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 ******************************************/ 34 typedef 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 45 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); } 46 47 ERR_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 63 const char* ERR_getErrorString(ERR_enum code); /* error_private.c */ 64 65 ERR_STATIC const char* ERR_getErrorName(size_t code) 66 { 67 return ERR_getErrorString(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 */ 79 static INLINE_KEYWORD UNUSED_ATTR 80 void _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