blob: 115b85fc27dd91ed36e46ed88b826612dc6bca3d [file] [log] [blame]
// Part of the Crubit project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
use regex::Regex;
use std::borrow::Cow;
use std::cell::RefCell;
use std::collections::BTreeMap;
use std::fmt::{self, Arguments, Display, Formatter};
use serde::Serialize;
#[doc(hidden)]
pub mod macro_internal {
pub use anyhow;
pub use arc_anyhow;
pub use std::format_args;
}
/// An error that stores its format string as well as the formatted message.
#[derive(Debug, Clone)]
pub struct FormattedError {
pub fmt: Cow<'static, str>,
pub message: Cow<'static, str>,
}
impl FormattedError {
pub fn new_static(fmt: &'static str, args: Arguments) -> arc_anyhow::Error {
arc_anyhow::Error::from(anyhow::Error::from(match args.as_str() {
// This format string has no parameters to format at runtime.
// Note: The compiler can perform optimizations to return `Some`, when even when
// `fmt` contains placeholders, so we store `fmt` instead of `s` for `fmt` field.
Some(s) => Self { fmt: Cow::Borrowed(fmt), message: Cow::Borrowed(s) },
// This format string has parameters and must be formatted.
None => Self { fmt: Cow::Borrowed(fmt), message: Cow::Owned(fmt::format(args)) },
}))
}
pub fn new_dynamic(err: impl Display) -> arc_anyhow::Error {
// Use the whole error as the format string. This is preferable to
// grouping all dynamic errors under the "{}" format string.
let message = format!("{}", err);
arc_anyhow::Error::from(anyhow::Error::from(Self {
fmt: Cow::Owned(message.clone()),
message: Cow::Owned(message),
}))
}
}
impl Display for FormattedError {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "{}", self.message)
}
}
impl std::error::Error for FormattedError {}
/// Evaluates to an [`arc_anyhow::Error`].
///
/// Otherwise similar to [`anyhow::anyhow`].
#[macro_export]
macro_rules! anyhow {
($fmt:literal $(,)?) => {
$crate::FormattedError::new_static(
$fmt,
$crate::macro_internal::format_args!($fmt),
)
};
($err:expr $(,)?) => {
$crate::FormattedError::new_dynamic($err)
};
($fmt:expr, $($arg:tt)*) => {
$crate::FormattedError::new_static(
$fmt,
$crate::macro_internal::format_args!($fmt, $($arg)*),
)
};
}
/// Returns a [`Result::Err`] containing an [`arc_anyhow::Error`].
///
/// Otherwise similar to [`anyhow::bail`].
#[macro_export]
macro_rules! bail {
($fmt:literal $(,)?) => {
return Err($crate::anyhow!($fmt))
};
($err:expr $(,)?) => {
return Err($crate::anyhow!($err))
};
($fmt:expr, $($arg:tt)*) => {
return Err($crate::anyhow!($fmt, $($arg)*))
};
}
/// Returns a [`Result::Err`] containing an [`arc_anyhow::Error`] if the given
/// condition evaluates to false.
///
/// Otherwise similar to [`anyhow::ensure`].
#[macro_export]
macro_rules! ensure {
($cond:expr, $fmt:literal $(,)?) => {
if !$cond { bail!($fmt); }
};
($cond:expr, $err:expr $(,)?) => {
if !$cond { bail!($err); }
};
($cond:expr, $fmt:expr, $($arg:tt)*) => {
if !$cond { bail!($fmt, $($arg)*); }
};
}
pub trait ErrorReporting: std::fmt::Debug {
/// Inserts a new error. Uses interior mutability so that references can be
/// shared freely.
fn insert(&self, error: &arc_anyhow::Error);
fn serialize_to_vec(&self) -> anyhow::Result<Vec<u8>>;
fn serialize_to_string(&self) -> anyhow::Result<String>;
}
/// A null [`ErrorReporting`] strategy.
#[derive(Debug)]
pub struct IgnoreErrors;
impl ErrorReporting for IgnoreErrors {
fn insert(&self, _error: &arc_anyhow::Error) {}
fn serialize_to_vec(&self) -> anyhow::Result<Vec<u8>> {
Ok(vec![])
}
fn serialize_to_string(&self) -> anyhow::Result<String> {
Ok(String::new())
}
}
fn hide_unstable_details(input: &str) -> String {
// Remove line:column in def id
let regex = Regex::new(r"DefId\(\d+:\d+ ~ ").unwrap();
regex.replace_all(input, "DefId(").to_string()
}
/// An aggregate of zero or more errors.
#[derive(Default, Debug)]
pub struct ErrorReport {
// The interior mutability / borrow_mut will never panic: it is never borrowed for longer than
// a method call, and the methods do not call each other.
map: RefCell<BTreeMap<Cow<'static, str>, ErrorReportEntry>>,
}
impl ErrorReport {
pub fn new() -> Self {
Self::default()
}
}
impl ErrorReporting for ErrorReport {
fn insert(&self, error: &arc_anyhow::Error) {
let root_cause = error.root_cause();
if let Some(error) = root_cause.downcast_ref::<FormattedError>() {
let sample_message = if error.message != error.fmt { &*error.message } else { "" };
self.map
.borrow_mut()
.entry(error.fmt.clone())
.or_default()
.add(Cow::Owned(hide_unstable_details(sample_message)));
} else {
self.map
.borrow_mut()
.entry(Cow::Borrowed("{}"))
.or_default()
.add(Cow::Owned(hide_unstable_details(&format!("{error}"))));
}
}
fn serialize_to_vec(&self) -> anyhow::Result<Vec<u8>> {
Ok(serde_json::to_vec(&*self.map.borrow())?)
}
fn serialize_to_string(&self) -> anyhow::Result<String> {
Ok(serde_json::to_string_pretty(&*self.map.borrow())?)
}
}
#[derive(Default, Debug, Serialize)]
struct ErrorReportEntry {
count: u64,
#[serde(skip_serializing_if = "String::is_empty")]
sample_message: String,
}
impl ErrorReportEntry {
fn add(&mut self, message: Cow<str>) {
if self.count == 0 {
self.sample_message = message.into_owned();
}
self.count += 1;
}
}
#[cfg(test)]
mod tests {
use super::*;
use googletest::prelude::*;
use arc_anyhow::Result;
#[gtest]
fn anyhow_1arg_static_plain() {
let arc_err = anyhow!("abc");
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc");
assert!(matches!(err.message, Cow::Borrowed(_)));
assert_eq!(err.message, "abc");
}
#[gtest]
fn anyhow_1arg_static_fmt() {
let some_var = "def";
let arc_err = anyhow!("abc{some_var}");
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc{some_var}");
assert!(matches!(err.message, Cow::Owned(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn anyhow_1arg_dynamic() {
let arc_err = anyhow!(format!("abc{}", "def"));
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Owned(_)));
assert_eq!(err.fmt, "abcdef");
assert!(matches!(err.message, Cow::Owned(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn anyhow_2arg() {
let arc_err = anyhow!("abc{}", "def");
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc{}");
assert!(matches!(err.message, Cow::Borrowed(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn bail_1arg_static_plain() {
let arc_err = (|| -> arc_anyhow::Result<()> { bail!("abc") })().unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc");
assert!(matches!(err.message, Cow::Borrowed(_)));
assert_eq!(err.message, "abc");
}
#[gtest]
fn bail_1arg_static_fmt() {
let some_var = "def";
let arc_err = (|| -> arc_anyhow::Result<()> { bail!("abc{some_var}") })().unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc{some_var}");
assert!(matches!(err.message, Cow::Owned(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn bail_1arg_dynamic() {
let arc_err =
(|| -> arc_anyhow::Result<()> { bail!(format!("abc{}", "def")) })().unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Owned(_)));
assert_eq!(err.fmt, "abcdef");
assert!(matches!(err.message, Cow::Owned(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn bail_2arg() {
let arc_err = (|| -> arc_anyhow::Result<()> { bail!("abc{}", "def") })().unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc{}");
assert!(matches!(err.message, Cow::Borrowed(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn ensure_pass() {
let f = || {
ensure!(true, "unused message");
Ok(())
};
f().unwrap();
}
#[gtest]
fn ensure_fail_1arg_static_plain() {
let arc_err = (|| {
ensure!(false, "abc");
Ok(())
})()
.unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc");
assert!(matches!(err.message, Cow::Borrowed(_)));
assert_eq!(err.message, "abc");
}
#[gtest]
fn ensure_fail_1arg_static_fmt() {
let some_var = "def";
let arc_err = (|| {
ensure!(false, "abc{some_var}");
Ok(())
})()
.unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc{some_var}");
assert!(matches!(err.message, Cow::Owned(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn ensure_fail_1arg_dynamic() {
let arc_err = (|| {
ensure!(false, format!("abc{}", "def"));
Ok(())
})()
.unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Owned(_)));
assert_eq!(err.fmt, "abcdef");
assert!(matches!(err.message, Cow::Owned(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn ensure_fail_2arg() {
let arc_err = (|| {
ensure!(false, "abc{}", "def");
Ok(())
})()
.unwrap_err();
let err: &FormattedError = arc_err.downcast_ref().unwrap();
assert!(matches!(err.fmt, Cow::Borrowed(_)));
assert_eq!(err.fmt, "abc{}");
assert!(matches!(err.message, Cow::Borrowed(_)));
assert_eq!(err.message, "abcdef");
}
#[gtest]
fn error_report() {
let report = ErrorReport::new();
report.insert(&anyhow!("abc{}", "def"));
report.insert(&anyhow!("abc{}", "123"));
report.insert(&anyhow!("error code: {}", 65535));
report.insert(&anyhow!("no parameters"));
report.insert(&anyhow!("no parameters"));
report.insert(&anyhow!("no parameters"));
report.insert(&anyhow::Error::msg("not attributed").into());
report.insert(&anyhow!("has context from arc_anyhow::context()").context("the context"));
report.insert(
&arc_anyhow::Context::context(
Result::<(), _>::Err(anyhow!("has context from arc_anyhow::Context::context()")),
"the context",
)
.unwrap_err(),
);
report.insert(
&arc_anyhow::Context::with_context(
Result::<(), _>::Err(anyhow!(
"has context from arc_anyhow::Context::with_context()"
)),
|| "the context",
)
.unwrap_err(),
);
report.insert(
&anyhow!("has three layers of context")
.context("context 1")
.context("context 2")
.context("context 3"),
);
assert_eq!(
report.serialize_to_string().unwrap(),
r#"{
"abc{}": {
"count": 2,
"sample_message": "abcdef"
},
"error code: {}": {
"count": 1,
"sample_message": "error code: 65535"
},
"has context from arc_anyhow::Context::context()": {
"count": 1
},
"has context from arc_anyhow::Context::with_context()": {
"count": 1
},
"has context from arc_anyhow::context()": {
"count": 1
},
"has three layers of context": {
"count": 1
},
"no parameters": {
"count": 3
},
"{}": {
"count": 1,
"sample_message": "not attributed"
}
}"#,
);
}
}