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