1 /*
2 * Copyright (c) Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11 /* Note : this module is expected to remain private, do not expose it */
12
13 #ifndef ERROR_H_MODULE
14 #define ERROR_H_MODULE
15
16
17
18 /* ****************************************
19 * Dependencies
20 ******************************************/
21 #include <linux/zstd_errors.h> /* enum list */
22 #include "compiler.h"
23 #include "debug.h"
24 #include "zstd_deps.h" /* size_t */
25
26
27 /* ****************************************
28 * Compiler-specific
29 ******************************************/
30 #define ERR_STATIC static __attribute__((unused))
31
32
33 /*-****************************************
34 * Customization (error_public.h)
35 ******************************************/
36 typedef ZSTD_ErrorCode ERR_enum;
37 #define PREFIX(name) ZSTD_error_##name
38
39
40 /*-****************************************
41 * Error codes handling
42 ******************************************/
43 #undef ERROR /* already defined on Visual Studio */
44 #define ERROR(name) ZSTD_ERROR(name)
45 #define ZSTD_ERROR(name) ((size_t)-PREFIX(name))
46
47 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
48
49 ERR_STATIC ERR_enum ERR_getErrorCode(size_t code) { if (!ERR_isError(code)) return (ERR_enum)0; return (ERR_enum) (0-code); }
50
51 /* check and forward error code */
52 #define CHECK_V_F(e, f) size_t const e = f; if (ERR_isError(e)) return e
53 #define CHECK_F(f) { CHECK_V_F(_var_err__, f); }
54
55
56 /*-****************************************
57 * Error Strings
58 ******************************************/
59
60 const char* ERR_getErrorString(ERR_enum code); /* error_private.c */
61
62 ERR_STATIC const char* ERR_getErrorName(size_t code)
63 {
64 return ERR_getErrorString(ERR_getErrorCode(code));
65 }
66
67 /*
68 * Ignore: this is an internal helper.
69 *
70 * This is a helper function to help force C99-correctness during compilation.
71 * Under strict compilation modes, variadic macro arguments can't be empty.
72 * However, variadic function arguments can be. Using a function therefore lets
73 * us statically check that at least one (string) argument was passed,
74 * independent of the compilation flags.
75 */
76 static INLINE_KEYWORD UNUSED_ATTR
77 void _force_has_format_string(const char *format, ...) {
78 (void)format;
79 }
80
81 /*
82 * Ignore: this is an internal helper.
83 *
84 * We want to force this function invocation to be syntactically correct, but
85 * we don't want to force runtime evaluation of its arguments.
86 */
87 #define _FORCE_HAS_FORMAT_STRING(...) \
88 if (0) { \
89 _force_has_format_string(__VA_ARGS__); \
90 }
91
92 #define ERR_QUOTE(str) #str
93
94 /*
95 * Return the specified error if the condition evaluates to true.
96 *
97 * In debug modes, prints additional information.
98 * In order to do that (particularly, printing the conditional that failed),
99 * this can't just wrap RETURN_ERROR().
100 */
101 #define RETURN_ERROR_IF(cond, err, ...) \
102 if (cond) { \
103 RAWLOG(3, "%s:%d: ERROR!: check %s failed, returning %s", \
104 __FILE__, __LINE__, ERR_QUOTE(cond), ERR_QUOTE(ERROR(err))); \
105 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
106 RAWLOG(3, ": " __VA_ARGS__); \
107 RAWLOG(3, "\n"); \
108 return ERROR(err); \
109 }
110
111 /*
112 * Unconditionally return the specified error.
113 *
114 * In debug modes, prints additional information.
115 */
116 #define RETURN_ERROR(err, ...) \
117 do { \
118 RAWLOG(3, "%s:%d: ERROR!: unconditional check failed, returning %s", \
119 __FILE__, __LINE__, ERR_QUOTE(ERROR(err))); \
120 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
121 RAWLOG(3, ": " __VA_ARGS__); \
122 RAWLOG(3, "\n"); \
123 return ERROR(err); \
124 } while(0);
125
126 /*
127 * If the provided expression evaluates to an error code, returns that error code.
128 *
129 * In debug modes, prints additional information.
130 */
131 #define FORWARD_IF_ERROR(err, ...) \
132 do { \
133 size_t const err_code = (err); \
134 if (ERR_isError(err_code)) { \
135 RAWLOG(3, "%s:%d: ERROR!: forwarding error in %s: %s", \
136 __FILE__, __LINE__, ERR_QUOTE(err), ERR_getErrorName(err_code)); \
137 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
138 RAWLOG(3, ": " __VA_ARGS__); \
139 RAWLOG(3, "\n"); \
140 return err_code; \
141 } \
142 } while(0);
143
144
145 #endif /* ERROR_H_MODULE */
146
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