Auto merge of #245 - servo:warn, r=SimonSapin

Fix a "will be a hard error" warning + drive-by

See individual commits

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Author: bors-servo

.travis.yml

@@ -3,6 +3,7 @@ rust:
   - nightly
   - beta
   - stable
+  - 1.30.0
 
 script:
   - cargo build --verbose

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cssparser"
-version = "0.25.4"
+version = "0.25.5"
 authors = [ "Simon Sapin <simon.sapin@exyr.org>" ]
 
 description = "Rust implementation of CSS Syntax Level 3"

build.rs

@@ -33,9 +33,12 @@ mod codegen {
         println!("cargo:rerun-if-changed={}", input.display());
 
         // We have stack overflows on Servo's CI.
-        let handle = Builder::new().stack_size(128 * 1024 * 1024).spawn(move || {
-            match_byte::expand(&input, &output);
-        }).unwrap();
+        let handle = Builder::new()
+            .stack_size(128 * 1024 * 1024)
+            .spawn(move || {
+                match_byte::expand(&input, &output);
+            })
+            .unwrap();
 
         handle.join().unwrap();
     }

build/match_byte.rs

@@ -12,18 +12,27 @@ use syn::parse::{Parse, ParseStream, Result};
 
 use proc_macro2::{Span, TokenStream};
 
-struct MatchByteParser {
-}
+struct MatchByteParser {}
 
 pub fn expand(from: &Path, to: &Path) {
     let mut source = String::new();
-    File::open(from).unwrap().read_to_string(&mut source).unwrap();
+    File::open(from)
+        .unwrap()
+        .read_to_string(&mut source)
+        .unwrap();
     let ast = syn::parse_file(&source).expect("Parsing rules.rs module");
     let mut m = MatchByteParser {};
     let ast = m.fold_file(ast);
 
-    let code = ast.into_token_stream().to_string().replace("{ ", "{\n").replace(" }", "\n}");
-    File::create(to).unwrap().write_all(code.as_bytes()).unwrap();
+    let code = ast
+        .into_token_stream()
+        .to_string()
+        .replace("{ ", "{\n")
+        .replace(" }", "\n}");
+    File::create(to)
+        .unwrap()
+        .write_all(code.as_bytes())
+        .unwrap();
 }
 
 struct MatchByte {
@@ -45,7 +54,7 @@ impl Parse for MatchByte {
                     arms.push(input.call(syn::Arm::parse)?);
                 }
                 arms
-            }
+            },
         })
     }
 }
@@ -55,16 +64,14 @@ fn get_byte_from_expr_lit(expr: &Box<syn::Expr>) -> u8 {
         syn::Expr::Lit(syn::ExprLit { ref lit, .. }) => {
             if let syn::Lit::Byte(ref byte) = *lit {
                 byte.value()
-            }
-            else {
+            } else {
                 panic!("Found a pattern that wasn't a byte")
             }
-        },
+        }
         _ => unreachable!(),
     }
 }
 
-
 /// Expand a TokenStream corresponding to the `match_byte` macro.
 ///
 /// ## Example
@@ -93,12 +100,12 @@ fn expand_match_byte(body: &TokenStream) -> syn::Expr {
 
         for pat in &arm.pats {
             match pat {
-                &syn::Pat::Lit(syn::PatLit{ref expr}) => {
+                &syn::Pat::Lit(syn::PatLit { ref expr }) => {
                     let value = get_byte_from_expr_lit(expr);
                     if table[value as usize] == 0 {
                         table[value as usize] = case_id as u8;
                     }
-                },
+                }
                 &syn::Pat::Range(syn::PatRange { ref lo, ref hi, .. }) => {
                     let lo = get_byte_from_expr_lit(lo);
                     let hi = get_byte_from_expr_lit(hi);
@@ -110,14 +117,14 @@ fn expand_match_byte(body: &TokenStream) -> syn::Expr {
                     if table[hi as usize] == 0 {
                         table[hi as usize] = case_id as u8;
                     }
-                },
+                }
                 &syn::Pat::Wild(_) => {
                     for byte in table.iter_mut() {
                         if *byte == 0 {
                             *byte = case_id as u8;
                         }
                     }
-                },
+                }
                 &syn::Pat::Ident(syn::PatIdent { ref ident, .. }) => {
                     assert_eq!(wildcard, None);
                     wildcard = Some(ident);
@@ -126,7 +133,7 @@ fn expand_match_byte(body: &TokenStream) -> syn::Expr {
                             *byte = case_id as u8;
                         }
                     }
-                },
+                }
                 _ => {
                     panic!("Unexpected pattern: {:?}. Buggy code ?", pat);
                 }
@@ -159,11 +166,14 @@ fn expand_match_byte(body: &TokenStream) -> syn::Expr {
 impl Fold for MatchByteParser {
     fn fold_stmt(&mut self, stmt: syn::Stmt) -> syn::Stmt {
         match stmt {
-            syn::Stmt::Item(syn::Item::Macro(syn::ItemMacro{ ref mac, .. })) => {
+            syn::Stmt::Item(syn::Item::Macro(syn::ItemMacro { ref mac, .. })) => {
                 if mac.path == parse_quote!(match_byte) {
-                    return syn::fold::fold_stmt(self, syn::Stmt::Expr(expand_match_byte(&mac.tts)))
+                    return syn::fold::fold_stmt(
+                        self,
+                        syn::Stmt::Expr(expand_match_byte(&mac.tts)),
+                    );
                 }
-            },
+            }
             _ => {}
         }
 
@@ -172,11 +182,11 @@ impl Fold for MatchByteParser {
 
     fn fold_expr(&mut self, expr: syn::Expr) -> syn::Expr {
         match expr {
-            syn::Expr::Macro(syn::ExprMacro{ ref mac, .. }) => {
+            syn::Expr::Macro(syn::ExprMacro { ref mac, .. }) => {
                 if mac.path == parse_quote!(match_byte) {
-                    return syn::fold::fold_expr(self, expand_match_byte(&mac.tts))
+                    return syn::fold::fold_expr(self, expand_match_byte(&mac.tts));
                 }
-            },
+            }
             _ => {}
         }
 

macros/lib.rs

@@ -2,17 +2,18 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#[macro_use] extern crate procedural_masquerade;
+#[macro_use]
+extern crate procedural_masquerade;
 extern crate phf_codegen;
 extern crate proc_macro;
 extern crate proc_macro2;
-#[macro_use] extern crate quote;
+#[macro_use]
+extern crate quote;
 extern crate syn;
 
-#[allow(unused_imports)] use std::ascii::AsciiExt;
+use proc_macro2::{TokenStream, TokenTree};
 use quote::TokenStreamExt;
 use std::iter;
-use proc_macro2::{TokenStream, TokenTree};
 
 define_proc_macros! {
     /// Input: the arms of a `match` expression.
@@ -88,12 +89,13 @@ define_proc_macros! {
     }
 }
 
-fn max_len<I: Iterator<Item=usize>>(lengths: I) -> String {
+fn max_len<I: Iterator<Item = usize>>(lengths: I) -> String {
     let max_length = lengths.max().expect("expected at least one string");
     quote!( const MAX_LENGTH: usize = #max_length; ).to_string()
 }
 
 fn string_literal(token: &TokenTree) -> String {
-    let lit: syn::LitStr = syn::parse2(iter::once(token.clone()).collect()).expect(&format!("expected string literal, got {:?}", token));
+    let lit: syn::LitStr = syn::parse2(iter::once(token.clone()).collect())
+        .expect(&format!("expected string literal, got {:?}", token));
     lit.value()
 }

procedural-masquerade/lib.rs

@@ -198,18 +198,35 @@ macro_rules! define_proc_macros {
 pub fn _extract_input(derive_input: &str) -> &str {
     let mut input = derive_input;
 
-    for expected in &["#[allow(unused)]", "enum", "ProceduralMasqueradeDummyType", "{",
-                     "Input", "=", "(0,", "stringify!", "("] {
+    for expected in &[
+        "#[allow(unused)]",
+        "enum",
+        "ProceduralMasqueradeDummyType",
+        "{",
+        "Input",
+        "=",
+        "(0,",
+        "stringify!",
+        "(",
+    ] {
         input = input.trim_start();
-        assert!(input.starts_with(expected),
-                "expected prefix {:?} not found in {:?}", expected, derive_input);
+        assert!(
+            input.starts_with(expected),
+            "expected prefix {:?} not found in {:?}",
+            expected,
+            derive_input
+        );
         input = &input[expected.len()..];
     }
 
     for expected in [")", ").0,", "}"].iter().rev() {
         input = input.trim_end();
-        assert!(input.ends_with(expected),
-                "expected suffix {:?} not found in {:?}", expected, derive_input);
+        assert!(
+            input.ends_with(expected),
+            "expected suffix {:?} not found in {:?}",
+            expected,
+            derive_input
+        );
         let end = input.len() - expected.len();
         input = &input[..end];
     }
@@ -227,33 +244,33 @@ macro_rules! define_invoke_proc_macro {
         #[doc(hidden)]
         #[macro_export]
         macro_rules! $macro_name {
-            ($proc_macro_name: ident ! $paren: tt) => {
-                #[derive($proc_macro_name)]
-                #[allow(unused)]
-                enum ProceduralMasqueradeDummyType {
-                    // The magic happens here.
-                    //
-                    // We use an `enum` with an explicit discriminant
-                    // because that is the only case where a type definition
-                    // can contain a (const) expression.
-                    //
-                    // `(0, "foo").0` evalutes to 0, with the `"foo"` part ignored.
-                    //
-                    // By the time the `#[proc_macro_derive]` function
-                    // implementing `#[derive($proc_macro_name)]` is called,
-                    // `$paren` has already been replaced with the input of this inner macro,
-                    // but `stringify!` has not been expanded yet.
-                    //
-                    // This how arbitrary tokens can be inserted
-                    // in the input to the `#[proc_macro_derive]` function.
-                    //
-                    // Later, `stringify!(...)` is expanded into a string literal
-                    // which is then ignored.
-                    // Using `stringify!` enables passing arbitrary tokens
-                    // rather than only what can be parsed as a const expression.
-                    Input = (0, stringify! $paren ).0
-                }
-            }
-        }
-    }
+                                    ($proc_macro_name: ident ! $paren: tt) => {
+                                        #[derive($proc_macro_name)]
+                                        #[allow(unused)]
+                                        enum ProceduralMasqueradeDummyType {
+                                            // The magic happens here.
+                                            //
+                                            // We use an `enum` with an explicit discriminant
+                                            // because that is the only case where a type definition
+                                            // can contain a (const) expression.
+                                            //
+                                            // `(0, "foo").0` evalutes to 0, with the `"foo"` part ignored.
+                                            //
+                                            // By the time the `#[proc_macro_derive]` function
+                                            // implementing `#[derive($proc_macro_name)]` is called,
+                                            // `$paren` has already been replaced with the input of this inner macro,
+                                            // but `stringify!` has not been expanded yet.
+                                            //
+                                            // This how arbitrary tokens can be inserted
+                                            // in the input to the `#[proc_macro_derive]` function.
+                                            //
+                                            // Later, `stringify!(...)` is expanded into a string literal
+                                            // which is then ignored.
+                                            // Using `stringify!` enables passing arbitrary tokens
+                                            // rather than only what can be parsed as a const expression.
+                                            Input = (0, stringify! $paren ).0
+                                        }
+                                    }
+                                }
+    };
 }