rename ctx->errno to ctx->err to avoid conflicts with a #define errno in the system...
[project/uci.git] / 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 #define __public
19 #ifdef UCI_PLUGIN_SUPPORT
20 #define __plugin extern
21 #else
22 #define __plugin static
23 #endif
24
25 struct uci_parse_context
26 {
27 /* error context */
28 const char *reason;
29 int line;
30 int byte;
31
32 /* private: */
33 struct uci_package *package;
34 struct uci_section *section;
35 bool merge;
36 FILE *file;
37 const char *name;
38 char *buf;
39 int bufsz;
40 };
41
42 __plugin void *uci_malloc(struct uci_context *ctx, size_t size);
43 __plugin void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size);
44 __plugin char *uci_strdup(struct uci_context *ctx, const char *str);
45 __plugin bool uci_validate_str(const char *str, bool name);
46 __plugin void uci_add_history(struct uci_context *ctx, struct uci_list *list, int cmd, char *section, char *option, char *value);
47 __plugin void uci_free_history(struct uci_history *h);
48 __plugin struct uci_package *uci_alloc_package(struct uci_context *ctx, const char *name);
49
50 #ifdef UCI_PLUGIN_SUPPORT
51 /**
52 * uci_add_backend: add an extra backend
53 * @ctx: uci context
54 * @name: name of the backend
55 *
56 * The default backend is "file", which uses /etc/config for config storage
57 */
58 __plugin int uci_add_backend(struct uci_context *ctx, struct uci_backend *b);
59
60 /**
61 * uci_add_backend: add an extra backend
62 * @ctx: uci context
63 * @name: name of the backend
64 *
65 * The default backend is "file", which uses /etc/config for config storage
66 */
67 __plugin int uci_del_backend(struct uci_context *ctx, struct uci_backend *b);
68 #endif
69
70 #define UCI_BACKEND(_var, _name, ...) \
71 struct uci_backend _var = { \
72 .e.list = { \
73 .next = &_var.e.list, \
74 .prev = &_var.e.list, \
75 }, \
76 .e.name = _name, \
77 .e.type = UCI_TYPE_BACKEND, \
78 .ptr = &_var, \
79 __VA_ARGS__ \
80 }
81
82
83 /*
84 * functions for debug and error handling, for internal use only
85 */
86
87 #ifdef UCI_DEBUG
88 #define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
89 #else
90 #define DPRINTF(...)
91 #endif
92
93 /*
94 * throw an uci exception and store the error number
95 * in the context.
96 */
97 #define UCI_THROW(ctx, err) do { \
98 DPRINTF("Exception: %s in %s, %s:%d\n", #err, __func__, __FILE__, __LINE__); \
99 longjmp(ctx->trap, err); \
100 } while (0)
101
102 /*
103 * store the return address for handling exceptions
104 * needs to be called in every externally visible library function
105 *
106 * NB: this does not handle recursion at all. Calling externally visible
107 * functions from other uci functions is only allowed at the end of the
108 * calling function, or by wrapping the function call in UCI_TRAP_SAVE
109 * and UCI_TRAP_RESTORE.
110 */
111 #define UCI_HANDLE_ERR(ctx) do { \
112 DPRINTF("ENTER: %s\n", __func__); \
113 int __val = 0; \
114 ctx->err = 0; \
115 if (!ctx) \
116 return UCI_ERR_INVAL; \
117 if (!ctx->internal) \
118 __val = setjmp(ctx->trap); \
119 ctx->internal = false; \
120 if (__val) { \
121 DPRINTF("LEAVE: %s, ret=%d\n", __func__, __val); \
122 ctx->err = __val; \
123 return __val; \
124 } \
125 } while (0)
126
127 /*
128 * In a block enclosed by UCI_TRAP_SAVE and UCI_TRAP_RESTORE, all exceptions
129 * are intercepted and redirected to the label specified in 'handler'
130 * after UCI_TRAP_RESTORE, or when reaching the 'handler' label, the old
131 * exception handler is restored
132 */
133 #define UCI_TRAP_SAVE(ctx, handler) do { \
134 jmp_buf __old_trap; \
135 int __val; \
136 memcpy(__old_trap, ctx->trap, sizeof(ctx->trap)); \
137 __val = setjmp(ctx->trap); \
138 if (__val) { \
139 ctx->err = __val; \
140 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
141 goto handler; \
142 }
143 #define UCI_TRAP_RESTORE(ctx) \
144 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
145 } while(0)
146
147 /**
148 * UCI_INTERNAL: Do an internal call of a public API function
149 *
150 * Sets Exception handling to passthrough mode.
151 * Allows API functions to change behavior compared to public use
152 */
153 #define UCI_INTERNAL(func, ctx, ...) do { \
154 ctx->internal = true; \
155 func(ctx, __VA_ARGS__); \
156 } while (0)
157
158 /*
159 * check the specified condition.
160 * throw an invalid argument exception if it's false
161 */
162 #define UCI_ASSERT(ctx, expr) do { \
163 if (!(expr)) { \
164 DPRINTF("[%s:%d] Assertion failed\n", __FILE__, __LINE__); \
165 UCI_THROW(ctx, UCI_ERR_INVAL); \
166 } \
167 } while (0)
168
169 #endif