error-chain-0.12.4/.cargo_vcs_info.json0000644000000001121371157632400134320ustar00{ "git": { "sha1": "210e7f6eac4397b28911cfac7f5daf4748ac554d" } } error-chain-0.12.4/.gitattributes010064400007660000024000000001101366477034000151240ustar0000000000000000*.rs text eol=lf *.lock text eol=lf *.txt text eol=lf *.toml text eol=lferror-chain-0.12.4/.gitignore010064400007660000024000000000261366477034000142270ustar0000000000000000*~ /target Cargo.lock error-chain-0.12.4/.travis.yml010064400007660000024000000035111366477052600143600ustar0000000000000000language: rust rust: - stable - beta - nightly # Oldest supported version for all features. # Use of https://github.com/rust-lang/rfcs/pull/16 # rustc-demangle uses feature `rename-dependency` - 1.32.0 # Oldest supported version as dependency, with no features, tests, or examples. - 1.13.0 sudo: false cache: cargo addons: apt: packages: - libcurl4-openssl-dev - libelf-dev - libdw-dev before_script: - | pip install 'travis-cargo<0.2' --user && export PATH=$HOME/.local/bin:$PATH if [ "$CHECK" = "true" ]; then rustup component add rustfmt ; fi script: - if [ "$CHECK" = "true" ]; then travis-cargo fmt -- -- --check ; fi - if [ "$CHECK" = "" ]; then travis-cargo build -- $FEATURES ; fi - if [ "$CHECK" = "" ]; then travis-cargo --skip 1.13.0 test -- $FEATURES ; fi after_success: - travis-cargo --only stable doc - travis-cargo --only stable doc-upload env: global: - secure: ncxJbvJM1vCZfcEftjsFKJMxxhKLgWKaR8Go9AMo0VB5fB2XVW/6NYO5bQEEYpOf1Nc/+2FbI2+Dkz0S/mJpUcNSfBgablCHgwU2sHse7KsoaqfHj2mf1E3exjzSHoP96hPGicC5zAjSXFjCgJPOUSGqqRaJ7z5AsJLhJT6LuK7QpvwPBZzklUN8T+n1sVmws8TNmRIbaniq/q6wYHANHcy6Dl59dx4sKwniUGiZdUhCiddVpoxbECSxc0A8mN2pk7/aW+WGxK3goBs5ZF7+JXF318F62pDcXQmR5CX6WdpenIcJ25g1Vg1WhQ4Ifpe17CN0bfxV8ShuzrQUThCDMffZCo9XySBtODdEowwK1UIpjnFLfIxjOs45Cd8o3tM2j0CfvtnjOz6BCdUU0qiwNPPNx0wFkx3ZiOfSh+FhBhvyPM12HN2tdN0esgVBItFmEci+sSIIXqjVL6DNiu5zTjbu0bs6COwlUWdmL6vmsZtq5tl7Cno9+C3szxRVAkShGydd04l9NYjqNEzTa1EPG50OsnVRKGdRiFzSxhc3BWExNKvcQ4v867t6/PpPkW6s4oXmYI3+De+8O7ExWc6a4alcrDXKlMs5fCb5Pcd4Ju9kowcjkoJo5yf2wW3Ox5R8SJpaEEpvyhx5O/qtIxjhHNzeo8Wsr/6gdNDv20r91TI= - TRAVIS_CARGO_NIGHTLY_FEATURE="" - RUSTFLAGS="-D warnings" matrix: - FEATURES=--features=backtrace - FEATURES=--no-default-features matrix: include: - env: CHECK=true rust: stable exclude: - env: FEATURES=--features=backtrace rust: 1.13.0 error-chain-0.12.4/CHANGELOG.md010064400007660000024000000125461371157522700140620ustar0000000000000000# 0.12.4 - [executable bits to support build platform linters](https://github.com/rust-lang-nursery/error-chain/pull/289) # 0.12.2 - [allow `Error::description` to be used for rust below 1.42](https://github.com/rust-lang-nursery/error-chain/pull/285) - [Improvements to has_backtrace_depending_on_env](https://github.com/rust-lang-nursery/error-chain/pull/277) - Backtrace support now requires rust 1.32.0 # 0.12.1 - [`std::error::Error::cause` deprecation update](https://github.com/rust-lang-nursery/error-chain/pull/255) - [Macro invocations use 2018 style](https://github.com/rust-lang-nursery/error-chain/pull/253) # 0.12.0 - [Remove `impl Deref for Error`](https://github.com/rust-lang-nursery/error-chain/pull/192) - [Fix warning](https://github.com/rust-lang-nursery/error-chain/pull/247) # 0.11.0 - Change last rust version supported to 1.14 - [Cache whether RUST_BACKTRACE is enabled in a relaxed atomic static.](https://github.com/rust-lang-nursery/error-chain/pull/210) - [Mask the `quick_error` macro from the doc](https://github.com/rust-lang-nursery/error-chain/pull/210) - [Make generated `ErrorKind` enums non-exhaustive](https://github.com/rust-lang-nursery/error-chain/pull/193) - All 0.11.0-rc.2 changes # 0.11.0-rc.2 - [Make `ErrorChainIter`'s field private](https://github.com/rust-lang-nursery/error-chain/issues/178) - [Rename `ErrorChainIter` to `Iter`](https://github.com/rust-lang-nursery/error-chain/issues/168) - [Implement `Debug` for `ErrorChainIter`](https://github.com/rust-lang-nursery/error-chain/issues/169) - [Rename `ChainedError::display` to `display_chain`](https://github.com/rust-lang-nursery/error-chain/issues/180) - [Add a new method for `Error`: `chain_err`.](https://github.com/rust-lang-nursery/error-chain/pull/141) - [Allow `chain_err` to be used on `Option`](https://github.com/rust-lang-nursery/error-chain/pull/156) - [Add support for creating an error chain on boxed trait errors (`Box`)](https://github.com/rust-lang-nursery/error-chain/pull/156) - [Remove lint for unused doc comment.](https://github.com/rust-lang-nursery/error-chain/pull/199) - [Hide error_chain_processed macro from documentation.](https://github.com/rust-lang-nursery/error-chain/pull/212) # 0.10.0 - [Add a new constructor for `Error`: `with_chain`.](https://github.com/rust-lang-nursery/error-chain/pull/126) - [Add the `ensure!` macro.](https://github.com/rust-lang-nursery/error-chain/pull/135) # 0.9.0 - Revert [Add a `Sync` bound to errors](https://github.com/rust-lang-nursery/error-chain/pull/110) # 0.8.1 - Add crates.io category. # 0.8.0 - [Add a `Sync` bound to errors](https://github.com/rust-lang-nursery/error-chain/pull/110) - [Add `ChainedError::display` to format error chains](https://github.com/rust-lang-nursery/error-chain/pull/113) # 0.7.2 - Add `quick_main!` (#88). - `allow(unused)` for the `Result` wrapper. - Minimum rust version supported is now 1.10 on some conditions (#103). # 0.7.1 - [Add the `bail!` macro](https://github.com/rust-lang-nursery/error-chain/pull/76) # 0.7.0 - [Rollback several design changes to fix regressions](https://github.com/rust-lang-nursery/error-chain/pull/75) - New `Variant(Error) #[attrs]` for `links` and `foreign_links`. - Hide implementation details from the doc. - Always generate `Error::backtrace`. # 0.6.2 - Allow dead code. # 0.6.1 - Fix wrong trait constraint in ResultExt implementation (#66). # 0.6.0 - Conditional compilation for error variants. - Backtrace generation is now a feature. - More standard trait implementations for extra convenience. - Remove ChainErr. - Remove need to specify `ErrorKind` in `links {}`. - Add ResultExt trait. - Error.1 is a struct instead of a tuple. - Error is now a struct. - The declarations order is more flexible. - Way better error reporting when there is a syntax error in the macro call. - `Result` generation can be disabled. - At most one declaration of each type can be present. # 0.5.0 - [Only generate backtraces with RUST_BACKTRACE set](https://github.com/rust-lang-nursery/error-chain/pull/27) - [Fixup matching, disallow repeating "types" section](https://github.com/rust-lang-nursery/error-chain/pull/26) - [Fix tests on stable/beta](https://github.com/rust-lang-nursery/error-chain/pull/28) - [Only deploy docs when tagged](https://github.com/rust-lang-nursery/error-chain/pull/30) Contributors: benaryorg, Brian Anderson, Georg Brandl # 0.4.2 - [Fix the resolution of the ErrorKind description method](https://github.com/rust-lang-nursery/error-chain/pull/24) Contributors: Brian Anderson # 0.4.1 (yanked) - [Fix a problem with resolving methods of the standard Error type](https://github.com/rust-lang-nursery/error-chain/pull/22) Contributors: Brian Anderson # 0.4.0 (yanked) - [Remove the foreign link description and forward to the foreign error](https://github.com/rust-lang-nursery/error-chain/pull/19) - [Allow missing sections](https://github.com/rust-lang-nursery/error-chain/pull/17) Contributors: Brian Anderson, Taylor Cramer # 0.3.0 - [Forward Display implementation for foreign errors](https://github.com/rust-lang-nursery/error-chain/pull/13) Contributors: Brian Anderson, Taylor Cramer # 0.2.2 - [Don't require `types` section in macro invocation](https://github.com/rust-lang-nursery/error-chain/pull/8) - [Add "quick start" to README](https://github.com/rust-lang-nursery/error-chain/pull/9) Contributors: Brian Anderson, Jake Shadle, Nate Mara error-chain-0.12.4/Cargo.lock0000644000000034731371157632400114220ustar00# This file is automatically @generated by Cargo. # It is not intended for manual editing. [[package]] name = "addr2line" version = "0.12.1" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "a49806b9dadc843c61e7c97e72490ad7f7220ae249012fbda9ad0609457c0543" dependencies = [ "gimli", ] [[package]] name = "backtrace" version = "0.3.48" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "0df2f85c8a2abbe3b7d7e748052fdd9b76a0458fdeb16ad4223f5eca78c7c130" dependencies = [ "addr2line", "cfg-if", "libc", "object", "rustc-demangle", ] [[package]] name = "cfg-if" version = "0.1.10" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822" [[package]] name = "error-chain" version = "0.12.4" dependencies = [ "backtrace", "version_check", ] [[package]] name = "gimli" version = "0.21.0" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "bcc8e0c9bce37868955864dbecd2b1ab2bdf967e6f28066d65aaac620444b65c" [[package]] name = "libc" version = "0.2.71" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "9457b06509d27052635f90d6466700c65095fdf75409b3fbdd903e988b886f49" [[package]] name = "object" version = "0.19.0" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "9cbca9424c482ee628fa549d9c812e2cd22f1180b9222c9200fdfa6eb31aecb2" [[package]] name = "rustc-demangle" version = "0.1.16" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783" [[package]] name = "version_check" version = "0.9.2" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "b5a972e5669d67ba988ce3dc826706fb0a8b01471c088cb0b6110b805cc36aed" error-chain-0.12.4/Cargo.toml0000644000000023161371157632400114400ustar00# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO # # When uploading crates to the registry Cargo will automatically # "normalize" Cargo.toml files for maximal compatibility # with all versions of Cargo and also rewrite `path` dependencies # to registry (e.g., crates.io) dependencies # # If you believe there's an error in this file please file an # issue against the rust-lang/cargo repository. If you're # editing this file be aware that the upstream Cargo.toml # will likely look very different (and much more reasonable) [package] name = "error-chain" version = "0.12.4" authors = ["Brian Anderson ", "Paul Colomiets ", "Colin Kiegel ", "Yamakaky ", "Andrew Gauger "] description = "Yet another error boilerplate library." documentation = "https://docs.rs/error-chain" readme = "README.md" keywords = ["error"] categories = ["rust-patterns"] license = "MIT/Apache-2.0" repository = "https://github.com/rust-lang-nursery/error-chain" [dependencies.backtrace] version = "0.3.3" optional = true [build-dependencies.version_check] version = "0.9" [features] default = ["backtrace", "example_generated"] example_generated = [] error-chain-0.12.4/Cargo.toml.orig010064400007660000024000000014301371157524500151260ustar0000000000000000[package] name = "error-chain" version = "0.12.4" # remember to update html_root_url authors = [ "Brian Anderson ", "Paul Colomiets ", "Colin Kiegel ", "Yamakaky ", "Andrew Gauger "] description = "Yet another error boilerplate library." keywords = ["error"] categories = ["rust-patterns"] documentation = "https://docs.rs/error-chain" repository = "https://github.com/rust-lang-nursery/error-chain" readme = "README.md" license = "MIT/Apache-2.0" [features] default = ["backtrace", "example_generated"] example_generated = [] [dependencies] backtrace = { version = "0.3.3", optional = true } [build-dependencies] version_check = "0.9" error-chain-0.12.4/LICENSE-APACHE010064400007660000024000000251371366477034000141750ustar0000000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. 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See the License for the specific language governing permissions and limitations under the License. error-chain-0.12.4/LICENSE-MIT010064400007660000024000000020671366477034000137020ustar0000000000000000Copyright (c) 2017 The Error-Chain Project Developers Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. 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IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. error-chain-0.12.4/README.md010064400007660000024000000026501366477034000135230ustar0000000000000000# error-chain - Consistent error handling for Rust [![Build Status](https://travis-ci.com/rust-lang-nursery/error-chain.svg?branch=master)](https://travis-ci.com/rust-lang-nursery/error-chain) [![Latest Version](https://img.shields.io/crates/v/error-chain.svg)](https://crates.io/crates/error-chain) [![License](https://img.shields.io/badge/license-MIT%2FApache--2.0-green.svg)](https://github.com/rust-lang-nursery/error-chain) `error-chain` makes it easy to take full advantage of Rust's error handling features without the overhead of maintaining boilerplate error types and conversions. It implements an opinionated strategy for defining your own error types, as well as conversions from others' error types. [Documentation (crates.io)](https://docs.rs/error-chain). [Documentation (master)](https://rust-lang-nursery.github.io/error-chain). ## Quick start If you just want to set up your new project with error-chain, follow the [quickstart.rs] template, and read this [intro] to error-chain. [quickstart.rs]: https://github.com/rust-lang-nursery/error-chain/blob/master/examples/quickstart.rs [intro]: http://brson.github.io/2016/11/30/starting-with-error-chain ## Supported Rust version Please view the beginning of the [Travis configuration file](.travis.yml) to see the oldest supported Rust version. Note that `error-chain` supports older versions of Rust when built with `default-features = false`. ## License MIT/Apache-2.0 error-chain-0.12.4/build.rs010064400007660000024000000012011366477052600137060ustar0000000000000000extern crate version_check; use std::env; use version_check::is_min_version; fn main() { // Switch on for versions that have Error::source // As introduced by https://github.com/rust-lang/rust/pull/53533 if is_min_version("1.30").unwrap_or(false) { println!("cargo:rustc-cfg=has_error_source"); } if is_min_version("1.42").unwrap_or(false) { println!("cargo:rustc-cfg=has_error_description_deprecated"); } // So we can get the build profile for has_backtrace_depending_on_env test if let Ok(profile) = env::var("PROFILE") { println!("cargo:rustc-cfg=build={:?}", profile); } } error-chain-0.12.4/examples/all.rs010064400007660000024000000015311366477052600152030ustar0000000000000000#[macro_use] extern crate error_chain; pub mod inner { error_chain! {} } #[cfg(feature = "a_feature")] pub mod feature { error_chain! {} } error_chain! { // Types generated by the macro. If empty or absent, it defaults to // Error, ErrorKind, Result; types { // With custom names: MyError, MyErrorKind, MyResult; // Without the `Result` wrapper: // Error, ErrorKind; } // Automatic bindings to other error types generated by `error_chain!`. links { Inner(inner::Error, inner::ErrorKind); // Attributes can be added at the end of the declaration. Feature(feature::Error, feature::ErrorKind) #[cfg(feature = "a_feature")]; } // Bindings to types implementing std::error::Error. foreign_links { Io(::std::io::Error); } } fn main() {} error-chain-0.12.4/examples/chain_err.rs010064400007660000024000000032421366477052600163660ustar0000000000000000//! Demonstrates usage of `Error::caused` method. This method enables chaining errors //! like `ResultExt::chain_err` but doesn't require the presence of a `Result` wrapper. #[macro_use] extern crate error_chain; use std::fs::File; mod errors { use super::LaunchStage; use std::io; error_chain! { foreign_links { Io(io::Error) #[doc = "Error during IO"]; } errors { Launch(phase: LaunchStage) { description("An error occurred during startup") display("Startup aborted: {:?} did not complete successfully", phase) } ConfigLoad(path: String) { description("Config file not found") display("Unable to read file `{}`", path) } } } impl From for ErrorKind { fn from(v: LaunchStage) -> Self { ErrorKind::Launch(v) } } } pub use errors::*; #[derive(Debug, Clone, PartialEq, Eq)] pub enum LaunchStage { ConfigLoad, ConfigParse, ConfigResolve, } /// Read the service config from the file specified. fn load_config(rel_path: &str) -> Result<()> { File::open(rel_path) .map(|_| ()) .chain_err(|| ErrorKind::ConfigLoad(rel_path.to_string())) } /// Launch the service. fn launch(rel_path: &str) -> Result<()> { load_config(rel_path).map_err(|e| match e { e @ Error(ErrorKind::ConfigLoad(_), _) => e.chain_err(|| LaunchStage::ConfigLoad), e => e.chain_err(|| "Unknown failure"), }) } fn main() { let chain = launch("does_not_exist.json").unwrap_err(); for err in chain.iter() { println!("{}", err); } } error-chain-0.12.4/examples/doc.rs010064400007660000024000000006671366477052600152110ustar0000000000000000#![deny(missing_docs)] //! This module is used to check that all generated items are documented. #[macro_use] extern crate error_chain; /// Inner module. pub mod inner { error_chain! {} } error_chain! { links { Inner(inner::Error, inner::ErrorKind) #[doc = "Doc"]; } foreign_links { Io(::std::io::Error) #[doc = "Io"]; } errors { /// Doc Test2 { } } } fn main() {} error-chain-0.12.4/examples/has_backtrace.rs010064400007660000024000000007111366477052600172040ustar0000000000000000//! Exits with exit code 0 if backtraces are disabled and 1 if they are enabled. //! Used by tests to make sure backtraces are available when they should be. Should not be used //! outside of the tests. #[macro_use] extern crate error_chain; error_chain! { errors { MyError } } fn main() { let err = Error::from(ErrorKind::MyError); let has_backtrace = err.backtrace().is_some(); ::std::process::exit(has_backtrace as i32); } error-chain-0.12.4/examples/quickstart.rs010064400007660000024000000046611366477052600166340ustar0000000000000000// Simple and robust error handling with error-chain! // Use this as a template for new projects. // `error_chain!` can recurse deeply #![recursion_limit = "1024"] // Import the macro. Don't forget to add `error-chain` in your // `Cargo.toml`! #[macro_use] extern crate error_chain; // We'll put our errors in an `errors` module, and other modules in // this crate will `use errors::*;` to get access to everything // `error_chain!` creates. mod errors { // Create the Error, ErrorKind, ResultExt, and Result types error_chain! {} } // This only gives access within this module. Make this `pub use errors::*;` // instead if the types must be accessible from other modules (e.g., within // a `links` section). use errors::*; fn main() { if let Err(ref e) = run() { use std::io::Write; let stderr = &mut ::std::io::stderr(); let errmsg = "Error writing to stderr"; writeln!(stderr, "error: {}", e).expect(errmsg); for e in e.iter().skip(1) { writeln!(stderr, "caused by: {}", e).expect(errmsg); } // The backtrace is not always generated. Try to run this example // with `RUST_BACKTRACE=1`. if let Some(backtrace) = e.backtrace() { writeln!(stderr, "backtrace: {:?}", backtrace).expect(errmsg); } ::std::process::exit(1); } } // The above main gives you maximum control over how the error is // formatted. If you don't care (i.e. you want to display the full // error during an assert) you can just call the `display_chain` method // on the error object #[allow(dead_code)] fn alternative_main() { if let Err(ref e) = run() { use error_chain::ChainedError; use std::io::Write; // trait which holds `display_chain` let stderr = &mut ::std::io::stderr(); let errmsg = "Error writing to stderr"; writeln!(stderr, "{}", e.display_chain()).expect(errmsg); ::std::process::exit(1); } } // Use this macro to auto-generate the main above. You may want to // set the `RUST_BACKTRACE` env variable to see a backtrace. // quick_main!(run); // Most functions will return the `Result` type, imported from the // `errors` module. It is a typedef of the standard `Result` type // for which the error type is always our own `Error`. fn run() -> Result<()> { use std::fs::File; // This operation will fail File::open("tretrete").chain_err(|| "unable to open tretrete file")?; Ok(()) } error-chain-0.12.4/examples/size.rs010064400007660000024000000016721366477034000154050ustar0000000000000000#[macro_use] extern crate error_chain; use std::mem::{size_of, size_of_val}; error_chain! { errors { AVariant Another } } fn main() { println!("Memory usage in bytes"); println!("---------------------"); println!("Result<()>: {}", size_of::>()); println!(" (): {}", size_of::<()>()); println!(" Error: {}", size_of::()); println!(" ErrorKind: {}", size_of::()); let msg = ErrorKind::Msg("test".into()); println!(" ErrorKind::Msg: {}", size_of_val(&msg)); println!(" String: {}", size_of::()); println!(" State: {}", size_of::()); let state = error_chain::State { next_error: None, backtrace: error_chain::InternalBacktrace::new(), }; println!(" State.next_error: {}", size_of_val(&state.next_error)); println!(" State.backtrace: {}", size_of_val(&state.backtrace)); } error-chain-0.12.4/src/backtrace.rs010064400007660000024000000063721366477052600153330ustar0000000000000000pub use self::imp::{Backtrace, InternalBacktrace}; #[cfg(feature = "backtrace")] mod imp { extern crate backtrace; use std::cell::UnsafeCell; use std::env; use std::fmt; use std::sync::atomic::{AtomicUsize, Ordering}; use std::sync::{Arc, Mutex}; /// Internal representation of a backtrace #[doc(hidden)] #[derive(Clone)] pub struct InternalBacktrace { backtrace: Option>, } struct MaybeResolved { resolved: Mutex, backtrace: UnsafeCell, } unsafe impl Send for MaybeResolved {} unsafe impl Sync for MaybeResolved {} pub use self::backtrace::Backtrace; impl InternalBacktrace { /// Returns a backtrace of the current call stack if `RUST_BACKTRACE` /// is set to anything but ``0``, and `None` otherwise. This is used /// in the generated error implementations. #[doc(hidden)] pub fn new() -> InternalBacktrace { static ENABLED: AtomicUsize = AtomicUsize::new(0); match ENABLED.load(Ordering::SeqCst) { 0 => { let enabled = match env::var_os("RUST_BACKTRACE") { Some(ref val) if val != "0" => true, _ => false, }; ENABLED.store(enabled as usize + 1, Ordering::SeqCst); if !enabled { return InternalBacktrace { backtrace: None }; } } 1 => return InternalBacktrace { backtrace: None }, _ => {} } InternalBacktrace { backtrace: Some(Arc::new(MaybeResolved { resolved: Mutex::new(false), backtrace: UnsafeCell::new(Backtrace::new_unresolved()), })), } } /// Acquire the internal backtrace #[doc(hidden)] pub fn as_backtrace(&self) -> Option<&Backtrace> { let bt = match self.backtrace { Some(ref bt) => bt, None => return None, }; let mut resolved = bt.resolved.lock().unwrap(); unsafe { if !*resolved { (*bt.backtrace.get()).resolve(); *resolved = true; } Some(&*bt.backtrace.get()) } } } impl fmt::Debug for InternalBacktrace { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.debug_struct("InternalBacktrace") .field("backtrace", &self.as_backtrace()) .finish() } } } #[cfg(not(feature = "backtrace"))] mod imp { /// Dummy type used when the `backtrace` feature is disabled. pub type Backtrace = (); /// Internal representation of a backtrace #[doc(hidden)] #[derive(Clone, Debug)] pub struct InternalBacktrace {} impl InternalBacktrace { /// Returns a new backtrace #[doc(hidden)] pub fn new() -> InternalBacktrace { InternalBacktrace {} } /// Returns the internal backtrace #[doc(hidden)] pub fn as_backtrace(&self) -> Option<&Backtrace> { None } } } error-chain-0.12.4/src/error_chain.rs010064400007660000024000000416211366477052600157030ustar0000000000000000#[doc(hidden)] #[macro_export] #[cfg(not(has_error_source))] macro_rules! impl_error_chain_cause_or_source { ( types { $error_kind_name:ident } foreign_links { $( $foreign_link_variant:ident ( $foreign_link_error_path:path ) $( #[$meta_foreign_links:meta] )*; )* } ) => { #[allow(unknown_lints, renamed_and_removed_lints)] #[allow(unused_doc_comment, unused_doc_comments)] fn cause(&self) -> Option<&::std::error::Error> { match self.1.next_error { Some(ref c) => Some(&**c), None => { match self.0 { $( $(#[$meta_foreign_links])* $error_kind_name::$foreign_link_variant(ref foreign_err) => { foreign_err.cause() } ) * _ => None } } } } }; } #[cfg(has_error_source)] #[doc(hidden)] #[macro_export] macro_rules! impl_error_chain_cause_or_source { ( types { $error_kind_name:ident } foreign_links { $( $foreign_link_variant:ident ( $foreign_link_error_path:path ) $( #[$meta_foreign_links:meta] )*; )* } ) => { #[allow(unknown_lints, renamed_and_removed_lints, bare_trait_objects)] #[allow(unused_doc_comment, unused_doc_comments)] fn source(&self) -> Option<&(std::error::Error + 'static)> { match self.1.next_error { Some(ref c) => Some(&**c), None => { match self.0 { $( $(#[$meta_foreign_links])* $error_kind_name::$foreign_link_variant(ref foreign_err) => { foreign_err.source() } ) * _ => None } } } } }; } /// Conditional usage of deprecated Error::description #[doc(hidden)] #[cfg(has_error_description_deprecated)] #[macro_export(local_inner_macros)] macro_rules! call_to_deprecated_description { ($e:ident) => { "" }; } #[doc(hidden)] #[cfg(not(has_error_description_deprecated))] #[macro_export(local_inner_macros)] macro_rules! call_to_deprecated_description { ($e:ident) => { ::std::error::Error::description($e) }; } /// Prefer to use `error_chain` instead of this macro. #[doc(hidden)] #[macro_export(local_inner_macros)] macro_rules! impl_error_chain_processed { // Default values for `types`. ( types {} $( $rest: tt )* ) => { impl_error_chain_processed! { types { Error, ErrorKind, ResultExt, Result; } $( $rest )* } }; // With `Result` wrapper. ( types { $error_name:ident, $error_kind_name:ident, $result_ext_name:ident, $result_name:ident; } $( $rest: tt )* ) => { impl_error_chain_processed! { types { $error_name, $error_kind_name, $result_ext_name; } $( $rest )* } /// Convenient wrapper around `std::Result`. #[allow(unused)] pub type $result_name = ::std::result::Result; }; // With `Msg` variant. ( types { $error_name:ident, $error_kind_name:ident, $($types:tt)* } links $links:tt foreign_links $foreign_links:tt errors { $($errors:tt)* } ) => { impl_error_chain_processed! { types { $error_name, $error_kind_name, $($types)* } skip_msg_variant links $links foreign_links $foreign_links errors { /// A convenient variant for String. Msg(s: String) { description(&s) display("{}", s) } $($errors)* } } impl<'a> From<&'a str> for $error_kind_name { fn from(s: &'a str) -> Self { $error_kind_name::Msg(s.into()) } } impl From for $error_kind_name { fn from(s: String) -> Self { $error_kind_name::Msg(s) } } impl<'a> From<&'a str> for $error_name { fn from(s: &'a str) -> Self { Self::from_kind(s.into()) } } impl From for $error_name { fn from(s: String) -> Self { Self::from_kind(s.into()) } } }; // Without `Result` wrapper or `Msg` variant. ( types { $error_name:ident, $error_kind_name:ident, $result_ext_name:ident; } skip_msg_variant links { $( $link_variant:ident ( $link_error_path:path, $link_kind_path:path ) $( #[$meta_links:meta] )*; ) * } foreign_links { $( $foreign_link_variant:ident ( $foreign_link_error_path:path ) $( #[$meta_foreign_links:meta] )*; )* } errors { $( $error_chunks:tt ) * } ) => { /// The Error type. /// /// This tuple struct is made of two elements: /// /// - an `ErrorKind` which is used to determine the type of the error. /// - An internal `State`, not meant for direct use outside of `error_chain` /// internals, containing: /// - a backtrace, generated when the error is created. /// - an error chain, used for the implementation of `Error::cause()`. #[derive(Debug)] pub struct $error_name( // The members must be `pub` for `links`. /// The kind of the error. pub $error_kind_name, /// Contains the error chain and the backtrace. #[doc(hidden)] pub $crate::State, ); impl $crate::ChainedError for $error_name { type ErrorKind = $error_kind_name; fn new(kind: $error_kind_name, state: $crate::State) -> $error_name { $error_name(kind, state) } fn from_kind(kind: Self::ErrorKind) -> Self { Self::from_kind(kind) } fn with_chain(error: E, kind: K) -> Self where E: ::std::error::Error + Send + 'static, K: Into { Self::with_chain(error, kind) } fn kind(&self) -> &Self::ErrorKind { self.kind() } fn iter(&self) -> $crate::Iter { $crate::Iter::new(Some(self)) } fn chain_err(self, error: F) -> Self where F: FnOnce() -> EK, EK: Into<$error_kind_name> { self.chain_err(error) } fn backtrace(&self) -> Option<&$crate::Backtrace> { self.backtrace() } impl_extract_backtrace!($error_name $error_kind_name $([$link_error_path, $(#[$meta_links])*])*); } #[allow(dead_code)] impl $error_name { /// Constructs an error from a kind, and generates a backtrace. pub fn from_kind(kind: $error_kind_name) -> $error_name { $error_name( kind, $crate::State::default(), ) } /// Constructs a chained error from another error and a kind, and generates a backtrace. pub fn with_chain(error: E, kind: K) -> $error_name where E: ::std::error::Error + Send + 'static, K: Into<$error_kind_name> { $error_name::with_boxed_chain(Box::new(error), kind) } /// Construct a chained error from another boxed error and a kind, and generates a backtrace #[allow(unknown_lints, bare_trait_objects)] pub fn with_boxed_chain(error: Box<::std::error::Error + Send>, kind: K) -> $error_name where K: Into<$error_kind_name> { $error_name( kind.into(), $crate::State::new::<$error_name>(error, ), ) } /// Returns the kind of the error. pub fn kind(&self) -> &$error_kind_name { &self.0 } /// Iterates over the error chain. pub fn iter(&self) -> $crate::Iter { $crate::ChainedError::iter(self) } /// Returns the backtrace associated with this error. pub fn backtrace(&self) -> Option<&$crate::Backtrace> { self.1.backtrace() } /// Extends the error chain with a new entry. pub fn chain_err(self, error: F) -> $error_name where F: FnOnce() -> EK, EK: Into<$error_kind_name> { $error_name::with_chain(self, Self::from_kind(error().into())) } /// A short description of the error. /// This method is identical to [`Error::description()`](https://doc.rust-lang.org/nightly/std/error/trait.Error.html#tymethod.description) pub fn description(&self) -> &str { self.0.description() } } impl ::std::error::Error for $error_name { #[cfg(not(has_error_description_deprecated))] fn description(&self) -> &str { self.description() } impl_error_chain_cause_or_source!{ types { $error_kind_name } foreign_links { $( $foreign_link_variant ( $foreign_link_error_path ) $( #[$meta_foreign_links] )*; )* } } } impl ::std::fmt::Display for $error_name { fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result { ::std::fmt::Display::fmt(&self.0, f) } } $( $(#[$meta_links])* impl From<$link_error_path> for $error_name { fn from(e: $link_error_path) -> Self { $error_name( $error_kind_name::$link_variant(e.0), e.1, ) } } ) * $( $(#[$meta_foreign_links])* impl From<$foreign_link_error_path> for $error_name { fn from(e: $foreign_link_error_path) -> Self { $error_name::from_kind( $error_kind_name::$foreign_link_variant(e) ) } } ) * impl From<$error_kind_name> for $error_name { fn from(e: $error_kind_name) -> Self { $error_name::from_kind(e) } } // The ErrorKind type // -------------- impl_error_chain_kind! { /// The kind of an error. #[derive(Debug)] pub enum $error_kind_name { $( $(#[$meta_links])* $link_variant(e: $link_kind_path) { description(e.description()) display("{}", e) } ) * $( $(#[$meta_foreign_links])* $foreign_link_variant(err: $foreign_link_error_path) { description(call_to_deprecated_description!(err)) display("{}", err) } ) * $($error_chunks)* } } $( $(#[$meta_links])* impl From<$link_kind_path> for $error_kind_name { fn from(e: $link_kind_path) -> Self { $error_kind_name::$link_variant(e) } } ) * impl From<$error_name> for $error_kind_name { fn from(e: $error_name) -> Self { e.0 } } // The ResultExt trait defines the `chain_err` method. /// Additional methods for `Result`, for easy interaction with this crate. pub trait $result_ext_name { /// If the `Result` is an `Err` then `chain_err` evaluates the closure, /// which returns *some type that can be converted to `ErrorKind`*, boxes /// the original error to store as the cause, then returns a new error /// containing the original error. fn chain_err(self, callback: F) -> ::std::result::Result where F: FnOnce() -> EK, EK: Into<$error_kind_name>; } impl $result_ext_name for ::std::result::Result where E: ::std::error::Error + Send + 'static { fn chain_err(self, callback: F) -> ::std::result::Result where F: FnOnce() -> EK, EK: Into<$error_kind_name> { self.map_err(move |e| { let state = $crate::State::new::<$error_name>(Box::new(e), ); $crate::ChainedError::new(callback().into(), state) }) } } impl $result_ext_name for ::std::option::Option { fn chain_err(self, callback: F) -> ::std::result::Result where F: FnOnce() -> EK, EK: Into<$error_kind_name> { self.ok_or_else(move || { $crate::ChainedError::from_kind(callback().into()) }) } } }; } /// Internal macro used for reordering of the fields. #[doc(hidden)] #[macro_export(local_inner_macros)] macro_rules! error_chain_processing { ( ({}, $($rest:tt)*) types $content:tt $( $tail:tt )* ) => { error_chain_processing! { ($content, $($rest)*) $($tail)* } }; ( ($a:tt, {}, $($rest:tt)*) links $content:tt $( $tail:tt )* ) => { error_chain_processing! { ($a, $content, $($rest)*) $($tail)* } }; ( ($a:tt, $b:tt, {}, $($rest:tt)*) foreign_links $content:tt $( $tail:tt )* ) => { error_chain_processing! { ($a, $b, $content, $($rest)*) $($tail)* } }; ( ($a:tt, $b:tt, $c:tt, {}, $($rest:tt)*) errors $content:tt $( $tail:tt )* ) => { error_chain_processing! { ($a, $b, $c, $content, $($rest)*) $($tail)* } }; ( ($a:tt, $b:tt, $c:tt, $d:tt, {}, $($rest:tt)*) skip_msg_variant $( $tail:tt )* ) => { error_chain_processing! { ($a, $b, $c, $d, {skip_msg_variant}, $($rest)*) $($tail)* } }; ( ($a:tt, $b:tt, $c:tt, $d:tt, {$($e:tt)*},) ) => { impl_error_chain_processed! { types $a $($e)* links $b foreign_links $c errors $d } }; } /// Macro for generating error types and traits. See crate level documentation for details. #[macro_export(local_inner_macros)] macro_rules! error_chain { ( $($args:tt)* ) => { error_chain_processing! { ({}, {}, {}, {}, {},) $($args)* } }; } /// Macro used to manage the `backtrace` feature. /// /// See /// https://www.reddit.com/r/rust/comments/57virt/hey_rustaceans_got_an_easy_question_ask_here/da5r4ti/?context=3 /// for more details. #[macro_export] #[doc(hidden)] macro_rules! impl_extract_backtrace { ($error_name: ident $error_kind_name: ident $([$link_error_path: path, $(#[$meta_links: meta])*])*) => { #[allow(unknown_lints, renamed_and_removed_lints, bare_trait_objects)] #[allow(unused_doc_comment, unused_doc_comments)] fn extract_backtrace(e: &(::std::error::Error + Send + 'static)) -> Option<$crate::InternalBacktrace> { if let Some(e) = e.downcast_ref::<$error_name>() { return Some(e.1.backtrace.clone()); } $( $( #[$meta_links] )* { if let Some(e) = e.downcast_ref::<$link_error_path>() { return Some(e.1.backtrace.clone()); } } ) * None } } } error-chain-0.12.4/src/example_generated.rs010064400007660000024000000026131366477052600170570ustar0000000000000000//! These modules show an example of code generated by the macro. **IT MUST NOT BE //! USED OUTSIDE THIS CRATE**. //! //! This is the basic error structure. You can see that `ErrorKind` //! has been populated in a variety of ways. All `ErrorKind`s get a //! `Msg` variant for basic errors. When strings are converted to //! `ErrorKind`s they become `ErrorKind::Msg`. The "links" defined in //! the macro are expanded to the `Inner` variant, and the //! "foreign links" to the `Io` variant. //! //! Both types come with a variety of `From` conversions as well: //! `Error` can be created from `ErrorKind`, `&str` and `String`, //! and the `links` and `foreign_links` error types. `ErrorKind` //! can be created from the corresponding `ErrorKind`s of the link //! types, as well as from `&str` and `String`. //! //! `into()` and `From::from` are used heavily to massage types into //! the right shape. Which one to use in any specific case depends on //! the influence of type inference, but there are some patterns that //! arise frequently. /// Another code generated by the macro. pub mod inner { error_chain! {} } error_chain! { links { Inner(inner::Error, inner::ErrorKind) #[doc = "Link to another `ErrorChain`."]; } foreign_links { Io(::std::io::Error) #[doc = "Link to a `std::io::Error` type."]; } errors { #[doc = "A custom error kind."] Custom } } error-chain-0.12.4/src/impl_error_chain_kind.rs010064400007660000024000000362031366477034000177230ustar0000000000000000/// From https://github.com/tailhook/quick-error /// Changes: /// - replace `impl Error` by `impl Item::description` /// - $imeta /// Because of the `#[macro_export(local_inner_macros)]` usage on `impl_error_chain_kind` that macro /// will only look inside this crate for macros to invoke. So using `stringify` or `write` from /// the standard library will fail. Thus we here create simple wrappers for them that are not /// exported as `local_inner_macros`, and thus they can in turn use the standard library macros. #[macro_export] macro_rules! stringify_internal { ($($t:tt)*) => { stringify!($($t)*) } } /// Macro used interally for output expanding an expression #[macro_export] macro_rules! write_internal { ($dst:expr, $($arg:tt)*) => (write!($dst, $($arg)*)) } #[macro_export(local_inner_macros)] #[doc(hidden)] macro_rules! impl_error_chain_kind { ( $(#[$meta:meta])* pub enum $name:ident { $($chunks:tt)* } ) => { impl_error_chain_kind!(SORT [pub enum $name $(#[$meta])* ] items [] buf [] queue [ $($chunks)* ]); }; // Queue is empty, can do the work (SORT [pub enum $name:ident $( #[$meta:meta] )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [ ] queue [ ] ) => { impl_error_chain_kind!(ENUM_DEFINITION [pub enum $name $( #[$meta] )*] body [] queue [$($( #[$imeta] )* => $iitem: $imode [$( $ivar: $ityp ),*] )*] ); impl_error_chain_kind!(IMPLEMENTATIONS $name {$( $iitem: $imode [$(#[$imeta])*] [$( $ivar: $ityp ),*] {$( $ifuncs )*} )*}); $( impl_error_chain_kind!(ERROR_CHECK $imode $($ifuncs)*); )* }; // Add meta to buffer (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )*] queue [ #[$qmeta:meta] $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )*] buf [$( #[$bmeta] )* #[$qmeta] ] queue [$( $tail )*]); }; // Add ident to buffer (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )*] queue [ $qitem:ident $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )*] buf [$(#[$bmeta])* => $qitem : UNIT [ ] ] queue [$( $tail )*]); }; // Flush buffer on meta after ident (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: $bmode:tt [$( $bvar:ident: $btyp:ty ),*] ] queue [ #[$qmeta:meta] $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] enum [$(#[$bmeta])* => $bitem: $bmode $(( $($btyp),* ))*] items [$($( #[$imeta:meta] )* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )* $bitem: $bmode [$( $bvar:$btyp ),*] {} ] buf [ #[$qmeta] ] queue [$( $tail )*]); }; // Add tuple enum-variant (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: UNIT [ ] ] queue [($( $qvar:ident: $qtyp:ty ),+) $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )*] buf [$( #[$bmeta] )* => $bitem: TUPLE [$( $qvar:$qtyp ),+] ] queue [$( $tail )*] ); }; // Add struct enum-variant - e.g. { descr: &'static str } (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: UNIT [ ] ] queue [{ $( $qvar:ident: $qtyp:ty ),+} $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )*] buf [$( #[$bmeta] )* => $bitem: STRUCT [$( $qvar:$qtyp ),+] ] queue [$( $tail )*]); }; // Add struct enum-variant, with excess comma - e.g. { descr: &'static str, } (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: UNIT [ ] ] queue [{$( $qvar:ident: $qtyp:ty ),+ ,} $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )*] buf [$( #[$bmeta] )* => $bitem: STRUCT [$( $qvar:$qtyp ),+] ] queue [$( $tail )*]); }; // Add braces and flush always on braces (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: $bmode:tt [$( $bvar:ident: $btyp:ty ),*] ] queue [ {$( $qfuncs:tt )*} $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )* $(#[$bmeta])* => $bitem: $bmode [$( $bvar:$btyp ),*] {$( $qfuncs )*} ] buf [ ] queue [$( $tail )*]); }; // Flush buffer on double ident (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: $bmode:tt [$( $bvar:ident: $btyp:ty ),*] ] queue [ $qitem:ident $( $tail:tt )*] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )* $(#[$bmeta])* => $bitem: $bmode [$( $bvar:$btyp ),*] {} ] buf [ => $qitem : UNIT [ ] ] queue [$( $tail )*]); }; // Flush buffer on end (SORT [$( $def:tt )*] items [$($( #[$imeta:meta] )* => $iitem:ident: $imode:tt [$( $ivar:ident: $ityp:ty ),*] {$( $ifuncs:tt )*} )* ] buf [$( #[$bmeta:meta] )* => $bitem:ident: $bmode:tt [$( $bvar:ident: $btyp:ty ),*] ] queue [ ] ) => { impl_error_chain_kind!(SORT [$( $def )*] items [$( $(#[$imeta])* => $iitem: $imode [$( $ivar:$ityp ),*] {$( $ifuncs )*} )* $(#[$bmeta])* => $bitem: $bmode [$( $bvar:$btyp ),*] {} ] buf [ ] queue [ ]); }; // Public enum (Queue Empty) (ENUM_DEFINITION [pub enum $name:ident $( #[$meta:meta] )*] body [$($( #[$imeta:meta] )* => $iitem:ident ($(($( $ttyp:ty ),+))*) {$({$( $svar:ident: $styp:ty ),*})*} )* ] queue [ ] ) => { $(#[$meta])* pub enum $name { $( $(#[$imeta])* $iitem $(($( $ttyp ),+))* $({$( $svar: $styp ),*})*, )* #[doc(hidden)] __Nonexhaustive {} } }; // Unit variant (ENUM_DEFINITION [$( $def:tt )*] body [$($( #[$imeta:meta] )* => $iitem:ident ($(($( $ttyp:ty ),+))*) {$({$( $svar:ident: $styp:ty ),*})*} )* ] queue [$( #[$qmeta:meta] )* => $qitem:ident: UNIT [ ] $( $queue:tt )*] ) => { impl_error_chain_kind!(ENUM_DEFINITION [ $($def)* ] body [$($( #[$imeta] )* => $iitem ($(($( $ttyp ),+))*) {$({$( $svar: $styp ),*})*} )* $( #[$qmeta] )* => $qitem () {} ] queue [ $($queue)* ] ); }; // Tuple variant (ENUM_DEFINITION [$( $def:tt )*] body [$($( #[$imeta:meta] )* => $iitem:ident ($(($( $ttyp:ty ),+))*) {$({$( $svar:ident: $styp:ty ),*})*} )* ] queue [$( #[$qmeta:meta] )* => $qitem:ident: TUPLE [$( $qvar:ident: $qtyp:ty ),+] $( $queue:tt )*] ) => { impl_error_chain_kind!(ENUM_DEFINITION [ $($def)* ] body [$($( #[$imeta] )* => $iitem ($(($( $ttyp ),+))*) {$({$( $svar: $styp ),*})*} )* $( #[$qmeta] )* => $qitem (($( $qtyp ),+)) {} ] queue [ $($queue)* ] ); }; // Struct variant (ENUM_DEFINITION [$( $def:tt )*] body [$($( #[$imeta:meta] )* => $iitem:ident ($(($( $ttyp:ty ),+))*) {$({$( $svar:ident: $styp:ty ),*})*} )* ] queue [$( #[$qmeta:meta] )* => $qitem:ident: STRUCT [$( $qvar:ident: $qtyp:ty ),*] $( $queue:tt )*] ) => { impl_error_chain_kind!(ENUM_DEFINITION [ $($def)* ] body [$($( #[$imeta] )* => $iitem ($(($( $ttyp ),+))*) {$({$( $svar: $styp ),*})*} )* $( #[$qmeta] )* => $qitem () {{$( $qvar: $qtyp ),*}} ] queue [ $($queue)* ] ); }; (IMPLEMENTATIONS $name:ident {$( $item:ident: $imode:tt [$(#[$imeta:meta])*] [$( $var:ident: $typ:ty ),*] {$( $funcs:tt )*} )*} ) => { #[allow(unknown_lints, unused, renamed_and_removed_lints)] #[allow(unused_doc_comment, unused_doc_comments)] impl ::std::fmt::Display for $name { fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result { match *self { $( $(#[$imeta])* impl_error_chain_kind!(ITEM_PATTERN $name $item: $imode [$( ref $var ),*] ) => { let display_fn = impl_error_chain_kind!(FIND_DISPLAY_IMPL $name $item: $imode {$( $funcs )*}); display_fn(self, fmt) } )* _ => Ok(()) } } } #[allow(unknown_lints, unused, renamed_and_removed_lints)] #[allow(unused_doc_comment, unused_doc_comments)] impl $name { /// A string describing the error kind. pub fn description(&self) -> &str { match *self { $( $(#[$imeta])* impl_error_chain_kind!(ITEM_PATTERN $name $item: $imode [$( ref $var ),*] ) => { impl_error_chain_kind!(FIND_DESCRIPTION_IMPL $item: $imode self fmt [$( $var ),*] {$( $funcs )*}) } )* _ => "", } } } }; (FIND_DISPLAY_IMPL $name:ident $item:ident: $imode:tt { display($self_:tt) -> ($( $exprs:tt )*) $( $tail:tt )*} ) => { |impl_error_chain_kind!(IDENT $self_): &$name, f: &mut ::std::fmt::Formatter| { write_internal!(f, $( $exprs )*) } }; (FIND_DISPLAY_IMPL $name:ident $item:ident: $imode:tt { display($pattern:expr) $( $tail:tt )*} ) => { |_, f: &mut ::std::fmt::Formatter| { write_internal!(f, $pattern) } }; (FIND_DISPLAY_IMPL $name:ident $item:ident: $imode:tt { display($pattern:expr, $( $exprs:tt )*) $( $tail:tt )*} ) => { |_, f: &mut ::std::fmt::Formatter| { write_internal!(f, $pattern, $( $exprs )*) } }; (FIND_DISPLAY_IMPL $name:ident $item:ident: $imode:tt { $t:tt $( $tail:tt )*} ) => { impl_error_chain_kind!(FIND_DISPLAY_IMPL $name $item: $imode {$( $tail )*}) }; (FIND_DISPLAY_IMPL $name:ident $item:ident: $imode:tt { } ) => { |self_: &$name, f: &mut ::std::fmt::Formatter| { write_internal!(f, "{}", self_.description()) } }; (FIND_DESCRIPTION_IMPL $item:ident: $imode:tt $me:ident $fmt:ident [$( $var:ident ),*] { description($expr:expr) $( $tail:tt )*} ) => { $expr }; (FIND_DESCRIPTION_IMPL $item:ident: $imode:tt $me:ident $fmt:ident [$( $var:ident ),*] { $t:tt $( $tail:tt )*} ) => { impl_error_chain_kind!(FIND_DESCRIPTION_IMPL $item: $imode $me $fmt [$( $var ),*] {$( $tail )*}) }; (FIND_DESCRIPTION_IMPL $item:ident: $imode:tt $me:ident $fmt:ident [$( $var:ident ),*] { } ) => { stringify_internal!($item) }; (ITEM_BODY $(#[$imeta:meta])* $item:ident: UNIT ) => { }; (ITEM_BODY $(#[$imeta:meta])* $item:ident: TUPLE [$( $typ:ty ),*] ) => { ($( $typ ),*) }; (ITEM_BODY $(#[$imeta:meta])* $item:ident: STRUCT [$( $var:ident: $typ:ty ),*] ) => { {$( $var:$typ ),*} }; (ITEM_PATTERN $name:ident $item:ident: UNIT [] ) => { $name::$item }; (ITEM_PATTERN $name:ident $item:ident: TUPLE [$( ref $var:ident ),*] ) => { $name::$item ($( ref $var ),*) }; (ITEM_PATTERN $name:ident $item:ident: STRUCT [$( ref $var:ident ),*] ) => { $name::$item {$( ref $var ),*} }; // This one should match all allowed sequences in "funcs" but not match // anything else. // This is to contrast FIND_* clauses which just find stuff they need and // skip everything else completely (ERROR_CHECK $imode:tt display($self_:tt) -> ($( $exprs:tt )*) $( $tail:tt )*) => { impl_error_chain_kind!(ERROR_CHECK_COMMA $imode $($tail)*); }; (ERROR_CHECK $imode:tt display($pattern: expr) $( $tail:tt )*) => { impl_error_chain_kind!(ERROR_CHECK_COMMA $imode $($tail)*); }; (ERROR_CHECK $imode:tt display($pattern: expr, $( $exprs:tt )*) $( $tail:tt )*) => { impl_error_chain_kind!(ERROR_CHECK_COMMA $imode $($tail)*); }; (ERROR_CHECK $imode:tt description($expr:expr) $( $tail:tt )*) => { impl_error_chain_kind!(ERROR_CHECK_COMMA $imode $($tail)*); }; (ERROR_CHECK $imode:tt ) => {}; (ERROR_CHECK_COMMA $imode:tt , $( $tail:tt )*) => { impl_error_chain_kind!(ERROR_CHECK $imode $($tail)*); }; (ERROR_CHECK_COMMA $imode:tt $( $tail:tt )*) => { impl_error_chain_kind!(ERROR_CHECK $imode $($tail)*); }; // Utility functions (IDENT $ident:ident) => { $ident } } error-chain-0.12.4/src/lib.rs010064400007660000024000000647721371157526300141640ustar0000000000000000#![deny(missing_docs)] #![doc(html_root_url = "https://docs.rs/error-chain/0.12.4")] //! A library for consistent and reliable error handling //! //! error-chain makes it easy to take full advantage of Rust's //! powerful error handling features without the overhead of //! maintaining boilerplate error types and conversions. It implements //! an opinionated strategy for defining your own error types, as well //! as conversions from others' error types. //! //! ## Quick start //! //! If you just want to set up your new project with error-chain, //! follow the [quickstart.rs] template, and read this [intro] //! to error-chain. //! //! [quickstart.rs]: https://github.com/rust-lang-nursery/error-chain/blob/master/examples/quickstart.rs //! [intro]: http://brson.github.io/2016/11/30/starting-with-error-chain //! //! ## Why error chain? //! //! * error-chain is easy to configure. Handle errors robustly with minimal //! effort. //! * Basic error handling requires no maintenance of custom error types //! nor the [`From`] conversions that make `?` work. //! * error-chain scales from simple error handling strategies to more //! rigorous. Return formatted strings for simple errors, only //! introducing error variants and their strong typing as needed for //! advanced error recovery. //! * error-chain makes it trivial to correctly manage the [cause] of //! the errors generated by your own code. This is the "chaining" //! in "error-chain". //! //! [cause]: https://doc.rust-lang.org/std/error/trait.Error.html#method.cause //! //! ## Principles of error-chain //! //! error-chain is based on the following principles: //! //! * No error should ever be discarded. This library primarily //! makes it easy to "chain" errors with the [`chain_err`] method. //! * Introducing new errors is trivial. Simple errors can be introduced //! at the error site with just a string. //! * Handling errors is possible with pattern matching. //! * Conversions between error types are done in an automatic and //! consistent way - [`From`] conversion behavior is never specified //! explicitly. //! * Errors implement [`Send`]. //! * Errors can carry backtraces. //! //! Similar to other libraries like [error-type] and [quick-error], //! this library introduces the error chaining mechanism originally //! employed by Cargo. The [`error_chain!`] macro declares the types //! and implementation boilerplate necessary for fulfilling a //! particular error-handling strategy. Most importantly it defines a //! custom error type (called [`Error`] by convention) and the [`From`] //! conversions that let the `?` operator work. //! //! This library differs in a few ways from previous error libs: //! //! * Instead of defining the custom [`Error`] type as an enum, it is a //! struct containing an [`ErrorKind`][] (which defines the //! [`description`] and [`display_chain`] methods for the error), an opaque, //! optional, boxed [`std::error::Error`]` + `[`Send`]` + 'static` object //! (which defines the [`cause`], and establishes the links in the //! error chain), and a [`Backtrace`]. //! * The macro also defines a [`ResultExt`] trait that defines a //! [`chain_err`] method. This method on all [`std::error::Error`]` + `[`Send`]` + 'static` //! types extends the error chain by boxing the current //! error into an opaque object and putting it inside a new concrete //! error. //! * It provides automatic [`From`] conversions between other error types //! defined by the [`error_chain!`] that preserve type information, //! and facilitate seamless error composition and matching of composed //! errors. //! * It provides automatic [`From`] conversions between any other error //! type that hides the type of the other error in the [`cause`] box. //! * If `RUST_BACKTRACE` is enabled, it collects a single backtrace at //! the earliest opportunity and propagates it down the stack through //! [`From`] and [`ResultExt`] conversions. //! //! To accomplish its goals it makes some tradeoffs: //! //! * The split between the [`Error`] and [`ErrorKind`] types can make it //! slightly more cumbersome to instantiate new (unchained) errors, //! requiring an [`Into`] or [`From`] conversion; as well as slightly //! more cumbersome to match on errors with another layer of types //! to match. //! * Because the error type contains [`std::error::Error`]` + `[`Send`]` + 'static` objects, //! it can't implement [`PartialEq`] for easy comparisons. //! //! ## Declaring error types //! //! Generally, you define one family of error types per crate, though //! it's also perfectly fine to define error types on a finer-grained //! basis, such as per module. //! //! Assuming you are using crate-level error types, typically you will //! define an `errors` module and inside it call [`error_chain!`]: //! //! ``` //! # #[macro_use] extern crate error_chain; //! mod other_error { //! error_chain! {} //! } //! //! error_chain! { //! // The type defined for this error. These are the conventional //! // and recommended names, but they can be arbitrarily chosen. //! // //! // It is also possible to leave this section out entirely, or //! // leave it empty, and these names will be used automatically. //! types { //! Error, ErrorKind, ResultExt, Result; //! } //! //! // Without the `Result` wrapper: //! // //! // types { //! // Error, ErrorKind, ResultExt; //! // } //! //! // Automatic conversions between this error chain and other //! // error chains. In this case, it will e.g. generate an //! // `ErrorKind` variant called `Another` which in turn contains //! // the `other_error::ErrorKind`, with conversions from //! // `other_error::Error`. //! // //! // Optionally, some attributes can be added to a variant. //! // //! // This section can be empty. //! links { //! Another(other_error::Error, other_error::ErrorKind) #[cfg(unix)]; //! } //! //! // Automatic conversions between this error chain and other //! // error types not defined by the `error_chain!`. These will be //! // wrapped in a new error with, in the first case, the //! // `ErrorKind::Fmt` variant. The description and cause will //! // forward to the description and cause of the original error. //! // //! // Optionally, some attributes can be added to a variant. //! // //! // This section can be empty. //! foreign_links { //! Fmt(::std::fmt::Error); //! Io(::std::io::Error) #[cfg(unix)]; //! } //! //! // Define additional `ErrorKind` variants. Define custom responses with the //! // `description` and `display` calls. //! errors { //! InvalidToolchainName(t: String) { //! description("invalid toolchain name") //! display("invalid toolchain name: '{}'", t) //! } //! //! // You can also add commas after description/display. //! // This may work better with some editor auto-indentation modes: //! UnknownToolchainVersion(v: String) { //! description("unknown toolchain version"), // note the , //! display("unknown toolchain version: '{}'", v), // trailing comma is allowed //! } //! } //! //! // If this annotation is left off, a variant `Msg(s: String)` will be added, and `From` //! // impls will be provided for `String` and `&str` //! skip_msg_variant //! } //! //! # fn main() {} //! ``` //! //! Each section, `types`, `links`, `foreign_links`, and `errors` may //! be omitted if it is empty. //! //! This populates the module with a number of definitions, //! the most important of which are the [`Error`] type //! and the [`ErrorKind`] type. An example of generated code can be found in the //! [example_generated](example_generated/index.html) module. //! //! ## Returning new errors //! //! Introducing new error chains, with a string message: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! # error_chain! {} //! fn foo() -> Result<()> { //! Err("foo error!".into()) //! } //! ``` //! //! Introducing new error chains, with an [`ErrorKind`]: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! error_chain! { //! errors { FooError } //! } //! //! fn foo() -> Result<()> { //! Err(ErrorKind::FooError.into()) //! } //! ``` //! //! Note that the return type is the typedef [`Result`], which is //! defined by the macro as `pub type Result = //! ::std::result::Result`. Note that in both cases //! [`.into()`] is called to convert a type into the [`Error`] type; both //! strings and [`ErrorKind`] have [`From`] conversions to turn them into //! [`Error`]. //! //! When the error is emitted behind the `?` operator, the explicit conversion //! isn't needed; `Err(ErrorKind)` will automatically be converted to `Err(Error)`. //! So the below is equivalent to the previous: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! # error_chain! { errors { FooError } } //! fn foo() -> Result<()> { //! Ok(Err(ErrorKind::FooError)?) //! } //! //! fn bar() -> Result<()> { //! Ok(Err("bogus!")?) //! } //! ``` //! //! ## The `bail!` macro //! //! The above method of introducing new errors works but is a little //! verbose. Instead, we can use the [`bail!`] macro, which performs an early return //! with conversions done automatically. //! //! With [`bail!`] the previous examples look like: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! # error_chain! { errors { FooError } } //! fn foo() -> Result<()> { //! if true { //! bail!(ErrorKind::FooError); //! } else { //! Ok(()) //! } //! } //! //! fn bar() -> Result<()> { //! if true { //! bail!("bogus!"); //! } else { //! Ok(()) //! } //! } //! ``` //! //! ## Chaining errors //! error-chain supports extending an error chain by appending new errors. //! This can be done on a Result or on an existing Error. //! //! To extend the error chain: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! # error_chain! {} //! # fn do_something() -> Result<()> { unimplemented!() } //! # fn test() -> Result<()> { //! let res: Result<()> = do_something().chain_err(|| "something went wrong"); //! # Ok(()) //! # } //! ``` //! //! [`chain_err`] can be called on any [`Result`] type where the contained //! error type implements [`std::error::Error`]` + `[`Send`]` + 'static`, as long as //! the [`Result`] type's corresponding [`ResultExt`] trait is in scope. If //! the [`Result`] is an `Err` then [`chain_err`] evaluates the closure, //! which returns *some type that can be converted to [`ErrorKind`]*, //! boxes the original error to store as the cause, then returns a new //! error containing the original error. //! //! Calling [`chain_err`][Error_chain_err] on an existing [`Error`] instance has //! the same signature and produces the same outcome as being called on a //! [`Result`] matching the properties described above. This is most useful when //! partially handling errors using the [`map_err`] function. //! //! To chain an error directly, use [`with_chain`]: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! # error_chain! {} //! # fn do_something() -> Result<()> { unimplemented!() } //! # fn test() -> Result<()> { //! let res: Result<()> = //! do_something().map_err(|e| Error::with_chain(e, "something went wrong")); //! # Ok(()) //! # } //! ``` //! //! ## Linking errors //! //! To convert an error from another error chain to this error chain: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() {} //! # mod other { error_chain! {} } //! error_chain! { //! links { //! OtherError(other::Error, other::ErrorKind); //! } //! } //! //! fn do_other_thing() -> other::Result<()> { unimplemented!() } //! //! # fn test() -> Result<()> { //! let res: Result<()> = do_other_thing().map_err(|e| e.into()); //! # Ok(()) //! # } //! ``` //! //! The [`Error`] and [`ErrorKind`] types implements [`From`] for the corresponding //! types of all linked error chains. Linked errors do not introduce a new //! cause to the error chain. //! //! ## Matching errors //! //! error-chain error variants are matched with simple patterns. //! [`Error`] is a tuple struct and its first field is the [`ErrorKind`], //! making dispatching on error kinds relatively compact: //! //! ``` //! # #[macro_use] extern crate error_chain; //! # fn main() { //! error_chain! { //! errors { //! InvalidToolchainName(t: String) { //! description("invalid toolchain name") //! display("invalid toolchain name: '{}'", t) //! } //! } //! } //! //! match Error::from("error!") { //! Error(ErrorKind::InvalidToolchainName(_), _) => { } //! Error(ErrorKind::Msg(_), _) => { } //! _ => { } //! } //! # } //! ``` //! //! Chained errors are also matched with (relatively) compact syntax //! //! ``` //! # #[macro_use] extern crate error_chain; //! mod utils { //! error_chain! { //! errors { //! BadStuff { //! description("bad stuff") //! } //! } //! } //! } //! //! mod app { //! error_chain! { //! links { //! Utils(::utils::Error, ::utils::ErrorKind); //! } //! } //! } //! //! //! # fn main() { //! match app::Error::from("error!") { //! app::Error(app::ErrorKind::Utils(utils::ErrorKind::BadStuff), _) => { } //! _ => { } //! } //! # } //! ``` //! //! ## Inspecting errors //! //! An error-chain error contains information about the error itself, a backtrace, and the chain //! of causing errors. For reporting purposes, this information can be accessed as follows. //! //! ``` //! # #[macro_use] extern crate error_chain; //! use error_chain::ChainedError; // for e.display_chain() //! //! error_chain! { //! errors { //! InvalidToolchainName(t: String) { //! description("invalid toolchain name") //! display("invalid toolchain name: '{}'", t) //! } //! } //! } //! //! # fn main() { //! // Generate an example error to inspect: //! let e = "xyzzy".parse::() //! .chain_err(|| ErrorKind::InvalidToolchainName("xyzzy".to_string())) //! .unwrap_err(); //! //! // Get the brief description of the error: //! assert_eq!(e.description(), "invalid toolchain name"); //! //! // Get the display version of the error: //! assert_eq!(e.to_string(), "invalid toolchain name: 'xyzzy'"); //! //! // Get the full cause and backtrace: //! println!("{}", e.display_chain().to_string()); //! // Error: invalid toolchain name: 'xyzzy' //! // Caused by: invalid digit found in string //! // stack backtrace: //! // 0: 0x7fa9f684fc94 - backtrace::backtrace::libunwind::trace //! // at src/backtrace/libunwind.rs:53 //! // - backtrace::backtrace::trace //! // at src/backtrace/mod.rs:42 //! // 1: 0x7fa9f6850b0e - backtrace::capture::{{impl}}::new //! // at out/capture.rs:79 //! // [..] //! # } //! ``` //! //! The [`Error`] and [`ErrorKind`] types also allow programmatic access to these elements. //! //! ## Foreign links //! //! Errors that do not conform to the same conventions as this library //! can still be included in the error chain. They are considered "foreign //! errors", and are declared using the `foreign_links` block of the //! [`error_chain!`] macro. [`Error`]s are automatically created from //! foreign errors by the `?` operator. //! //! Foreign links and regular links have one crucial difference: //! [`From`] conversions for regular links *do not introduce a new error //! into the error chain*, while conversions for foreign links *always //! introduce a new error into the error chain*. So for the example //! above all errors deriving from the [`std::fmt::Error`] type will be //! presented to the user as a new [`ErrorKind`] variant, and the //! cause will be the original [`std::fmt::Error`] error. In contrast, when //! `other_error::Error` is converted to `Error` the two `ErrorKind`s //! are converted between each other to create a new `Error` but the //! old error is discarded; there is no "cause" created from the //! original error. //! //! ## Backtraces //! //! If the `RUST_BACKTRACE` environment variable is set to anything //! but ``0``, the earliest non-foreign error to be generated creates //! a single backtrace, which is passed through all [`From`] conversions //! and [`chain_err`] invocations of compatible types. To read the //! backtrace just call the [`backtrace`] method. //! //! Backtrace generation can be disabled by turning off the `backtrace` feature. //! //! The Backtrace contains a Vec of [`BacktraceFrame`]s that can be operated //! on directly. For example, to only see the files and line numbers of code //! within your own project. //! //! ``` //! # #[macro_use] //! # extern crate error_chain; //! # mod errors { //! # error_chain! { //! # foreign_links { //! # Io(::std::io::Error); //! # } //! # } //! # } //! # use errors::*; //! # #[cfg(feature="backtrace")] //! # fn main() { //! if let Err(ref e) = open_file() { //! if let Some(backtrace) = e.backtrace() { //! let frames = backtrace.frames(); //! for frame in frames.iter() { //! for symbol in frame.symbols().iter() { //! if let (Some(file), Some(lineno)) = (symbol.filename(), symbol.lineno()) { //! if file.display().to_string()[0..3] == "src".to_string(){ //! println!("{}:{}", file.display().to_string(), lineno); //! } //! } //! } //! } //! } //! }; //! # } //! # #[cfg(not(feature="backtrace"))] //! # fn main() { } //! //! fn open_file() -> Result<()> { //! std::fs::File::open("does_not_exist")?; //! Ok(()) //! } //! ``` //! //! ## Iteration //! //! The [`iter`] method returns an iterator over the chain of error boxes. //! //! [error-type]: https://github.com/DanielKeep/rust-error-type //! [quick-error]: https://github.com/tailhook/quick-error //! [`display_chain`]: trait.ChainedError.html#method.display_chain //! [`error_chain!`]: macro.error_chain.html //! [`bail!`]: macro.bail.html //! [`Backtrace`]: struct.Backtrace.html //! [`Error`]: example_generated/struct.Error.html //! [`with_chain`]: example_generated/struct.Error.html#method.with_chain //! [Error_chain_err]: example_generated/struct.Error.html#method.chain_err //! [`cause`]: example_generated/struct.Error.html#method.cause //! [`backtrace`]: example_generated/struct.Error.html#method.backtrace //! [`iter`]: example_generated/struct.Error.html#method.iter //! [`ErrorKind`]: example_generated/enum.ErrorKind.html //! [`description`]: example_generated/enum.ErrorKind.html#method.description //! [`Result`]: example_generated/type.Result.html //! [`ResultExt`]: example_generated/trait.ResultExt.html //! [`chain_err`]: example_generated/trait.ResultExt.html#tymethod.chain_err //! [`std::error::Error`]: https://doc.rust-lang.org/std/error/trait.Error.html //! [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html //! [`Into`]: https://doc.rust-lang.org/std/convert/trait.Into.html //! [`From`]: https://doc.rust-lang.org/std/convert/trait.From.html //! [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html //! [`std::fmt::Error`]: https://doc.rust-lang.org/std/fmt/struct.Error.html //! [`.into()`]: https://doc.rust-lang.org/std/convert/trait.Into.html#tymethod.into //! [`map_err`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map_err //! [`BacktraceFrame`]: https://docs.rs/backtrace/0.3.2/backtrace/struct.BacktraceFrame.html use std::error; use std::fmt; use std::iter::Iterator; #[macro_use] mod impl_error_chain_kind; #[macro_use] mod error_chain; #[macro_use] mod quick_main; pub use quick_main::ExitCode; mod backtrace; #[cfg(feature = "example_generated")] pub mod example_generated; pub use backtrace::Backtrace; #[doc(hidden)] pub use backtrace::InternalBacktrace; #[derive(Debug)] #[allow(unknown_lints, bare_trait_objects)] /// Iterator over the error chain using the `Error::cause()` method. pub struct Iter<'a>(Option<&'a error::Error>); impl<'a> Iter<'a> { /// Returns a new iterator over the error chain using `Error::cause()`. #[allow(unknown_lints, bare_trait_objects)] pub fn new(err: Option<&'a error::Error>) -> Iter<'a> { Iter(err) } } #[allow(unknown_lints, bare_trait_objects)] impl<'a> Iterator for Iter<'a> { type Item = &'a error::Error; fn next<'b>(&'b mut self) -> Option<&'a error::Error> { match self.0.take() { Some(e) => { self.0 = match () { #[cfg(not(has_error_source))] () => e.cause(), #[cfg(has_error_source)] () => e.source(), }; Some(e) } None => None, } } } /// This trait is implemented on all the errors generated by the `error_chain` /// macro. pub trait ChainedError: error::Error + Send + 'static { /// Associated kind type. type ErrorKind; /// Constructs an error from a kind, and generates a backtrace. fn from_kind(kind: Self::ErrorKind) -> Self where Self: Sized; /// Constructs a chained error from another error and a kind, and generates a backtrace. fn with_chain(error: E, kind: K) -> Self where Self: Sized, E: ::std::error::Error + Send + 'static, K: Into; /// Returns the kind of the error. fn kind(&self) -> &Self::ErrorKind; /// Iterates over the error chain. fn iter(&self) -> Iter; /// Returns the backtrace associated with this error. fn backtrace(&self) -> Option<&Backtrace>; /// Returns an object which implements `Display` for printing the full /// context of this error. /// /// The full cause chain and backtrace, if present, will be printed. fn display_chain<'a>(&'a self) -> DisplayChain<'a, Self> { DisplayChain(self) } /// Extends the error chain with a new entry. fn chain_err(self, error: F) -> Self where F: FnOnce() -> EK, EK: Into; /// Creates an error from its parts. #[doc(hidden)] fn new(kind: Self::ErrorKind, state: State) -> Self where Self: Sized; /// Returns the first known backtrace, either from its State or from one /// of the errors from `foreign_links`. #[doc(hidden)] #[allow(unknown_lints, bare_trait_objects)] fn extract_backtrace(e: &(error::Error + Send + 'static)) -> Option where Self: Sized; } /// A struct which formats an error for output. #[derive(Debug)] pub struct DisplayChain<'a, T: 'a + ?Sized>(&'a T); impl<'a, T> fmt::Display for DisplayChain<'a, T> where T: ChainedError, { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { writeln!(fmt, "Error: {}", self.0)?; for e in self.0.iter().skip(1) { writeln!(fmt, "Caused by: {}", e)?; } if let Some(backtrace) = ChainedError::backtrace(self.0) { writeln!(fmt, "{:?}", backtrace)?; } Ok(()) } } /// Common state between errors. #[derive(Debug)] #[doc(hidden)] #[allow(unknown_lints, bare_trait_objects)] pub struct State { /// Next error in the error chain. pub next_error: Option>, /// Backtrace for the current error. pub backtrace: InternalBacktrace, } impl Default for State { fn default() -> State { State { next_error: None, backtrace: InternalBacktrace::new(), } } } impl State { /// Creates a new State type #[allow(unknown_lints, bare_trait_objects)] pub fn new(e: Box) -> State { let backtrace = CE::extract_backtrace(&*e).unwrap_or_else(InternalBacktrace::new); State { next_error: Some(e), backtrace: backtrace, } } /// Returns the inner backtrace if present. pub fn backtrace(&self) -> Option<&Backtrace> { self.backtrace.as_backtrace() } } /// Exits a function early with an error /// /// The `bail!` macro provides an easy way to exit a function. /// `bail!(expr)` is equivalent to writing. /// /// ``` /// # #[macro_use] extern crate error_chain; /// # error_chain! { } /// # fn main() { } /// # fn foo() -> Result<()> { /// # let expr = ""; /// return Err(expr.into()); /// # } /// ``` /// /// And as shorthand it takes a formatting string a la `println!`: /// /// ``` /// # #[macro_use] extern crate error_chain; /// # error_chain! { } /// # fn main() { } /// # fn foo() -> Result<()> { /// # let n = 0; /// bail!("bad number: {}", n); /// # } /// ``` /// /// # Examples /// /// Bailing on a custom error: /// /// ``` /// # #[macro_use] extern crate error_chain; /// # fn main() {} /// error_chain! { /// errors { FooError } /// } /// /// fn foo() -> Result<()> { /// if bad_condition() { /// bail!(ErrorKind::FooError); /// } /// /// Ok(()) /// } /// /// # fn bad_condition() -> bool { true } /// ``` /// /// Bailing on a formatted string: /// /// ``` /// # #[macro_use] extern crate error_chain; /// # fn main() {} /// error_chain! { } /// /// fn foo() -> Result<()> { /// if let Some(bad_num) = bad_condition() { /// bail!("so bad: {}", bad_num); /// } /// /// Ok(()) /// } /// /// # fn bad_condition() -> Option { None } /// ``` #[macro_export] macro_rules! bail { ($e:expr) => { return Err($e.into()); }; ($fmt:expr, $($arg:tt)+) => { return Err(format!($fmt, $($arg)+).into()); }; } /// Exits a function early with an error if the condition is not satisfied /// /// The `ensure!` macro is a convenience helper that provides a way to exit /// a function with an error if the given condition fails. /// /// As an example, `ensure!(condition, "error code: {}", errcode)` is equivalent to /// /// ``` /// # #[macro_use] extern crate error_chain; /// # error_chain! { } /// # fn main() { } /// # fn foo() -> Result<()> { /// # let errcode = 0u8; /// # let condition = true; /// if !condition { /// bail!("error code: {}", errcode); /// } /// # Ok(()) /// # } /// ``` /// /// See documentation for `bail!` macro for further details. #[macro_export(local_inner_macros)] macro_rules! ensure { ($cond:expr, $e:expr) => { if !($cond) { bail!($e); } }; ($cond:expr, $fmt:expr, $($arg:tt)+) => { if !($cond) { bail!($fmt, $($arg)+); } }; } #[doc(hidden)] pub mod mock { error_chain! {} } error-chain-0.12.4/src/quick_main.rs010064400007660000024000000034121366477052600155240ustar0000000000000000/// Convenient wrapper to be able to use `?` and such in the main. You can /// use it with a separated function: /// /// ``` /// # #[macro_use] extern crate error_chain; /// # error_chain! {} /// # fn main() { /// quick_main!(run); /// # } /// /// fn run() -> Result<()> { /// Err("error".into()) /// } /// ``` /// /// or with a closure: /// /// ``` /// # #[macro_use] extern crate error_chain; /// # error_chain! {} /// # fn main() { /// quick_main!(|| -> Result<()> { /// Err("error".into()) /// }); /// # } /// ``` /// /// You can also set the exit value of the process by returning a type that implements [`ExitCode`](trait.ExitCode.html): /// /// ``` /// # #[macro_use] extern crate error_chain; /// # error_chain! {} /// # fn main() { /// quick_main!(run); /// # } /// /// fn run() -> Result { /// Err("error".into()) /// } /// ``` #[macro_export] macro_rules! quick_main { ($main:expr) => { fn main() { use std::io::Write; ::std::process::exit(match $main() { Ok(ret) => $crate::ExitCode::code(ret), Err(ref e) => { write!( &mut ::std::io::stderr(), "{}", $crate::ChainedError::display_chain(e) ) .expect("Error writing to stderr"); 1 } }); } }; } /// Represents a value that can be used as the exit status of the process. /// See [`quick_main!`](macro.quick_main.html). pub trait ExitCode { /// Returns the value to use as the exit status. fn code(self) -> i32; } impl ExitCode for i32 { fn code(self) -> i32 { self } } impl ExitCode for () { fn code(self) -> i32 { 0 } } error-chain-0.12.4/tests/quick_main.rs010064400007660000024000000005571366477034000161000ustar0000000000000000#![allow(dead_code)] #[macro_use] extern crate error_chain; error_chain!(); mod unit { use super::*; quick_main!(run); fn run() -> Result<()> { Ok(()) } } mod i32 { use super::*; quick_main!(run); fn run() -> Result { Ok(1) } } mod closure { use super::*; quick_main!(|| -> Result<()> { Ok(()) }); } error-chain-0.12.4/tests/tests.rs010064400007660000024000000351761366477052600151350ustar0000000000000000#![allow(dead_code)] #[macro_use] extern crate error_chain; #[test] fn smoke_test_1() { error_chain! { types { Error, ErrorKind, ResultExt, Result; } links { } foreign_links { } errors { } }; } #[test] fn smoke_test_2() { error_chain! { types { } links { } foreign_links { } errors { } }; } #[test] fn smoke_test_3() { error_chain! { links { } foreign_links { } errors { } }; } #[test] fn smoke_test_4() { error_chain! { links { } foreign_links { } errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code") display("http request returned an unsuccessful status code: {}", e) } } }; } #[test] fn smoke_test_5() { error_chain! { types { } links { } foreign_links { } errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code") display("http request returned an unsuccessful status code: {}", e) } } }; } #[test] fn smoke_test_6() { error_chain! { errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code") display("http request returned an unsuccessful status code: {}", e) } } }; } #[test] fn smoke_test_7() { error_chain! { types { } foreign_links { } errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code") display("http request returned an unsuccessful status code: {}", e) } } }; } #[test] fn smoke_test_8() { error_chain! { types { } links { } links { } foreign_links { } foreign_links { } errors { FileNotFound AccessDenied } }; } #[test] fn order_test_1() { error_chain! { types { } links { } foreign_links { } errors { } }; } #[test] fn order_test_2() { error_chain! { links { } types { } foreign_links { } errors { } }; } #[test] fn order_test_3() { error_chain! { foreign_links { } links { } errors { } types { } }; } #[test] fn order_test_4() { error_chain! { errors { } types { } foreign_links { } }; } #[test] fn order_test_5() { error_chain! { foreign_links { } types { } }; } #[test] fn order_test_6() { error_chain! { links { } errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code") display("http request returned an unsuccessful status code: {}", e) } } foreign_links { } }; } #[test] fn order_test_7() { error_chain! { links { } foreign_links { } types { Error, ErrorKind, ResultExt, Result; } }; } #[test] fn order_test_8() { error_chain! { links { } foreign_links { } foreign_links { } types { Error, ErrorKind, ResultExt, Result; } }; } #[test] fn empty() { error_chain! {}; } #[test] #[cfg(feature = "backtrace")] fn has_backtrace_depending_on_env() { use std::path::PathBuf; use std::process::Command; let cmd_folder = if cfg!(build = "debug") { "debug" } else if cfg!(build = "release") { "release" } else { panic!("Unknown build config"); }; let cmd_path = if cfg!(windows) { PathBuf::from(format!( "./target/{}/examples/has_backtrace.exe", cmd_folder )) } else { PathBuf::from(format!("./target/{}/examples/has_backtrace", cmd_folder)) }; let mut cmd = Command::new(cmd_path); // missing RUST_BACKTRACE and RUST_BACKTRACE=0 cmd.env_remove("RUST_BACKTRACE"); assert_eq!(cmd.status().unwrap().code().unwrap(), 0); cmd.env("RUST_BACKTRACE", "0"); assert_eq!(cmd.status().unwrap().code().unwrap(), 0); // RUST_BACKTRACE set to anything but 0 cmd.env("RUST_BACKTRACE", "yes"); assert_eq!(cmd.status().unwrap().code().unwrap(), 1); cmd.env("RUST_BACKTRACE", "1"); assert_eq!(cmd.status().unwrap().code().unwrap(), 1); } #[test] fn chain_err() { use std::fmt; error_chain! { foreign_links { Fmt(fmt::Error); } errors { Test } } let _: Result<()> = Err(fmt::Error).chain_err(|| ""); let _: Result<()> = Err(Error::from_kind(ErrorKind::Test)).chain_err(|| ""); } /// Verify that an error chain is extended one by `Error::chain_err`, with /// the new error added to the end. #[test] fn error_chain_err() { error_chain! { errors { Test } } let base = Error::from(ErrorKind::Test); let ext = base.chain_err(|| "Test passes"); if let Error(ErrorKind::Msg(_), _) = ext { // pass } else { panic!("The error should be wrapped. {:?}", ext); } } #[test] fn links() { mod test { error_chain! {} } error_chain! { links { Test(test::Error, test::ErrorKind); } } } #[cfg(test)] mod foreign_link_test { use std::fmt; // Note: foreign errors must be `pub` because they appear in the // signature of the public foreign_link_error_path #[derive(Debug)] pub struct ForeignError { cause: ForeignErrorCause, } impl ::std::error::Error for ForeignError { fn description(&self) -> &'static str { "Foreign error description" } #[cfg(not(has_error_source))] fn cause(&self) -> Option<&::std::error::Error> { Some(&self.cause) } #[cfg(has_error_source)] fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { Some(&self.cause) } } impl fmt::Display for ForeignError { fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { write!(formatter, "Foreign error display") } } #[derive(Debug)] pub struct ForeignErrorCause {} impl ::std::error::Error for ForeignErrorCause { fn description(&self) -> &'static str { "Foreign error cause description" } #[cfg(not(has_error_source))] fn cause(&self) -> Option<&::std::error::Error> { None } #[cfg(has_error_source)] fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { None } } impl fmt::Display for ForeignErrorCause { fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { write!(formatter, "Foreign error cause display") } } error_chain! { types{ Error, ErrorKind, ResultExt, Result; } links {} foreign_links { Foreign(ForeignError); Io(::std::io::Error); } errors {} } #[test] fn display_underlying_error() { let chained_error = try_foreign_error().err().unwrap(); assert_eq!( format!( "{}", ForeignError { cause: ForeignErrorCause {} } ), format!("{}", chained_error) ); } #[test] #[cfg(not(has_error_source))] fn finds_cause() { let chained_error = try_foreign_error().err().unwrap(); assert_eq!( format!("{}", ForeignErrorCause {}), format!("{}", ::std::error::Error::cause(&chained_error).unwrap()) ); } #[test] #[cfg(has_error_source)] fn finds_source() { let chained_error = try_foreign_error().err().unwrap(); assert_eq!( format!("{}", ForeignErrorCause {}), format!("{}", ::std::error::Error::source(&chained_error).unwrap()) ); } #[test] #[allow(unknown_lints, bare_trait_objects)] fn iterates() { let chained_error = try_foreign_error().err().unwrap(); let mut error_iter = chained_error.iter(); assert!(!format!("{:?}", error_iter).is_empty()); assert_eq!( format!( "{}", ForeignError { cause: ForeignErrorCause {} } ), format!("{}", error_iter.next().unwrap()) ); assert_eq!( format!("{}", ForeignErrorCause {}), format!("{}", error_iter.next().unwrap()) ); assert_eq!( format!("{:?}", None as Option<&::std::error::Error>), format!("{:?}", error_iter.next()) ); } fn try_foreign_error() -> Result<()> { Err(ForeignError { cause: ForeignErrorCause {}, })?; Ok(()) } } #[cfg(test)] mod attributes_test { #[allow(unused_imports)] use std::io; #[cfg(not(test))] mod inner { error_chain! {} } error_chain! { types { Error, ErrorKind, ResultExt, Result; } links { Inner(inner::Error, inner::ErrorKind) #[cfg(not(test))]; } foreign_links { Io(io::Error) #[cfg(not(test))]; } errors { #[cfg(not(test))] AnError { } } } } #[test] fn with_result() { error_chain! { types { Error, ErrorKind, ResultExt, Result; } } let _: Result<()> = Ok(()); } #[test] fn without_result() { error_chain! { types { Error, ErrorKind, ResultExt; } } let _: Result<(), ()> = Ok(()); } #[test] fn documentation() { mod inner { error_chain! {} } error_chain! { links { Inner(inner::Error, inner::ErrorKind) #[doc = "Doc"]; } foreign_links { Io(::std::io::Error) #[doc = "Doc"]; } errors { /// Doc Variant } } } #[cfg(test)] mod multiple_error_same_mod { error_chain! { types { MyError, MyErrorKind, MyResultExt, MyResult; } } error_chain! {} } #[doc(test)] #[deny(dead_code)] mod allow_dead_code { error_chain! {} } // Make sure links actually work! #[test] fn rustup_regression() { error_chain! { links { Download(error_chain::mock::Error, error_chain::mock::ErrorKind); } foreign_links { } errors { LocatingWorkingDir { description("could not locate working directory") } } } } #[test] fn error_patterns() { error_chain! { links { } foreign_links { } errors { } } // Tuples look nice when matching errors match Error::from("Test") { Error(ErrorKind::Msg(_), _) => {} _ => {} } } #[test] fn result_match() { error_chain! {} fn ok() -> Result<()> { Ok(()) } match ok() { Ok(()) => {} Err(Error(ErrorKind::Msg(_), _)) => {} Err(..) => {} } } #[test] fn error_first() { error_chain! { errors { LocatingWorkingDir { description("could not locate working directory") } } links { Download(error_chain::mock::Error, error_chain::mock::ErrorKind); } foreign_links { } } } #[test] fn bail() { error_chain! { errors { Foo } } fn foo() -> Result<()> { bail!(ErrorKind::Foo) } fn bar() -> Result<()> { bail!("bar") } fn baz() -> Result<()> { bail!("{}", "baz") } } #[test] fn ensure() { error_chain! { errors { Bar } } fn foo(x: u8) -> Result<()> { ensure!(x == 42, ErrorKind::Bar); Ok(()) } assert!(foo(42).is_ok()); assert!(foo(0).is_err()); } /// Since the `types` declaration is a list of symbols, check if we /// don't change their meaning or order. #[test] fn types_declarations() { error_chain! { types { MyError, MyErrorKind, MyResultExt, MyResult; } } MyError::from_kind(MyErrorKind::Msg("".into())); let err: Result<(), ::std::io::Error> = Ok(()); MyResultExt::chain_err(err, || "").unwrap(); let _: MyResult<()> = Ok(()); } #[test] /// Calling chain_err over a `Result` containing an error to get a chained error /// and constructing a MyError directly, passing it an error should be equivalent. fn rewrapping() { use std::env::VarError::{self, NotPresent, NotUnicode}; error_chain! { foreign_links { VarErr(VarError); } types { MyError, MyErrorKind, MyResultExt, MyResult; } } let result_a_from_func: Result = Err(VarError::NotPresent); let result_b_from_func: Result = Err(VarError::NotPresent); let our_error_a = result_a_from_func.map_err(|e| match e { NotPresent => MyError::with_chain(e, "env var wasn't provided"), NotUnicode(_) => MyError::with_chain(e, "env var was bork文字化ã"), }); let our_error_b = result_b_from_func.or_else(|e| match e { NotPresent => Err(e).chain_err(|| "env var wasn't provided"), NotUnicode(_) => Err(e).chain_err(|| "env var was bork文字化ã"), }); assert_eq!( format!("{}", our_error_a.unwrap_err()), format!("{}", our_error_b.unwrap_err()) ); } #[test] fn comma_in_errors_impl() { error_chain! { links { } foreign_links { } errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code"), display("http request returned an unsuccessful status code: {}", e) } } }; } #[test] fn trailing_comma_in_errors_impl() { error_chain! { links { } foreign_links { } errors { HttpStatus(e: u32) { description("http request returned an unsuccessful status code"), display("http request returned an unsuccessful status code: {}", e), } } }; } #[test] fn skipping_msg_variant() { error_chain! { skip_msg_variant errors { MyMsg(s: String) { description(&s) display("{}", s) } } } let x = Error::from_kind(ErrorKind::MyMsg("some string".into())); // This would fail to compile if we generate a `Msg` variant match *x.kind() { ErrorKind::MyMsg(_) => {} ErrorKind::__Nonexhaustive {} => {} } }