);                                         \
+    WRITE_FIELD(this, offset, Smi::FromInt(value));            \
   }
 
+#define SMI_ACCESSORS(holder, name, offset) \
+  SMI_ACCESSORS_CHECKED(holder, name, offset, true)
+
 #define SYNCHRONIZED_SMI_ACCESSORS(holder, name, offset)    \
   int holder::synchronized_##name() const {                 \
     Object* value = ACQUIRE_READ_FIELD(this, offset);       \
     return Smi::cast(value)->value();                       \
   }                                                         \
   void holder::synchronized_set_##name(int value) {         \
     RELEASE_WRITE_FIELD(this, offset, Smi::FromInt(value)); \
   }
 
 #define NOBARRIER_SMI_ACCESSORS(holder, name, offset)          \
@@ skipping 5450 matching lines @@
 
 ACCESSORS(Script, source, Object, kSourceOffset)
 ACCESSORS(Script, name, Object, kNameOffset)
 SMI_ACCESSORS(Script, id, kIdOffset)
 SMI_ACCESSORS(Script, line_offset, kLineOffsetOffset)
 SMI_ACCESSORS(Script, column_offset, kColumnOffsetOffset)
 ACCESSORS(Script, context_data, Object, kContextOffset)
 ACCESSORS(Script, wrapper, HeapObject, kWrapperOffset)
 SMI_ACCESSORS(Script, type, kTypeOffset)
 ACCESSORS(Script, line_ends, Object, kLineEndsOffset)
-ACCESSORS(Script, eval_from_shared, Object, kEvalFromSharedOffset)
-SMI_ACCESSORS(Script, eval_from_position, kEvalFromPositionOffset)
+ACCESSORS_CHECKED(Script, eval_from_shared, Object, kEvalFromSharedOffset,

[Yang, 2016/06/16 13:49:35]

I have plans to move the EvalFromShared and EvalFromPosition fields into a
separate FixedArray (because I need to add yet another field for eval scripts).
Could you do the same? We would replace these two fields by a TypeSpecificData
field.

[Clemens Hammacher, 2016/06/17 18:01:55]

Sure, that change would be compatible with wasm. All we need is getting the wasm
object and the function index from the script.

+                  this->type() != TYPE_WASM)
+SMI_ACCESSORS_CHECKED(Script, eval_from_position, kEvalFromPositionOffset,
+                      this->type() != TYPE_WASM)
 ACCESSORS(Script, shared_function_infos, Object, kSharedFunctionInfosOffset)
 SMI_ACCESSORS(Script, flags, kFlagsOffset)
 ACCESSORS(Script, source_url, Object, kSourceUrlOffset)
 ACCESSORS(Script, source_mapping_url, Object, kSourceMappingUrlOffset)
+ACCESSORS_CHECKED(Script, wasm_object, JSObject, kEvalFromSharedOffset,
+                  this->type() == TYPE_WASM)
+SMI_ACCESSORS_CHECKED(Script, wasm_function_index, kEvalFromPositionOffset,
+                      this->type() == TYPE_WASM)
 
 Script::CompilationType Script::compilation_type() {
   return BooleanBit::get(flags(), kCompilationTypeBit) ?
       COMPILATION_TYPE_EVAL : COMPILATION_TYPE_HOST;
 }
 void Script::set_compilation_type(CompilationType type) {
   set_flags(BooleanBit::set(flags(), kCompilationTypeBit,
       type == COMPILATION_TYPE_EVAL));
 }
 bool Script::hide_source() { return BooleanBit::get(flags(), kHideSourceBit); }
@@ skipping 2323 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_