1 /*
2 * Copyright (c) Meta Platforms, Inc. and affiliates.
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 * Dependencies
18 ******************************************/
19 #include "../zstd_errors.h" /* enum list */
20 #include "compiler.h"
21 #include "debug.h"
22 #include "zstd_deps.h" /* size_t */
23
24 /* ****************************************
25 * Compiler-specific
26 ******************************************/
27 #if defined(__GNUC__)
28 # define ERR_STATIC static __attribute__((unused))
29 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
30 # define ERR_STATIC static inline
31 #elif defined(_MSC_VER)
32 # define ERR_STATIC static __inline
33 #else
34 # define ERR_STATIC static /* this version may generate warnings for unused static functions; disable the relevant warning */
35 #endif
36
37
38 /*-****************************************
39 * Customization (error_public.h)
40 ******************************************/
41 typedef ZSTD_ErrorCode ERR_enum;
42 #define PREFIX(name) ZSTD_error_##name
43
44
45 /*-****************************************
46 * Error codes handling
47 ******************************************/
48 #undef ERROR /* already defined on Visual Studio */
49 #define ERROR(name) ZSTD_ERROR(name)
50 #define ZSTD_ERROR(name) ((size_t)-PREFIX(name))
51
ERR_isError(size_t code)52 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
53
ERR_getErrorCode(size_t code)54 ERR_STATIC ERR_enum ERR_getErrorCode(size_t code) { if (!ERR_isError(code)) return (ERR_enum)0; return (ERR_enum) (0-code); }
55
56 /* check and forward error code */
57 #define CHECK_V_F(e, f) \
58 size_t const e = f; \
59 do { \
60 if (ERR_isError(e)) \
61 return e; \
62 } while (0)
63 #define CHECK_F(f) do { CHECK_V_F(_var_err__, f); } while (0)
64
65
66 /*-****************************************
67 * Error Strings
68 ******************************************/
69
70 const char* ERR_getErrorString(ERR_enum code); /* error_private.c */
71
ERR_getErrorName(size_t code)72 ERR_STATIC const char* ERR_getErrorName(size_t code)
73 {
74 return ERR_getErrorString(ERR_getErrorCode(code));
75 }
76
77 /**
78 * Ignore: this is an internal helper.
79 *
80 * This is a helper function to help force C99-correctness during compilation.
81 * Under strict compilation modes, variadic macro arguments can't be empty.
82 * However, variadic function arguments can be. Using a function therefore lets
83 * us statically check that at least one (string) argument was passed,
84 * independent of the compilation flags.
85 */
86 static INLINE_KEYWORD UNUSED_ATTR
_force_has_format_string(const char * format,...)87 void _force_has_format_string(const char *format, ...) {
88 (void)format;
89 }
90
91 /**
92 * Ignore: this is an internal helper.
93 *
94 * We want to force this function invocation to be syntactically correct, but
95 * we don't want to force runtime evaluation of its arguments.
96 */
97 #define _FORCE_HAS_FORMAT_STRING(...) \
98 do { \
99 if (0) { \
100 _force_has_format_string(__VA_ARGS__); \
101 } \
102 } while (0)
103
104 #define ERR_QUOTE(str) #str
105
106 /**
107 * Return the specified error if the condition evaluates to true.
108 *
109 * In debug modes, prints additional information.
110 * In order to do that (particularly, printing the conditional that failed),
111 * this can't just wrap RETURN_ERROR().
112 */
113 #define RETURN_ERROR_IF(cond, err, ...) \
114 do { \
115 if (cond) { \
116 RAWLOG(3, "%s:%d: ERROR!: check %s failed, returning %s", \
117 __FILE__, __LINE__, ERR_QUOTE(cond), ERR_QUOTE(ERROR(err))); \
118 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
119 RAWLOG(3, ": " __VA_ARGS__); \
120 RAWLOG(3, "\n"); \
121 return ERROR(err); \
122 } \
123 } while (0)
124
125 /**
126 * Unconditionally return the specified error.
127 *
128 * In debug modes, prints additional information.
129 */
130 #define RETURN_ERROR(err, ...) \
131 do { \
132 RAWLOG(3, "%s:%d: ERROR!: unconditional check failed, returning %s", \
133 __FILE__, __LINE__, ERR_QUOTE(ERROR(err))); \
134 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
135 RAWLOG(3, ": " __VA_ARGS__); \
136 RAWLOG(3, "\n"); \
137 return ERROR(err); \
138 } while(0)
139
140 /**
141 * If the provided expression evaluates to an error code, returns that error code.
142 *
143 * In debug modes, prints additional information.
144 */
145 #define FORWARD_IF_ERROR(err, ...) \
146 do { \
147 size_t const err_code = (err); \
148 if (ERR_isError(err_code)) { \
149 RAWLOG(3, "%s:%d: ERROR!: forwarding error in %s: %s", \
150 __FILE__, __LINE__, ERR_QUOTE(err), ERR_getErrorName(err_code)); \
151 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
152 RAWLOG(3, ": " __VA_ARGS__); \
153 RAWLOG(3, "\n"); \
154 return err_code; \
155 } \
156 } while(0)
157
158 #endif /* ERROR_H_MODULE */
159