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******************************************/
36typedef 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
47ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
48
49ERR_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
60const char* ERR_getErrorString(ERR_enum code);   /* error_private.c */
61
62ERR_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 */
76static INLINE_KEYWORD UNUSED_ATTR
77void _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