1 files changed, 127 insertions, 0 deletions
diff --git a/js/src/shell/jsshell.cpp b/js/src/shell/jsshell.cpp
new file mode 100644
index 0000000000..ec7fadbc7a
--- /dev/null
+++ b/js/src/shell/jsshell.cpp
@@ -0,0 +1,127 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// jsshell.cpp - Utilities for the JS shell
+
+#include "shell/jsshell.h"
+
+#include "mozilla/Sprintf.h"
+
+#include "jsapi.h"
+#include "jsfriendapi.h"
+
+#include "util/StringBuffer.h"
+
+using namespace JS;
+
+namespace js {
+namespace shell {
+
+// Generate 'usage' and 'help' properties for the given object.
+// JS_DefineFunctionsWithHelp will define individual function objects with both
+// of those properties (eg getpid.usage = "getpid()" and getpid.help = "return
+// the process id"). This function will generate strings for an "interface
+// object", eg os.file, which contains some number of functions.
+//
+// .usage will be set to "<name> - interface object".
+//
+// .help will be set to a newline-separated list of functions that have either
+// 'help' or 'usage' properties. Functions are described with their usage
+// strings, if they have them, else with just their names.
+//
+bool GenerateInterfaceHelp(JSContext* cx, HandleObject obj, const char* name) {
+  RootedIdVector idv(cx);
+  if (!GetPropertyKeys(cx, obj, JSITER_OWNONLY | JSITER_HIDDEN, &idv)) {
+    return false;
+  }
+
+  JSStringBuilder buf(cx);
+  int numEntries = 0;
+  for (size_t i = 0; i < idv.length(); i++) {
+    RootedId id(cx, idv[i]);
+    RootedValue v(cx);
+    if (!JS_GetPropertyById(cx, obj, id, &v)) {
+      return false;
+    }
+    if (!v.isObject()) {
+      continue;
+    }
+    RootedObject prop(cx, &v.toObject());
+
+    RootedValue usage(cx);
+    RootedValue help(cx);
+    if (!JS_GetProperty(cx, prop, "usage", &usage)) {
+      return false;
+    }
+    if (!JS_GetProperty(cx, prop, "help", &help)) {
+      return false;
+    }
+    if (!usage.isString() && !help.isString()) {
+      continue;
+    }
+
+    if (numEntries && !buf.append("\n")) {
+      return false;
+    }
+    numEntries++;
+
+    if (!buf.append("  ", 2)) {
+      return false;
+    }
+
+    if (!buf.append(usage.isString() ? usage.toString() : JSID_TO_STRING(id))) {
+      return false;
+    }
+  }
+
+  RootedString s(cx, buf.finishString());
+  if (!s || !JS_DefineProperty(cx, obj, "help", s, 0)) {
+    return false;
+  }
+
+  buf.clear();
+  if (!buf.append(name, strlen(name)) ||
+      !buf.append(" - interface object with ", 25)) {
+    return false;
+  }
+  char cbuf[100];
+  SprintfLiteral(cbuf, "%d %s", numEntries,
+                 numEntries == 1 ? "entry" : "entries");
+  if (!buf.append(cbuf, strlen(cbuf))) {
+    return false;
+  }
+  s = buf.finishString();
+  if (!s || !JS_DefineProperty(cx, obj, "usage", s, 0)) {
+    return false;
+  }
+
+  return true;
+}
+
+bool CreateAlias(JSContext* cx, const char* dstName,
+                 JS::HandleObject namespaceObj, const char* srcName) {
+  RootedObject global(cx, JS::GetNonCCWObjectGlobal(namespaceObj));
+
+  RootedValue val(cx);
+  if (!JS_GetProperty(cx, namespaceObj, srcName, &val)) {
+    return false;
+  }
+
+  if (!val.isObject()) {
+    JS_ReportErrorASCII(cx, "attempted to alias nonexistent function");
+    return false;
+  }
+
+  RootedObject function(cx, &val.toObject());
+  if (!JS_DefineProperty(cx, global, dstName, function, 0)) {
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace shell
+}  // namespace js