src: teach llnode how to print Symbol properties names

Closes: #156
nodejs · Jul 12, 2018 · 9d031f3 · 9d031f3
1 parent baf4cae
commit 9d031f3
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Showing 7 changed files with 56 additions and 1 deletion.
diff --git a/src/llv8-constants.cc b/src/llv8-constants.cc
@@ -481,6 +481,11 @@ void Frame::Load() {
 }
 
 
+void Symbol::Load() {
+  kNameOffset = LoadConstant("class_Symbol__name__Object");
+}
+
+
 void Types::Load() {
   kFirstNonstringType = LoadConstant("FirstNonstringType");
   kFirstJSObjectType =
@@ -507,6 +512,7 @@ void Types::Load() {
   kSharedFunctionInfoType =
       LoadConstant("type_SharedFunctionInfo__SHARED_FUNCTION_INFO_TYPE");
   kScriptType = LoadConstant("type_Script__SCRIPT_TYPE");
+  kSymbolType = LoadConstant("type_Symbol__SYMBOL_TYPE");
 
   if (kJSAPIObjectType == -1) {
     common_->Load();

diff --git a/src/llv8-constants.h b/src/llv8-constants.h
@@ -458,6 +458,18 @@ class Frame : public Module {
   void Load();
 };
 
+
+class Symbol : public Module {
+ public:
+  CONSTANTS_DEFAULT_METHODS(Symbol);
+
+  int64_t kNameOffset;
+
+ protected:
+  void Load();
+};
+
+
 class Types : public Module {
  public:
   CONSTANTS_DEFAULT_METHODS(Types);
@@ -483,6 +495,7 @@ class Types : public Module {
   int64_t kJSDateType;
   int64_t kSharedFunctionInfoType;
   int64_t kScriptType;
+  int64_t kSymbolType;
 
  protected:
   void Load();

diff --git a/src/llv8-inl.h b/src/llv8-inl.h
@@ -155,6 +155,8 @@ ACCESSOR(Map, MaybeConstructor, map()->kMaybeConstructorOffset, HeapObject)
 ACCESSOR(Map, InstanceDescriptors, map()->kInstanceDescriptorsOffset,
          HeapObject)
 
+ACCESSOR(Symbol, Name, symbol()->kNameOffset, HeapObject)
+
 inline int64_t Map::BitField3(Error& err) {
   return v8()->LoadUnsigned(LeaField(v8()->map()->kBitField3Offset), 4, err);
 }

diff --git a/src/llv8.cc b/src/llv8.cc
@@ -55,6 +55,7 @@ void LLV8::Load(SBTarget target) {
   descriptor_array.Assign(target, &common);
   name_dictionary.Assign(target, &common);
   frame.Assign(target, &common);
+  symbol.Assign(target, &common);
   types.Assign(target, &common);
 }
 
@@ -757,6 +758,11 @@ std::string HeapObject::ToString(Error& err) {
     return str.ToString(err);
   }
 
+  if (type == v8()->types()->kSymbolType) {
+    Symbol symbol(this);
+    return symbol.ToString(err);
+  }
+
   return "<non-string>";
 }
 
@@ -955,6 +961,15 @@ std::string HeapNumber::Inspect(Error& err) {
 }
 
 
+std::string Symbol::ToString(Error& err) {
+  if (!String::IsString(v8(), Name(err), err)) {
+    return "<unnamed-symbol>";
+  }
+  HeapObject name = Name(err);
+  return "@@" + String(name).ToString(err);
+}
+
+
 std::string String::ToString(Error& err) {
   int64_t repr = Representation(err);
   if (err.Fail()) return std::string();

diff --git a/src/llv8.h b/src/llv8.h
@@ -129,6 +129,15 @@ class Map : public HeapObject {
   HeapObject Constructor(Error& err);
 };
 
+class Symbol : public HeapObject {
+ public:
+  V8_VALUE_DEFAULT_METHODS(Symbol, HeapObject)
+
+  HeapObject Name(Error& err);
+
+  std::string ToString(Error& err);
+};
+
 class String : public HeapObject {
  public:
   V8_VALUE_DEFAULT_METHODS(String, HeapObject)
@@ -511,6 +520,7 @@ class LLV8 {
   constants::DescriptorArray descriptor_array;
   constants::NameDictionary name_dictionary;
   constants::Frame frame;
+  constants::Symbol symbol;
   constants::Types types;
 
   friend class Value;
@@ -544,6 +554,7 @@ class LLV8 {
   friend class JSRegExp;
   friend class JSDate;
   friend class CodeMap;
+  friend class Symbol;
   friend class llnode::FindJSObjectsVisitor;
   friend class llnode::FindObjectsCmd;
   friend class llnode::FindReferencesCmd;

diff --git a/test/fixtures/inspect-scenario.js b/test/fixtures/inspect-scenario.js
@@ -6,6 +6,8 @@ const zlib = require('zlib');
 
 let outerVar = 'outer variable';
 
+const oneSymbol = Symbol("oneSymbol");
+
 exports.holder = {};
 
 function makeThin(a, b) {
@@ -61,6 +63,7 @@ function closure() {
   c.hashmap[4] = undefined;
   c.hashmap[23] = /regexp/;
   c.hashmap[25] = (a,b)=>{a+b};
+  c.hashmap[oneSymbol] = 42;
 
   let scopedVar = 'scoped value';
   let scopedAPI = zlib.createDeflate()._handle;

diff --git a/test/plugin/inspect-test.js b/test/plugin/inspect-test.js
@@ -51,7 +51,7 @@ const hashMapTests = {
         const arrowSource = 'source:\n' +
             'function c.hashmap.(anonymous function)(a,b)=>{a+b}\n' +
             '>';
-    
+
         t.ok(lines.includes(arrowSource),
             'hashmap[25] should have the correct function source');
         cb(null);
@@ -300,6 +300,11 @@ const hashMapTests = {
         cb(null);
       });
     }]
+  },
+  // .@@oneSymbol=<Smi: 42>
+  'symbol': {
+    re: /.@@oneSymbol=<Smi: 42>/,
+    desc: '.@@oneSymbol Symbol property',
   }
 };