xref: /linux/lib/zstd/common/error_private.h (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18)
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 
ERR_isError(size_t code)47 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
48 
ERR_getErrorCode(size_t code)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 
ERR_getErrorName(size_t code)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
_force_has_format_string(const char * format,...)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