macho-demangle 0.5.6

#![deny(missing_docs)]
//! Process-free Rust, C++, and Swift symbol demangling and normalization.

use std::borrow::Cow;
use std::collections::HashMap;
use swift_demangler::raw::{Node, NodeKind};
use swift_demangler::{Context, MetadataKind, Symbol, TypeKind};

/// Owned, process-free Swift mangling evidence.
pub mod swift_evidence;

/// Closed nominal kinds carried by an emitted Swift type-metadata symbol.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum SwiftNominalMetadataKind {
    /// Class metadata.
    Class,
    /// Structure metadata.
    Struct,
    /// Enumeration metadata.
    Enum,
}

/// Typed identity carried by an emitted Swift type-metadata symbol.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct SwiftTypeMetadataIdentity {
    /// Fully-qualified nominal type name.
    pub name: String,
    /// Nominal ABI kind.
    pub kind: SwiftNominalMetadataKind,
}

/// Strict classification of one possible emitted Swift type-metadata symbol.
///
/// The parser's third-party syntax tree remains private to this crate. Callers
/// receive only Macho-owned, forward-closed evidence and cannot accidentally
/// couple policy code to parser implementation details.
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum SwiftTypeMetadataSymbolEvidence {
    /// The name is not an emitted type-metadata symbol.
    NotTypeMetadata,
    /// The name carries one supported, already-materialized nominal identity.
    Metadata(SwiftTypeMetadataIdentity),
    /// The symbol is structurally metadata, but its nominal kind is unsupported.
    Unsupported {
        /// Stable, non-sensitive rejection detail.
        detail: String,
    },
    /// The name has the emitted-metadata shape but cannot be decoded.
    Malformed {
        /// Stable, non-sensitive rejection detail.
        detail: String,
    },
}

/// Cached demangler for symbol-heavy CLI output.
#[derive(Debug, Default)]
pub struct SymbolDemangler {
    enabled: bool,
    cache: HashMap<String, Option<String>>,
}

impl SymbolDemangler {
    /// Performs new.
    pub fn new(enabled: bool) -> Self {
        Self {
            enabled,
            cache: HashMap::new(),
        }
    }

    /// Performs precompute.
    pub fn precompute<'a>(&mut self, names: impl IntoIterator<Item = &'a str>) {
        if !self.enabled {
            return;
        }

        for name in names {
            if self.cache.contains_key(name) {
                continue;
            }

            if let Some(demangled) = demangle_rust_or_cpp(name) {
                self.cache.insert(name.to_owned(), Some(demangled));
                continue;
            }

            if let Some(demangled) = demangle_swift_symbol(name) {
                self.cache.insert(name.to_owned(), Some(demangled));
                continue;
            }

            self.cache.insert(name.to_owned(), None);
        }
    }

    /// Performs format.
    pub fn format<'a>(&mut self, name: &'a str) -> Cow<'a, str> {
        if !self.enabled {
            return Cow::Borrowed(name);
        }

        if !self.cache.contains_key(name) {
            self.precompute([name]);
        }

        match self.cache.get(name).and_then(|entry| entry.as_ref()) {
            Some(demangled) => Cow::Owned(demangled.clone()),
            None => Cow::Borrowed(name),
        }
    }
}

/// Demangle a Rust, C++, or Swift symbol name when possible.
pub fn demangle_symbol(name: &str) -> Option<String> {
    let mut demangler = SymbolDemangler::new(true);
    demangler.precompute([name]);
    demangler.cache.remove(name).flatten()
}

/// Demangle a C++ symbol, including a return type when the ABI encoding carries one.
pub fn demangle_cpp_symbol(name: &str) -> Option<String> {
    demangle_cpp_symbol_with_options(name, cpp_demangle::DemangleOptions::default())
}

/// Demangle a C++ symbol while omitting any encoded return type.
pub fn demangle_cpp_symbol_without_return_type(name: &str) -> Option<String> {
    demangle_cpp_symbol_with_options(
        name,
        cpp_demangle::DemangleOptions::default().no_return_type(),
    )
}

/// Demangle a legacy Swift Objective-C runtime name in-process.
pub fn demangle_swift_symbol(name: &str) -> Option<String> {
    let candidate = swift_candidate(name)?;
    swift_demangler::demangle(candidate).or_else(|| demangle_legacy_swift_runtime_name(candidate))
}

/// Decode the typed identity of an emitted Swift type-metadata symbol.
///
/// Narrower than display demangling: accessors, descriptors, protocols,
/// functions, and unsupported nominal kinds are not admitted as
/// already-materialized type metadata.
pub fn swift_type_metadata_identity(name: &str) -> Option<SwiftTypeMetadataIdentity> {
    match classify_swift_type_metadata_symbol(name) {
        SwiftTypeMetadataSymbolEvidence::Metadata(identity) => Some(identity),
        SwiftTypeMetadataSymbolEvidence::NotTypeMetadata
        | SwiftTypeMetadataSymbolEvidence::Unsupported { .. }
        | SwiftTypeMetadataSymbolEvidence::Malformed { .. } => None,
    }
}

/// Strictly classify an emitted Swift type-metadata symbol.
///
/// Only the `...N` value-metadata production is considered a candidate.
/// Accessors (`...Ma`), descriptors (`...Mn`), functions, and unrelated Swift
/// symbols are outside this evidence surface.
pub fn classify_swift_type_metadata_symbol(name: &str) -> SwiftTypeMetadataSymbolEvidence {
    let Some(candidate) = swift_candidate(name) else {
        return SwiftTypeMetadataSymbolEvidence::NotTypeMetadata;
    };
    if !candidate.ends_with('N') {
        return SwiftTypeMetadataSymbolEvidence::NotTypeMetadata;
    }
    let context = Context::new();
    let Some(root) = Node::parse(&context, candidate) else {
        return SwiftTypeMetadataSymbolEvidence::Malformed {
            detail: "Swift emitted type-metadata mangling is malformed".into(),
        };
    };
    let Some(symbol) = Symbol::from_node(root) else {
        return SwiftTypeMetadataSymbolEvidence::Malformed {
            detail: "Swift emitted type-metadata mangling has no typed symbol".into(),
        };
    };
    let Symbol::Metadata(metadata) = symbol else {
        return SwiftTypeMetadataSymbolEvidence::Malformed {
            detail: "Swift emitted type-metadata mangling decoded as a different symbol kind"
                .into(),
        };
    };
    if metadata.kind() != MetadataKind::Type {
        return SwiftTypeMetadataSymbolEvidence::Unsupported {
            detail: "Swift emitted metadata is not type metadata".into(),
        };
    }
    let Some(metadata_type) = metadata.metadata_type() else {
        return SwiftTypeMetadataSymbolEvidence::Malformed {
            detail: "Swift emitted type metadata has no metadata type".into(),
        };
    };
    let TypeKind::Named(named) = metadata_type.kind() else {
        return SwiftTypeMetadataSymbolEvidence::Unsupported {
            detail: "Swift emitted type metadata is not a named nominal type".into(),
        };
    };
    let kind = match named.raw().kind() {
        NodeKind::Class => SwiftNominalMetadataKind::Class,
        NodeKind::Structure => SwiftNominalMetadataKind::Struct,
        NodeKind::Enum => SwiftNominalMetadataKind::Enum,
        _ => {
            return SwiftTypeMetadataSymbolEvidence::Unsupported {
                detail: "Swift emitted type metadata has an unsupported nominal kind".into(),
            };
        }
    };
    let full_name = named.full_name();
    let name = if full_name.starts_with('(') {
        let Some(boundary) = full_name.find("):") else {
            return SwiftTypeMetadataSymbolEvidence::Malformed {
                detail: "Swift extension metadata identity has no declaration boundary".into(),
            };
        };
        full_name[boundary + 2..].to_owned()
    } else {
        full_name
    };
    if name.is_empty() {
        return SwiftTypeMetadataSymbolEvidence::Malformed {
            detail: "Swift emitted type metadata has an invalid qualified name".into(),
        };
    }
    SwiftTypeMetadataSymbolEvidence::Metadata(SwiftTypeMetadataIdentity { name, kind })
}

fn demangle_legacy_swift_runtime_name(name: &str) -> Option<String> {
    let mut parser = LegacySwiftRuntimeName::new(name.strip_prefix("_Tt")?);
    let components = parser.parse_nominal_type()?;
    if parser.remaining() == "_" {
        parser.advance(1)?;
    }
    parser.remaining().is_empty().then(|| components.join("."))
}

struct LegacySwiftRuntimeName<'a> {
    input: &'a str,
    offset: usize,
}

impl<'a> LegacySwiftRuntimeName<'a> {
    fn new(input: &'a str) -> Self {
        Self { input, offset: 0 }
    }

    fn parse_nominal_type(&mut self) -> Option<Vec<&'a str>> {
        match self.next_byte()? {
            b'C' | b'V' | b'O' | b'P' => {}
            _ => return None,
        }

        let mut components = self.parse_context()?;
        components.push(self.parse_decl_name()?);
        Some(components)
    }

    fn parse_context(&mut self) -> Option<Vec<&'a str>> {
        match self.peek_byte()? {
            b'C' | b'V' | b'O' | b'P' => self.parse_nominal_type(),
            b's' => {
                self.advance(1)?;
                Some(vec!["Swift"])
            }
            _ => Some(vec![self.parse_identifier()?]),
        }
    }

    fn parse_decl_name(&mut self) -> Option<&'a str> {
        if self.peek_byte() == Some(b'P') {
            self.advance(1)?;
            self.parse_identifier()?;
        }
        self.parse_identifier()
    }

    fn parse_identifier(&mut self) -> Option<&'a str> {
        let start = self.offset;
        while self.peek_byte().is_some_and(|byte| byte.is_ascii_digit()) {
            self.offset += 1;
        }
        if self.offset == start {
            return None;
        }
        let length = self.input[start..self.offset].parse::<usize>().ok()?;
        let identifier_start = self.offset;
        self.advance(length)?;
        let identifier = &self.input[identifier_start..self.offset];
        (!identifier.is_empty()).then_some(identifier)
    }

    fn peek_byte(&self) -> Option<u8> {
        self.input.as_bytes().get(self.offset).copied()
    }

    fn next_byte(&mut self) -> Option<u8> {
        let byte = self.peek_byte()?;
        self.offset += 1;
        Some(byte)
    }

    fn advance(&mut self, length: usize) -> Option<()> {
        let end = self.offset.checked_add(length)?;
        self.input.get(self.offset..end)?;
        self.offset = end;
        Some(())
    }

    fn remaining(&self) -> &'a str {
        &self.input[self.offset..]
    }
}

fn demangle_cpp_symbol_with_options(
    name: &str,
    options: cpp_demangle::DemangleOptions,
) -> Option<String> {
    for candidate in symbol_candidates(name) {
        if !looks_like_cpp_symbol(candidate) {
            continue;
        }
        let symbol = cpp_demangle::Symbol::new(candidate).ok()?;
        let demangled = symbol.demangle_with_options(&options).ok()?;
        return Some(simplify_cpp_demangled(&demangled));
    }
    None
}

/// Return either the original name or a demangled replacement.
pub fn format_symbol<'a>(name: &'a str, demangle: bool) -> Cow<'a, str> {
    if !demangle {
        return Cow::Borrowed(name);
    }

    match demangle_symbol(name) {
        Some(demangled) => Cow::Owned(demangled),
        None => Cow::Borrowed(name),
    }
}

fn demangle_rust_or_cpp(name: &str) -> Option<String> {
    for candidate in symbol_candidates(name) {
        if is_rust_v0_symbol(candidate)
            && let Some(demangled) = demangle_rust_symbol(candidate)
        {
            return Some(demangled);
        }

        if is_likely_legacy_rust_symbol(candidate)
            && let Some(demangled) = demangle_rust_symbol(candidate)
        {
            return Some(demangled);
        }

        if looks_like_cpp_symbol(candidate)
            && let Ok(symbol) = cpp_demangle::Symbol::new(candidate)
            && let Ok(demangled) = symbol.demangle()
        {
            return Some(simplify_cpp_demangled(&demangled));
        }

        if candidate.starts_with("_ZN")
            && let Some(demangled) = demangle_rust_symbol(candidate)
        {
            return Some(demangled);
        }
    }

    None
}

fn demangle_rust_symbol(name: &str) -> Option<String> {
    const MACHO_TLV_INIT_SUFFIX: &str = "$tlv$init";

    let (mangled, suffix) = match name.strip_suffix(MACHO_TLV_INIT_SUFFIX) {
        Some(mangled) => (mangled, MACHO_TLV_INIT_SUFFIX),
        None => (name, ""),
    };
    let demangled = rustc_demangle::try_demangle(mangled).ok()?;

    Some(format!("{demangled}{suffix}"))
}

fn symbol_candidates(name: &str) -> impl Iterator<Item = &str> {
    [Some(name), macho_stripped_candidate(name)]
        .into_iter()
        .flatten()
}

fn macho_stripped_candidate(name: &str) -> Option<&str> {
    let stripped = name.strip_prefix('_')?;
    if is_rust_v0_symbol(stripped)
        || stripped.starts_with("_ZN")
        || looks_like_cpp_symbol(stripped)
        || looks_like_swift_symbol(stripped)
    {
        Some(stripped)
    } else {
        None
    }
}

fn is_rust_v0_symbol(name: &str) -> bool {
    name.starts_with("_R")
}

fn is_likely_legacy_rust_symbol(name: &str) -> bool {
    name.starts_with("_ZN") && has_legacy_rust_hash(name)
}

fn has_legacy_rust_hash(name: &str) -> bool {
    let bytes = name.as_bytes();
    for index in 0..bytes.len() {
        if bytes[index] != b'h' {
            continue;
        }

        let mut end = index + 1;
        while end < bytes.len() && bytes[end].is_ascii_hexdigit() {
            end += 1;
        }

        if end > index + 8 && end <= index + 17 {
            return true;
        }
    }

    false
}

fn looks_like_cpp_symbol(name: &str) -> bool {
    name.starts_with("_Z")
}

fn swift_candidate(name: &str) -> Option<&str> {
    symbol_candidates(name).find(|candidate| looks_like_swift_symbol(candidate))
}

fn looks_like_swift_symbol(name: &str) -> bool {
    name.starts_with("$s")
        || name.starts_with("$S")
        || name.starts_with("$e")
        || name.starts_with("_Tt")
}

fn simplify_cpp_demangled(text: &str) -> String {
    let normalized = text.replace("std::__1::", "std::");
    let simplified = simplify_cpp_fragment(&normalized);
    simplify_cpp_abi_wrapper(&simplified)
}

fn simplify_cpp_fragment(input: &str) -> String {
    let mut out = String::with_capacity(input.len());
    let mut index = 0;

    while index < input.len() {
        let Some(ch) = input[index..].chars().next() else {
            break;
        };

        if is_template_name_start(ch) {
            let mut name_end = index + ch.len_utf8();
            while let Some(next) = input[name_end..].chars().next() {
                if is_template_name_char(next) {
                    name_end += next.len_utf8();
                } else {
                    break;
                }
            }

            if input[name_end..].starts_with('<')
                && let Some(template_end) = find_matching_angle(input, name_end)
            {
                let name = &input[index..name_end];
                let inner = &input[name_end + 1..template_end];
                let args: Vec<String> = split_top_level_args(inner)
                    .into_iter()
                    .map(|arg| simplify_cpp_fragment(arg.trim()))
                    .collect();
                out.push_str(&simplify_template(name, &args));
                index = template_end + 1;
                continue;
            }
        }

        out.push(ch);
        index += ch.len_utf8();
    }

    out
}

fn is_template_name_start(ch: char) -> bool {
    ch.is_ascii_alphabetic() || ch == '_'
}

fn is_template_name_char(ch: char) -> bool {
    ch.is_ascii_alphanumeric() || matches!(ch, '_' | ':')
}

fn find_matching_angle(input: &str, open_index: usize) -> Option<usize> {
    let mut depth = 0usize;

    for (offset, ch) in input[open_index..].char_indices() {
        match ch {
            '<' => depth += 1,
            '>' => {
                depth = depth.checked_sub(1)?;
                if depth == 0 {
                    return Some(open_index + offset);
                }
            }
            _ => {}
        }
    }

    None
}

fn split_top_level_args(input: &str) -> Vec<&str> {
    let mut args = Vec::new();
    let mut start = 0usize;
    let mut angle_depth = 0usize;
    let mut paren_depth = 0usize;

    for (index, ch) in input.char_indices() {
        match ch {
            '<' => angle_depth += 1,
            '>' => angle_depth = angle_depth.saturating_sub(1),
            '(' => paren_depth += 1,
            ')' => paren_depth = paren_depth.saturating_sub(1),
            ',' if angle_depth == 0 && paren_depth == 0 => {
                args.push(&input[start..index]);
                start = index + 1;
            }
            _ => {}
        }
    }

    args.push(&input[start..]);
    args
}

fn simplify_template(name: &str, args: &[String]) -> String {
    if let Some(alias) = simplify_string_like(name, args) {
        return alias;
    }

    if let Some(alias) = simplify_stream_like(name, args) {
        return alias;
    }

    if let Some(simplified) = simplify_allocator_container(name, args) {
        return simplified;
    }

    if let Some(simplified) = simplify_set_like(name, args) {
        return simplified;
    }

    if let Some(simplified) = simplify_map_like(name, args) {
        return simplified;
    }

    format!("{name}<{}>", args.join(", "))
}

fn simplify_string_like(name: &str, args: &[String]) -> Option<String> {
    let alias_base = match name {
        "std::basic_string" => "string",
        "std::basic_string_view" => "string_view",
        _ => return None,
    };

    if args.len() != 3 && args.len() != 2 {
        return None;
    }

    let kind = char_type_prefix(args[0].as_str())?;

    let traits = format!("std::char_traits<{}>", args[0]);
    if args[1] != traits {
        return None;
    }

    if name == "std::basic_string" && args[2] != format!("std::allocator<{}>", args[0]) {
        return None;
    }

    Some(format!("std::{kind}{alias_base}"))
}

fn simplify_stream_like(name: &str, args: &[String]) -> Option<String> {
    let alias_base = match name {
        "std::basic_stringbuf" => "stringbuf",
        "std::basic_stringstream" => "stringstream",
        "std::basic_istringstream" => "istringstream",
        "std::basic_ostringstream" => "ostringstream",
        "std::basic_filebuf" => "filebuf",
        "std::basic_ifstream" => "ifstream",
        "std::basic_ofstream" => "ofstream",
        "std::basic_fstream" => "fstream",
        _ => return None,
    };

    let kind = match args.first().map(String::as_str) {
        Some("char") => "",
        Some("wchar_t") => "w",
        _ => return None,
    };

    let traits = format!("std::char_traits<{}>", args[0]);
    match name {
        "std::basic_stringbuf"
        | "std::basic_stringstream"
        | "std::basic_istringstream"
        | "std::basic_ostringstream" => {
            if args.len() != 3 || args[1] != traits {
                return None;
            }
            if args[2] != format!("std::allocator<{}>", args[0]) {
                return None;
            }
        }
        "std::basic_filebuf"
        | "std::basic_ifstream"
        | "std::basic_ofstream"
        | "std::basic_fstream" => {
            if args.len() != 2 || args[1] != traits {
                return None;
            }
        }
        _ => return None,
    }

    Some(format!("std::{kind}{alias_base}"))
}

fn char_type_prefix(arg: &str) -> Option<&'static str> {
    match arg {
        "char" => Some(""),
        "wchar_t" => Some("w"),
        "char8_t" => Some("u8"),
        "char16_t" => Some("u16"),
        "char32_t" => Some("u32"),
        _ => None,
    }
}

fn simplify_allocator_container(name: &str, args: &[String]) -> Option<String> {
    let container = match name {
        "std::vector" | "std::list" | "std::deque" | "std::forward_list" => name,
        _ => return None,
    };

    if args.len() != 2 {
        return None;
    }

    if args[1] != format!("std::allocator<{}>", args[0]) {
        return None;
    }

    Some(format!("{container}<{}>", args[0]))
}

fn simplify_set_like(name: &str, args: &[String]) -> Option<String> {
    match name {
        "std::set" | "std::multiset" => {
            if args.len() != 3 {
                return None;
            }
            if args[1] == format!("std::less<{}>", args[0])
                && args[2] == format!("std::allocator<{}>", args[0])
            {
                return Some(format!("{name}<{}>", args[0]));
            }
        }
        "std::unordered_set" | "std::unordered_multiset" => {
            if args.len() != 4 {
                return None;
            }
            if args[1] == format!("std::hash<{}>", args[0])
                && args[2] == format!("std::equal_to<{}>", args[0])
                && args[3] == format!("std::allocator<{}>", args[0])
            {
                return Some(format!("{name}<{}>", args[0]));
            }
        }
        _ => {}
    }

    None
}

fn simplify_map_like(name: &str, args: &[String]) -> Option<String> {
    match name {
        "std::map" | "std::multimap" => {
            if args.len() != 4 {
                return None;
            }
            if args[2] == format!("std::less<{}>", args[0])
                && args[3] == format!("std::allocator<std::pair<{} const, {}>>", args[0], args[1])
            {
                return Some(format!("{name}<{}, {}>", args[0], args[1]));
            }
        }
        "std::unordered_map" | "std::unordered_multimap" => {
            if args.len() != 5 {
                return None;
            }
            if args[2] == format!("std::hash<{}>", args[0])
                && args[3] == format!("std::equal_to<{}>", args[0])
                && args[4] == format!("std::allocator<std::pair<{} const, {}>>", args[0], args[1])
            {
                return Some(format!("{name}<{}, {}>", args[0], args[1]));
            }
        }
        _ => {}
    }

    None
}

fn simplify_cpp_abi_wrapper(text: &str) -> String {
    if let Some(name) = text
        .strip_prefix("{vtable(")
        .and_then(|inner| inner.strip_suffix(")}"))
    {
        return format!("vtable for {}", name.trim());
    }

    if let Some(name) = text
        .strip_prefix("{typeinfo(")
        .and_then(|inner| inner.strip_suffix(")}"))
    {
        return format!("typeinfo for {}", name.trim());
    }

    if let Some(name) = text
        .strip_prefix("{vtt(")
        .and_then(|inner| inner.strip_suffix(")}"))
    {
        return format!("vtt for {}", name.trim());
    }

    if let Some(inner) = text
        .strip_prefix("{virtual override thunk(")
        .and_then(|value| value.strip_suffix(")}"))
    {
        return simplify_virtual_override_thunk(inner);
    }

    text.trim().to_owned()
}

fn simplify_virtual_override_thunk(inner: &str) -> String {
    if let Some(rest) = inner.strip_prefix("{offset(")
        && let Some((offset, target)) = rest.split_once(")},")
    {
        return format!(
            "virtual override thunk [offset {}] {}",
            offset.trim(),
            target.trim()
        );
    }

    format!("virtual override thunk {}", inner.trim())
}

#[cfg(test)]
mod tests {
    use super::{
        SwiftNominalMetadataKind, SwiftTypeMetadataSymbolEvidence, SymbolDemangler,
        classify_swift_type_metadata_symbol, demangle_swift_symbol, demangle_symbol, format_symbol,
        simplify_cpp_demangled, swift_type_metadata_identity,
    };

    #[test]
    fn demangles_macho_cpp_symbol() {
        let demangled = demangle_symbol("__Z3foov").expect("expected C++ demangling");
        assert_eq!(demangled, "foo()");
    }

    #[test]
    fn demangles_legacy_rust_symbol() {
        let demangled =
            demangle_symbol("__ZN3foo17h05af221e174051e9E").expect("expected Rust demangling");
        assert_eq!(demangled, "foo::h05af221e174051e9");
    }

    #[test]
    fn demangles_macho_rust_thread_local_initializer() {
        let demangled = demangle_symbol(
            "__RNvNCNKNvNtCsfTOUOv1Xnuk_12tracing_core10dispatcher13CURRENT_STATE0023___RUST_STD_INTERNAL_VAL$tlv$init",
        )
        .expect("expected Rust thread-local initializer demangling");

        assert_eq!(
            demangled,
            "tracing_core[b9337ccb037ca08e]::dispatcher::CURRENT_STATE::{K#0}::{closure#0}::__RUST_STD_INTERNAL_VAL$tlv$init"
        );
    }

    #[test]
    fn demangles_legacy_swift_objc_runtime_names_in_process() {
        assert_eq!(
            demangle_swift_symbol("_TtC7iMazing10BackupData").as_deref(),
            Some("iMazing.BackupData")
        );
        assert_eq!(
            demangle_swift_symbol("_TtP7iMazing10Switchable_").as_deref(),
            Some("iMazing.Switchable")
        );
        assert_eq!(
            demangle_swift_symbol("_TtCC7iMazing12LottieHelper10LottieInfo").as_deref(),
            Some("iMazing.LottieHelper.LottieInfo")
        );
        assert_eq!(
            demangle_swift_symbol("_$s4Demo6WidgetCMn").as_deref(),
            Some("nominal type descriptor for Demo.Widget")
        );
    }

    #[test]
    fn retains_typed_swift_metadata_identity() {
        let identity = swift_type_metadata_identity("_$s4Demo6WidgetVN")
            .expect("expected emitted structure metadata");
        assert_eq!(identity.name, "Demo.Widget");
        assert_eq!(identity.kind, SwiftNominalMetadataKind::Struct);
        assert!(swift_type_metadata_identity("_$s4Demo6WidgetVMa").is_none());
        assert!(matches!(
            classify_swift_type_metadata_symbol("_$s4Demo6WidgetVMa"),
            SwiftTypeMetadataSymbolEvidence::NotTypeMetadata
        ));
        assert!(matches!(
            classify_swift_type_metadata_symbol("_$s4Demo6WidgetVN"),
            SwiftTypeMetadataSymbolEvidence::Metadata(_)
        ));
        assert!(matches!(
            classify_swift_type_metadata_symbol("_$s4Demo6WidgetVxN"),
            SwiftTypeMetadataSymbolEvidence::Malformed { .. }
        ));
        let extension = swift_type_metadata_identity("_$sSo8NSNumberC6plutilE15BetterSwiftTypeON")
            .expect("expected metadata nested in an extension");
        assert_eq!(extension.name, "__C.NSNumber.BetterSwiftType");
        let private = swift_type_metadata_identity(
            "_$s13SwiftPlan00040aB7Private33_C754C3B558BDB8C9E83DFE94C8941DB3LLVN",
        )
        .expect("expected private emitted structure metadata");
        assert_eq!(
            private.name,
            "SwiftPlan0004.(SwiftPlan0004Private in _C754C3B558BDB8C9E83DFE94C8941DB3)"
        );
        assert_eq!(private.kind, SwiftNominalMetadataKind::Struct);
    }

    #[test]
    fn leaves_plain_c_symbol_untouched() {
        assert!(demangle_symbol("_printf").is_none());
        assert_eq!(format_symbol("_printf", false), "_printf");
        assert_eq!(format_symbol("_printf", true), "_printf");
    }

    #[test]
    fn caches_batch_demangles_for_cpp_and_rust() {
        let mut demangler = SymbolDemangler::new(true);
        demangler.precompute(["__Z3foov", "__ZN3foo17h05af221e174051e9E"]);

        assert_eq!(demangler.format("__Z3foov"), "foo()");
        assert_eq!(
            demangler.format("__ZN3foo17h05af221e174051e9E"),
            "foo::h05af221e174051e9"
        );
    }

    #[test]
    fn simplifies_libcxx_string_and_list_spellings() {
        let simplified = simplify_cpp_demangled(
            "FileMgr::GetDirInfo(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&, std::__1::list<file_info, std::__1::allocator<file_info> >&, bool*)",
        );

        assert_eq!(
            simplified,
            "FileMgr::GetDirInfo(std::string&, std::list<file_info>&, bool*)"
        );
    }

    #[test]
    fn simplifies_typeinfo_stream_aliases() {
        let simplified = simplify_cpp_demangled(
            "typeinfo name for std::__1::basic_stringstream<char, std::__1::char_traits<char>, std::__1::allocator<char> >",
        );

        assert_eq!(simplified, "typeinfo name for std::stringstream");
    }

    #[test]
    fn simplifies_vtable_and_thunk_wrappers() {
        assert_eq!(
            simplify_cpp_demangled("{vtable(CWeChatMgr)}"),
            "vtable for CWeChatMgr"
        );
        assert_eq!(
            simplify_cpp_demangled(
                "{virtual override thunk({offset(-16)}, MainWindow::~MainWindow())}"
            ),
            "virtual override thunk [offset -16] MainWindow::~MainWindow()"
        );
    }
}