Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 759 insertions, 0 deletions

diff --git a/vendor/proc-macro2/tests/test.rs b/vendor/proc-macro2/tests/test.rs
new file mode 100644
index 0000000..b75cd55
--- /dev/null
+++ b/vendor/proc-macro2/tests/test.rs
@@ -0,0 +1,759 @@
+#![allow(
+    clippy::assertions_on_result_states,
+    clippy::items_after_statements,
+    clippy::non_ascii_literal,
+    clippy::octal_escapes
+)]
+
+use proc_macro2::{Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
+use std::iter;
+use std::str::{self, FromStr};
+
+#[test]
+fn idents() {
+    assert_eq!(
+        Ident::new("String", Span::call_site()).to_string(),
+        "String"
+    );
+    assert_eq!(Ident::new("fn", Span::call_site()).to_string(), "fn");
+    assert_eq!(Ident::new("_", Span::call_site()).to_string(), "_");
+}
+
+#[test]
+fn raw_idents() {
+    assert_eq!(
+        Ident::new_raw("String", Span::call_site()).to_string(),
+        "r#String"
+    );
+    assert_eq!(Ident::new_raw("fn", Span::call_site()).to_string(), "r#fn");
+}
+
+#[test]
+#[should_panic(expected = "`r#_` cannot be a raw identifier")]
+fn ident_raw_underscore() {
+    Ident::new_raw("_", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "`r#super` cannot be a raw identifier")]
+fn ident_raw_reserved() {
+    Ident::new_raw("super", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "Ident is not allowed to be empty; use Option<Ident>")]
+fn ident_empty() {
+    Ident::new("", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "Ident cannot be a number; use Literal instead")]
+fn ident_number() {
+    Ident::new("255", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "\"a#\" is not a valid Ident")]
+fn ident_invalid() {
+    Ident::new("a#", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "not a valid Ident")]
+fn raw_ident_empty() {
+    Ident::new("r#", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "not a valid Ident")]
+fn raw_ident_number() {
+    Ident::new("r#255", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "\"r#a#\" is not a valid Ident")]
+fn raw_ident_invalid() {
+    Ident::new("r#a#", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "not a valid Ident")]
+fn lifetime_empty() {
+    Ident::new("'", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = "not a valid Ident")]
+fn lifetime_number() {
+    Ident::new("'255", Span::call_site());
+}
+
+#[test]
+#[should_panic(expected = r#""'a#" is not a valid Ident"#)]
+fn lifetime_invalid() {
+    Ident::new("'a#", Span::call_site());
+}
+
+#[test]
+fn literal_string() {
+    assert_eq!(Literal::string("foo").to_string(), "\"foo\"");
+    assert_eq!(Literal::string("\"").to_string(), "\"\\\"\"");
+    assert_eq!(Literal::string("didn't").to_string(), "\"didn't\"");
+    assert_eq!(
+        Literal::string("a\00b\07c\08d\0e\0").to_string(),
+        "\"a\\x000b\\x007c\\08d\\0e\\0\"",
+    );
+
+    "\"\\\r\n    x\"".parse::<TokenStream>().unwrap();
+    "\"\\\r\n  \rx\"".parse::<TokenStream>().unwrap_err();
+}
+
+#[test]
+fn literal_raw_string() {
+    "r\"\r\n\"".parse::<TokenStream>().unwrap();
+
+    fn raw_string_literal_with_hashes(n: usize) -> String {
+        let mut literal = String::new();
+        literal.push('r');
+        literal.extend(iter::repeat('#').take(n));
+        literal.push('"');
+        literal.push('"');
+        literal.extend(iter::repeat('#').take(n));
+        literal
+    }
+
+    raw_string_literal_with_hashes(255)
+        .parse::<TokenStream>()
+        .unwrap();
+
+    // https://github.com/rust-lang/rust/pull/95251
+    raw_string_literal_with_hashes(256)
+        .parse::<TokenStream>()
+        .unwrap_err();
+}
+
+#[test]
+fn literal_byte_string() {
+    assert_eq!(Literal::byte_string(b"").to_string(), "b\"\"");
+    assert_eq!(
+        Literal::byte_string(b"\0\t\n\r\"\\2\x10").to_string(),
+        "b\"\\0\\t\\n\\r\\\"\\\\2\\x10\"",
+    );
+    assert_eq!(
+        Literal::byte_string(b"a\00b\07c\08d\0e\0").to_string(),
+        "b\"a\\x000b\\x007c\\08d\\0e\\0\"",
+    );
+
+    "b\"\\\r\n    x\"".parse::<TokenStream>().unwrap();
+    "b\"\\\r\n  \rx\"".parse::<TokenStream>().unwrap_err();
+    "b\"\\\r\n  \u{a0}x\"".parse::<TokenStream>().unwrap_err();
+    "br\"\u{a0}\"".parse::<TokenStream>().unwrap_err();
+}
+
+#[test]
+fn literal_c_string() {
+    let strings = r###"
+        c"hello\x80我叫\u{1F980}"  // from the RFC
+        cr"\"
+        cr##"Hello "world"!"##
+        c"\t\n\r\"\\"
+    "###;
+
+    let mut tokens = strings.parse::<TokenStream>().unwrap().into_iter();
+
+    for expected in &[
+        r#"c"hello\x80我叫\u{1F980}""#,
+        r#"cr"\""#,
+        r###"cr##"Hello "world"!"##"###,
+        r#"c"\t\n\r\"\\""#,
+    ] {
+        match tokens.next().unwrap() {
+            TokenTree::Literal(literal) => {
+                assert_eq!(literal.to_string(), *expected);
+            }
+            unexpected => panic!("unexpected token: {:?}", unexpected),
+        }
+    }
+
+    if let Some(unexpected) = tokens.next() {
+        panic!("unexpected token: {:?}", unexpected);
+    }
+
+    for invalid in &[r#"c"\0""#, r#"c"\x00""#, r#"c"\u{0}""#, "c\"\0\""] {
+        if let Ok(unexpected) = invalid.parse::<TokenStream>() {
+            panic!("unexpected token: {:?}", unexpected);
+        }
+    }
+}
+
+#[test]
+fn literal_character() {
+    assert_eq!(Literal::character('x').to_string(), "'x'");
+    assert_eq!(Literal::character('\'').to_string(), "'\\''");
+    assert_eq!(Literal::character('"').to_string(), "'\"'");
+}
+
+#[test]
+fn literal_integer() {
+    assert_eq!(Literal::u8_suffixed(10).to_string(), "10u8");
+    assert_eq!(Literal::u16_suffixed(10).to_string(), "10u16");
+    assert_eq!(Literal::u32_suffixed(10).to_string(), "10u32");
+    assert_eq!(Literal::u64_suffixed(10).to_string(), "10u64");
+    assert_eq!(Literal::u128_suffixed(10).to_string(), "10u128");
+    assert_eq!(Literal::usize_suffixed(10).to_string(), "10usize");
+
+    assert_eq!(Literal::i8_suffixed(10).to_string(), "10i8");
+    assert_eq!(Literal::i16_suffixed(10).to_string(), "10i16");
+    assert_eq!(Literal::i32_suffixed(10).to_string(), "10i32");
+    assert_eq!(Literal::i64_suffixed(10).to_string(), "10i64");
+    assert_eq!(Literal::i128_suffixed(10).to_string(), "10i128");
+    assert_eq!(Literal::isize_suffixed(10).to_string(), "10isize");
+
+    assert_eq!(Literal::u8_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::u16_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::u32_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::u64_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::u128_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::usize_unsuffixed(10).to_string(), "10");
+
+    assert_eq!(Literal::i8_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::i16_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::i32_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::i64_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::i128_unsuffixed(10).to_string(), "10");
+    assert_eq!(Literal::isize_unsuffixed(10).to_string(), "10");
+}
+
+#[test]
+fn literal_float() {
+    assert_eq!(Literal::f32_suffixed(10.0).to_string(), "10f32");
+    assert_eq!(Literal::f64_suffixed(10.0).to_string(), "10f64");
+
+    assert_eq!(Literal::f32_unsuffixed(10.0).to_string(), "10.0");
+    assert_eq!(Literal::f64_unsuffixed(10.0).to_string(), "10.0");
+}
+
+#[test]
+fn literal_suffix() {
+    fn token_count(p: &str) -> usize {
+        p.parse::<TokenStream>().unwrap().into_iter().count()
+    }
+
+    assert_eq!(token_count("999u256"), 1);
+    assert_eq!(token_count("999r#u256"), 3);
+    assert_eq!(token_count("1."), 1);
+    assert_eq!(token_count("1.f32"), 3);
+    assert_eq!(token_count("1.0_0"), 1);
+    assert_eq!(token_count("1._0"), 3);
+    assert_eq!(token_count("1._m"), 3);
+    assert_eq!(token_count("\"\"s"), 1);
+    assert_eq!(token_count("r\"\"r"), 1);
+    assert_eq!(token_count("b\"\"b"), 1);
+    assert_eq!(token_count("br\"\"br"), 1);
+    assert_eq!(token_count("r#\"\"#r"), 1);
+    assert_eq!(token_count("'c'c"), 1);
+    assert_eq!(token_count("b'b'b"), 1);
+    assert_eq!(token_count("0E"), 1);
+    assert_eq!(token_count("0o0A"), 1);
+    assert_eq!(token_count("0E--0"), 4);
+    assert_eq!(token_count("0.0ECMA"), 1);
+}
+
+#[test]
+fn literal_iter_negative() {
+    let negative_literal = Literal::i32_suffixed(-3);
+    let tokens = TokenStream::from(TokenTree::Literal(negative_literal));
+    let mut iter = tokens.into_iter();
+    match iter.next().unwrap() {
+        TokenTree::Punct(punct) => {
+            assert_eq!(punct.as_char(), '-');
+            assert_eq!(punct.spacing(), Spacing::Alone);
+        }
+        unexpected => panic!("unexpected token {:?}", unexpected),
+    }
+    match iter.next().unwrap() {
+        TokenTree::Literal(literal) => {
+            assert_eq!(literal.to_string(), "3i32");
+        }
+        unexpected => panic!("unexpected token {:?}", unexpected),
+    }
+    assert!(iter.next().is_none());
+}
+
+#[test]
+fn literal_parse() {
+    assert!("1".parse::<Literal>().is_ok());
+    assert!("-1".parse::<Literal>().is_ok());
+    assert!("-1u12".parse::<Literal>().is_ok());
+    assert!("1.0".parse::<Literal>().is_ok());
+    assert!("-1.0".parse::<Literal>().is_ok());
+    assert!("-1.0f12".parse::<Literal>().is_ok());
+    assert!("'a'".parse::<Literal>().is_ok());
+    assert!("\"\n\"".parse::<Literal>().is_ok());
+    assert!("0 1".parse::<Literal>().is_err());
+    assert!(" 0".parse::<Literal>().is_err());
+    assert!("0 ".parse::<Literal>().is_err());
+    assert!("/* comment */0".parse::<Literal>().is_err());
+    assert!("0/* comment */".parse::<Literal>().is_err());
+    assert!("0// comment".parse::<Literal>().is_err());
+    assert!("- 1".parse::<Literal>().is_err());
+    assert!("- 1.0".parse::<Literal>().is_err());
+    assert!("-\"\"".parse::<Literal>().is_err());
+}
+
+#[test]
+fn literal_span() {
+    let positive = "0.1".parse::<Literal>().unwrap();
+    let negative = "-0.1".parse::<Literal>().unwrap();
+    let subspan = positive.subspan(1..2);
+
+    #[cfg(not(span_locations))]
+    {
+        let _ = negative;
+        assert!(subspan.is_none());
+    }
+
+    #[cfg(span_locations)]
+    {
+        assert_eq!(positive.span().start().column, 0);
+        assert_eq!(positive.span().end().column, 3);
+        assert_eq!(negative.span().start().column, 0);
+        assert_eq!(negative.span().end().column, 4);
+        assert_eq!(subspan.unwrap().source_text().unwrap(), ".");
+    }
+
+    assert!(positive.subspan(1..4).is_none());
+}
+
+#[cfg(span_locations)]
+#[test]
+fn source_text() {
+    let input = "    𓀕 a z    ";
+    let mut tokens = input
+        .parse::<proc_macro2::TokenStream>()
+        .unwrap()
+        .into_iter();
+
+    let first = tokens.next().unwrap();
+    assert_eq!("𓀕", first.span().source_text().unwrap());
+
+    let second = tokens.next().unwrap();
+    let third = tokens.next().unwrap();
+    assert_eq!("z", third.span().source_text().unwrap());
+    assert_eq!("a", second.span().source_text().unwrap());
+}
+
+#[test]
+fn roundtrip() {
+    fn roundtrip(p: &str) {
+        println!("parse: {}", p);
+        let s = p.parse::<TokenStream>().unwrap().to_string();
+        println!("first: {}", s);
+        let s2 = s.parse::<TokenStream>().unwrap().to_string();
+        assert_eq!(s, s2);
+    }
+    roundtrip("a");
+    roundtrip("<<");
+    roundtrip("<<=");
+    roundtrip(
+        "
+        1
+        1.0
+        1f32
+        2f64
+        1usize
+        4isize
+        4e10
+        1_000
+        1_0i32
+        8u8
+        9
+        0
+        0xffffffffffffffffffffffffffffffff
+        1x
+        1u80
+        1f320
+    ",
+    );
+    roundtrip("'a");
+    roundtrip("'_");
+    roundtrip("'static");
+    roundtrip("'\\u{10__FFFF}'");
+    roundtrip("\"\\u{10_F0FF__}foo\\u{1_0_0_0__}\"");
+}
+
+#[test]
+fn fail() {
+    fn fail(p: &str) {
+        if let Ok(s) = p.parse::<TokenStream>() {
+            panic!("should have failed to parse: {}\n{:#?}", p, s);
+        }
+    }
+    fail("' static");
+    fail("r#1");
+    fail("r#_");
+    fail("\"\\u{0000000}\""); // overlong unicode escape (rust allows at most 6 hex digits)
+    fail("\"\\u{999999}\""); // outside of valid range of char
+    fail("\"\\u{_0}\""); // leading underscore
+    fail("\"\\u{}\""); // empty
+    fail("b\"\r\""); // bare carriage return in byte string
+    fail("r\"\r\""); // bare carriage return in raw string
+    fail("\"\\\r  \""); // backslash carriage return
+    fail("'aa'aa");
+    fail("br##\"\"#");
+    fail("\"\\\n\u{85}\r\"");
+}
+
+#[cfg(span_locations)]
+#[test]
+fn span_test() {
+    check_spans(
+        "\
+/// This is a document comment
+testing 123
+{
+  testing 234
+}",
+        &[
+            (1, 0, 1, 30),  // #
+            (1, 0, 1, 30),  // [ ... ]
+            (1, 0, 1, 30),  // doc
+            (1, 0, 1, 30),  // =
+            (1, 0, 1, 30),  // "This is..."
+            (2, 0, 2, 7),   // testing
+            (2, 8, 2, 11),  // 123
+            (3, 0, 5, 1),   // { ... }
+            (4, 2, 4, 9),   // testing
+            (4, 10, 4, 13), // 234
+        ],
+    );
+}
+
+#[cfg(procmacro2_semver_exempt)]
+#[cfg(not(nightly))]
+#[test]
+fn default_span() {
+    let start = Span::call_site().start();
+    assert_eq!(start.line, 1);
+    assert_eq!(start.column, 0);
+    let end = Span::call_site().end();
+    assert_eq!(end.line, 1);
+    assert_eq!(end.column, 0);
+    let source_file = Span::call_site().source_file();
+    assert_eq!(source_file.path().to_string_lossy(), "<unspecified>");
+    assert!(!source_file.is_real());
+}
+
+#[cfg(procmacro2_semver_exempt)]
+#[test]
+fn span_join() {
+    let source1 = "aaa\nbbb"
+        .parse::<TokenStream>()
+        .unwrap()
+        .into_iter()
+        .collect::<Vec<_>>();
+    let source2 = "ccc\nddd"
+        .parse::<TokenStream>()
+        .unwrap()
+        .into_iter()
+        .collect::<Vec<_>>();
+
+    assert!(source1[0].span().source_file() != source2[0].span().source_file());
+    assert_eq!(
+        source1[0].span().source_file(),
+        source1[1].span().source_file()
+    );
+
+    let joined1 = source1[0].span().join(source1[1].span());
+    let joined2 = source1[0].span().join(source2[0].span());
+    assert!(joined1.is_some());
+    assert!(joined2.is_none());
+
+    let start = joined1.unwrap().start();
+    let end = joined1.unwrap().end();
+    assert_eq!(start.line, 1);
+    assert_eq!(start.column, 0);
+    assert_eq!(end.line, 2);
+    assert_eq!(end.column, 3);
+
+    assert_eq!(
+        joined1.unwrap().source_file(),
+        source1[0].span().source_file()
+    );
+}
+
+#[test]
+fn no_panic() {
+    let s = str::from_utf8(b"b\'\xc2\x86  \x00\x00\x00^\"").unwrap();
+    assert!(s.parse::<TokenStream>().is_err());
+}
+
+#[test]
+fn punct_before_comment() {
+    let mut tts = TokenStream::from_str("~// comment").unwrap().into_iter();
+    match tts.next().unwrap() {
+        TokenTree::Punct(tt) => {
+            assert_eq!(tt.as_char(), '~');
+            assert_eq!(tt.spacing(), Spacing::Alone);
+        }
+        wrong => panic!("wrong token {:?}", wrong),
+    }
+}
+
+#[test]
+fn joint_last_token() {
+    // This test verifies that we match the behavior of libproc_macro *not* in
+    // the range nightly-2020-09-06 through nightly-2020-09-10, in which this
+    // behavior was temporarily broken.
+    // See https://github.com/rust-lang/rust/issues/76399
+
+    let joint_punct = Punct::new(':', Spacing::Joint);
+    let stream = TokenStream::from(TokenTree::Punct(joint_punct));
+    let punct = match stream.into_iter().next().unwrap() {
+        TokenTree::Punct(punct) => punct,
+        _ => unreachable!(),
+    };
+    assert_eq!(punct.spacing(), Spacing::Joint);
+}
+
+#[test]
+fn raw_identifier() {
+    let mut tts = TokenStream::from_str("r#dyn").unwrap().into_iter();
+    match tts.next().unwrap() {
+        TokenTree::Ident(raw) => assert_eq!("r#dyn", raw.to_string()),
+        wrong => panic!("wrong token {:?}", wrong),
+    }
+    assert!(tts.next().is_none());
+}
+
+#[test]
+fn test_debug_ident() {
+    let ident = Ident::new("proc_macro", Span::call_site());
+
+    #[cfg(not(span_locations))]
+    let expected = "Ident(proc_macro)";
+
+    #[cfg(span_locations)]
+    let expected = "Ident { sym: proc_macro }";
+
+    assert_eq!(expected, format!("{:?}", ident));
+}
+
+#[test]
+fn test_debug_tokenstream() {
+    let tts = TokenStream::from_str("[a + 1]").unwrap();
+
+    #[cfg(not(span_locations))]
+    let expected = "\
+TokenStream [
+    Group {
+        delimiter: Bracket,
+        stream: TokenStream [
+            Ident {
+                sym: a,
+            },
+            Punct {
+                char: '+',
+                spacing: Alone,
+            },
+            Literal {
+                lit: 1,
+            },
+        ],
+    },
+]\
+    ";
+
+    #[cfg(not(span_locations))]
+    let expected_before_trailing_commas = "\
+TokenStream [
+    Group {
+        delimiter: Bracket,
+        stream: TokenStream [
+            Ident {
+                sym: a
+            },
+            Punct {
+                char: '+',
+                spacing: Alone
+            },
+            Literal {
+                lit: 1
+            }
+        ]
+    }
+]\
+    ";
+
+    #[cfg(span_locations)]
+    let expected = "\
+TokenStream [
+    Group {
+        delimiter: Bracket,
+        stream: TokenStream [
+            Ident {
+                sym: a,
+                span: bytes(2..3),
+            },
+            Punct {
+                char: '+',
+                spacing: Alone,
+                span: bytes(4..5),
+            },
+            Literal {
+                lit: 1,
+                span: bytes(6..7),
+            },
+        ],
+        span: bytes(1..8),
+    },
+]\
+    ";
+
+    #[cfg(span_locations)]
+    let expected_before_trailing_commas = "\
+TokenStream [
+    Group {
+        delimiter: Bracket,
+        stream: TokenStream [
+            Ident {
+                sym: a,
+                span: bytes(2..3)
+            },
+            Punct {
+                char: '+',
+                spacing: Alone,
+                span: bytes(4..5)
+            },
+            Literal {
+                lit: 1,
+                span: bytes(6..7)
+            }
+        ],
+        span: bytes(1..8)
+    }
+]\
+    ";
+
+    let actual = format!("{:#?}", tts);
+    if actual.ends_with(",\n]") {
+        assert_eq!(expected, actual);
+    } else {
+        assert_eq!(expected_before_trailing_commas, actual);
+    }
+}
+
+#[test]
+fn default_tokenstream_is_empty() {
+    let default_token_stream = <TokenStream as Default>::default();
+
+    assert!(default_token_stream.is_empty());
+}
+
+#[test]
+fn tokenstream_size_hint() {
+    let tokens = "a b (c d) e".parse::<TokenStream>().unwrap();
+
+    assert_eq!(tokens.into_iter().size_hint(), (4, Some(4)));
+}
+
+#[test]
+fn tuple_indexing() {
+    // This behavior may change depending on https://github.com/rust-lang/rust/pull/71322
+    let mut tokens = "tuple.0.0".parse::<TokenStream>().unwrap().into_iter();
+    assert_eq!("tuple", tokens.next().unwrap().to_string());
+    assert_eq!(".", tokens.next().unwrap().to_string());
+    assert_eq!("0.0", tokens.next().unwrap().to_string());
+    assert!(tokens.next().is_none());
+}
+
+#[cfg(span_locations)]
+#[test]
+fn non_ascii_tokens() {
+    check_spans("// abc", &[]);
+    check_spans("// ábc", &[]);
+    check_spans("// abc x", &[]);
+    check_spans("// ábc x", &[]);
+    check_spans("/* abc */ x", &[(1, 10, 1, 11)]);
+    check_spans("/* ábc */ x", &[(1, 10, 1, 11)]);
+    check_spans("/* ab\nc */ x", &[(2, 5, 2, 6)]);
+    check_spans("/* áb\nc */ x", &[(2, 5, 2, 6)]);
+    check_spans("/*** abc */ x", &[(1, 12, 1, 13)]);
+    check_spans("/*** ábc */ x", &[(1, 12, 1, 13)]);
+    check_spans(r#""abc""#, &[(1, 0, 1, 5)]);
+    check_spans(r#""ábc""#, &[(1, 0, 1, 5)]);
+    check_spans(r##"r#"abc"#"##, &[(1, 0, 1, 8)]);
+    check_spans(r##"r#"ábc"#"##, &[(1, 0, 1, 8)]);
+    check_spans("r#\"a\nc\"#", &[(1, 0, 2, 3)]);
+    check_spans("r#\"á\nc\"#", &[(1, 0, 2, 3)]);
+    check_spans("'a'", &[(1, 0, 1, 3)]);
+    check_spans("'á'", &[(1, 0, 1, 3)]);
+    check_spans("//! abc", &[(1, 0, 1, 7), (1, 0, 1, 7), (1, 0, 1, 7)]);
+    check_spans("//! ábc", &[(1, 0, 1, 7), (1, 0, 1, 7), (1, 0, 1, 7)]);
+    check_spans("//! abc\n", &[(1, 0, 1, 7), (1, 0, 1, 7), (1, 0, 1, 7)]);
+    check_spans("//! ábc\n", &[(1, 0, 1, 7), (1, 0, 1, 7), (1, 0, 1, 7)]);
+    check_spans("/*! abc */", &[(1, 0, 1, 10), (1, 0, 1, 10), (1, 0, 1, 10)]);
+    check_spans("/*! ábc */", &[(1, 0, 1, 10), (1, 0, 1, 10), (1, 0, 1, 10)]);
+    check_spans("/*! a\nc */", &[(1, 0, 2, 4), (1, 0, 2, 4), (1, 0, 2, 4)]);
+    check_spans("/*! á\nc */", &[(1, 0, 2, 4), (1, 0, 2, 4), (1, 0, 2, 4)]);
+    check_spans("abc", &[(1, 0, 1, 3)]);
+    check_spans("ábc", &[(1, 0, 1, 3)]);
+    check_spans("ábć", &[(1, 0, 1, 3)]);
+    check_spans("abc// foo", &[(1, 0, 1, 3)]);
+    check_spans("ábc// foo", &[(1, 0, 1, 3)]);
+    check_spans("ábć// foo", &[(1, 0, 1, 3)]);
+    check_spans("b\"a\\\n c\"", &[(1, 0, 2, 3)]);
+}
+
+#[cfg(span_locations)]
+fn check_spans(p: &str, mut lines: &[(usize, usize, usize, usize)]) {
+    let ts = p.parse::<TokenStream>().unwrap();
+    check_spans_internal(ts, &mut lines);
+    assert!(lines.is_empty(), "leftover ranges: {:?}", lines);
+}
+
+#[cfg(span_locations)]
+fn check_spans_internal(ts: TokenStream, lines: &mut &[(usize, usize, usize, usize)]) {
+    for i in ts {
+        if let Some((&(sline, scol, eline, ecol), rest)) = lines.split_first() {
+            *lines = rest;
+
+            let start = i.span().start();
+            assert_eq!(start.line, sline, "sline did not match for {}", i);
+            assert_eq!(start.column, scol, "scol did not match for {}", i);
+
+            let end = i.span().end();
+            assert_eq!(end.line, eline, "eline did not match for {}", i);
+            assert_eq!(end.column, ecol, "ecol did not match for {}", i);
+
+            if let TokenTree::Group(g) = i {
+                check_spans_internal(g.stream().clone(), lines);
+            }
+        }
+    }
+}
+
+#[test]
+fn whitespace() {
+    // space, horizontal tab, vertical tab, form feed, carriage return, line
+    // feed, non-breaking space, left-to-right mark, right-to-left mark
+    let various_spaces = " \t\u{b}\u{c}\r\n\u{a0}\u{200e}\u{200f}";
+    let tokens = various_spaces.parse::<TokenStream>().unwrap();
+    assert_eq!(tokens.into_iter().count(), 0);
+
+    let lone_carriage_returns = " \r \r\r\n ";
+    lone_carriage_returns.parse::<TokenStream>().unwrap();
+}
+
+#[test]
+fn byte_order_mark() {
+    let string = "\u{feff}foo";
+    let tokens = string.parse::<TokenStream>().unwrap();
+    match tokens.into_iter().next().unwrap() {
+        TokenTree::Ident(ident) => assert_eq!(ident, "foo"),
+        _ => unreachable!(),
+    }
+
+    let string = "foo\u{feff}";
+    string.parse::<TokenStream>().unwrap_err();
+}