Mask lints the same way as serde

Fixes rust-num#20.

Author: cuviper

ci/rustup.sh

@@ -1,12 +1,12 @@
 #!/bin/sh
 # Use rustup to locally run the same suite of tests as .travis.yml.
-# (You should first install/update 1.15.0, stable, beta, and nightly.)
+# (You should first install/update the rust versions listed below.)
 
 set -ex
 
 export TRAVIS_RUST_VERSION
-for TRAVIS_RUST_VERSION in 1.15.0 stable beta nightly; do
+for TRAVIS_RUST_VERSION in 1.15.0 1.20.0 1.26.0 1.31.0 stable beta nightly; do
     run="rustup run $TRAVIS_RUST_VERSION"
-    $run cargo build --verbose
     $run $PWD/ci/test_full.sh
+    env FEATURES="full-syntax" $run $PWD/ci/test_full.sh
 done

ci/test_full.sh

@@ -6,4 +6,15 @@ echo Testing num-derive on rustc ${TRAVIS_RUST_VERSION}
 
 # num-derive should build and test everywhere.
 cargo build --verbose --features="$FEATURES"
-cargo test --verbose --features="$FEATURES"
+
+# Some cargo versions were buggy about passing dev-deps to rustdoc,
+# but worked when docs were tested separately.
+case "$TRAVIS_RUST_VERSION" in
+    1.20.0 | 1.26.0 )
+        cargo test --verbose --features="$FEATURES" --tests
+        cargo test --verbose --features="$FEATURES" --doc
+        ;;
+    *)
+        cargo test --verbose --features="$FEATURES"
+        ;;
+esac

src/lib.rs

@@ -74,20 +74,29 @@ fn dummy_const_trick<T: quote::ToTokens>(
     exp: T,
 ) -> proc_macro2::TokenStream {
     let dummy_const = Ident::new(
-        &format!(
-            "_IMPL_NUM_{}_FOR_{}",
-            trait_.to_uppercase(),
-            format!("{}", name).to_uppercase()
-        ),
+        &format!("_IMPL_NUM_{}_FOR_{}", trait_, unraw(name)),
         Span::call_site(),
     );
     quote! {
+        #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
+            #[allow(unknown_lints)]
+            #[cfg_attr(feature = "cargo-clippy", allow(useless_attribute))]
+            #[allow(rust_2018_idioms)]
+            extern crate num_traits as _num_traits;
             #exp
         };
     }
 }
 
+#[allow(deprecated)]
+fn unraw(ident: &proc_macro2::Ident) -> String {
+    // str::trim_start_matches was added in 1.30, trim_left_matches deprecated
+    // in 1.33. We currently support rustc back to 1.15 so we need to continue
+    // to use the deprecated one.
+    ident.to_string().trim_left_matches("r#").to_owned()
+}
+
 // If `data` is a newtype, return the type it's wrapping.
 fn newtype_inner(data: &syn::Data) -> Option<syn::Type> {
     match data {
@@ -182,7 +191,6 @@ pub fn from_primitive(input: TokenStream) -> TokenStream {
         };
 
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::FromPrimitive for #name {
                 fn from_i64(n: i64) -> Option<Self> {
                     <#inner_ty as _num_traits::FromPrimitive>::from_i64(n).map(#name)
@@ -261,9 +269,6 @@ pub fn from_primitive(input: TokenStream) -> TokenStream {
         };
 
         quote! {
-            #[allow(unused_qualifications)]
-            extern crate num_traits as _num_traits;
-
             impl _num_traits::FromPrimitive for #name {
                 #[allow(trivial_numeric_casts)]
                 fn from_i64(#from_i64_var: i64) -> Option<Self> {
@@ -350,7 +355,6 @@ pub fn to_primitive(input: TokenStream) -> TokenStream {
         };
 
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::ToPrimitive for #name {
                 fn to_i64(&self) -> Option<i64> {
                     <#inner_ty as _num_traits::ToPrimitive>::to_i64(&self.0)
@@ -432,9 +436,6 @@ pub fn to_primitive(input: TokenStream) -> TokenStream {
         };
 
         quote! {
-            #[allow(unused_qualifications)]
-            extern crate num_traits as _num_traits;
-
             impl _num_traits::ToPrimitive for #name {
                 #[allow(trivial_numeric_casts)]
                 fn to_i64(&self) -> Option<i64> {
@@ -518,7 +519,6 @@ pub fn num_cast(input: TokenStream) -> TokenStream {
         "NumCast",
         &name,
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::NumCast for #name {
                 fn from<T: _num_traits::ToPrimitive>(n: T) -> Option<Self> {
                     <#inner_ty as _num_traits::NumCast>::from(n).map(#name)
@@ -541,7 +541,6 @@ pub fn zero(input: TokenStream) -> TokenStream {
         "Zero",
         &name,
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::Zero for #name {
                 fn zero() -> Self {
                     #name(<#inner_ty as _num_traits::Zero>::zero())
@@ -567,7 +566,6 @@ pub fn one(input: TokenStream) -> TokenStream {
         "One",
         &name,
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::One for #name {
                 fn one() -> Self {
                     #name(<#inner_ty as _num_traits::One>::one())
@@ -593,7 +591,6 @@ pub fn num(input: TokenStream) -> TokenStream {
         "Num",
         &name,
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::Num for #name {
                 type FromStrRadixErr = <#inner_ty as _num_traits::Num>::FromStrRadixErr;
                 fn from_str_radix(s: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
@@ -618,7 +615,6 @@ pub fn float(input: TokenStream) -> TokenStream {
         "Float",
         &name,
         quote! {
-            extern crate num_traits as _num_traits;
             impl _num_traits::Float for #name {
                 fn nan() -> Self {
                     #name(<#inner_ty as _num_traits::Float>::nan())