Issue #2173 - Add a new PNK_PROPERTYNAME to hold location information about property access name

Based-on: m-c 1378808/2

10 files changed, 104 insertions, 76 deletions

diff --git a/js/src/builtin/ReflectParse.cpp b/js/src/builtin/ReflectParse.cpp
index a9c354fa7c..d63c1dd493 100644
--- a/js/src/builtin/ReflectParse.cpp
+++ b/js/src/builtin/ReflectParse.cpp
@@ -3066,20 +3066,20 @@ ASTSerializer::expression(ParseNode* pn, MutableHandleValue dst)
       case PNK_OPTDOT:
       case PNK_DOT:
       {
-        MOZ_ASSERT(pn->pn_pos.encloses(pn->pn_expr->pn_pos));
+        MOZ_ASSERT(pn->pn_pos.encloses(pn->pn_left->pn_pos));
 
         RootedValue expr(cx);
         RootedValue propname(cx);
-        RootedAtom pnAtom(cx, pn->pn_atom);
+        RootedAtom pnAtom(cx, pn->pn_right->pn_atom);
 
         bool isSuper = pn->is<PropertyAccess>() &&
                        pn->as<PropertyAccess>().isSuper();
 
         if (isSuper) {
-            if (!builder.super(&pn->pn_expr->pn_pos, &expr))
+            if (!builder.super(&pn->pn_left->pn_pos, &expr))
                 return false;
         } else {
-            if (!expression(pn->pn_expr, &expr))
+            if (!expression(pn->pn_left, &expr))
                 return false;
         }
 
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index 8c3e74155e..3997d1cf3e 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -1090,7 +1090,7 @@ BytecodeEmitter::checkSideEffects(ParseNode* pn, bool* answer)
       // Watch out for getters!
       case PNK_DOT:
       case PNK_OPTDOT:
-        MOZ_ASSERT(pn->isArity(PN_NAME));
+        MOZ_ASSERT(pn->isArity(PN_BINARY));
         *answer = true;
         return true;
 
@@ -1497,6 +1497,7 @@ BytecodeEmitter::checkSideEffects(ParseNode* pn, bool* answer)
       case PNK_CALLSITEOBJ:      // by PNK_TAGGED_TEMPLATE
       case PNK_POSHOLDER:        // by PNK_NEWTARGET
       case PNK_SUPERBASE:        // by PNK_ELEM and others
+      case PNK_PROPERTYNAME:     // by PNK_DOT
         MOZ_CRASH("handled by parent nodes");
 
       case PNK_LIMIT: // invalid sentinel value
@@ -1813,11 +1814,11 @@ BytecodeEmitter::emitPropLHS(ParseNode* pn)
     MOZ_ASSERT(pn->isKind(PNK_DOT));
     MOZ_ASSERT(!pn->as<PropertyAccess>().isSuper());
 
-    ParseNode* pn2 = pn->pn_expr;
+    ParseNode* pn2 = pn->pn_left;
 
     /*
      * If the object operand is also a dotted property reference, reverse the
-     * list linked via pn_expr temporarily so we can iterate over it from the
+     * list linked via pn_left temporarily so we can iterate over it from the
      * bottom up (reversing again as we go), to avoid excessive recursion.
      */
     if (pn2->isKind(PNK_DOT) && !pn2->as<PropertyAccess>().isSuper()) {
@@ -1825,9 +1826,9 @@ BytecodeEmitter::emitPropLHS(ParseNode* pn)
         ParseNode* pnup = nullptr;
         ParseNode* pndown;
         for (;;) {
-            /* Reverse pndot->pn_expr to point up, not down. */
-            pndown = pndot->pn_expr;
-            pndot->pn_expr = pnup;
+            /* Reverse pndot->pn_left to point up, not down. */
+            pndown = pndot->pn_left;
+            pndot->pn_left = pnup;
             if (!pndown->isKind(PNK_DOT) || pndown->as<PropertyAccess>().isSuper())
                 break;
             pnup = pndot;
@@ -1840,12 +1841,12 @@ BytecodeEmitter::emitPropLHS(ParseNode* pn)
 
         do {
             /* Walk back up the list, emitting annotated name ops. */
-            if (!emitAtomOp(pndot->pn_atom, JSOP_GETPROP))
+            if (!emitAtomOp(pndot->pn_right->pn_atom, JSOP_GETPROP))
                 return false;
 
-            /* Reverse the pn_expr link again. */
-            pnup = pndot->pn_expr;
-            pndot->pn_expr = pndown;
+            /* Reverse the pn_left link again. */
+            pnup = pndot->pn_left;
+            pndot->pn_left = pndown;
             pndown = pndot;
         } while ((pndot = pnup) != nullptr);
         return true;
@@ -2505,7 +2506,7 @@ BytecodeEmitter::emitDestructuringLHSRef(ParseNode* target, size_t* emitted)
             // SUPERBASE is pushed onto THIS in poe.prepareForRhs below.
             *emitted = 2;
         } else {
-            if (!emitTree(target->pn_expr))                // OBJ
+            if (!emitTree(target->pn_left))               // OBJ
                 return false;
             *emitted = 1;
         }
@@ -9080,8 +9081,9 @@ BytecodeEmitter::emitTree(ParseNode* pn, ValueUsage valueUsage /* = ValueUsage::
             return false;
         break;
 
+      case PNK_PROPERTYNAME:
       case PNK_POSHOLDER:
-        MOZ_FALLTHROUGH_ASSERT("Should never try to emit PNK_POSHOLDER");
+        MOZ_FALLTHROUGH_ASSERT("Should never try to emit PNK_POSHOLDER or PNK_PROPERTYNAME");
 
       default:
         MOZ_ASSERT(0);
diff --git a/js/src/frontend/FoldConstants.cpp b/js/src/frontend/FoldConstants.cpp
index abeebadddf..3b11e8de37 100644
--- a/js/src/frontend/FoldConstants.cpp
+++ b/js/src/frontend/FoldConstants.cpp
@@ -367,6 +367,7 @@ ContainsHoistedDeclaration(ExclusiveContext* cx, ParseNode* node, bool* result)
       case PNK_COMMA:
       case PNK_ARRAY:
       case PNK_OBJECT:
+      case PNK_PROPERTYNAME:
       case PNK_DOT:
       case PNK_ELEM:
       case PNK_ARGUMENTS:
@@ -1367,11 +1368,14 @@ FoldElement(ExclusiveContext* cx, ParseNode** nodePtr, Parser<FullParseHandler>&
 
     // Optimization 3: We have expr["foo"] where foo is not an index.  Convert
     // to a property access (like expr.foo) that optimizes better downstream.
+    ParseNode* nameNode = parser.handler.newPropertyName(name, key->pn_pos);
+    if (!nameNode)
+        return false;
     ParseNode* dottedAccess;
     if (node->isKind(PNK_OPTELEM)) {
-        dottedAccess = parser.handler.newOptionalPropertyAccess(expr, name, node->pn_pos.end);
+        dottedAccess = parser.handler.newOptionalPropertyAccess(expr, nameNode);
     } else {
-        dottedAccess = parser.handler.newPropertyAccess(expr, name, node->pn_pos.end);
+        dottedAccess = parser.handler.newPropertyAccess(expr, nameNode);
     }
     if (!dottedAccess) {
         return false;
@@ -1646,14 +1650,14 @@ FoldDottedProperty(ExclusiveContext* cx, ParseNode* node, Parser<FullParseHandle
                    bool inGenexpLambda)
 {
     MOZ_ASSERT(node->isKind(PNK_DOT) || node->isKind(PNK_OPTDOT));
-    MOZ_ASSERT(node->isArity(PN_NAME));
+    MOZ_ASSERT(node->isArity(PN_BINARY));
 
     // Iterate through a long chain of dotted property accesses to find the
     // most-nested non-dotted property node, then fold that.
-    ParseNode** nested = &node->pn_expr;
+    ParseNode** nested = &node->pn_left;
     while ((*nested)->isKind(PNK_DOT) || (*nested)->isKind(PNK_OPTDOT)) {
-        MOZ_ASSERT((*nested)->isArity(PN_NAME));
-        nested = &(*nested)->pn_expr;
+        MOZ_ASSERT((*nested)->isArity(PN_BINARY));
+        nested = &(*nested)->pn_left;
     }
 
     return Fold(cx, nested, parser, inGenexpLambda);
@@ -1953,6 +1957,9 @@ Fold(ExclusiveContext* cx, ParseNode** pnp, Parser<FullParseHandler>& parser, bo
         MOZ_ASSERT(pn->isArity(PN_NAME));
         return Fold(cx, &pn->pn_expr, parser, inGenexpLambda);
 
+      case PNK_PROPERTYNAME:
+        MOZ_CRASH("unreachable, handled by ::Dot");
+
       case PNK_OPTDOT:
       case PNK_DOT:
         return FoldDottedProperty(cx, pn, parser, inGenexpLambda);
diff --git a/js/src/frontend/FullParseHandler.h b/js/src/frontend/FullParseHandler.h
index 786a5c32dd..d5a8c1ab4e 100644
--- a/js/src/frontend/FullParseHandler.h
+++ b/js/src/frontend/FullParseHandler.h
@@ -707,16 +707,20 @@ class FullParseHandler
         return new_<DebuggerStatement>(pos);
     }
 
-    ParseNode* newPropertyAccess(ParseNode* pn, PropertyName* name, uint32_t end) {
-        return new_<PropertyAccess>(pn, name, pn->pn_pos.begin, end);
+    ParseNode* newPropertyName(PropertyName* name, const TokenPos& pos) {
+        return new_<NameNode>(PNK_PROPERTYNAME, JSOP_NOP, name, pos);
+    }
+
+    ParseNode* newPropertyAccess(ParseNode* expr, ParseNode* key) {
+        return new_<PropertyAccess>(expr, key, expr->pn_pos.begin, key->pn_pos.end);
     }
 
     ParseNode* newPropertyByValue(ParseNode* lhs, ParseNode* index, uint32_t end) {
         return new_<PropertyByValue>(lhs, index, lhs->pn_pos.begin, end);
     }
 
-    ParseNode* newOptionalPropertyAccess(ParseNode* pn, PropertyName* name, uint32_t end) {
-        return new_<OptionalPropertyAccess>(pn, name, pn->pn_pos.begin, end);
+    ParseNode* newOptionalPropertyAccess(ParseNode* expr, ParseNode* key) {
+        return new_<OptionalPropertyAccess>(expr, key, expr->pn_pos.begin, key->pn_pos.end);
     }
 
     ParseNode* newOptionalPropertyByValue(ParseNode* lhs, ParseNode* index, uint32_t end) {
diff --git a/js/src/frontend/NameFunctions.cpp b/js/src/frontend/NameFunctions.cpp
index e82775b884..76433fcc80 100644
--- a/js/src/frontend/NameFunctions.cpp
+++ b/js/src/frontend/NameFunctions.cpp
@@ -74,11 +74,11 @@ class NameResolver
     bool nameExpression(ParseNode* n, bool* foundName) {
         switch (n->getKind()) {
           case PNK_DOT:
-            if (!nameExpression(n->expr(), foundName))
+            if (!nameExpression(n->pn_left, foundName))
                 return false;
             if (!*foundName)
                 return true;
-            return appendPropertyReference(n->pn_atom);
+            return appendPropertyReference(n->pn_right->pn_atom);
 
           case PNK_NAME:
             *foundName = true;
@@ -800,12 +800,12 @@ class NameResolver
           }
 
           case PNK_DOT:
-            MOZ_ASSERT(cur->isArity(PN_NAME));
+            MOZ_ASSERT(cur->isArity(PN_BINARY));
 
             // Super prop nodes do not have a meaningful LHS
             if (cur->as<PropertyAccess>().isSuper())
                 break;
-            if (!resolve(cur->expr(), prefix))
+            if (!resolve(cur->pn_left, prefix))
                 return false;
             break;
 
@@ -840,6 +840,7 @@ class NameResolver
           case PNK_EXPORT_SPEC: // by PNK_EXPORT_SPEC_LIST
           case PNK_CALLSITEOBJ: // by PNK_TAGGED_TEMPLATE
           case PNK_CLASSNAMES:  // by PNK_CLASS
+          case PNK_PROPERTYNAME: // by PNK_DOT
             MOZ_CRASH("should have been handled by a parent node");
 
           case PNK_LIMIT: // invalid sentinel value
diff --git a/js/src/frontend/ParseNode.cpp b/js/src/frontend/ParseNode.cpp
index 71b57910c7..5de58b9a29 100644
--- a/js/src/frontend/ParseNode.cpp
+++ b/js/src/frontend/ParseNode.cpp
@@ -265,6 +265,8 @@ PushNodeChildren(ParseNode* pn, NodeStack* stack)
       case PNK_WHILE:
       case PNK_SWITCH:
       case PNK_NEW:
+      case PNK_OPTDOT:
+      case PNK_DOT:
       case PNK_OPTCALL:
       case PNK_CALL:
       case PNK_SUPERCALL:
@@ -489,9 +491,8 @@ PushNodeChildren(ParseNode* pn, NodeStack* stack)
       }
 
       case PNK_LABEL:
-      case PNK_OPTDOT:
-      case PNK_DOT:
       case PNK_NAME:
+      case PNK_PROPERTYNAME:
         return PushNameNodeChildren(pn, stack);
 
       case PNK_LEXICALSCOPE:
@@ -731,6 +732,21 @@ UnaryNode::dump(int indent)
 void
 BinaryNode::dump(int indent)
 {
+    if (isKind(PNK_DOT)) {
+        fprintf(stderr, "(.");
+
+        DumpParseTree(pn_right, indent + 2);
+
+        fprintf(stderr, " ");
+        if (as<PropertyAccess>().isSuper())
+            fprintf(stderr, "super");
+        else
+            DumpParseTree(pn_left, indent + 2);
+
+        fprintf(stderr, ")");
+        return;
+    }
+
     const char* name = parseNodeNames[getKind()];
     fprintf(stderr, "(%s ", name);
     indent += strlen(name) + 2;
@@ -803,10 +819,7 @@ DumpName(const CharT* s, size_t len)
 void
 NameNode::dump(int indent)
 {
-    if (isKind(PNK_NAME) || isKind(PNK_DOT)) {
-        if (isKind(PNK_DOT))
-            fprintf(stderr, "(.");
-
+    if (isKind(PNK_NAME) || isKind(PNK_PROPERTYNAME)) {
         if (!pn_atom) {
             fprintf(stderr, "#<null name>");
         } else if (getOp() == JSOP_GETARG && pn_atom->length() == 0) {
@@ -821,15 +834,6 @@ NameNode::dump(int indent)
             else
                 DumpName(pn_atom->twoByteChars(nogc), pn_atom->length());
         }
-
-        if (isKind(PNK_DOT)) {
-            fputc(' ', stderr);
-            if (as<PropertyAccess>().isSuper())
-                fprintf(stderr, "super");
-            else
-                DumpParseTree(expr(), indent + 2);
-            fputc(')', stderr);
-        }
         return;
     }
 
diff --git a/js/src/frontend/ParseNode.h b/js/src/frontend/ParseNode.h
index 68bdfdc200..7f42b57eeb 100644
--- a/js/src/frontend/ParseNode.h
+++ b/js/src/frontend/ParseNode.h
@@ -32,6 +32,7 @@ class ObjectBox;
     F(POSTINCREMENT) \
     F(PREDECREMENT) \
     F(POSTDECREMENT) \
+    F(PROPERTYNAME) \
     F(DOT) \
     F(ELEM) \
     F(OPTDOT) \
@@ -396,9 +397,9 @@ IsTypeofKind(ParseNodeKind kind)
  *                          contains are nullish. An optional chain can also
  *                          contain nodes such as PNK_DOT, PNK_ELEM, PNK_NAME,
  *                          PNK_CALL, etc. These are evaluated normally.
- * PNK_OPTDOT   name        pn_expr: MEMBER expr to left of .
+ * PNK_OPTDOT   binary      pn_left: MEMBER expr to left of .
  *                          short circuits back to PNK_OPTCHAIN if nullish.
- *                          pn_atom: name to right of .
+ *                          pn_right: PropertyName to right of .
  * PNK_OPTELEM  binary      pn_left: MEMBER expr to left of [
  *                          short circuits back to PNK_OPTCHAIN if nullish.
  *                          pn_right: expr between [ and ]
@@ -406,8 +407,10 @@ IsTypeofKind(ParseNodeKind kind)
  *                          pn_count: 1 + N (where N is number of args)
  *                          call is a MEMBER expr naming a callable object,
  *                          short circuits back to PNK_OPTCHAIN if nullish.
- * PNK_DOT      name        pn_expr: MEMBER expr to left of .
- *                          pn_atom: name to right of .
+ * PNK_PROPERTYNAME         pn_atom: property being accessed
+ *              name        
+ * PNK_DOT      binary      pn_left: MEMBER expr to left of .
+ *                          pn_right: PropertyName to right of .
  * PNK_ELEM     binary      pn_left: MEMBER expr to left of [
  *                          pn_right: expr between [ and ]
  * PNK_CALL     binary      pn_left: callee expression on the left of the (
@@ -600,8 +603,7 @@ class ParseNode
                 FunctionBox* funbox;    /* function object */
             };
             ParseNode*  expr;           /* module or function body, var
-                                           initializer, argument default, or
-                                           base object of PNK_DOT */
+                                           initializer, or argument default */
         } name;
         struct {
             LexicalScope::Data* bindings;
@@ -1223,44 +1225,45 @@ class RegExpLiteral : public NullaryNode
     }
 };
 
-class PropertyAccessBase : public ParseNode
+class PropertyAccessBase : public BinaryNode
 {
   public:
-    PropertyAccessBase(ParseNodeKind kind, ParseNode* lhs, PropertyName* name,
-                       uint32_t begin, uint32_t end)
-      : ParseNode(kind, JSOP_NOP, PN_NAME, TokenPos(begin, end))
+    /*
+     * PropertyAccess nodes can have any expression/'super' as left-hand
+     * side, but the name must be a ParseNodeKind::PropertyName node.
+     */
+    PropertyAccessBase(ParseNodeKind kind, ParseNode* lhs, ParseNode* name, uint32_t begin, uint32_t end)
+      : BinaryNode(kind, JSOP_NOP, TokenPos(begin, end), lhs, name)
     {
         MOZ_ASSERT(lhs != nullptr);
         MOZ_ASSERT(name != nullptr);
-        pn_u.name.expr = lhs;
-        pn_u.name.atom = name;
     }
 
     static bool test(const ParseNode& node) {
         bool match = node.isKind(PNK_DOT) ||
                      node.isKind(PNK_OPTDOT);
-        MOZ_ASSERT_IF(match, node.isArity(PN_NAME));
+        MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
+        MOZ_ASSERT_IF(match, node.pn_right->isKind(PNK_PROPERTYNAME));
         return match;
     }
 
     ParseNode& expression() const {
-        return *pn_u.name.expr;
+        return *pn_u.binary.left;
     }
 
     PropertyName& name() const {
-        return *pn_u.name.atom->asPropertyName();
+        return *pn_u.binary.right->pn_atom->asPropertyName();
     }
 
     JSAtom* nameAtom() const {
-        return pn_u.name.atom;
+        return pn_u.binary.right->pn_atom;
     }
 };
 
 class PropertyAccess : public PropertyAccessBase
 {
   public:
-    PropertyAccess(ParseNode* lhs, PropertyName* name, uint32_t begin,
-                   uint32_t end)
+    PropertyAccess(ParseNode* lhs, ParseNode* name, uint32_t begin, uint32_t end)
       : PropertyAccessBase(PNK_DOT, lhs, name, begin, end)
     {
         MOZ_ASSERT(lhs != nullptr);
@@ -1269,7 +1272,8 @@ class PropertyAccess : public PropertyAccessBase
 
     static bool test(const ParseNode& node) {
         bool match = node.isKind(PNK_DOT);
-        MOZ_ASSERT_IF(match, node.isArity(PN_NAME));
+        MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
+        MOZ_ASSERT_IF(match, node.pn_right->isKind(PNK_PROPERTYNAME));
         return match;
     }
 
@@ -1282,8 +1286,7 @@ class PropertyAccess : public PropertyAccessBase
 class OptionalPropertyAccess : public PropertyAccessBase
 {
   public:
-    OptionalPropertyAccess(ParseNode* lhs, PropertyName* name, uint32_t begin,
-                           uint32_t end)
+    OptionalPropertyAccess(ParseNode* lhs, ParseNode* name, uint32_t begin, uint32_t end)
       : PropertyAccessBase(PNK_OPTDOT, lhs, name, begin, end)
     {
         MOZ_ASSERT(lhs != nullptr);
@@ -1292,7 +1295,8 @@ class OptionalPropertyAccess : public PropertyAccessBase
 
     static bool test(const ParseNode& node) {
         bool match = node.isKind(PNK_OPTDOT);
-        MOZ_ASSERT_IF(match, node.isArity(PN_NAME));
+        MOZ_ASSERT_IF(match, node.isArity(PN_BINARY));
+        MOZ_ASSERT_IF(match, node.pn_right->isKind(PNK_PROPERTYNAME));
         return match;
     }
 };
diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 08812741af..779cd692c6 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -9333,11 +9333,14 @@ Parser<ParseHandler>::memberPropertyAccess(
         error(JSMSG_BAD_SUPERPROP, "property");
         return null();
     }
+    Node name = handler.newPropertyName(field, pos());
+    if (!name)
+        return null();    
     if (optionalKind == OptionalKind::Optional) {
         MOZ_ASSERT(!handler.isSuperBase(lhs));
-        return handler.newOptionalPropertyAccess(lhs, field, pos().end);
+        return handler.newOptionalPropertyAccess(lhs, name);
     }
-    return handler.newPropertyAccess(lhs, field, pos().end);
+    return handler.newPropertyAccess(lhs, name);
 }
 
 template <class ParseHandler>
diff --git a/js/src/frontend/SyntaxParseHandler.h b/js/src/frontend/SyntaxParseHandler.h
index 2ada163938..bca7400e55 100644
--- a/js/src/frontend/SyntaxParseHandler.h
+++ b/js/src/frontend/SyntaxParseHandler.h
@@ -360,13 +360,16 @@ class SyntaxParseHandler
     }
     Node newDebuggerStatement(const TokenPos& pos) { return NodeGeneric; }
 
-    Node newPropertyAccess(Node pn, PropertyName* name, uint32_t end) {
+    Node newPropertyName(PropertyName* name, const TokenPos& pos) {
         lastAtom = name;
+        return NodeGeneric;
+    }
+
+    Node newPropertyAccess(Node expr, Node key) {
         return NodeDottedProperty;
     }
 
-    Node newOptionalPropertyAccess(Node pn, PropertyName* name, uint32_t end) {
-        lastAtom = name;
+    Node newOptionalPropertyAccess(Node expr, Node key) {
         return NodeOptionalDottedProperty;
     }
 
diff --git a/js/src/wasm/AsmJS.cpp b/js/src/wasm/AsmJS.cpp
index be7db1a0a3..f359d19c2a 100644
--- a/js/src/wasm/AsmJS.cpp
+++ b/js/src/wasm/AsmJS.cpp
@@ -643,16 +643,16 @@ static ParseNode*
 DotBase(ParseNode* pn)
 {
     MOZ_ASSERT(pn->isKind(PNK_DOT));
-    MOZ_ASSERT(pn->isArity(PN_NAME));
-    return pn->expr();
+    MOZ_ASSERT(pn->isArity(PN_BINARY));
+    return pn->pn_left;
 }
 
 static PropertyName*
 DotMember(ParseNode* pn)
 {
     MOZ_ASSERT(pn->isKind(PNK_DOT));
-    MOZ_ASSERT(pn->isArity(PN_NAME));
-    return pn->pn_atom->asPropertyName();
+    MOZ_ASSERT(pn->isArity(PN_BINARY));
+    return pn->pn_right->pn_atom->asPropertyName();
 }
 
 static ParseNode*