Bug 469177 - red/green analysis (cx->fp) doesn't actually run the analysis, r=jorendorff

js/src/jsstack.js

@@ -99,8 +99,13 @@ function RedGreenCheck(fndecl, trace) {
   // Using walk_tree to walk the isns is a little crazy but robust.
   //
   this.hasRed = false;
+  let self = this;         // Allow our 'this' to be accessed inside closure
   for (let bb in cfg_bb_iterator(cfg)) {
     for (let isn in bb_isn_iterator(bb)) {
+      // Treehydra objects don't support reading never-defined properties
+      // as undefined, so we have to explicitly initialize anything we want
+      // to check for later.
+      isn.redInfo = undefined;
       walk_tree(isn, function(t, stack) {
         switch (TREE_CODE(t)) {
           case FIELD_DECL:
@@ -109,7 +114,7 @@ function RedGreenCheck(fndecl, trace) {
               // location_of(t) is the location of the declaration.
               isn.redInfo = ["cannot access JS_REQUIRES_STACK variable " + varName,
                              location_of(stack[stack.length - 1])];
-              this.hasRed = true;
+              self.hasRed = true;
             }
             break;
           case CALL_EXPR:
@@ -120,7 +125,7 @@ function RedGreenCheck(fndecl, trace) {
                 let calleeName = dehydra_convert(callee).name;
                 isn.redInfo = ["cannot call JS_REQUIRES_STACK function " + calleeName,
                               location_of(t)];
-                this.hasRed = true;
+                self.hasRed = true;
               } else if (isTurnRed(callee)) {
                 isn.turnRed = true;
               }
@@ -156,7 +161,7 @@ RedGreenCheck.prototype.flowState = function(isn, state) {
   let redInfo = isn.redInfo;
   if (green && redInfo) {
     error(redInfo[0], redInfo[1]);
-    delete isn.redInfo;  // avoid duplicate messages about this instruction
+    isn.redInfo = undefined;  // avoid duplicate messages about this instruction
   }
 
   // If we call a TURNS_RED function, it doesn't take effect until after the