1 files changed, 112 insertions, 0 deletions
diff --git a/gcc/testsuite/rust/compile/issue-3898.rs b/gcc/testsuite/rust/compile/issue-3898.rs
new file mode 100644
index 0000000..114370c
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-3898.rs
@@ -0,0 +1,112 @@
+// { dg-additional-options "-frust-compile-until=lowering" }
+
+#[lang = "sized"]
+trait Sized {}
+
+enum Result<T, E> {
+    Ok(T),
+    Err(E),
+}
+
+use Result::{Err, Ok};
+
+struct Utf8Error;
+
+const CONT_MASK: u8 = 15;
+const TAG_CONT_U8: u8 = 15;
+
+#[inline(always)]
+pub fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
+    let mut index = 0;
+    let len = 64;
+
+    let usize_bytes = 8;
+    let ascii_block_size = 2 * usize_bytes;
+    let blocks_end = if len >= ascii_block_size {
+        len - ascii_block_size + 1
+    } else {
+        0
+    };
+
+    while index < len {
+        let old_offset = index;
+        macro_rules! err {
+            ($error_len: expr) => {
+                return Err(Utf8Error)
+            };
+        }
+
+        macro_rules! next {
+            () => {{
+                index += 1;
+                // we needed data, but there was none: error!
+                if index >= len {
+                    err!(None)
+                }
+                v[index]
+            }};
+        }
+
+        let first = v[index];
+        if first >= 128 {
+            let w = 15;
+            // 2-byte encoding is for codepoints  \u{0080} to  \u{07ff}
+            //        first  C2 80        last DF BF
+            // 3-byte encoding is for codepoints  \u{0800} to  \u{ffff}
+            //        first  E0 A0 80     last EF BF BF
+            //   excluding surrogates codepoints  \u{d800} to  \u{dfff}
+            //               ED A0 80 to       ED BF BF
+            // 4-byte encoding is for codepoints \u{1000}0 to \u{10ff}ff
+            //        first  F0 90 80 80  last F4 8F BF BF
+            //
+            // Use the UTF-8 syntax from the RFC
+            //
+            // https://tools.ietf.org/html/rfc3629
+            // UTF8-1      = %x00-7F
+            // UTF8-2      = %xC2-DF UTF8-tail
+            // UTF8-3      = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2( UTF8-tail ) /
+            //               %xED %x80-9F UTF8-tail / %xEE-EF 2( UTF8-tail )
+            // UTF8-4      = %xF0 %x90-BF 2( UTF8-tail ) / %xF1-F3 3( UTF8-tail ) /
+            //               %xF4 %x80-8F 2( UTF8-tail )
+            match w {
+                2 => {
+                    if next!() & !CONT_MASK != TAG_CONT_U8 {
+                        err!(Some(1))
+                    }
+                }
+                3 => {
+                    match (first, next!()) {
+                        (0xE0, 0xA0..=0xBF)
+                        | (0xE1..=0xEC, 0x80..=0xBF)
+                        | (0xED, 0x80..=0x9F)
+                        | (0xEE..=0xEF, 0x80..=0xBF) => {}
+                        _ => err!(Some(1)),
+                    }
+                    if next!() & !CONT_MASK != TAG_CONT_U8 {
+                        err!(Some(2))
+                    }
+                }
+                4 => {
+                    match (first, next!()) {
+                        (0xF0, 0x90..=0xBF) | (0xF1..=0xF3, 0x80..=0xBF) | (0xF4, 0x80..=0x8F) => {}
+                        _ => err!(Some(1)),
+                    }
+                    if next!() & !CONT_MASK != TAG_CONT_U8 {
+                        err!(Some(2))
+                    }
+                    if next!() & !CONT_MASK != TAG_CONT_U8 {
+                        err!(Some(3))
+                    }
+                }
+                _ => err!(Some(1)),
+            }
+            index += 1;
+        } else {
+            index += 1;
+        }
+    }
+
+    Ok(())
+}
+
+fn main() {}