rust/tests/source/issue_5730.rs

macro_rules! statement {
    () => {;};
}
Prevent ICE when formatting an empty-ish macro arm (#5833) Fixes 5730 Previously rustfmt was attempting to slice a string with an invalid range (`start > end`), leading to the ICE. When formatting a macro transcriber snippet consisting of a lone semicolon, the snippet was being formatted into the empty string, leading the enclosing `fn main() {\n}` added by `format_code_block` to be formatted into `fn main() {}`. However, rustfmt was assuming that the enclosing function string's length had been left unchanged. This was leading to an invalid range being constructed when attempting to trim off the enclosing function. The fix is to just clamp the range's start to be less than or equal to the range's end, since if `end < start` there's nothing to iterate over anyway. 2023-07-18 20:48:57 -05:00			`macro_rules! statement {`
			`() => {;};`
			`}`