Bump MSRV to 1.31.0 + commits from #319 (#329)

* Update proc_macro2, syn, quote
* Update MSRV to 1.31.0 as discussed in #319

Author: djc

.travis.yml

@@ -1,12 +1,12 @@
 language: rust
 rust:
-    - 1.18.0
+    - 1.31.0
     - stable
     - beta
     - nightly
 cache: cargo
 script:
-  - if [ "$TRAVIS_RUST_VERSION" == "1.18.0" ]; then cp Cargo.lock.ci Cargo.lock; fi
+  - if [ "$TRAVIS_RUST_VERSION" == "1.31.0" ]; then cp Cargo.lock.ci Cargo.lock; fi
   - cargo test
   - cargo test --features backtrace
   - cargo check --no-default-features

Cargo.lock.ci

@@ -6,11 +6,11 @@ homepage = "https://rust-lang-nursery.github.io/failure/"
 license = "MIT OR Apache-2.0"
 name = "failure"
 repository = "https://github.com/rust-lang-nursery/failure"
-version = "0.1.5"
+version = "0.1.6"
 
 [dependencies.failure_derive]
 optional = true
-version = "0.1.5"
+version = "0.1.6"
 path = "./failure_derive"
 
 [dependencies.backtrace]

Cargo.toml

@@ -100,8 +100,8 @@ pub fn read_toolchains(path: PathBuf) -> Result<Toolchains, Error>
 ## Requirements
 
 Both failure and failure_derive are intended to compile on all stable versions
-of Rust newer than 1.18.0, as well as the latest beta and the latest nightly.
-If either crate fails to compile on any version newer than 1.18.0, please open
+of Rust newer than 1.31.0, as well as the latest beta and the latest nightly.
+If either crate fails to compile on any version newer than 1.31.0, please open
 an issue.
 
 failure is **no_std** compatible, though some aspects of it (primarily the

README.md

@@ -6,14 +6,14 @@ name = "failure_derive"
 repository = "https://github.com/withoutboats/failure_derive"
 homepage = "https://rust-lang-nursery.github.io/failure/"
 documentation = "https://docs.rs/failure"
-version = "0.1.5"
+version = "0.1.6"
 build = "build.rs"
 
 [dependencies]
-quote = "0.6.3"
-syn = "0.15.0"
-synstructure = "0.10.0"
-proc-macro2 = "0.4.8"
+quote = "1"
+syn = "1.0.3"
+synstructure = "0.12.0"
+proc-macro2 = "1"
 
 [dev-dependencies.failure]
 version = "0.1.0"

failure_derive/Cargo.toml

@@ -25,6 +25,12 @@ impl Error {
     }
 }
 
+impl From<syn::Error> for Error {
+    fn from(e: syn::Error) -> Error {
+        Error(e.to_compile_error())
+    }
+}
+
 decl_derive!([Fail, attributes(fail, cause)] => fail_derive);
 
 fn fail_derive(s: synstructure::Structure) -> TokenStream {
@@ -120,7 +126,7 @@ fn display_body(s: &synstructure::Structure) -> Result<Option<quote::__rt::Token
         }
 
         let format_string = match msg.nested[0] {
-            syn::NestedMeta::Meta(syn::Meta::NameValue(ref nv)) if nv.ident == "display" => {
+            syn::NestedMeta::Meta(syn::Meta::NameValue(ref nv)) if nv.path.is_ident("display") => {
                 nv.lit.clone()
             }
             _ => {
@@ -131,12 +137,12 @@ fn display_body(s: &synstructure::Structure) -> Result<Option<quote::__rt::Token
             }
         };
         let args = msg.nested.iter().skip(1).map(|arg| match *arg {
-            syn::NestedMeta::Literal(syn::Lit::Int(ref i)) => {
-                let bi = &v.bindings()[i.value() as usize];
+            syn::NestedMeta::Lit(syn::Lit::Int(ref i)) => {
+                let bi = &v.bindings()[i.base10_parse::<usize>()?];
                 Ok(quote!(#bi))
             }
-            syn::NestedMeta::Meta(syn::Meta::Word(ref id)) => {
-                let id_s = id.to_string();
+            syn::NestedMeta::Meta(syn::Meta::Path(ref path)) => {
+                let id_s = path.get_ident().map(syn::Ident::to_string).unwrap_or("".to_string());
                 if id_s.starts_with("_") {
                     if let Ok(idx) = id_s[1..].parse::<usize>() {
                         let bi = match v.bindings().get(idx) {
@@ -160,15 +166,16 @@ fn display_body(s: &synstructure::Structure) -> Result<Option<quote::__rt::Token
                     }
                 }
                 for bi in v.bindings() {
-                    if bi.ast().ident.as_ref() == Some(id) {
+                    let id = bi.ast().ident.as_ref();
+                    if id.is_some() && path.is_ident(id.unwrap()) {
                         return Ok(quote!(#bi));
                     }
                 }
                 return Err(Error::new(
                     arg.span(),
                     &format!(
-                        "Couldn't find field `{}` in `{}::{}`",
-                        id,
+                        "Couldn't find field `{:?}` in `{}::{}`",
+                        path,
                         s.ast().ident,
                         v.ast().ident
                     )
@@ -192,8 +199,8 @@ fn display_body(s: &synstructure::Structure) -> Result<Option<quote::__rt::Token
 fn find_error_msg(attrs: &[syn::Attribute]) -> Result<Option<syn::MetaList>, Error> {
     let mut error_msg = None;
     for attr in attrs {
-        if let Some(meta) = attr.interpret_meta() {
-            if meta.name() == "fail" {
+        if let Ok(meta) = attr.parse_meta() {
+            if meta.path().is_ident("fail") {
                 if error_msg.is_some() {
                     return Err(Error::new(
                         meta.span(),
@@ -223,7 +230,7 @@ fn is_backtrace(bi: &&synstructure::BindingInfo) -> bool {
                 segments: ref path, ..
             },
         }) => path.last().map_or(false, |s| {
-            s.value().ident == "Backtrace" && s.value().arguments.is_empty()
+            s.ident == "Backtrace" && s.arguments.is_empty()
         }),
         _ => false,
     }
@@ -232,18 +239,18 @@ fn is_backtrace(bi: &&synstructure::BindingInfo) -> bool {
 fn is_cause(bi: &&synstructure::BindingInfo) -> bool {
     let mut found_cause = false;
     for attr in &bi.ast().attrs {
-        if let Some(meta) = attr.interpret_meta() {
-            if meta.name() == "cause" {
+        if let Ok(meta) = attr.parse_meta() {
+            if meta.path().is_ident("cause") {
                 if found_cause {
                     panic!("Cannot have two `cause` attributes");
                 }
                 found_cause = true;
             }
-            if meta.name() == "fail" {
+            if meta.path().is_ident("fail") {
                 if let syn::Meta::List(ref list) = meta {
                     if let Some(ref pair) = list.nested.first() {
-                        if let &&syn::NestedMeta::Meta(syn::Meta::Word(ref word)) = pair.value() {
-                            if word == "cause" {
+                        if let &&syn::NestedMeta::Meta(syn::Meta::Path(ref path)) = pair {
+                            if path.is_ident("cause") {
                                 if found_cause {
                                     panic!("Cannot have two `cause` attributes");
                                 }

failure_derive/src/lib.rs

@@ -58,8 +58,8 @@ fn wrap_backtrace_error() {
         .and_then(|err| err.downcast_ref::<io::Error>())
         .is_some());
     assert!(err.backtrace().is_some());
-    assert!(err.backtrace().is_empty());
-    assert_eq!(err.backtrace().is_empty(), err.backtrace().to_string().trim().is_empty());
+    assert!(err.backtrace().unwrap().is_empty());
+    assert!(err.backtrace().unwrap().to_string().trim().is_empty());
 }
 
 #[derive(Fail, Debug)]
@@ -93,6 +93,6 @@ fn wrap_enum_error() {
         .and_then(|err| err.downcast_ref::<fmt::Error>())
         .is_some());
     assert!(err.backtrace().is_some());
-    assert!(err.backtrace().is_empty());
-    assert_eq!(err.backtrace().is_empty(), err.backtrace().to_string().trim().is_empty());
+    assert!(err.backtrace().unwrap().is_empty());
+    assert!(err.backtrace().unwrap().to_string().trim().is_empty());
 }

failure_derive/tests/wraps.rs

@@ -8,20 +8,20 @@ use Fail;
 /// custom cause.
 pub trait AsFail {
     /// Converts a reference to `Self` into a dynamic trait object of `Fail`.
-    fn as_fail(&self) -> &Fail;
+    fn as_fail(&self) -> &dyn Fail;
 }
 
 impl<T> AsFail for T
 where
     T: Fail,
 {
-    fn as_fail(&self) -> &Fail {
+    fn as_fail(&self) -> &dyn Fail {
         self
     }
 }
 
-impl AsFail for Fail {
-    fn as_fail(&self) -> &Fail {
+impl AsFail for dyn Fail {
+    fn as_fail(&self) -> &dyn Fail {
         self
     }
 }
@@ -30,7 +30,7 @@ with_std! {
     use error::Error;
 
     impl AsFail for Error {
-        fn as_fail(&self) -> &Fail {
+        fn as_fail(&self) -> &dyn Fail {
             self.as_fail()
         }
     }

src/as_fail.rs

@@ -2,7 +2,7 @@ use std::error::Error;
 use std::fmt;
 use Fail;
 
-pub struct BoxStd(pub Box<Error + Send + Sync + 'static>);
+pub struct BoxStd(pub Box<dyn Error + Send + Sync + 'static>);
 
 impl fmt::Display for BoxStd {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

src/box_std.rs

@@ -39,14 +39,14 @@ with_std! {
         }
     }
 
-    impl From<Error> for Box<StdError> {
-        fn from(error: Error) -> Box<StdError> {
+    impl From<Error> for Box<dyn StdError> {
+        fn from(error: Error) -> Box<dyn StdError> {
             Box::new(Compat { error })
         }
     }
 
-    impl From<Error> for Box<StdError + Send + Sync> {
-        fn from(error: Error) -> Box<StdError + Send + Sync> {
+    impl From<Error> for Box<dyn StdError + Send + Sync> {
+        fn from(error: Error) -> Box<dyn StdError + Send + Sync> {
             Box::new(Compat { error })
         }
     }

src/compat.rs

@@ -112,7 +112,7 @@ with_std! {
             self.failure.as_cause().and_then(|x| x.name())
         }
 
-        fn cause(&self) -> Option<&Fail> {
+        fn cause(&self) -> Option<&dyn Fail> {
             self.failure.as_cause()
         }
 
@@ -146,7 +146,7 @@ with_std! {
             }
         }
 
-        fn as_cause(&self) -> Option<&Fail> {
+        fn as_cause(&self) -> Option<&dyn Fail> {
             match *self {
                 Either::This(_)         => None,
                 Either::That(ref error) => Some(error.as_fail())

src/context.rs

@@ -4,7 +4,7 @@ use Fail;
 use backtrace::Backtrace;
 
 pub(crate) struct ErrorImpl {
-    inner: Box<Inner<Fail>>,
+    inner: Box<Inner<dyn Fail>>,
 }
 
 struct Inner<F: ?Sized + Fail> {
@@ -25,11 +25,11 @@ impl<F: Fail> From<F> for ErrorImpl {
 }
 
 impl ErrorImpl {
-    pub(crate) fn failure(&self) -> &Fail {
+    pub(crate) fn failure(&self) -> &dyn Fail {
         &self.inner.failure
     }
 
-    pub(crate) fn failure_mut(&mut self) -> &mut Fail {
+    pub(crate) fn failure_mut(&mut self) -> &mut dyn Fail {
         &mut self.inner.failure
     }
 

src/error/error_impl.rs

@@ -60,13 +60,13 @@ impl Error {
     /// }
     /// ```
     #[cfg(feature = "std")]
-    pub fn from_boxed_compat(err: Box<StdError + Sync + Send + 'static>) -> Error {
+    pub fn from_boxed_compat(err: Box<dyn StdError + Sync + Send + 'static>) -> Error {
         Error::from(BoxStd(err))
     }
 
     /// Return a reference to the underlying failure that this `Error`
     /// contains.
-    pub fn as_fail(&self) -> &Fail {
+    pub fn as_fail(&self) -> &dyn Fail {
         self.imp.failure()
     }
 
@@ -82,7 +82,7 @@ impl Error {
     /// This method has been deprecated in favor of the [Error::as_fail] method,
     /// which does the same thing.
     #[deprecated(since = "0.1.2", note = "please use 'as_fail()' method instead")]
-    pub fn cause(&self) -> &Fail {
+    pub fn cause(&self) -> &dyn Fail {
         self.as_fail()
     }
 
@@ -133,7 +133,7 @@ impl Error {
 
     /// Returns the "root cause" of this error - the last value in the
     /// cause chain which does not return an underlying `cause`.
-    pub fn find_root_cause(&self) -> &Fail {
+    pub fn find_root_cause(&self) -> &dyn Fail {
         self.as_fail().find_root_cause()
     }
 
@@ -173,7 +173,7 @@ impl Error {
 
     /// Deprecated alias to `find_root_cause`.
     #[deprecated(since = "0.1.2", note = "please use the 'find_root_cause()' method instead")]
-    pub fn root_cause(&self) -> &Fail {
+    pub fn root_cause(&self) -> &dyn Fail {
         ::find_root_cause(self.as_fail())
     }
 
@@ -201,8 +201,8 @@ impl Debug for Error {
     }
 }
 
-impl AsRef<Fail> for Error {
-    fn as_ref(&self) -> &Fail {
+impl AsRef<dyn Fail> for Error {
+    fn as_ref(&self) -> &dyn Fail {
         self.as_fail()
     }
 }