diff options
Diffstat (limited to 'src/common')
| -rw-r--r-- | src/common/CMakeLists.txt | 4 | ||||
| -rw-r--r-- | src/common/error.cpp | 75 | ||||
| -rw-r--r-- | src/common/error.h | 52 | ||||
| -rw-r--r-- | src/common/expect.cpp | 70 | ||||
| -rw-r--r-- | src/common/expect.h | 447 |
5 files changed, 648 insertions, 0 deletions
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt index c6bac2199..e89dbbc24 100644 --- a/src/common/CMakeLists.txt +++ b/src/common/CMakeLists.txt @@ -33,6 +33,8 @@ set(common_sources command_line.cpp dns_utils.cpp download.cpp + error.cpp + expect.cpp util.cpp i18n.cpp password.cpp @@ -55,6 +57,8 @@ set(common_private_headers common_fwd.h dns_utils.h download.h + error.h + expect.h http_connection.h int-util.h pod-class.h diff --git a/src/common/error.cpp b/src/common/error.cpp new file mode 100644 index 000000000..e091e4478 --- /dev/null +++ b/src/common/error.cpp @@ -0,0 +1,75 @@ +// Copyright (c) 2018, The Monero Project +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +#include "error.h" + +#include <string> + +namespace +{ + struct category final : std::error_category + { + virtual const char* name() const noexcept override final + { + return "common_category()"; + } + + virtual std::string message(int value) const override final + { + switch (common_error(value)) + { + case common_error::kInvalidArgument: + return make_error_code(std::errc::invalid_argument).message(); + case common_error::kInvalidErrorCode: + return "expect<T> was given an error value of zero"; + default: + break; + } + return "Unknown basic_category() value"; + } + + virtual std::error_condition default_error_condition(int value) const noexcept override final + { + // maps specific errors to generic `std::errc` cases. + switch (common_error(value)) + { + case common_error::kInvalidArgument: + case common_error::kInvalidErrorCode: + return std::errc::invalid_argument; + default: + break; + } + return std::error_condition{value, *this}; + } + }; +} + +std::error_category const& common_category() noexcept +{ + static const category instance{}; + return instance; +} + diff --git a/src/common/error.h b/src/common/error.h new file mode 100644 index 000000000..6fef3eb4b --- /dev/null +++ b/src/common/error.h @@ -0,0 +1,52 @@ +// Copyright (c) 2018, The Monero Project +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +#pragma once + +#include <system_error> +#include <type_traits> + +enum class common_error : int +{ + // 0 is reserved for no error, as per expect<T> + kInvalidArgument = 1, //!< A function argument is invalid + kInvalidErrorCode //!< Default `std::error_code` given to `expect<T>` +}; + +std::error_category const& common_category() noexcept; + +inline std::error_code make_error_code(::common_error value) noexcept +{ + return std::error_code{int(value), common_category()}; +} + +namespace std +{ + template<> + struct is_error_code_enum<::common_error> + : true_type + {}; +} diff --git a/src/common/expect.cpp b/src/common/expect.cpp new file mode 100644 index 000000000..c86e23e95 --- /dev/null +++ b/src/common/expect.cpp @@ -0,0 +1,70 @@ +// +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include "expect.h" + +#include <easylogging++.h> +#include <string> + +namespace detail +{ + namespace + { + std::string generate_error(const char* msg, const char* file, unsigned line) + { + std::string error_msg{}; + if (msg) + { + error_msg.append(msg); + if (file) + error_msg.append(" ("); + } + if (file) + { + error_msg.append("thrown at "); + + // remove path, get just filename + extension + char buff[256] = {0}; + el::base::utils::File::buildBaseFilename(file, buff, sizeof(buff) - 1); + error_msg.append(buff); + + error_msg.push_back(':'); + error_msg.append(std::to_string(line)); + } + if (msg && file) + error_msg.push_back(')'); + return error_msg; + } + } + + void expect::throw_(std::error_code ec, const char* msg, const char* file, unsigned line) + { + if (msg || file) + throw std::system_error{ec, generate_error(msg, file, line)}; + throw std::system_error{ec}; + } +} // detail diff --git a/src/common/expect.h b/src/common/expect.h new file mode 100644 index 000000000..326242502 --- /dev/null +++ b/src/common/expect.h @@ -0,0 +1,447 @@ +// Copyright (c) 2018, The Monero Project +// +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#pragma once + +#include <cassert> +#include <system_error> +#include <type_traits> +#include <utility> + +#include "common/error.h" + +//! If precondition fails, return `::error::kInvalidArgument` in current scope. +#define MONERO_PRECOND(...) \ + do \ + { \ + if (!( __VA_ARGS__ )) \ + return {::common_error::kInvalidArgument}; \ + } while (0) + +//! Check `expect<void>` and return errors in current scope. +#define MONERO_CHECK(...) \ + do \ + { \ + const ::expect<void> result = __VA_ARGS__ ; \ + if (!result) \ + return result.error(); \ + } while (0) + +/*! Get `T` from `expect<T>` by `std::move` as-if by function call. + `expect<void>` returns nothing. + + \throw std::system_error with `expect<T>::error()`, filename and line + number when `expect<T>::has_error() == true`.*/ +#define MONERO_UNWRAP(...) \ + ::detail::expect::unwrap( __VA_ARGS__ , nullptr, __FILE__ , __LINE__ ) + +/* \throw std::system_error with `code` and `msg` as part of the details. The +filename and line number will automatically be injected into the explanation +string. `code` can be any enum convertible to `std::error_code`. */ +#define MONERO_THROW(code, msg) \ + ::detail::expect::throw_( code , msg , __FILE__ , __LINE__ ) + + +template<typename> class expect; + +namespace detail +{ + // Shortens the characters in the places that `enable_if` is used below. + template<bool C> + using enable_if = typename std::enable_if<C>::type; + + struct expect + { + //! \throw std::system_error with `ec`, optional `msg` and/or optional `file` + `line`. + static void throw_(std::error_code ec, const char* msg, const char* file, unsigned line); + + //! If `result.has_error()` call `throw_`. Otherwise, \return `*result` by move. + template<typename T> + static T unwrap(::expect<T>&& result, const char* error_msg, const char* file, unsigned line) + { + if (!result) + throw_(result.error(), error_msg, file, line); + return std::move(*result); + } + + //! If `result.has_error()` call `throw_`. + static void unwrap(::expect<void>&& result, const char* error_msg, const char* file, unsigned line); + }; +} + +/*! + `expect<T>` is a value or error implementation, similar to Rust std::result + or various C++ proposals (boost::expected, boost::outcome). This + implementation currently has a strict error type, `std::error_code`, and a + templated value type `T`. `expect<T>` is implicitly convertible from `T` + or `std::error_code`, and one `expect<T>` object type is implicitly + convertible to another `expect<U>` object iff the destination value type + can be implicitly constructed from the source value type (i.e. + `struct U { ... U(T src) { ...} ... };`). + + `operator==` and `operator!=` are the only comparison operators provided; + comparison between different value types is allowed provided the two values + types have a `operator==` defined between them (i.e. + `assert(expect<int>{100} == expect<short>{100});`). Comparisons can also be + done against `std::error_code` objects or error code enums directly (i.e. + `assert(expect<int>{make_error_code(common_error::kInvalidArgument)} == error::kInvalidArgument)`). + Comparison of default constructed `std::error_code` will always fail. + "Generic" comparisons can be done with `std::error_condition` via the `matches` + method only (i.e. + `assert(expect<int>{make_error_code{common_error::kInvalidErrorCode}.matches(std::errc::invalid_argument))`), + `operator==` and `operator!=` will not work with `std::errc` or + `std::error_condition`. A comparison with `matches` is more expensive + because an equivalency between error categories is computed, but is + recommended when an error can be one of several categories (this is going + to be the case in nearly every situation when calling a function from + another C++ struct/class). + + `expect<void>` is a special case with no stored value. It is used by + functions that can fail, but otherwise would return `void`. It is useful + for consistency; all macros, standalone functions, and comparison operators + work with `expect<void>`. + + \note See `src/common/error.h` for creating a custom error enum. + */ +template<typename T> +class expect +{ + static_assert(std::is_nothrow_destructible<T>(), "T must have a nothrow destructor"); + + template<typename U> + static constexpr bool is_convertible() noexcept + { + return std::is_constructible<T, U>() && + std::is_convertible<U, T>(); + } + + // MEMBERS + std::error_code code_; + typename std::aligned_storage<sizeof(T), alignof(T)>::type storage_; + // MEMBERS + + T& get() noexcept + { + assert(has_value()); + return *reinterpret_cast<T*>(std::addressof(storage_)); + } + + T const& get() const noexcept + { + assert(has_value()); + return *reinterpret_cast<T const*>(std::addressof(storage_)); + } + + template<typename U> + void store(U&& value) noexcept(std::is_nothrow_constructible<T, U>()) + { + new (std::addressof(storage_)) T{std::forward<U>(value)}; + code_ = std::error_code{}; + } + + void maybe_throw() const + { + if (has_error()) + ::detail::expect::throw_(error(), nullptr, nullptr, 0); + } + +public: + using value_type = T; + using error_type = std::error_code; + + expect() = delete; + + /*! Store an error, `code`, in the `expect` object. If `code` creates a + `std::error_code` object whose `.value() == 0`, then `error()` will be set + to `::common_error::kInvalidErrorCode`. */ + expect(std::error_code const& code) noexcept + : code_(code), storage_() + { + if (!has_error()) + code_ = ::common_error::kInvalidErrorCode; + } + + //! Store a value, `val`, in the `expect` object. + expect(T val) noexcept(std::is_nothrow_move_constructible<T>()) + : code_(), storage_() + { + store(std::move(val)); + } + + expect(expect const& src) noexcept(std::is_nothrow_copy_constructible<T>()) + : code_(src.error()), storage_() + { + if (src.has_value()) + store(src.get()); + } + + //! Copy conversion from `U` to `T`. + template<typename U, typename = detail::enable_if<is_convertible<U const&>()>> + expect(expect<U> const& src) noexcept(std::is_nothrow_constructible<T, U const&>()) + : code_(src.error()), storage_() + { + if (src.has_value()) + store(*src); + } + + expect(expect&& src) noexcept(std::is_nothrow_move_constructible<T>()) + : code_(src.error()), storage_() + { + if (src.has_value()) + store(std::move(src.get())); + } + + //! Move conversion from `U` to `T`. + template<typename U, typename = detail::enable_if<is_convertible<U>()>> + expect(expect<U>&& src) noexcept(std::is_nothrow_constructible<T, U>()) + : code_(src.error()), storage_() + { + if (src.has_value()) + store(std::move(*src)); + } + + ~expect() noexcept + { + if (has_value()) + get().~T(); + } + + expect& operator=(expect const& src) noexcept(std::is_nothrow_copy_constructible<T>() && std::is_nothrow_copy_assignable<T>()) + { + if (this != std::addressof(src)) + { + if (has_value() && src.has_value()) + get() = src.get(); + else if (has_value()) + get().~T(); + else if (src.has_value()) + store(src.get()); + code_ = src.error(); + } + return *this; + } + + /*! Move `src` into `this`. If `src.has_value() && addressof(src) != this` + then `src.value() will be in a "moved from state". */ + expect& operator=(expect&& src) noexcept(std::is_nothrow_move_constructible<T>() && std::is_nothrow_move_assignable<T>()) + { + if (this != std::addressof(src)) + { + if (has_value() && src.has_value()) + get() = std::move(src.get()); + else if (has_value()) + get().~T(); + else if (src.has_value()) + store(std::move(src.get())); + code_ = src.error(); + } + return *this; + } + + //! \return True if `this` is storing a value instead of an error. + explicit operator bool() const noexcept { return has_value(); } + + //! \return True if `this` is storing an error instead of a value. + bool has_error() const noexcept { return bool(code_); } + + //! \return True if `this` is storing a value instead of an error. + bool has_value() const noexcept { return !has_error(); } + + //! \return Error - always safe to call. Empty when `!has_error()`. + std::error_code error() const noexcept { return code_; } + + //! \return Value if `has_value()` otherwise \throw `std::system_error{error()}`. + T& value() & + { + maybe_throw(); + return get(); + } + + //! \return Value if `has_value()` otherwise \throw `std::system_error{error()}`. + T const& value() const & + { + maybe_throw(); + return get(); + } + + /*! Same as other overloads, but expressions such as `foo(bar().value())` + will automatically perform moves with no copies. */ + T&& value() && + { + maybe_throw(); + return std::move(get()); + } + + //! \return Value, \pre `has_value()`. + T* operator->() noexcept { return std::addressof(get()); } + //! \return Value, \pre `has_value()`. + T const* operator->() const noexcept { return std::addressof(get()); } + //! \return Value, \pre `has_value()`. + T& operator*() noexcept { return get(); } + //! \return Value, \pre `has_value()`. + T const& operator*() const noexcept { return get(); } + + /*! + \note This function is `noexcept` when `U == T` is `noexcept`. + \return True if `has_value() == rhs.has_value()` and if values or errors are equal. + */ + template<typename U> + bool equal(expect<U> const& rhs) const noexcept(noexcept(*std::declval<expect<T>>() == *rhs)) + { + return has_value() && rhs.has_value() ? + get() == *rhs : error() == rhs.error(); + } + + //! \return False if `has_value()`, otherwise `error() == rhs`. + bool equal(std::error_code const& rhs) const noexcept + { + return has_error() && error() == rhs; + } + + /*! + \note This function is `noexcept` when `U == T` is `noexcept`. + \return False if `has_error()`, otherwise `value() == rhs`. + */ + template<typename U, typename = detail::enable_if<!std::is_constructible<std::error_code, U>::value>> + bool equal(U const& rhs) const noexcept(noexcept(*std::declval<expect<T>>() == rhs)) + { + return has_value() && get() == rhs; + } + + //! \return False if `has_value()`, otherwise `error() == rhs`. + bool matches(std::error_condition const& rhs) const noexcept + { + return has_error() && error() == rhs; + } +}; + +template<> +class expect<void> +{ + std::error_code code_; + +public: + using value_type = void; + using error_type = std::error_code; + + //! Create a successful object. + expect() = default; + + expect(std::error_code const& code) noexcept + : code_(code) + { + if (!has_error()) + code_ = ::common_error::kInvalidErrorCode; + } + + expect(expect const&) = default; + ~expect() = default; + expect& operator=(expect const&) = default; + + //! \return True if `this` is storing a value instead of an error. + explicit operator bool() const noexcept { return !has_error(); } + + //! \return True if `this` is storing an error instead of a value. + bool has_error() const noexcept { return bool(code_); } + + //! \return Error - alway + std::error_code error() const noexcept { return code_; } + + //! \return `error() == rhs.error()`. + bool equal(expect const& rhs) const noexcept + { + return error() == rhs.error(); + } + + //! \return `has_error() && error() == rhs`. + bool equal(std::error_code const& rhs) const noexcept + { + return has_error() && error() == rhs; + } + + //! \return False if `has_value()`, otherwise `error() == rhs`. + bool matches(std::error_condition const& rhs) const noexcept + { + return has_error() && error() == rhs; + } +}; + +//! \return An `expect<void>` object with `!has_error()`. +inline expect<void> success() noexcept { return expect<void>{}; } + +template<typename T, typename U> +inline +bool operator==(expect<T> const& lhs, expect<U> const& rhs) noexcept(noexcept(lhs.equal(rhs))) +{ + return lhs.equal(rhs); +} + +template<typename T, typename U> +inline +bool operator==(expect<T> const& lhs, U const& rhs) noexcept(noexcept(lhs.equal(rhs))) +{ + return lhs.equal(rhs); +} + +template<typename T, typename U> +inline +bool operator==(T const& lhs, expect<U> const& rhs) noexcept(noexcept(rhs.equal(lhs))) +{ + return rhs.equal(lhs); +} + +template<typename T, typename U> +inline +bool operator!=(expect<T> const& lhs, expect<U> const& rhs) noexcept(noexcept(lhs.equal(rhs))) +{ + return !lhs.equal(rhs); +} + +template<typename T, typename U> +inline +bool operator!=(expect<T> const& lhs, U const& rhs) noexcept(noexcept(lhs.equal(rhs))) +{ + return !lhs.equal(rhs); +} + +template<typename T, typename U> +inline +bool operator!=(T const& lhs, expect<U> const& rhs) noexcept(noexcept(rhs.equal(lhs))) +{ + return !rhs.equal(lhs); +} + +namespace detail +{ + inline void expect::unwrap(::expect<void>&& result, const char* error_msg, const char* file, unsigned line) + { + if (!result) + throw_(result.error(), error_msg, file, line); + } +} + |