add uci_set_backend()
[project/uci.git] / 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 UCI_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 DPRINTF("Exception: %s in %s, %s:%d\n", #err, __func__, __FILE__, __LINE__); \
31 longjmp(ctx->trap, err); \
32 } while (0)
33
34 /*
35 * store the return address for handling exceptions
36 * needs to be called in every externally visible library function
37 *
38 * NB: this does not handle recursion at all. Calling externally visible
39 * functions from other uci functions is only allowed at the end of the
40 * calling function, or by wrapping the function call in UCI_TRAP_SAVE
41 * and UCI_TRAP_RESTORE.
42 */
43 #define UCI_HANDLE_ERR(ctx) do { \
44 DPRINTF("ENTER: %s\n", __func__); \
45 int __val = 0; \
46 ctx->errno = 0; \
47 if (!ctx) \
48 return UCI_ERR_INVAL; \
49 if (!ctx->internal) \
50 __val = setjmp(ctx->trap); \
51 ctx->internal = false; \
52 if (__val) { \
53 DPRINTF("LEAVE: %s, ret=%d\n", __func__, __val); \
54 ctx->errno = __val; \
55 return __val; \
56 } \
57 } while (0)
58
59 /*
60 * In a block enclosed by UCI_TRAP_SAVE and UCI_TRAP_RESTORE, all exceptions
61 * are intercepted and redirected to the label specified in 'handler'
62 * after UCI_TRAP_RESTORE, or when reaching the 'handler' label, the old
63 * exception handler is restored
64 */
65 #define UCI_TRAP_SAVE(ctx, handler) do { \
66 jmp_buf __old_trap; \
67 int __val; \
68 memcpy(__old_trap, ctx->trap, sizeof(ctx->trap)); \
69 __val = setjmp(ctx->trap); \
70 if (__val) { \
71 ctx->errno = __val; \
72 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
73 goto handler; \
74 }
75 #define UCI_TRAP_RESTORE(ctx) \
76 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
77 } while(0)
78
79 /**
80 * UCI_INTERNAL: Do an internal call of a public API function
81 *
82 * Sets Exception handling to passthrough mode.
83 * Allows API functions to change behavior compared to public use
84 */
85 #define UCI_INTERNAL(func, ctx, ...) do { \
86 ctx->internal = true; \
87 func(ctx, __VA_ARGS__); \
88 } while (0)
89
90 /*
91 * check the specified condition.
92 * throw an invalid argument exception if it's false
93 */
94 #define UCI_ASSERT(ctx, expr) do { \
95 if (!(expr)) { \
96 DPRINTF("[%s:%d] Assertion failed\n", __FILE__, __LINE__); \
97 UCI_THROW(ctx, UCI_ERR_INVAL); \
98 } \
99 } while (0)
100