plugins/xpcom/XpcomDebug.cpp

/*
 * Copyright 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

#include <cstring>

#include "XpcomDebug.h"
#include "JavaObject.h"

#ifdef _WINDOWS
// avoid deprecation warnings for strncpy
#define strncpy(d,s,c) strncpy_s((d),(c),(s),(c))

#include <cstdarg>
inline int snprintf(char* buf, size_t buflen, const char* fmt, ...) {
  va_list args;
  va_start(args, fmt);
  int n = _vsnprintf_s(buf, buflen, buflen, fmt, args);
  va_end(args);
  return n;
}

#endif

std::string dumpJsVal(JSContext* ctx, jsval v) {
  char buf[70];
  if (v == JSVAL_VOID) {
    strncpy(buf, "undef", sizeof(buf));
  } else if (v == JSVAL_NULL) {
    strncpy(buf, "null", sizeof(buf));
  } else {
    switch (JSVAL_TAG(v)) {
      case JSVAL_OBJECT:
      {
        JSObject* obj = JSVAL_TO_OBJECT(v);
        if (JavaObject::isJavaObject(ctx, obj)) {
          int oid = JavaObject::getObjectId(ctx, obj);
          snprintf(buf, sizeof(buf), "JavaObj(%d)", oid);
        } else {
          JSClass* jsClass = JS_GET_CLASS(ctx, obj);
          const char* name = jsClass->name ? jsClass->name : "<null>";
          snprintf(buf, sizeof(buf), "Object(%.20s @ %p)", name, obj);
        }
        break;
      }
      case JSVAL_INT:
        snprintf(buf, sizeof(buf), "int(%d)", JSVAL_TO_INT(v));
        break;
      case JSVAL_DOUBLE:
        snprintf(buf, sizeof(buf), "double(%lf)", *JSVAL_TO_DOUBLE(v));
        break;
      case JSVAL_STRING:
      {
        JSString* str = JSVAL_TO_STRING(v);
        size_t len = JS_GetStringLength(str);
        const char* continued = "";
        if (len > 20) {
          len = 20;
          continued = "...";
        }
        // TODO: trashes Unicode
        snprintf(buf, sizeof(buf), "string(%.*s%s)", static_cast<int>(len),
            JS_GetStringBytes(str), continued);
        break;
      }
      case JSVAL_BOOLEAN:
        snprintf(buf, sizeof(buf), "bool(%s)", JSVAL_TO_BOOLEAN(v) ? "true"
            : " false");
        break;
    }
  }
  buf[sizeof(buf) - 1] = 0;
  return std::string(buf);
}