1/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
2/*
3 * Copyright (c) Meta Platforms, Inc. and affiliates.
4 * All rights reserved.
5 *
6 * This source code is licensed under both the BSD-style license (found in the
7 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
8 * in the COPYING file in the root directory of this source tree).
9 * You may select, at your option, one of the above-listed licenses.
10 */
11
12/* Note : this module is expected to remain private, do not expose it */
13
14#ifndef ERROR_H_MODULE
15#define ERROR_H_MODULE
16
17/* ****************************************
18* Dependencies
19******************************************/
20#include <linux/zstd_errors.h> /* enum list */
21#include "compiler.h"
22#include "debug.h"
23#include "zstd_deps.h" /* size_t */
24
25/* ****************************************
26* Compiler-specific
27******************************************/
28#define ERR_STATIC static __attribute__((unused))
29
30
31/*-****************************************
32* Customization (error_public.h)
33******************************************/
34typedef ZSTD_ErrorCode ERR_enum;
35#define PREFIX(name) ZSTD_error_##name
36
37
38/*-****************************************
39* Error codes handling
40******************************************/
41#undef ERROR /* already defined on Visual Studio */
42#define ERROR(name) ZSTD_ERROR(name)
43#define ZSTD_ERROR(name) ((size_t)-PREFIX(name))
44
45ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
46
47ERR_STATIC ERR_enum ERR_getErrorCode(size_t code) { if (!ERR_isError(code)) return (ERR_enum)0; return (ERR_enum) (0-code); }
48
49/* check and forward error code */
50#define CHECK_V_F(e, f) \
51 size_t const e = f; \
52 do { \
53 if (ERR_isError(e)) \
54 return e; \
55 } while (0)
56#define CHECK_F(f) do { CHECK_V_F(_var_err__, f); } while (0)
57
58
59/*-****************************************
60* Error Strings
61******************************************/
62
63const char* ERR_getErrorString(ERR_enum code); /* error_private.c */
64
65ERR_STATIC const char* ERR_getErrorName(size_t code)
66{
67 return ERR_getErrorString(code: ERR_getErrorCode(code));
68}
69
70/*
71 * Ignore: this is an internal helper.
72 *
73 * This is a helper function to help force C99-correctness during compilation.
74 * Under strict compilation modes, variadic macro arguments can't be empty.
75 * However, variadic function arguments can be. Using a function therefore lets
76 * us statically check that at least one (string) argument was passed,
77 * independent of the compilation flags.
78 */
79static INLINE_KEYWORD UNUSED_ATTR
80void _force_has_format_string(const char *format, ...) {
81 (void)format;
82}
83
84/*
85 * Ignore: this is an internal helper.
86 *
87 * We want to force this function invocation to be syntactically correct, but
88 * we don't want to force runtime evaluation of its arguments.
89 */
90#define _FORCE_HAS_FORMAT_STRING(...) \
91 do { \
92 if (0) { \
93 _force_has_format_string(__VA_ARGS__); \
94 } \
95 } while (0)
96
97#define ERR_QUOTE(str) #str
98
99/*
100 * Return the specified error if the condition evaluates to true.
101 *
102 * In debug modes, prints additional information.
103 * In order to do that (particularly, printing the conditional that failed),
104 * this can't just wrap RETURN_ERROR().
105 */
106#define RETURN_ERROR_IF(cond, err, ...) \
107 do { \
108 if (cond) { \
109 RAWLOG(3, "%s:%d: ERROR!: check %s failed, returning %s", \
110 __FILE__, __LINE__, ERR_QUOTE(cond), ERR_QUOTE(ERROR(err))); \
111 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
112 RAWLOG(3, ": " __VA_ARGS__); \
113 RAWLOG(3, "\n"); \
114 return ERROR(err); \
115 } \
116 } while (0)
117
118/*
119 * Unconditionally return the specified error.
120 *
121 * In debug modes, prints additional information.
122 */
123#define RETURN_ERROR(err, ...) \
124 do { \
125 RAWLOG(3, "%s:%d: ERROR!: unconditional check failed, returning %s", \
126 __FILE__, __LINE__, ERR_QUOTE(ERROR(err))); \
127 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
128 RAWLOG(3, ": " __VA_ARGS__); \
129 RAWLOG(3, "\n"); \
130 return ERROR(err); \
131 } while(0)
132
133/*
134 * If the provided expression evaluates to an error code, returns that error code.
135 *
136 * In debug modes, prints additional information.
137 */
138#define FORWARD_IF_ERROR(err, ...) \
139 do { \
140 size_t const err_code = (err); \
141 if (ERR_isError(err_code)) { \
142 RAWLOG(3, "%s:%d: ERROR!: forwarding error in %s: %s", \
143 __FILE__, __LINE__, ERR_QUOTE(err), ERR_getErrorName(err_code)); \
144 _FORCE_HAS_FORMAT_STRING(__VA_ARGS__); \
145 RAWLOG(3, ": " __VA_ARGS__); \
146 RAWLOG(3, "\n"); \
147 return err_code; \
148 } \
149 } while(0)
150
151#endif /* ERROR_H_MODULE */
152