Add ICE test

1 files changed, 472 insertions, 0 deletions

diff --git a/src/test/rustdoc-ui/scrape-examples-ice.rs b/src/test/rustdoc-ui/scrape-examples-ice.rs
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+// compile-flags: -Z unstable-options --scrape-examples-output-path t.calls --scrape-examples-target-crate foobar
+// check-pass
+
+// Copyright 2013-2016 The rust-url developers.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! URLs use special characters to indicate the parts of the request.
+//! For example, a `?` question mark marks the end of a path and the start of a query string.
+//! In order for that character to exist inside a path, it needs to be encoded differently.
+//!
+//! Percent encoding replaces reserved characters with the `%` escape character
+//! followed by a byte value as two hexadecimal digits.
+//! For example, an ASCII space is replaced with `%20`.
+//!
+//! When encoding, the set of characters that can (and should, for readability) be left alone
+//! depends on the context.
+//! The `?` question mark mentioned above is not a separator when used literally
+//! inside of a query string, and therefore does not need to be encoded.
+//! The [`AsciiSet`] parameter of [`percent_encode`] and [`utf8_percent_encode`]
+//! lets callers configure this.
+//!
+//! This crate deliberately does not provide many different sets.
+//! Users should consider in what context the encoded string will be used,
+//! read relevant specifications, and define their own set.
+//! This is done by using the `add` method of an existing set.
+//!
+//! # Examples
+//!
+//! ```
+//! use percent_encoding::{utf8_percent_encode, AsciiSet, CONTROLS};
+//!
+//! /// https://url.spec.whatwg.org/#fragment-percent-encode-set
+//! const FRAGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
+//!
+//! assert_eq!(utf8_percent_encode("foo <bar>", FRAGMENT).to_string(), "foo%20%3Cbar%3E");
+//! ```
+
+#![no_std]
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+#[cfg(feature = "alloc")]
+use alloc::{
+    borrow::{Cow, ToOwned},
+    string::String,
+    vec::Vec,
+};
+use core::{fmt, mem, slice, str};
+
+/// Represents a set of characters or bytes in the ASCII range.
+///
+/// This is used in [`percent_encode`] and [`utf8_percent_encode`].
+/// This is similar to [percent-encode sets](https://url.spec.whatwg.org/#percent-encoded-bytes).
+///
+/// Use the `add` method of an existing set to define a new set. For example:
+///
+/// ```
+/// use percent_encoding::{AsciiSet, CONTROLS};
+///
+/// /// https://url.spec.whatwg.org/#fragment-percent-encode-set
+/// const FRAGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`');
+/// ```
+pub struct AsciiSet {
+    mask: [Chunk; ASCII_RANGE_LEN / BITS_PER_CHUNK],
+}
+
+type Chunk = u32;
+
+const ASCII_RANGE_LEN: usize = 0x80;
+
+const BITS_PER_CHUNK: usize = 8 * mem::size_of::<Chunk>();
+
+impl AsciiSet {
+    /// Called with UTF-8 bytes rather than code points.
+    /// Not used for non-ASCII bytes.
+    const fn contains(&self, byte: u8) -> bool {
+        let chunk = self.mask[byte as usize / BITS_PER_CHUNK];
+        let mask = 1 << (byte as usize % BITS_PER_CHUNK);
+        (chunk & mask) != 0
+    }
+
+    fn should_percent_encode(&self, byte: u8) -> bool {
+        !byte.is_ascii() || self.contains(byte)
+    }
+
+    pub const fn add(&self, byte: u8) -> Self {
+        let mut mask = self.mask;
+        mask[byte as usize / BITS_PER_CHUNK] |= 1 << (byte as usize % BITS_PER_CHUNK);
+        AsciiSet { mask }
+    }
+
+    pub const fn remove(&self, byte: u8) -> Self {
+        let mut mask = self.mask;
+        mask[byte as usize / BITS_PER_CHUNK] &= !(1 << (byte as usize % BITS_PER_CHUNK));
+        AsciiSet { mask }
+    }
+}
+
+/// The set of 0x00 to 0x1F (C0 controls), and 0x7F (DEL).
+///
+/// Note that this includes the newline and tab characters, but not the space 0x20.
+///
+/// <https://url.spec.whatwg.org/#c0-control-percent-encode-set>
+pub const CONTROLS: &AsciiSet = &AsciiSet {
+    mask: [
+        !0_u32, // C0: 0x00 to 0x1F (32 bits set)
+        0,
+        0,
+        1 << (0x7F_u32 % 32), // DEL: 0x7F (one bit set)
+    ],
+};
+
+macro_rules! static_assert {
+    ($( $bool: expr, )+) => {
+        fn _static_assert() {
+            $(
+                let _ = mem::transmute::<[u8; $bool as usize], u8>;
+            )+
+        }
+    }
+}
+
+static_assert! {
+    CONTROLS.contains(0x00),
+    CONTROLS.contains(0x1F),
+    !CONTROLS.contains(0x20),
+    !CONTROLS.contains(0x7E),
+    CONTROLS.contains(0x7F),
+}
+
+/// Everything that is not an ASCII letter or digit.
+///
+/// This is probably more eager than necessary in any context.
+pub const NON_ALPHANUMERIC: &AsciiSet = &CONTROLS
+    .add(b' ')
+    .add(b'!')
+    .add(b'"')
+    .add(b'#')
+    .add(b'$')
+    .add(b'%')
+    .add(b'&')
+    .add(b'\'')
+    .add(b'(')
+    .add(b')')
+    .add(b'*')
+    .add(b'+')
+    .add(b',')
+    .add(b'-')
+    .add(b'.')
+    .add(b'/')
+    .add(b':')
+    .add(b';')
+    .add(b'<')
+    .add(b'=')
+    .add(b'>')
+    .add(b'?')
+    .add(b'@')
+    .add(b'[')
+    .add(b'\\')
+    .add(b']')
+    .add(b'^')
+    .add(b'_')
+    .add(b'`')
+    .add(b'{')
+    .add(b'|')
+    .add(b'}')
+    .add(b'~');
+
+/// Return the percent-encoding of the given byte.
+///
+/// This is unconditional, unlike `percent_encode()` which has an `AsciiSet` parameter.
+///
+/// # Examples
+///
+/// ```
+/// use percent_encoding::percent_encode_byte;
+///
+/// assert_eq!("foo bar".bytes().map(percent_encode_byte).collect::<String>(),
+///            "%66%6F%6F%20%62%61%72");
+/// ```
+pub fn percent_encode_byte(byte: u8) -> &'static str {
+    let index = usize::from(byte) * 3;
+    &"\
+      %00%01%02%03%04%05%06%07%08%09%0A%0B%0C%0D%0E%0F\
+      %10%11%12%13%14%15%16%17%18%19%1A%1B%1C%1D%1E%1F\
+      %20%21%22%23%24%25%26%27%28%29%2A%2B%2C%2D%2E%2F\
+      %30%31%32%33%34%35%36%37%38%39%3A%3B%3C%3D%3E%3F\
+      %40%41%42%43%44%45%46%47%48%49%4A%4B%4C%4D%4E%4F\
+      %50%51%52%53%54%55%56%57%58%59%5A%5B%5C%5D%5E%5F\
+      %60%61%62%63%64%65%66%67%68%69%6A%6B%6C%6D%6E%6F\
+      %70%71%72%73%74%75%76%77%78%79%7A%7B%7C%7D%7E%7F\
+      %80%81%82%83%84%85%86%87%88%89%8A%8B%8C%8D%8E%8F\
+      %90%91%92%93%94%95%96%97%98%99%9A%9B%9C%9D%9E%9F\
+      %A0%A1%A2%A3%A4%A5%A6%A7%A8%A9%AA%AB%AC%AD%AE%AF\
+      %B0%B1%B2%B3%B4%B5%B6%B7%B8%B9%BA%BB%BC%BD%BE%BF\
+      %C0%C1%C2%C3%C4%C5%C6%C7%C8%C9%CA%CB%CC%CD%CE%CF\
+      %D0%D1%D2%D3%D4%D5%D6%D7%D8%D9%DA%DB%DC%DD%DE%DF\
+      %E0%E1%E2%E3%E4%E5%E6%E7%E8%E9%EA%EB%EC%ED%EE%EF\
+      %F0%F1%F2%F3%F4%F5%F6%F7%F8%F9%FA%FB%FC%FD%FE%FF\
+      "[index..index + 3]
+}
+
+/// Percent-encode the given bytes with the given set.
+///
+/// Non-ASCII bytes and bytes in `ascii_set` are encoded.
+///
+/// The return type:
+///
+/// * Implements `Iterator<Item = &str>` and therefore has a `.collect::<String>()` method,
+/// * Implements `Display` and therefore has a `.to_string()` method,
+/// * Implements `Into<Cow<str>>` borrowing `input` when none of its bytes are encoded.
+///
+/// # Examples
+///
+/// ```
+/// use percent_encoding::{percent_encode, NON_ALPHANUMERIC};
+///
+/// assert_eq!(percent_encode(b"foo bar?", NON_ALPHANUMERIC).to_string(), "foo%20bar%3F");
+/// ```
+#[inline]
+pub fn percent_encode<'a>(input: &'a [u8], ascii_set: &'static AsciiSet) -> PercentEncode<'a> {
+    PercentEncode {
+        bytes: input,
+        ascii_set,
+    }
+}
+
+/// Percent-encode the UTF-8 encoding of the given string.
+///
+/// See [`percent_encode`] regarding the return type.
+///
+/// # Examples
+///
+/// ```
+/// use percent_encoding::{utf8_percent_encode, NON_ALPHANUMERIC};
+///
+/// assert_eq!(utf8_percent_encode("foo bar?", NON_ALPHANUMERIC).to_string(), "foo%20bar%3F");
+/// ```
+#[inline]
+pub fn utf8_percent_encode<'a>(input: &'a str, ascii_set: &'static AsciiSet) -> PercentEncode<'a> {
+    percent_encode(input.as_bytes(), ascii_set)
+}
+
+/// The return type of [`percent_encode`] and [`utf8_percent_encode`].
+#[derive(Clone)]
+pub struct PercentEncode<'a> {
+    bytes: &'a [u8],
+    ascii_set: &'static AsciiSet,
+}
+
+impl<'a> Iterator for PercentEncode<'a> {
+    type Item = &'a str;
+
+    fn next(&mut self) -> Option<&'a str> {
+        if let Some((&first_byte, remaining)) = self.bytes.split_first() {
+            if self.ascii_set.should_percent_encode(first_byte) {
+                self.bytes = remaining;
+                Some(percent_encode_byte(first_byte))
+            } else {
+                // The unsafe blocks here are appropriate because the bytes are
+                // confirmed as a subset of UTF-8 in should_percent_encode.
+                for (i, &byte) in remaining.iter().enumerate() {
+                    if self.ascii_set.should_percent_encode(byte) {
+                        // 1 for first_byte + i for previous iterations of this loop
+                        let (unchanged_slice, remaining) = self.bytes.split_at(1 + i);
+                        self.bytes = remaining;
+                        return Some(unsafe { str::from_utf8_unchecked(unchanged_slice) });
+                    }
+                }
+                let unchanged_slice = self.bytes;
+                self.bytes = &[][..];
+                Some(unsafe { str::from_utf8_unchecked(unchanged_slice) })
+            }
+        } else {
+            None
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        if self.bytes.is_empty() {
+            (0, Some(0))
+        } else {
+            (1, Some(self.bytes.len()))
+        }
+    }
+}
+
+impl<'a> fmt::Display for PercentEncode<'a> {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for c in (*self).clone() {
+            formatter.write_str(c)?
+        }
+        Ok(())
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl<'a> From<PercentEncode<'a>> for Cow<'a, str> {
+    fn from(mut iter: PercentEncode<'a>) -> Self {
+        match iter.next() {
+            None => "".into(),
+            Some(first) => match iter.next() {
+                None => first.into(),
+                Some(second) => {
+                    let mut string = first.to_owned();
+                    string.push_str(second);
+                    string.extend(iter);
+                    string.into()
+                }
+            },
+        }
+    }
+}
+
+/// Percent-decode the given string.
+///
+/// <https://url.spec.whatwg.org/#string-percent-decode>
+///
+/// See [`percent_decode`] regarding the return type.
+#[inline]
+pub fn percent_decode_str(input: &str) -> PercentDecode<'_> {
+    percent_decode(input.as_bytes())
+}
+
+/// Percent-decode the given bytes.
+///
+/// <https://url.spec.whatwg.org/#percent-decode>
+///
+/// Any sequence of `%` followed by two hexadecimal digits is decoded.
+/// The return type:
+///
+/// * Implements `Into<Cow<u8>>` borrowing `input` when it contains no percent-encoded sequence,
+/// * Implements `Iterator<Item = u8>` and therefore has a `.collect::<Vec<u8>>()` method,
+/// * Has `decode_utf8()` and `decode_utf8_lossy()` methods.
+///
+/// # Examples
+///
+/// ```
+/// use percent_encoding::percent_decode;
+///
+/// assert_eq!(percent_decode(b"foo%20bar%3f").decode_utf8().unwrap(), "foo bar?");
+/// ```
+#[inline]
+pub fn percent_decode(input: &[u8]) -> PercentDecode<'_> {
+    PercentDecode {
+        bytes: input.iter(),
+    }
+}
+
+/// The return type of [`percent_decode`].
+#[derive(Clone, Debug)]
+pub struct PercentDecode<'a> {
+    bytes: slice::Iter<'a, u8>,
+}
+
+fn after_percent_sign(iter: &mut slice::Iter<'_, u8>) -> Option<u8> {
+    let mut cloned_iter = iter.clone();
+    let h = char::from(*cloned_iter.next()?).to_digit(16)?;
+    let l = char::from(*cloned_iter.next()?).to_digit(16)?;
+    *iter = cloned_iter;
+    Some(h as u8 * 0x10 + l as u8)
+}
+
+impl<'a> Iterator for PercentDecode<'a> {
+    type Item = u8;
+
+    fn next(&mut self) -> Option<u8> {
+        self.bytes.next().map(|&byte| {
+            if byte == b'%' {
+                after_percent_sign(&mut self.bytes).unwrap_or(byte)
+            } else {
+                byte
+            }
+        })
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let bytes = self.bytes.len();
+        ((bytes + 2) / 3, Some(bytes))
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl<'a> From<PercentDecode<'a>> for Cow<'a, [u8]> {
+    fn from(iter: PercentDecode<'a>) -> Self {
+        match iter.if_any() {
+            Some(vec) => Cow::Owned(vec),
+            None => Cow::Borrowed(iter.bytes.as_slice()),
+        }
+    }
+}
+
+impl<'a> PercentDecode<'a> {
+    /// If the percent-decoding is different from the input, return it as a new bytes vector.
+    #[cfg(feature = "alloc")]
+    fn if_any(&self) -> Option<Vec<u8>> {
+        let mut bytes_iter = self.bytes.clone();
+        while bytes_iter.any(|&b| b == b'%') {
+            if let Some(decoded_byte) = after_percent_sign(&mut bytes_iter) {
+                let initial_bytes = self.bytes.as_slice();
+                let unchanged_bytes_len = initial_bytes.len() - bytes_iter.len() - 3;
+                let mut decoded = initial_bytes[..unchanged_bytes_len].to_owned();
+                decoded.push(decoded_byte);
+                decoded.extend(PercentDecode { bytes: bytes_iter });
+                return Some(decoded);
+            }
+        }
+        // Nothing to decode
+        None
+    }
+
+    /// Decode the result of percent-decoding as UTF-8.
+    ///
+    /// This is return `Err` when the percent-decoded bytes are not well-formed in UTF-8.
+    #[cfg(feature = "alloc")]
+    pub fn decode_utf8(self) -> Result<Cow<'a, str>, str::Utf8Error> {
+        match self.clone().into() {
+            Cow::Borrowed(bytes) => match str::from_utf8(bytes) {
+                Ok(s) => Ok(s.into()),
+                Err(e) => Err(e),
+            },
+            Cow::Owned(bytes) => match String::from_utf8(bytes) {
+                Ok(s) => Ok(s.into()),
+                Err(e) => Err(e.utf8_error()),
+            },
+        }
+    }
+
+    /// Decode the result of percent-decoding as UTF-8, lossily.
+    ///
+    /// Invalid UTF-8 percent-encoded byte sequences will be replaced � U+FFFD,
+    /// the replacement character.
+    #[cfg(feature = "alloc")]
+    pub fn decode_utf8_lossy(self) -> Cow<'a, str> {
+        decode_utf8_lossy(self.clone().into())
+    }
+}
+
+#[cfg(feature = "alloc")]
+fn decode_utf8_lossy(input: Cow<'_, [u8]>) -> Cow<'_, str> {
+    // Note: This function is duplicated in `form_urlencoded/src/query_encoding.rs`.
+    match input {
+        Cow::Borrowed(bytes) => String::from_utf8_lossy(bytes),
+        Cow::Owned(bytes) => {
+            match String::from_utf8_lossy(&bytes) {
+                Cow::Borrowed(utf8) => {
+                    // If from_utf8_lossy returns a Cow::Borrowed, then we can
+                    // be sure our original bytes were valid UTF-8. This is because
+                    // if the bytes were invalid UTF-8 from_utf8_lossy would have
+                    // to allocate a new owned string to back the Cow so it could
+                    // replace invalid bytes with a placeholder.
+
+                    // First we do a debug_assert to confirm our description above.
+                    let raw_utf8: *const [u8];
+                    raw_utf8 = utf8.as_bytes();
+                    debug_assert!(raw_utf8 == &*bytes as *const [u8]);
+
+                    // Given we know the original input bytes are valid UTF-8,
+                    // and we have ownership of those bytes, we re-use them and
+                    // return a Cow::Owned here.
+                    Cow::Owned(unsafe { String::from_utf8_unchecked(bytes) })
+                }
+                Cow::Owned(s) => Cow::Owned(s),
+            }
+        }
+    }
+}