Bug 1165486 - Debug function to dump static scope chain of scripts. (r=efaust)

js/src/shell/js.cpp

@@ -4318,6 +4318,36 @@ ReflectTrackedOptimizations(JSContext* cx, unsigned argc, Value* vp)
     return true;
 }
 
+#ifdef DEBUG
+static bool
+DumpStaticScopeChain(JSContext* cx, unsigned argc, Value* vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+    RootedObject callee(cx, &args.callee());
+
+    if (args.length() != 1) {
+        ReportUsageError(cx, callee, "Wrong number of arguments");
+        return false;
+    }
+
+    if (!args[0].isObject() || !args[0].toObject().is<JSFunction>()) {
+        ReportUsageError(cx, callee, "Argument must be an interpreted function");
+        return false;
+    }
+
+    RootedFunction fun(cx, &args[0].toObject().as<JSFunction>());
+    if (!fun->isInterpreted()) {
+        ReportUsageError(cx, callee, "Argument must be an interpreted function");
+        return false;
+    }
+
+    js::DumpStaticScopeChain(fun->getOrCreateScript(cx));
+
+    args.rval().setUndefined();
+    return true;
+}
+#endif
+
 namespace js {
 namespace shell {
 
@@ -4966,6 +4996,12 @@ static const JSFunctionSpecWithHelp fuzzing_unsafe_functions[] = {
 "  any. If |fun| is not a scripted function or has not been compiled by\n"
 "  Ion, null is returned."),
 
+#ifdef DEBUG
+    JS_FN_HELP("dumpStaticScopeChain", DumpStaticScopeChain, 1, 0,
+"dumpStaticScopeChain(fun)",
+"  Prints the static scope chain of an interpreted function fun."),
+#endif
+
     JS_FS_HELP_END
 };
 

js/src/vm/ScopeObject.cpp

@@ -2561,6 +2561,36 @@ js::HasNonSyntacticStaticScopeChain(JSObject* staticScope)
 
 #ifdef DEBUG
 
+void
+js::DumpStaticScopeChain(JSScript* script)
+{
+    JSObject* enclosingScope = script->enclosingStaticScope();
+    for (StaticScopeIter<NoGC> ssi(enclosingScope); !ssi.done(); ssi++) {
+        switch (ssi.type()) {
+          case StaticScopeIter<NoGC>::Function:
+            fprintf(stdout, "function");
+            break;
+          case StaticScopeIter<NoGC>::Block:
+            fprintf(stdout, "block");
+            break;
+          case StaticScopeIter<NoGC>::With:
+            fprintf(stdout, "with");
+            break;
+          case StaticScopeIter<NoGC>::NamedLambda:
+            fprintf(stdout, "named lambda");
+            break;
+          case StaticScopeIter<NoGC>::Eval:
+            fprintf(stdout, "eval");
+            break;
+          case StaticScopeIter<NoGC>::NonSyntactic:
+            fprintf(stdout, "non-syntactic");
+            break;
+        }
+        fprintf(stdout, " -> ");
+    }
+    fprintf(stdout, "global\n");
+}
+
 typedef HashSet<PropertyName*> PropertyNameSet;
 
 static bool

js/src/vm/ScopeObject.h

@@ -1176,6 +1176,7 @@ CreateScopeObjectsForScopeChain(JSContext* cx, AutoObjectVector& scopeChain,
 bool HasNonSyntacticStaticScopeChain(JSObject* staticScope);
 
 #ifdef DEBUG
+void DumpStaticScopeChain(JSScript* script);
 bool
 AnalyzeEntrainedVariables(JSContext* cx, HandleScript script);
 #endif