EvaluateNonCompileAndGo, finally

gistfile1.diff

diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -843,17 +843,32 @@ Evaluate(JSContext *cx, unsigned argc, j
         return false;
 
     if ((JS_GetClass(thisobj)->flags & JSCLASS_IS_GLOBAL) != JSCLASS_IS_GLOBAL) {
         JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_UNEXPECTED_TYPE,
                              "this-value passed to evaluate()", "not a global object");
         return false;
     }
 
-    return JS_EvaluateUCScript(cx, thisobj, codeChars, codeLength, "@evaluate", 0, vp);
+    // Separate compile and execute steps for the benefit of EvaluteNonCompileAndGo, below.
+    // JS_EvaulateUCScript is shorter, but it always enables the compile-and-go option.
+    JSScript *script = JS_CompileUCScript(cx, thisobj, codeChars, codeLength, "@evaluate", 1);
+    if (!script)
+        return false;
+    return JS_ExecuteScript(cx, thisobj, script, vp);
 }
 
+static JSBool
+EvaluateNonCompileAndGo(JSContext *cx, unsigned argc, jsval *vp)
+{
+    uint32_t saved = JS_GetOptions(cx);
+    JS_SetOptions(cx, saved & ~JSOPTION_COMPILE_N_GO);
+    bool ok = Evaluate(cx, argc, vp);
+    JS_SetOptions(cx, saved);
+    return ok;
+}
+
 static JSString *
 FileAsString(JSContext *cx, const char *pathname)
 {
     FILE *file;
     JSString *str = NULL;
     size_t len, cc;
@@ -3526,16 +3541,20 @@ static JSFunctionSpecWithHelp shell_func
     JS_FN_HELP("load", Load, 1, 0,
 "load(['foo.js' ...])",
 "  Load files named by string arguments."),
 
     JS_FN_HELP("evaluate", Evaluate, 1, 0,
 "evaluate(code)",
 "  Evaluate code as though it were the contents of a file."),
 
+    JS_FN_HELP("evaluateNonCompileAndGo", EvaluateNonCompileAndGo, 1, 0,
+"evaluateNonCompileAndGo(code)",
+"  Evaluate code like evaluate() but with compile-and-go turned off."),
+
     JS_FN_HELP("evalWithLocation", EvaluateWithLocation, 3, 0,
 "evalWithLocation(code, filename, lineno)",
 "  Eval code as if loaded from the given filename and line number."),
 
     JS_FN_HELP("run", Run, 1, 0,
 "run('foo.js')",
 "  Run the file named by the first argument, returning the number of\n"
 "  of milliseconds spent compiling and executing it."),