Code change:
Given the following code: The current output is: Ideally the output should look like: Right now, cargo and rustc operate basically independently of each other. The summary ("aborting ..." and "could not compile ...") is repeated twice, and both have different, incompatible ways to get more info about what went wrong. There's no reason to repeat these twice; we could include all the same information in half the space if we can get cargo and rustc to cooperate. I suggest the way this be implemented is by keeping rustc's output the same when run standalone, but omitting "aborting due to ..." and "for more information ..." when run with . Then cargo can aggregate the info it used to print into its own errors by using the JSON output. cc (meta note: I thought of this while working on , which has fully 12 lines of "metadata" after the 5 line error. Most builds are not that bad in comparison, but I do think it shows that it needs support from all the tools in the stack to keep the verbosity down.)
I'm not sure whether making the decision on the error format scheme is the right way to go. I can't think of any reason not to do it, unless the implementation is messy, so

Related discussion:
text: <ins> // Copyright 2013 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! Cross-platform file path handling (re-write) use container::Container; use c_str::CString; use clone::Clone; use iter::Iterator; use option::{Option, None, Some}; use str; use str::StrSlice; use vec; use vec::{CopyableVector, OwnedCopyableVector, OwnedVector}; use vec::{ImmutableEqVector, ImmutableVector}; pub mod posix; pub mod windows; /// Typedef for POSIX file paths. /// See `posix::Path` for more info. pub type PosixPath = posix::Path; /// Typedef for Windows file paths. /// See `windows::Path` for more info. pub type WindowsPath = windows::Path; /// Typedef for the platform-native path type #[cfg(unix)] pub type Path = PosixPath; /// Typedef for the platform-native path type #[cfg(windows)] pub type Path = WindowsPath; /// Typedef for the POSIX path component iterator. /// See `posix::ComponentIter` for more info. pub type PosixComponentIter<'self> = posix::ComponentIter<'self>; // /// Typedef for the Windows path component iterator. // /// See `windows::ComponentIter` for more info. // pub type WindowsComponentIter<'self> = windows::ComponentIter<'self>; /// Typedef for the platform-native component iterator #[cfg(unix)] pub type ComponentIter<'self> = PosixComponentIter<'self>; // /// Typedef for the platform-native component iterator //#[cfg(windows)] //pub type ComponentIter<'self> = WindowsComponentIter<'self>; // Condition that is raised when a NUL is found in a byte vector given to a Path function condition! { // this should be a &[u8] but there's a lifetime issue null_byte: ~[u8] -> ~[u8]; } /// A trait that represents the generic operations available on paths pub trait GenericPath: Clone + GenericPathUnsafe { /// Creates a new Path from a byte vector. /// The resulting Path will always be normalized. /// /// # Failure /// /// Raises the `null_byte` condition if the path contains a NUL. /// /// See individual Path impls for additional restrictions. #[inline] fn from_vec(path: &[u8]) -> Self { if contains_nul(path) { let path = self::null_byte::cond.raise(path.to_owned()); assert!(!contains_nul(path)); unsafe { GenericPathUnsafe::from_vec_unchecked(path) } } else { unsafe { GenericPathUnsafe::from_vec_unchecked(path) } } } /// Creates a new Path from a string. /// The resulting Path will always be normalized. /// /// # Failure /// /// Raises the `null_byte` condition if the path contains a NUL. #[inline] fn from_str(path: &str) -> Self { let v = path.as_bytes(); if contains_nul(v) { GenericPath::from_vec(path.as_bytes()) // let from_vec handle the condition } else { unsafe { GenericPathUnsafe::from_str_unchecked(path) } } } /// Creates a new Path from a CString. /// The resulting Path will always be normalized. /// /// See individual Path impls for potential restrictions. #[inline] fn from_c_str(path: CString) -> Self { // CStrings can't contain NULs unsafe { GenericPathUnsafe::from_vec_unchecked(path.as_bytes()) } } /// Returns the path as a string, if possible. /// If the path is not representable in utf-8, this returns None. #[inline] fn as_str<'a>(&'a self) -> Option<&'a str> { str::from_utf8_slice_opt(self.as_vec()) } /// Returns the path as a byte vector fn as_vec<'a>(&'a self) -> &'a [u8]; /// Returns the directory component of `self`, as a byte vector (with no trailing separator). /// If `self` has no directory component, returns ['.']. fn dirname<'a>(&'a self) -> &'a [u8]; /// Returns the directory component of `self`, as a string, if possible. /// See `dirname` for details. #[inline] fn dirname_str<'a>(&'a self) -> Option<&'a str> { str::from_utf8_slice_opt(self.dirname()) } /// Returns the file component of `self`, as a byte vector. /// If `self` represents the root of the file hierarchy, returns the empty vector. /// If `self` is ".", returns the empty vector. fn filename<'a>(&'a self) -> &'a [u8]; /// Returns the file component of `self`, as a string, if possible. /// See `filename` for details. #[inline] fn filename_str<'a>(&'a self) -> Option<&'a str> { str::from_utf8_slice_opt(self.filename()) } /// Returns the stem of the filename of `self`, as a byte vector. /// The stem is the portion of the filename just before the last '.'. /// If there is no '.', the entire filename is returned. fn filestem<'a>(&'a self) -> &'a [u8] { let name = self.filename(); let dot = '.' as u8; match name.rposition_elem(&dot) { None | Some(0) => name, Some(1) if name == bytes!("..") => name, Some(pos) => name.slice_to(pos) } } /// Returns the stem of the filename of `self`, as a string, if possible. /// See `filestem` for details. #[inline] fn filestem_str<'a>(&'a self) -> Option<&'a str> { str::from_utf8_slice_opt(self.filestem()) } /// Returns the extension of the filename of `self`, as an optional byte vector. /// The extension is the portion of the filename just after the last '.'. /// If there is no extension, None is returned. /// If the filename ends in '.', the empty vector is returned. fn extension<'a>(&'a self) -> Option<&'a [u8]> { let name = self.filename(); let dot = '.' as u8; match name.rposition_elem(&dot) { None | Some(0) => None, Some(1) if name == bytes!("..") => None, Some(pos) => Some(name.slice_from(pos+1)) } } /// Returns the extension of the filename of `self`, as a string, if possible. /// See `extension` for details. #[inline] fn extension_str<'a>(&'a self) -> Option<&'a str> { self.extension().and_then(|v| str::from_utf8_slice_opt(v)) } /// Replaces the directory portion of the path with the given byte vector. /// If `self` represents the root of the filesystem hierarchy, the last path component /// of the given byte vector becomes the filename. /// /// # Failure /// /// Raises the `null_byte` condition if the dirname contains a NUL. #[inline] fn set_dirname(&mut self, dirname: &[u8]) { if contains_nul(dirname) { let dirname = self::null_byte::cond.raise(dirname.to_owned()); assert!(!contains_nul(dirname)); unsafe { self.set_dirname_unchecked(dirname) } } else { unsafe { self.set_dirname_unchecked(dirname) } } } /// Replaces the directory portion of the path with the given string. /// See `set_dirname` for details. #[inline] fn set_dirname_str(&mut self, dirname: &str) { if contains_nul(dirname.as_bytes()) { self.set_dirname(dirname.as_bytes()) // triggers null_byte condition } else { unsafe { self.set_dirname_str_unchecked(dirname) } } } /// Replaces the filename portion of the path with the given byte vector. /// If the replacement name is [], this is equivalent to popping the path. /// /// # Failure /// /// Raises the `null_byte` condition if the filename contains a NUL. #[inline] fn set_filename(&mut self, filename: &[u8]) { if contains_nul(filename) { let filename = self::null_byte::cond.raise(filename.to_owned()); assert!(!contains_nul(filename)); unsafe { self.set_filename_unchecked(filename) } } else { unsafe { self.set_filename_unchecked(filename) } } } /// Replaces the filename portion of the path with the given string. /// See `set_filename` for details. #[inline] fn set_filename_str(&mut self, filename: &str) { if contains_nul(filename.as_bytes()) { self.set_filename(filename.as_bytes()) // triggers null_byte condition } else { unsafe { self.set_filename_str_unchecked(filename) } } } /// Replaces the filestem with the given byte vector. /// If there is no extension in `self` (or `self` has no filename), this is equivalent /// to `set_filename`. Otherwise, if the given byte vector is [], the extension (including /// the preceding '.') becomes the new filename. /// /// # Failure /// /// Raises the `null_byte` condition if the filestem contains a NUL. fn set_filestem(&mut self, filestem: &[u8]) { // borrowck is being a pain here let val = { let name = self.filename(); if !name.is_empty() { let dot = '.' as u8; match name.rposition_elem(&dot) { None | Some(0) => None, Some(idx) => { let mut v; if contains_nul(filestem) { let filestem = self::null_byte::cond.raise(filestem.to_owned()); assert!(!contains_nul(filestem)); v = vec::with_capacity(filestem.len() + name.len() - idx); v.push_all(filestem); } else { v = vec::with_capacity(filestem.len() + name.len() - idx); v.push_all(filestem); } v.push_all(name.slice_from(idx)); Some(v) } } } else { None } }; match val { None => self.set_filename(filestem), Some(v) => unsafe { self.set_filename_unchecked(v) } } } /// Replaces the filestem with the given string. /// See `set_filestem` for details. #[inline] fn set_filestem_str(&mut self, filestem: &str) { self.set_filestem(filestem.as_bytes()) } /// Replaces the extension with the given byte vector. /// If there is no extension in `self`, this adds one. /// If the given byte vector is [], this removes the extension. /// If `self` has no filename, this is a no-op. /// /// # Failure /// /// Raises the `null_byte` condition if the extension contains a NUL. fn set_extension(&mut self, extension: &[u8]) { // borrowck causes problems here too let val = { let name = self.filename(); if !name.is_empty() { let dot = '.' as u8; match name.rposition_elem(&dot) { None | Some(0) => { if extension.is_empty() { None } else { let mut v; if contains_nul(extension) { let extension = self::null_byte::cond.raise(extension.to_owned()); assert!(!contains_nul(extension)); v = vec::with_capacity(name.len() + extension.len() + 1); v.push_all(name); v.push(dot); v.push_all(extension); } else { v = vec::with_capacity(name.len() + extension.len() + 1); v.push_all(name); v.push(dot); v.push_all(extension); } Some(v) } } Some(idx) => { if extension.is_empty() { Some(name.slice_to(idx).to_owned()) } else { let mut v; if contains_nul(extension) { let extension = self::null_byte::cond.raise(extension.to_owned()); assert!(!contains_nul(extension)); v = vec::with_capacity(idx + extension.len() + 1); v.push_all(name.slice_to(idx+1)); v.push_all(extension); } else { v = vec::with_capacity(idx + extension.len() + 1); v.push_all(name.slice_to(idx+1)); v.push_all(extension); } Some(v) } } } } else { None } }; match val { None => (), Some(v) => unsafe { self.set_filename_unchecked(v) } } } /// Replaces the extension with the given string. /// See `set_extension` for details. #[inline] fn set_extension_str(&mut self, extension: &str) { self.set_extension(extension.as_bytes()) } /// Returns a new Path constructed by replacing the dirname with the given byte vector. /// See `set_dirname` for details. /// /// # Failure /// /// Raises the `null_byte` condition if the dirname contains a NUL. #[inline] fn with_dirname(&self, dirname: &[u8]) -> Self { let mut p = self.clone(); p.set_dirname(dirname); p } /// Returns a new Path constructed by replacing the dirname with the given string. /// See `set_dirname` for details. #[inline] fn with_dirname_str(&self, dirname: &str) -> Self { let mut p = self.clone(); p.set_dirname_str(dirname); p } /// Returns a new Path constructed by replacing the filename with the given byte vector. /// See `set_filename` for details. /// /// # Failure /// /// Raises the `null_byte` condition if the filename contains a NUL. #[inline] fn with_filename(&self, filename: &[u8]) -> Self { let mut p = self.clone(); p.set_filename(filename); p } /// Returns a new Path constructed by replacing the filename with the given string. /// See `set_filename` for details. #[inline] fn with_filename_str(&self, filename: &str) -> Self { let mut p = self.clone(); p.set_filename_str(filename); p } /// Returns a new Path constructed by setting the filestem to the given byte vector. /// See `set_filestem` for details. /// /// # Failure /// /// Raises the `null_byte` condition if the filestem contains a NUL. #[inline] fn with_filestem(&self, filestem: &[u8]) -> Self { let mut p = self.clone(); p.set_filestem(filestem); p } /// Returns a new Path constructed by setting the filestem to the given string. /// See `set_filestem` for details. #[inline] fn with_filestem_str(&self, filestem: &str) -> Self { let mut p = self.clone(); p.set_filestem_str(filestem); p } /// Returns a new Path constructed by setting the extension to the given byte vector. /// See `set_extension` for details. /// /// # Failure /// /// Raises the `null_byte` condition if the extension contains a NUL. #[inline] fn with_extension(&self, extension: &[u8]) -> Self { let mut p = self.clone(); p.set_extension(extension); p } /// Returns a new Path constructed by setting the extension to the given string. /// See `set_extension` for details. #[inline] fn with_extension_str(&self, extension: &str) -> Self { let mut p = self.clone(); p.set_extension_str(extension); p } /// Returns the directory component of `self`, as a Path. /// If `self` represents the root of the filesystem hierarchy, returns `self`. fn dir_path(&self) -> Self { // self.dirname() returns a NUL-free vector unsafe { GenericPathUnsafe::from_vec_unchecked(self.dirname()) } } /// Returns the file component of `self`, as a relative Path. /// If `self` represents the root of the filesystem hierarchy, returns None. fn file_path(&self) -> Option<Self> { // self.filename() returns a NUL-free vector match self.filename() { [] => None, v => Some(unsafe { GenericPathUnsafe::from_vec_unchecked(v) }) } } /// Pushes a path (as a byte vector) onto `self`. /// If the argument represents an absolute path, it replaces `self`. /// /// # Failure /// /// Raises the `null_byte` condition if the path contains a NUL. #[inline] fn push(&mut self, path: &[u8]) { if contains_nul(path) { let path = self::null_byte::cond.raise(path.to_owned()); assert!(!contains_nul(path)); unsafe { self.push_unchecked(path) } } else { unsafe { self.push_unchecked(path) } } } /// Pushes a path (as a string) onto `self. /// See `push` for details. #[inline] fn push_str(&mut self, path: &str) { if contains_nul(path.as_bytes()) { self.push(path.as_bytes()) // triggers null_byte condition } else { unsafe { self.push_str_unchecked(path) } } } /// Pushes a Path onto `self`. /// If the argument represents an absolute path, it replaces `self`. #[inline] fn push_path(&mut self, path: &Self) { self.push(path.as_vec()) } /// Pops the last path component off of `self` and returns it. /// If `self` represents the root of the file hierarchy, None is returned. fn pop_opt(&mut self) -> Option<~[u8]>; /// Pops the last path component off of `self` and returns it as a string, if possible. /// `self` will still be modified even if None is returned. /// See `pop_opt` for details. #[inline] fn pop_opt_str(&mut self) -> Option<~str> { self.pop_opt().and_then(|v| str::from_utf8_owned_opt(v)) } /// Returns a new Path constructed by joining `self` with the given path (as a byte vector). /// If the given path is absolute, the new Path will represent just that. /// /// # Failure /// /// Raises the `null_byte` condition if the path contains a NUL. #[inline] fn join(&self, path: &[u8]) -> Self { let mut p = self.clone(); p.push(path); p } /// Returns a new Path constructed by joining `self` with the given path (as a string). /// See `join` for details. #[inline] fn join_str(&self, path: &str) -> Self { let mut p = self.clone(); p.push_str(path); p } /// Returns a new Path constructed by joining `self` with the given path. /// If the given path is absolute, the new Path will represent just that. #[inline] fn join_path(&self, path: &Self) -> Self { let mut p = self.clone(); p.push_path(path); p } /// Returns whether `self` represents an absolute path. /// An absolute path is defined as one that, when joined to another path, will /// yield back the same absolute path. fn is_absolute(&self) -> bool; /// Returns whether `self` is equal to, or is an ancestor of, the given path. /// If both paths are relative, they are compared as though they are relative /// to the same parent path. fn is_ancestor_of(&self, other: &Self) -> bool; /// Returns the Path that, were it joined to `base`, would yield `self`. /// If no such path exists, None is returned. /// If `self` is absolute and `base` is relative, or on Windows if both /// paths refer to separate drives, an absolute path is returned. fn path_relative_from(&self, base: &Self) -> Option<Self>; } /// A trait that represents the unsafe operations on GenericPaths pub trait GenericPathUnsafe { /// Creates a new Path from a byte vector without checking for null bytes. /// The resulting Path will always be normalized. unsafe fn from_vec_unchecked(path: &[u8]) -> Self; /// Creates a new Path from a str without checking for null bytes. /// The resulting Path will always be normalized. #[inline] unsafe fn from_str_unchecked(path: &str) -> Self { GenericPathUnsafe::from_vec_unchecked(path.as_bytes()) } /// Replaces the directory portion of the path with the given byte vector without /// checking for null bytes. /// See `set_dirname` for details. unsafe fn set_dirname_unchecked(&mut self, dirname: &[u8]); /// Replaces the directory portion of the path with the given str without /// checking for null bytes. /// See `set_dirname_str` for details. #[inline] unsafe fn set_dirname_str_unchecked(&mut self, dirname: &str) { self.set_dirname_unchecked(dirname.as_bytes()) } /// Replaces the filename portion of the path with the given byte vector without /// checking for null bytes. /// See `set_filename` for details. unsafe fn set_filename_unchecked(&mut self, filename: &[u8]); /// Replaces the filename portion of the path with the given str without /// checking for null bytes. /// See `set_filename_str` for details. #[inline] unsafe fn set_filename_str_unchecked(&mut self, filename: &str) { self.set_filename_unchecked(filename.as_bytes()) } /// Pushes a byte vector onto `self` without checking for null bytes. /// See `push` for details. unsafe fn push_unchecked(&mut self, path: &[u8]); /// Pushes a str onto `self` without checking for null bytes. /// See `push_str` for details. #[inline] unsafe fn push_str_unchecked(&mut self, path: &str) { self.push_unchecked(path.as_bytes()) } } #[inline(always)] fn contains_nul(v: &[u8]) -> bool { v.iter().any(|&x| x == 0) } </ins>