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 #if defined (__cplusplus)
17 extern "C" {
18 #endif
19
20
21 /* ****************************************
22 * Dependencies
23 ******************************************/
24 #include "../zstd_errors.h" /* enum list */
25 #include "compiler.h"
26 #include "debug.h"
27 #include "zstd_deps.h" /* size_t */
28
29
30 /* ****************************************
31 * Compiler-specific
32 ******************************************/
33 #if defined(__GNUC__)
34 # define ERR_STATIC static __attribute__((unused))
35 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
36 # define ERR_STATIC static inline
37 #elif defined(_MSC_VER)
38 # define ERR_STATIC static __inline
39 #else
40 # define ERR_STATIC static /* this version may generate warnings for unused static functions; disable the relevant warning */
41 #endif
42
43
44 /*-****************************************
45 * Customization (error_public.h)
46 ******************************************/
47 typedef ZSTD_ErrorCode ERR_enum;
48 #define PREFIX(name) ZSTD_error_##name
49
50
51 /*-****************************************
52 * Error codes handling
53 ******************************************/
54 #undef ERROR /* already defined on Visual Studio */
55 #define ERROR(name) ZSTD_ERROR(name)
56 #define ZSTD_ERROR(name) ((size_t)-PREFIX(name))
57
ERR_isError(size_t code)58 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
59
ERR_getErrorCode(size_t code)60 ERR_STATIC ERR_enum ERR_getErrorCode(size_t code) { if (!ERR_isError(code)) return (ERR_enum)0; return (ERR_enum) (0-code); }
61
62 /* check and forward error code */
63 #define CHECK_V_F(e, f) \
64 size_t const e = f; \
65 do { \
66 if (ERR_isError(e)) \
67 return e; \
68 } while (0)
69 #define CHECK_F(f) do { CHECK_V_F(_var_err__, f); } while (0)
70
71
72 /*-****************************************
73 * Error Strings
74 ******************************************/
75
76 const char* ERR_getErrorString(ERR_enum code); /* error_private.c */
77
ERR_getErrorName(size_t code)78 ERR_STATIC const char* ERR_getErrorName(size_t code)
79 {
80 return ERR_getErrorString(ERR_getErrorCode(code));
81 }
82
83 /**
84 * Ignore: this is an internal helper.
85 *
86 * This is a helper function to help force C99-correctness during compilation.
87 * Under strict compilation modes, variadic macro arguments can't be empty.
88 * However, variadic function arguments can be. Using a function therefore lets
89 * us statically check that at least one (string) argument was passed,
90 * independent of the compilation flags.
91 */
92 static INLINE_KEYWORD UNUSED_ATTR
_force_has_format_string(const char * format,...)93 void _force_has_format_string(const char *format, ...) {
94 (void)format;
95 }
96
97 /**
98 * Ignore: this is an internal helper.
99 *
100 * We want to force this function invocation to be syntactically correct, but
101 * we don't want to force runtime evaluation of its arguments.
102 */
103 #define _FORCE_HAS_FORMAT_STRING(...) \
104 do { \
105 if (0) { \
106 _force_has_format_string(__VA_ARGS__); \
107 } \
108 } while (0)
109
110 #define ERR_QUOTE(str) #str
111
112 /**
113 * Return the specified error if the condition evaluates to true.
114 *
115 * In debug modes, prints additional information.
116 * In order to do that (particularly, printing the conditional that failed),
117 * this can't just wrap RETURN_ERROR().
118 */
119 #define RETURN_ERROR_IF(cond, err, ...) \
120 do { \
121 if (cond) { \
122 RAWLOG(3, "%s:%d: ERROR!: check %s failed, returning %s", \
123 __FILE__, __LINE__, ERR_QUOTE(cond), ERR_QUOTE(ERROR(err))); \
124 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
125 RAWLOG(3, ": " __VA_ARGS__); \
126 RAWLOG(3, "\n"); \
127 return ERROR(err); \
128 } \
129 } while (0)
130
131 /**
132 * Unconditionally return the specified error.
133 *
134 * In debug modes, prints additional information.
135 */
136 #define RETURN_ERROR(err, ...) \
137 do { \
138 RAWLOG(3, "%s:%d: ERROR!: unconditional check failed, returning %s", \
139 __FILE__, __LINE__, ERR_QUOTE(ERROR(err))); \
140 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
141 RAWLOG(3, ": " __VA_ARGS__); \
142 RAWLOG(3, "\n"); \
143 return ERROR(err); \
144 } while(0)
145
146 /**
147 * If the provided expression evaluates to an error code, returns that error code.
148 *
149 * In debug modes, prints additional information.
150 */
151 #define FORWARD_IF_ERROR(err, ...) \
152 do { \
153 size_t const err_code = (err); \
154 if (ERR_isError(err_code)) { \
155 RAWLOG(3, "%s:%d: ERROR!: forwarding error in %s: %s", \
156 __FILE__, __LINE__, ERR_QUOTE(err), ERR_getErrorName(err_code)); \
157 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
158 RAWLOG(3, ": " __VA_ARGS__); \
159 RAWLOG(3, "\n"); \
160 return err_code; \
161 } \
162 } while(0)
163
164 #if defined (__cplusplus)
165 }
166 #endif
167
168 #endif /* ERROR_H_MODULE */
169