hphp/util/exception.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16 #pragma once
  17
  18 #include <cstdarg>
  19 #include <stdexcept>
  20 #include <string>
  21
  22 #include "hphp/util/portability.h"
  23
  24 namespace HPHP {
  25 ///////////////////////////////////////////////////////////////////////////////
  26
  27 struct BaseException : std::exception {};
  28
  29 struct Exception : BaseException {
  30   explicit Exception() = default;
  31   explicit Exception(ATTRIBUTE_PRINTF_STRING const char *fmt, ...)
  32     ATTRIBUTE_PRINTF(2,3);
  33   explicit Exception(const std::string& msg);
  34   Exception(const Exception& e);
  35
  36   // Try not to use this function (or the other varargs-based things) in new
  37   // code.  (You probably shouldn't be using Exception directly either.)
  38   void format(ATTRIBUTE_PRINTF_STRING const char *fmt, va_list ap)
  39     ATTRIBUTE_PRINTF(2,0);
  40
  41   void setMessage(const char *msg) { m_msg = msg ? msg : "";}
  42
  43   ~Exception() noexcept override {}
  44   const char* what() const noexcept override;
  45
  46   struct Deleter {
  47     Exception* m_e;
  48     Deleter() : m_e(nullptr) {}
  49     explicit Deleter(Exception* e) : m_e(e) {}
  50     ~Deleter() { delete m_e; }
  51   };
  52
  53   virtual Exception* clone() {
  54     return new Exception(*this);
  55   }
  56   virtual void throwException() {
  57     Deleter deleter(this);
  58     throw *this;
  59   }
  60
  61   /**
  62    * Error message without stacktrace.
  63    */
  64   const std::string& getMessage() const { return m_msg; }
  65
  66 protected:
  67   mutable std::string m_msg;
  68   mutable std::string m_what;
  69 };
  70
  71 #define EXCEPTION_COMMON_IMPL(cls)               \
  72   cls* clone() override {                        \
  73     return new cls(*this);                       \
  74   }                                              \
  75   void throwException() override {               \
  76     Deleter deleter(this);                       \
  77     throw *this;                                 \
  78   }
  79
  80 ///////////////////////////////////////////////////////////////////////////////
  81
  82 struct FileOpenException : Exception {
  83   explicit FileOpenException(const std::string& filename)
  84       : Exception("Unable to open file %s", filename.c_str()) {
  85   }
  86
  87   EXCEPTION_COMMON_IMPL(FileOpenException);
  88 };
  89
  90 ///////////////////////////////////////////////////////////////////////////////
  91
  92 }
  93