neo-decompiler 0.11.0

use super::super::super::HighLevelEmitter;

impl HighLevelEmitter {
    /// Removes `goto label_X;` (or the try-context `leave label_X;` form)
    /// when the resume target sits at the very next code line *or* one or
    /// more close-braces past it.
    ///
    /// `leave` is the high-level encoding of `ENDTRY <target>` — semantically
    /// "exit the try block, run finally, resume at target". When the resume
    /// target is the next instruction, the lowered C#/pseudocode would
    /// auto-execute finally on any try exit anyway, so the explicit transfer
    /// is dead code that only adds visual noise. The same logic applies when
    /// a `goto`/`leave` is the last statement of a block (e.g. a catch body)
    /// whose closing `}` is immediately followed by the target label.
    pub(crate) fn eliminate_fallthrough_gotos(statements: &mut [String]) {
        let mut index = 0;
        while index < statements.len() {
            let trimmed = statements[index].trim().to_string();
            let Some(label) = trimmed
                .strip_prefix("goto ")
                .or_else(|| trimmed.strip_prefix("leave "))
                .and_then(|s| s.strip_suffix(';'))
                .map(|s| s.trim().to_string())
            else {
                index += 1;
                continue;
            };

            let label_line = format!("{label}:");
            // Walk forward past blank/comment/close-brace lines to find the
            // next executable statement. If it is the matching label, the
            // transfer is dead — control would have reached the label
            // through structural fall-out anyway.
            let mut probe = index + 1;
            while probe < statements.len() {
                let t = statements[probe].trim();
                if t.is_empty() || t.starts_with("//") || t == "}" {
                    probe += 1;
                    continue;
                }
                if t == label_line {
                    statements[index].clear();
                }
                break;
            }
            index += 1;
        }
    }
}