Bug 1130811 - Actually use PNK_CATCHLIST so that PNK_CATCH isn't used for multiple arities and situations in practice. r=shu

--HG--
extra : rebase_source : 123c0e24385b70984557964e73ec9bc30050fe24

js/src/frontend/BytecodeEmitter.cpp

@@ -4575,7 +4575,10 @@ EmitTry(ExclusiveContext *cx, BytecodeEmitter *bce, ParseNode *pn)
     ptrdiff_t tryEnd = bce->offset();
 
     // If this try has a catch block, emit it.
-    if (ParseNode *pn2 = pn->pn_kid2) {
+    ParseNode *catchList = pn->pn_kid2;
+    if (catchList) {
+        MOZ_ASSERT(catchList->isKind(PNK_CATCHLIST));
+
         // The emitted code for a catch block looks like:
         //
         // [pushblockscope]             only if any local aliased
@@ -4601,7 +4604,7 @@ EmitTry(ExclusiveContext *cx, BytecodeEmitter *bce, ParseNode *pn)
         // code if appropriate, and is also used for the catch-all trynote for
         // capturing exceptions thrown from catch{} blocks.
         //
-        for (ParseNode *pn3 = pn2->pn_head; pn3; pn3 = pn3->pn_next) {
+        for (ParseNode *pn3 = catchList->pn_head; pn3; pn3 = pn3->pn_next) {
             MOZ_ASSERT(bce->stackDepth == depth);
 
             // Emit the lexical scope and catch body.
@@ -4676,7 +4679,7 @@ EmitTry(ExclusiveContext *cx, BytecodeEmitter *bce, ParseNode *pn)
 
     // Add the try note last, to let post-order give us the right ordering
     // (first to last for a given nesting level, inner to outer by level).
-    if (pn->pn_kid2 && !bce->tryNoteList.append(JSTRY_CATCH, depth, tryStart, tryEnd))
+    if (catchList && !bce->tryNoteList.append(JSTRY_CATCH, depth, tryStart, tryEnd))
         return false;
 
     // If we've got a finally, mark try+catch region with additional

js/src/frontend/FullParseHandler.h

@@ -600,6 +600,9 @@ class FullParseHandler
         return new_<ListNode>(kind, op, kid);
     }
 
+    ParseNode *newCatchList() {
+        return new_<ListNode>(PNK_CATCHLIST, JSOP_NOP, pos());
+    }
 
     ParseNode *newCommaExpressionList(ParseNode *kid) {
         return newList(PNK_COMMA, kid, JSOP_NOP);

js/src/frontend/ParseNode.h

@@ -286,10 +286,11 @@ enum ParseNodeKind
  *                          pn_kid3:  update expr after second ';' or nullptr
  * PNK_THROW    unary       pn_op: JSOP_THROW, pn_kid: exception
  * PNK_TRY      ternary     pn_kid1: try block
- *                          pn_kid2: null or PNK_CATCHLIST list of
- *                          PNK_LEXICALSCOPE nodes, each with pn_expr pointing
- *                          to a PNK_CATCH node
+ *                          pn_kid2: null or PNK_CATCHLIST list
  *                          pn_kid3: null or finally block
+ * PNK_CATCHLIST list       pn_head: list of PNK_LEXICALSCOPE nodes, one per
+ *                                   catch-block, each with pn_expr pointing
+ *                                   to a PNK_CATCH node
  * PNK_CATCH    ternary     pn_kid1: PNK_NAME, PNK_ARRAY, or PNK_OBJECT catch var node
  *                                   (PNK_ARRAY or PNK_OBJECT if destructuring)
  *                          pn_kid2: null or the catch guard expression

js/src/frontend/Parser.cpp

@@ -5629,7 +5629,7 @@ Parser<ParseHandler>::tryStatement()
     if (!tokenStream.getToken(&tt))
         return null();
     if (tt == TOK_CATCH) {
-        catchList = handler.newList(PNK_CATCH);
+        catchList = handler.newCatchList();
         if (!catchList)
             return null();
 

js/src/frontend/SyntaxParseHandler.h

@@ -267,6 +267,10 @@ class SyntaxParseHandler
         return NodeGeneric;
     }
 
+    Node newCatchList() {
+        return newList(PNK_CATCHLIST, JSOP_NOP);
+    }
+
     Node newCommaExpressionList(Node kid) {
         return NodeUnparenthesizedCommaExpr;
     }

js/src/jsreflect.cpp

@@ -2302,11 +2302,11 @@ ASTSerializer::tryStatement(ParseNode *pn, MutableHandleValue dst)
     NodeVector guarded(cx);
     RootedValue unguarded(cx, NullValue());
 
-    if (pn->pn_kid2) {
-        if (!guarded.reserve(pn->pn_kid2->pn_count))
+    if (ParseNode *catchList = pn->pn_kid2) {
+        if (!guarded.reserve(catchList->pn_count))
             return false;
 
-        for (ParseNode *next = pn->pn_kid2->pn_head; next; next = next->pn_next) {
+        for (ParseNode *next = catchList->pn_head; next; next = next->pn_next) {
             RootedValue clause(cx);
             bool isGuarded;
             if (!catchClause(next->pn_expr, &isGuarded, &clause))