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 */