err.h

   1 /*
   2  * libuci - Library for the Unified Configuration Interface
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 /*
  16  * functions for debug and error handling, for internal use only
  17  */
  18
  19 #ifdef DEBUG
  20 #define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
  21 #else
  22 #define DPRINTF(...)
  23 #endif
  24
  25 /*
  26  * throw an uci exception and store the error number
  27  * in the context.
  28  */
  29 #define UCI_THROW(ctx, err) do {        \
  30         longjmp(ctx->trap, err);        \
  31 } while (0)
  32
  33 /*
  34  * store the return address for handling exceptions
  35  * needs to be called in every externally visible library function
  36  *
  37  * NB: this does not handle recursion at all. Calling externally visible
  38  * functions from other uci functions is only allowed at the end of the
  39  * calling function.
  40  */
  41 #define UCI_HANDLE_ERR(ctx) do {        \
  42         int __val;                      \
  43         if (!ctx)                       \
  44                 return UCI_ERR_INVAL;   \
  45         __val = setjmp(ctx->trap);      \
  46         if (__val) {                    \
  47                 ctx->errno = __val;     \
  48                 return __val;           \
  49         }                               \
  50 } while (0)
  51
  52 /*
  53  * In a block enclosed by UCI_TRAP_SAVE and UCI_TRAP_RESTORE, all exceptions
  54  * are intercepted and redirected to the label specified in 'handler'
  55  * after UCI_TRAP_RESTORE, or when reaching the 'handler' label, the old
  56  * exception handler is restored
  57  */
  58 #define UCI_TRAP_SAVE(ctx, handler) do {   \
  59         jmp_buf __old_trap;             \
  60         int __val;                      \
  61         memcpy(__old_trap, ctx->trap, sizeof(ctx->trap)); \
  62         __val = setjmp(ctx->trap);      \
  63         if (__val) {                    \
  64                 ctx->errno = __val;     \
  65                 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
  66                 goto handler;           \
  67         }
  68 #define UCI_TRAP_RESTORE(ctx)           \
  69         memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
  70 } while(0)
  71
  72 /*
  73  * check the specified condition.
  74  * throw an invalid argument exception if it's false
  75  */
  76 #define UCI_ASSERT(ctx, expr) do {      \
  77         if (!(expr)) {                  \
  78                 DPRINTF("[%s:%d] Assertion failed\n", __FILE__, __LINE__); \
  79                 UCI_THROW(ctx, UCI_ERR_INVAL);  \
  80         }                               \
  81 } while (0)
  82