Merge pull request #28 from RustCrypto/simplify-alloc-gating

signature: Simplify alloc gating

.travis.yml

@@ -2,17 +2,11 @@ language: rust
 cache: cargo
 
 rust:
-  - 1.31.0
+  - 1.36.0
   - stable
   - beta
   - nightly
 
-install:
-  - rustup component add rustfmt
-  - rustup component add clippy
-  - rustup target add thumbv7em-none-eabihf
-  - rustup target add wasm32-unknown-unknown
-
 script:
   - cargo test --verbose --release
   - cargo test --verbose --all-features --release
@@ -25,23 +19,22 @@ matrix:
   include:
     - name: "Rust: stable (thumbv7em-none-eabihf)"
       rust: stable
-      script:
-        - cd signature-crate && cargo build --target thumbv7em-none-eabihf --no-default-features --release
+      install: rustup target add thumbv7em-none-eabihf
+      script: cd signature-crate && cargo build --target thumbv7em-none-eabihf --no-default-features --release
     - name: "Rust: stable (wasm32-unknown-unknown)"
       rust: stable
-      script:
-        - cd signature-crate && cargo build --target wasm32-unknown-unknown --no-default-features --release
+      install: rustup target add wasm32-unknown-unknown
+      script: cd signature-crate && cargo build --target wasm32-unknown-unknown --no-default-features --release
     - name: rustfmt
       rust: stable
-      script:
-        - cargo fmt --all -- --check
+      install: rustup component add rustfmt
+      script: cargo fmt --all -- --check
     - name: clippy
+      install: rustup component add clippy
       rust: stable
-      script:
-        - cargo clippy --all
+      script: cargo clippy --all
     - name: docs
-      script:
-        - cargo doc --all --no-deps
+      script: cargo doc --all --no-deps
 
 branches:
   only:

signature-crate/README.md

@@ -7,14 +7,17 @@
 [![Build Status][build-image]][build-link]
 
 This crate contains traits which provide generic, object-safe APIs for
-generating and verifying [digital signatures].
+generating and verifying [digital signatures][1].
 
-The long-term goal is to use this crate in conjunction with the
-[`ecdsa`][ecdsa-crate] and [`ed25519`][ed25519-crate], however those crates
-are a work-in-progress.
+It's presently useful in conjunction with the [`ed25519`][2] crate.
+Support is also planned for the [`ecdsa`][3] and [`rsa`][4] crates.
 
 [Documentation][docs-link]
 
+## Requirements
+
+- Rust **1.36+**
+
 ## License
 
 All crates licensed under either of
@@ -37,12 +40,13 @@ dual licensed as above, without any additional terms or conditions.
 [docs-image]: https://docs.rs/signature/badge.svg
 [docs-link]: https://docs.rs/signature/
 [license-image]: https://img.shields.io/badge/license-Apache2.0/MIT-blue.svg
-[rustc-image]: https://img.shields.io/badge/rustc-1.31+-blue.svg
+[rustc-image]: https://img.shields.io/badge/rustc-1.36+-blue.svg
 [build-image]: https://travis-ci.org/RustCrypto/signatures.svg?branch=master
 [build-link]: https://travis-ci.org/RustCrypto/signatures
 
 [//]: # (general links)
 
-[digital signatures]: https://en.wikipedia.org/wiki/Digital_signature
-[ecdsa-crate]: https://github.com/RustCrypto/signatures/tree/master/ecdsa
-[ed25519-crate]: https://github.com/RustCrypto/signatures/tree/master/ed25519
+[1]: https://en.wikipedia.org/wiki/Digital_signature
+[2]: https://github.com/RustCrypto/signatures/tree/master/ed25519
+[3]: https://github.com/RustCrypto/signatures/tree/master/ecdsa
+[4]: https://github.com/RustCrypto/RSA

signature-crate/src/error.rs

@@ -3,14 +3,14 @@
 use core::fmt::{self, Display};
 
 #[cfg(feature = "std")]
-use std::{boxed::Box, error::Error as StdError};
+use std::boxed::Box;
 
 /// Signature errors
 #[derive(Debug, Default)]
 pub struct Error {
     /// Cause of the error (if applicable)
     #[cfg(feature = "std")]
-    cause: Option<Box<dyn StdError>>,
+    cause: Option<Box<dyn std::error::Error>>,
 }
 
 impl Error {
@@ -23,7 +23,7 @@ impl Error {
     #[cfg(feature = "std")]
     pub fn from_cause<E>(cause: E) -> Self
     where
-        E: Into<Box<dyn StdError>>,
+        E: Into<Box<dyn std::error::Error>>,
     {
         Self {
             cause: Some(cause.into()),
@@ -32,7 +32,7 @@ impl Error {
 
     /// Borrow the error's underlying cause (if available)
     #[cfg(feature = "std")]
-    pub fn cause(&self) -> Option<&dyn StdError> {
+    pub fn cause(&self) -> Option<&dyn std::error::Error> {
         self.cause.as_ref().map(|c| c.as_ref())
     }
 
@@ -40,16 +40,16 @@ impl Error {
     ///
     /// Panics if the error does not have a cause.
     #[cfg(feature = "std")]
-    pub fn into_cause(self) -> Box<dyn StdError> {
+    pub fn into_cause(self) -> Box<dyn std::error::Error> {
         self.cause
             .expect("into_cause called on an error with no cause")
     }
 
     /// Attempt to downcast this error's cause into a concrete type
     #[cfg(feature = "std")]
-    pub fn downcast<T>(self) -> Result<Box<T>, Box<dyn StdError>>
+    pub fn downcast<T>(self) -> Result<Box<T>, Box<dyn std::error::Error>>
     where
-        T: StdError + 'static,
+        T: std::error::Error + 'static,
     {
         self.cause
             .map(|cause| cause.downcast())
@@ -60,33 +60,30 @@ impl Error {
     #[cfg(feature = "std")]
     pub fn downcast_ref<T>(&self) -> Option<&T>
     where
-        T: StdError + 'static,
+        T: std::error::Error + 'static,
     {
         self.cause.as_ref().and_then(|cause| cause.downcast_ref())
     }
 }
 
-#[cfg(not(feature = "std"))]
 impl Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "signature error")
-    }
-}
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "signature error")?;
 
-#[cfg(feature = "std")]
-impl Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if let Some(ref cause) = self.cause {
-            write!(f, "{}", cause)
-        } else {
-            write!(f, "signature error")
+        #[cfg(feature = "std")]
+        {
+            if let Some(ref cause) = self.cause {
+                write!(f, ": {}", cause)?;
+            }
         }
+
+        Ok(())
     }
 }
 
 #[cfg(feature = "std")]
-impl StdError for Error {
-    fn cause(&self) -> Option<&dyn StdError> {
+impl std::error::Error for Error {
+    fn cause(&self) -> Option<&dyn std::error::Error> {
         self.cause.as_ref().map(|cause| cause.as_ref())
     }
 }

signature-crate/src/lib.rs

@@ -3,20 +3,11 @@
 //! cryptography.
 
 #![no_std]
-#![deny(
-    warnings,
-    missing_docs,
-    trivial_casts,
-    trivial_numeric_casts,
-    unsafe_code,
-    unused_import_braces,
-    unused_qualifications
-)]
+#![forbid(unsafe_code)]
+#![warn(missing_docs, rust_2018_idioms, unused_qualifications)]
 #![doc(html_root_url = "https://docs.rs/signature/0.2.0")]
 
-#[cfg(all(feature = "alloc", not(feature = "std")))]
-#[allow(unused_imports)] // rustc bug?
-#[macro_use]
+#[cfg(feature = "alloc")]
 extern crate alloc;
 
 #[cfg(feature = "std")]
@@ -36,7 +27,6 @@ pub use signature_derive::{Signer, Verifier};
 pub use digest;
 
 mod error;
-mod prelude;
 mod signature;
 mod signer;
 mod verifier;

signature-crate/src/prelude.rs

@@ -1,7 +0,0 @@
-//! Crate-local prelude (for alloc-dependent features like `Vec`)
-
-#[cfg(all(feature = "alloc", not(feature = "std")))]
-pub use alloc::vec::Vec;
-
-#[cfg(feature = "std")]
-pub use std::vec::Vec;

signature-crate/src/signature.rs

@@ -2,7 +2,7 @@ use core::fmt::Debug;
 
 use crate::error::Error;
 #[cfg(feature = "alloc")]
-use crate::prelude::*;
+use alloc::vec::Vec;
 
 /// Trait impl'd by concrete types that represent digital signatures
 pub trait Signature: AsRef<[u8]> + Debug + Sized {