uci_internal.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 #ifndef __UCI_INTERNAL_H
  16 #define __UCI_INTERNAL_H
  17
  18 struct uci_parse_context
  19 {
  20         /* error context */
  21         const char *reason;
  22         int line;
  23         int byte;
  24
  25         /* private: */
  26         struct uci_package *package;
  27         struct uci_section *section;
  28         bool merge;
  29         FILE *file;
  30         const char *name;
  31         char *buf;
  32         int bufsz;
  33 };
  34
  35 static void uci_add_history(struct uci_context *ctx, struct uci_list *list, int cmd, char *section, char *option, char *value);
  36 static void uci_free_history(struct uci_history *h);
  37
  38 /*
  39  * functions for debug and error handling, for internal use only
  40  */
  41
  42 #ifdef UCI_DEBUG
  43 #define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
  44 #else
  45 #define DPRINTF(...)
  46 #endif
  47
  48 /*
  49  * throw an uci exception and store the error number
  50  * in the context.
  51  */
  52 #define UCI_THROW(ctx, err) do {        \
  53         DPRINTF("Exception: %s in %s, %s:%d\n", #err, __func__, __FILE__, __LINE__); \
  54         longjmp(ctx->trap, err);        \
  55 } while (0)
  56
  57 /*
  58  * store the return address for handling exceptions
  59  * needs to be called in every externally visible library function
  60  *
  61  * NB: this does not handle recursion at all. Calling externally visible
  62  * functions from other uci functions is only allowed at the end of the
  63  * calling function, or by wrapping the function call in UCI_TRAP_SAVE
  64  * and UCI_TRAP_RESTORE.
  65  */
  66 #define UCI_HANDLE_ERR(ctx) do {        \
  67         DPRINTF("ENTER: %s\n", __func__); \
  68         int __val = 0;                  \
  69         ctx->errno = 0;                 \
  70         if (!ctx)                       \
  71                 return UCI_ERR_INVAL;   \
  72         if (!ctx->internal)             \
  73                 __val = setjmp(ctx->trap); \
  74         ctx->internal = false;          \
  75         if (__val) {                    \
  76                 DPRINTF("LEAVE: %s, ret=%d\n", __func__, __val); \
  77                 ctx->errno = __val;     \
  78                 return __val;           \
  79         }                               \
  80 } while (0)
  81
  82 /*
  83  * In a block enclosed by UCI_TRAP_SAVE and UCI_TRAP_RESTORE, all exceptions
  84  * are intercepted and redirected to the label specified in 'handler'
  85  * after UCI_TRAP_RESTORE, or when reaching the 'handler' label, the old
  86  * exception handler is restored
  87  */
  88 #define UCI_TRAP_SAVE(ctx, handler) do {   \
  89         jmp_buf __old_trap;             \
  90         int __val;                      \
  91         memcpy(__old_trap, ctx->trap, sizeof(ctx->trap)); \
  92         __val = setjmp(ctx->trap);      \
  93         if (__val) {                    \
  94                 ctx->errno = __val;     \
  95                 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
  96                 goto handler;           \
  97         }
  98 #define UCI_TRAP_RESTORE(ctx)           \
  99         memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
 100 } while(0)
 101
 102 /**
 103  * UCI_INTERNAL: Do an internal call of a public API function
 104  *
 105  * Sets Exception handling to passthrough mode.
 106  * Allows API functions to change behavior compared to public use
 107  */
 108 #define UCI_INTERNAL(func, ctx, ...) do { \
 109         ctx->internal = true;           \
 110         func(ctx, __VA_ARGS__);         \
 111 } while (0)
 112
 113 /*
 114  * check the specified condition.
 115  * throw an invalid argument exception if it's false
 116  */
 117 #define UCI_ASSERT(ctx, expr) do {      \
 118         if (!(expr)) {                  \
 119                 DPRINTF("[%s:%d] Assertion failed\n", __FILE__, __LINE__); \
 120                 UCI_THROW(ctx, UCI_ERR_INVAL);  \
 121         }                               \
 122 } while (0)
 123
 124 #endif