llvm-native-core 0.1.15

//! LLVM Attributes — function, parameter, and return attributes.
//!
//! Clean-room behavioral reconstruction. Phase 2 — LLVM.IR.2 Court.
//!
//! @llvm_behavior: In LLVM, attributes are key-value annotations attached
//! to functions, parameters, and return values. They guide optimization,
//! code generation, and semantics. Function attributes like `noinline`,
//! `readnone`, and `noreturn` describe global properties. Parameter
//! attributes like `zeroext`, `align`, `dereferenceable` constrain
//! individual arguments.
//!
//! The attribute system supports:
//! - Enum attributes: fixed, well-known attribute kinds
//! - String attributes: arbitrary key-value pairs
//! - Attribute groups: bundles of attributes referenced by ID

use std::collections::HashMap;

/// Function attribute kinds — attributes that apply to a function as a whole.
///
/// @llvm_behavior: These correspond to `llvm::Attribute::AttrKind` in C++.
/// Each variant maps to a known LLVM function or call-site attribute.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum AttributeKind {
    // === Optimization hints ===
    /// Disable inlining of this function.
    NoInline,
    /// Force inlining of this function (hint).
    AlwaysInline,
    /// Disable all optimizations on this function.
    OptimizeNone,
    /// Prefer optimizing for code size.
    OptimizeForSize,
    /// Prefer optimizing for speed.
    OptimizeForSpeed,

    // === Memory effects ===
    /// Function does not read or write memory.
    ReadNone,
    /// Function only reads memory (no writes).
    ReadOnly,
    /// Function only writes memory (no reads of accessible memory).
    WriteOnly,
    /// Function only accesses memory reachable through its arguments.
    ArgMemOnly,
    /// Function only accesses memory that is inaccessible to the caller.
    InaccessibleMemOnly,
    /// Function only accesses memory reachable through arguments or
    /// inaccessible memory.
    InaccessibleMemOrArgMemOnly,

    // === Exception handling ===
    /// Function does not unwind (no exceptions).
    NoUnwind,
    /// Function never returns (e.g., exit, abort).
    NoReturn,
    /// Function will return normally (not an infinite loop).
    WillReturn,

    // === Stack protection ===
    /// Enable stack protector (canary).
    Ssp,
    /// Require stack protector (always insert canary).
    SspReq,
    /// Strong stack protector (more aggressive heuristics).
    SspStrong,

    // === Sanitizers ===
    /// Enable AddressSanitizer instrumentation.
    SanitizeAddress,
    /// Enable ThreadSanitizer instrumentation.
    SanitizeThread,
    /// Enable MemorySanitizer instrumentation.
    SanitizeMemory,
    /// Enable Hardware-assisted AddressSanitizer instrumentation.
    SanitizeHwAddress,
    /// Disable sanitizer instrumentation for this function.
    NoSanitize,
    /// Enable SanitizerCoverage instrumentation.
    SanitizeCoverage,

    // === Security ===
    /// Enable ShadowCallStack instrumentation.
    ShadowCallStack,
    /// Enable Speculative Load Hardening mitigation.
    SpeculativeLoadHardening,
    /// Disable control-flow enforcement checks.
    NoCfCheck,

    // === Calling convention / ABI ===
    /// Align the stack to at least N bytes on entry.
    AlignStack(u32),
    /// Function uses a naked calling convention (no prologue/epilogue).
    Naked,
    /// Disable implicit floating-point instructions.
    NoImplicitFloat,
    /// Disable red zone (no stack access below SP).
    NoRedZone,
    /// Request unwind table generation.
    UWTable,
    /// Frame pointer management: all, none, non-leaf.
    FramePointer(FramePointerKind),

    // === Inlining / merging ===
    /// Hint that inlining this function is desirable.
    InlineHint,
    /// Prevent merging of identical functions.
    NoMerge,
    /// Function returns twice (like setjmp or fork).
    ReturnsTwice,
    /// Use jump table for switch lowering.
    JumpTable,

    // === Concurrency / progress ===
    /// Function will eventually return (makes forward progress).
    MustProgress,
    /// Function is convergent (threads must execute same path).
    Convergent,
    /// Function cannot diverge (no divergent branches).
    NoDivergenceSource,

    // === Profiling / debugging ===
    /// Disable profile instrumentation for this function.
    NoProfile,
    /// Skip profile-based optimizations.
    SkipProfile,
    /// Prefer optimization hints from source-level debug info.
    OptDebug,
    /// Optimize for fuzzing (add coverage instrumentation).
    OptForFuzzing,

    // === Allocator hints ===
    /// The function is an allocator: allocsize(N, M) indicates that
    /// parameter N contains the allocation size, and parameter M
    /// contains the element count (optional).
    AllocSize(u32, Option<u32>),
    /// Pointer argument is allocation result (for memory analysis).
    AllocPtr,

    // === Builtin / library ===
    /// Disable builtin recognition for this function.
    NoBuiltin,
    /// Function is a callback (may be called from unknown context).
    NoCallback,
    /// Lazy binding (PLT) not needed for this function.
    NonLazyBind,

    // === Security hardening ===
    /// Enable SafeStack for this function.
    SafeStack,
    /// Enable Memory Tagging Extension sanitizer.
    SanitizeMemTag,
    /// Disable sanitizer instrumentation entirely.
    DisableSanitizerInstrumentation,
    /// Patchable function entry for hotpatching.
    Hotpatch,
    /// FnRetThunkExtern: use external return thunk for mitigation.
    FnRetThunkExtern,

    // === Floating-point ===
    /// Restrict floating-point transformations for strict compliance.
    StrictFP,
    /// Classify which floating-point classes are valid for this function.
    NoFPClass(u32),

    // === Vector / scalable ===
    /// The function has unknown vscale range (scalable vector).
    VScaleRange(u32, u32),

    // === Speculation ===
    /// Function is speculatable (can be speculated safely).
    Speculatable,

    // === Other function attributes ===
    /// Function cannot be duplicated (e.g., for jump threading).
    NoDuplicate,
    /// Function does not recurse (no self or mutual recursion).
    NoRecurse,
    /// Function does not synchronize (no locks, atomics, or volatile).
    NoSync,
    /// Function does not free memory.
    NoFree,
    /// Function is cold (rarely executed).
    Cold,
    /// Function is hot (frequently executed).
    Hot,
    /// Minimize code size (stronger than OptimizeForSize).
    Minsize,
    /// The null pointer is valid for this function.
    NullPointerIsValid,
    /// Use sample-based profile data for this function.
    UseSampleProfile,

    // === String-keyed attribute ===
    /// A named attribute with a key and optional value string.
    /// Used for target-specific and extended attributes.
    StringAttribute(String, String),
}

/// Frame pointer kind for the `frame-pointer` attribute.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum FramePointerKind {
    /// Always preserve frame pointer.
    All,
    /// Only preserve in non-leaf functions.
    NonLeaf,
    /// Never preserve frame pointer.
    None,
}

impl AttributeKind {
    /// Parse an attribute kind from its LLVM assembly string representation.
    ///
    /// @llvm_behavior: Recognizes the standard attribute names as emitted
    /// by `llvm-as` and `opt`. Returns `None` for unrecognized strings.
    pub fn from_string(s: &str) -> Option<Self> {
        match s {
            "noinline" => Some(AttributeKind::NoInline),
            "alwaysinline" => Some(AttributeKind::AlwaysInline),
            "optnone" => Some(AttributeKind::OptimizeNone),
            "optsize" => Some(AttributeKind::OptimizeForSize),
            "optforspeed" => Some(AttributeKind::OptimizeForSpeed),

            "readnone" | "memory(none)" => Some(AttributeKind::ReadNone),
            "readonly" | "memory(read)" => Some(AttributeKind::ReadOnly),
            "writeonly" | "memory(write)" => Some(AttributeKind::WriteOnly),
            "argmemonly" => Some(AttributeKind::ArgMemOnly),
            "inaccessiblememonly" => Some(AttributeKind::InaccessibleMemOnly),
            "inaccessiblemem_or_argmemonly" => Some(AttributeKind::InaccessibleMemOrArgMemOnly),

            "nounwind" => Some(AttributeKind::NoUnwind),
            "noreturn" => Some(AttributeKind::NoReturn),
            "willreturn" => Some(AttributeKind::WillReturn),

            "ssp" => Some(AttributeKind::Ssp),
            "sspreq" => Some(AttributeKind::SspReq),
            "sspstrong" => Some(AttributeKind::SspStrong),

            "sanitize_address" => Some(AttributeKind::SanitizeAddress),
            "sanitize_thread" => Some(AttributeKind::SanitizeThread),
            "sanitize_memory" => Some(AttributeKind::SanitizeMemory),
            "sanitize_hwaddress" => Some(AttributeKind::SanitizeHwAddress),
            "nosanitize" => Some(AttributeKind::NoSanitize),
            "sanitize_coverage" => Some(AttributeKind::SanitizeCoverage),

            "shadowcallstack" => Some(AttributeKind::ShadowCallStack),
            "speculative_load_hardening" => Some(AttributeKind::SpeculativeLoadHardening),
            "nocf_check" => Some(AttributeKind::NoCfCheck),

            "noduplicate" => Some(AttributeKind::NoDuplicate),
            "norecurse" => Some(AttributeKind::NoRecurse),
            "nosync" => Some(AttributeKind::NoSync),
            "nofree" => Some(AttributeKind::NoFree),
            "cold" => Some(AttributeKind::Cold),
            "hot" => Some(AttributeKind::Hot),
            "minsize" => Some(AttributeKind::Minsize),
            "null_pointer_is_valid" => Some(AttributeKind::NullPointerIsValid),
            "use_sample_profile" => Some(AttributeKind::UseSampleProfile),

            // === New: calling convention / ABI ===
            "naked" => Some(AttributeKind::Naked),
            "noimplicitfloat" => Some(AttributeKind::NoImplicitFloat),
            "noredzone" => Some(AttributeKind::NoRedZone),
            "uwtable" => Some(AttributeKind::UWTable),
            s if s.starts_with("alignstack(") => {
                let inner = &s["alignstack(".len()..s.len() - 1];
                inner.parse::<u32>().ok().map(AttributeKind::AlignStack)
            }
            s if s.starts_with("frame-pointer=") => {
                let kind = &s["frame-pointer=".len()..];
                Some(AttributeKind::FramePointer(match kind {
                    "all" => FramePointerKind::All,
                    "non-leaf" => FramePointerKind::NonLeaf,
                    _ => FramePointerKind::None,
                }))
            }

            // === New: inlining / merging ===
            "inlinehint" => Some(AttributeKind::InlineHint),
            "nomerge" => Some(AttributeKind::NoMerge),
            "returns_twice" => Some(AttributeKind::ReturnsTwice),
            "jumptable" => Some(AttributeKind::JumpTable),

            // === New: concurrency / progress ===
            "mustprogress" => Some(AttributeKind::MustProgress),
            "convergent" => Some(AttributeKind::Convergent),
            "noduplicatesource" => Some(AttributeKind::NoDivergenceSource),

            // === New: profiling / debugging ===
            "noprofile" => Some(AttributeKind::NoProfile),
            "skipprofile" => Some(AttributeKind::SkipProfile),
            "optdebug" => Some(AttributeKind::OptDebug),
            "optforfuzzing" => Some(AttributeKind::OptForFuzzing),

            // === New: allocator hints ===
            s if s.starts_with("allocsize(") => {
                let inner = &s["allocsize(".len()..s.len() - 1];
                let parts: Vec<&str> = inner.split(',').collect();
                let p0 = parts[0].trim().parse::<u32>().ok()?;
                let p1 = if parts.len() > 1 {
                    parts[1].trim().parse::<u32>().ok()
                } else {
                    None
                };
                Some(AttributeKind::AllocSize(p0, p1))
            }
            "allocptr" => Some(AttributeKind::AllocPtr),

            // === New: builtin / library ===
            "nobuiltin" => Some(AttributeKind::NoBuiltin),
            "nocallback" => Some(AttributeKind::NoCallback),
            "nonlazybind" => Some(AttributeKind::NonLazyBind),

            // === New: security hardening ===
            "safestack" => Some(AttributeKind::SafeStack),
            "sanitize_memtag" => Some(AttributeKind::SanitizeMemTag),
            "disable_sanitizer_instrumentation" => {
                Some(AttributeKind::DisableSanitizerInstrumentation)
            }
            "hotpatch" => Some(AttributeKind::Hotpatch),
            "fn_ret_thunk_extern" => Some(AttributeKind::FnRetThunkExtern),

            // === New: floating-point ===
            "strictfp" => Some(AttributeKind::StrictFP),
            s if s.starts_with("nofpclass(") => {
                let inner = &s["nofpclass(".len()..s.len() - 1];
                inner.parse::<u32>().ok().map(AttributeKind::NoFPClass)
            }

            // === New: vector / scalable ===
            s if s.starts_with("vscale_range(") => {
                let inner = &s["vscale_range(".len()..s.len() - 1];
                let parts: Vec<&str> = inner.split(',').collect();
                let min = parts[0].trim().parse::<u32>().ok()?;
                let max = if parts.len() > 1 {
                    parts[1].trim().parse::<u32>().ok()?
                } else {
                    min
                };
                Some(AttributeKind::VScaleRange(min, max))
            }

            // === New: speculation ===
            "speculatable" => Some(AttributeKind::Speculatable),

            _ => {
                // Try to parse as a string attribute: "key" or "key=value"
                if let Some(eq_pos) = s.find('=') {
                    let key = s[..eq_pos].to_string();
                    let value = s[eq_pos + 1..].to_string();
                    Some(AttributeKind::StringAttribute(key, value))
                } else {
                    None
                }
            }
        }
    }

    /// Convert this attribute kind to its LLVM assembly string representation.
    ///
    /// @llvm_behavior: Produces the canonical attribute name used in `.ll`
    /// files. String attributes are formatted as `"key"="value"`.
    pub fn to_string(&self) -> String {
        match self {
            AttributeKind::NoInline => "noinline".to_string(),
            AttributeKind::AlwaysInline => "alwaysinline".to_string(),
            AttributeKind::OptimizeNone => "optnone".to_string(),
            AttributeKind::OptimizeForSize => "optsize".to_string(),
            AttributeKind::OptimizeForSpeed => "optforspeed".to_string(),

            AttributeKind::ReadNone => "readnone".to_string(),
            AttributeKind::ReadOnly => "readonly".to_string(),
            AttributeKind::WriteOnly => "writeonly".to_string(),
            AttributeKind::ArgMemOnly => "argmemonly".to_string(),
            AttributeKind::InaccessibleMemOnly => "inaccessiblememonly".to_string(),
            AttributeKind::InaccessibleMemOrArgMemOnly => {
                "inaccessiblemem_or_argmemonly".to_string()
            }

            AttributeKind::NoUnwind => "nounwind".to_string(),
            AttributeKind::NoReturn => "noreturn".to_string(),
            AttributeKind::WillReturn => "willreturn".to_string(),

            AttributeKind::Ssp => "ssp".to_string(),
            AttributeKind::SspReq => "sspreq".to_string(),
            AttributeKind::SspStrong => "sspstrong".to_string(),

            AttributeKind::SanitizeAddress => "sanitize_address".to_string(),
            AttributeKind::SanitizeThread => "sanitize_thread".to_string(),
            AttributeKind::SanitizeMemory => "sanitize_memory".to_string(),
            AttributeKind::SanitizeHwAddress => "sanitize_hwaddress".to_string(),
            AttributeKind::NoSanitize => "nosanitize".to_string(),
            AttributeKind::SanitizeCoverage => "sanitize_coverage".to_string(),

            AttributeKind::ShadowCallStack => "shadowcallstack".to_string(),
            AttributeKind::SpeculativeLoadHardening => "speculative_load_hardening".to_string(),
            AttributeKind::NoCfCheck => "nocf_check".to_string(),

            AttributeKind::NoDuplicate => "noduplicate".to_string(),
            AttributeKind::NoRecurse => "norecurse".to_string(),
            AttributeKind::NoSync => "nosync".to_string(),
            AttributeKind::NoFree => "nofree".to_string(),
            AttributeKind::Cold => "cold".to_string(),
            AttributeKind::Hot => "hot".to_string(),
            AttributeKind::Minsize => "minsize".to_string(),
            AttributeKind::NullPointerIsValid => "null_pointer_is_valid".to_string(),
            AttributeKind::UseSampleProfile => "use_sample_profile".to_string(),

            // === New: calling convention / ABI ===
            AttributeKind::AlignStack(n) => format!("alignstack({})", n),
            AttributeKind::Naked => "naked".to_string(),
            AttributeKind::NoImplicitFloat => "noimplicitfloat".to_string(),
            AttributeKind::NoRedZone => "noredzone".to_string(),
            AttributeKind::UWTable => "uwtable".to_string(),
            AttributeKind::FramePointer(kind) => format!(
                "frame-pointer={}",
                match kind {
                    FramePointerKind::All => "all",
                    FramePointerKind::NonLeaf => "non-leaf",
                    FramePointerKind::None => "none",
                }
            ),

            // === New: inlining / merging ===
            AttributeKind::InlineHint => "inlinehint".to_string(),
            AttributeKind::NoMerge => "nomerge".to_string(),
            AttributeKind::ReturnsTwice => "returns_twice".to_string(),
            AttributeKind::JumpTable => "jumptable".to_string(),

            // === New: concurrency / progress ===
            AttributeKind::MustProgress => "mustprogress".to_string(),
            AttributeKind::Convergent => "convergent".to_string(),
            AttributeKind::NoDivergenceSource => "noduplicatesource".to_string(),

            // === New: profiling / debugging ===
            AttributeKind::NoProfile => "noprofile".to_string(),
            AttributeKind::SkipProfile => "skipprofile".to_string(),
            AttributeKind::OptDebug => "optdebug".to_string(),
            AttributeKind::OptForFuzzing => "optforfuzzing".to_string(),

            // === New: allocator hints ===
            AttributeKind::AllocSize(p0, Some(p1)) => format!("allocsize({}, {})", p0, p1),
            AttributeKind::AllocSize(p0, None) => format!("allocsize({})", p0),
            AttributeKind::AllocPtr => "allocptr".to_string(),

            // === New: builtin / library ===
            AttributeKind::NoBuiltin => "nobuiltin".to_string(),
            AttributeKind::NoCallback => "nocallback".to_string(),
            AttributeKind::NonLazyBind => "nonlazybind".to_string(),

            // === New: security hardening ===
            AttributeKind::SafeStack => "safestack".to_string(),
            AttributeKind::SanitizeMemTag => "sanitize_memtag".to_string(),
            AttributeKind::DisableSanitizerInstrumentation => {
                "disable_sanitizer_instrumentation".to_string()
            }
            AttributeKind::Hotpatch => "hotpatch".to_string(),
            AttributeKind::FnRetThunkExtern => "fn_ret_thunk_extern".to_string(),

            // === New: floating-point ===
            AttributeKind::StrictFP => "strictfp".to_string(),
            AttributeKind::NoFPClass(n) => format!("nofpclass({})", n),

            // === New: vector / scalable ===
            AttributeKind::VScaleRange(min, max) => format!("vscale_range({}, {})", min, max),

            // === New: speculation ===
            AttributeKind::Speculatable => "speculatable".to_string(),

            AttributeKind::StringAttribute(key, val) => format!("\"{}\"=\"{}\"", key, val),
        }
    }

    /// Returns true if this is a memory-effect attribute.
    pub fn is_memory_attr(&self) -> bool {
        matches!(
            self,
            AttributeKind::ReadNone
                | AttributeKind::ReadOnly
                | AttributeKind::WriteOnly
                | AttributeKind::ArgMemOnly
                | AttributeKind::InaccessibleMemOnly
                | AttributeKind::InaccessibleMemOrArgMemOnly
        )
    }

    /// Returns true if this is a sanitizer attribute.
    pub fn is_sanitizer_attr(&self) -> bool {
        matches!(
            self,
            AttributeKind::SanitizeAddress
                | AttributeKind::SanitizeThread
                | AttributeKind::SanitizeMemory
                | AttributeKind::SanitizeHwAddress
                | AttributeKind::NoSanitize
                | AttributeKind::SanitizeCoverage
                | AttributeKind::SanitizeMemTag
                | AttributeKind::DisableSanitizerInstrumentation
        )
    }

    /// Returns true if this is a security-related attribute.
    pub fn is_security_attr(&self) -> bool {
        matches!(
            self,
            AttributeKind::Ssp
                | AttributeKind::SspReq
                | AttributeKind::SspStrong
                | AttributeKind::ShadowCallStack
                | AttributeKind::SpeculativeLoadHardening
                | AttributeKind::NoCfCheck
                | AttributeKind::SafeStack
                | AttributeKind::Hotpatch
                | AttributeKind::FnRetThunkExtern
        )
    }

    /// Returns true if this is an inlining-related attribute.
    pub fn is_inline_attr(&self) -> bool {
        matches!(
            self,
            AttributeKind::NoInline
                | AttributeKind::AlwaysInline
                | AttributeKind::InlineHint
                | AttributeKind::NoMerge
        )
    }

    /// Returns true if this is a floating-point attribute.
    pub fn is_fp_attr(&self) -> bool {
        matches!(self, AttributeKind::StrictFP | AttributeKind::NoFPClass(_))
    }

    /// Returns true if this attribute carries a numeric argument.
    pub fn has_numeric_arg(&self) -> bool {
        matches!(
            self,
            AttributeKind::AlignStack(_)
                | AttributeKind::AllocSize(_, _)
                | AttributeKind::NoFPClass(_)
                | AttributeKind::VScaleRange(_, _)
        )
    }
}

/// Parameter and return value attribute kinds.
///
/// @llvm_behavior: These correspond to `llvm::Attribute` parameter/return
/// attributes. Some are parameter-only (like `ByVal`, `StructRet`), others
/// can appear on both parameters and return values (like `ZeroExt`,
/// `NoAlias`). Variants like `Dereferenceable` and `Align` carry numeric
/// arguments.
#[derive(Debug, Clone, PartialEq)]
pub enum ParamAttrKind {
    /// Zero-extend the value before passing (integer promotion).
    ZeroExt,
    /// Sign-extend the value before passing.
    SignExt,
    /// The parameter does not alias any other accessible memory.
    NoAlias,
    /// The parameter is not captured by the function.
    NoCapture,
    /// The function does not free this parameter.
    NoFree,
    /// The parameter cannot be null.
    NonNull,
    /// The parameter is only read (not written).
    ReadOnly,
    /// The parameter is only written (not read).
    WriteOnly,
    /// The pointer parameter is dereferenceable for at least N bytes.
    Dereferenceable(u64),
    /// The pointer parameter is dereferenceable for at least N bytes, or null.
    DereferenceableOrNull(u64),
    /// The parameter has at least the given alignment.
    Align(u32),
    /// Pass the argument by value (copy) using the given type.
    ByVal(crate::types::Type),
    /// The parameter is a struct return value (sret).
    StructRet(crate::types::Type),
    /// Pass the argument in a register.
    InReg,
    /// The value is returned (used in return position to refer to parameter).
    Returned,
    /// The argument is an immediate constant.
    ImmArg,
    /// Sign-extend the value (alias for SignExt, used in some contexts).
    SExt,
    /// The value has no undefined bits.
    NoUndef,
    /// Pass the argument by reference using the given type.
    ByRef(crate::types::Type),
    /// The parameter memory is preallocated (for coroutines).
    Preallocated(crate::types::Type),

    // === Extended parameter attributes ===
    /// The argument is passed in the inalloca slot (Windows x86).
    InAlloca(crate::types::Type),
    /// Nest pointer for calling conventions with nested functions.
    Nest,
    /// Element type for the pointer parameter.
    ElementType(crate::types::Type),
    /// The pointer argument is allocation result (for memory analysis).
    AllocPtr,
    /// Classify which floating-point classes are valid.
    NoFPClass(u32),
    /// Range of possible values: `range(min, max)`.
    Range(u64, u64),
    /// The parameter has a constant initial execution TLS model.
    InitialExec,
    /// Swift async context parameter.
    SwiftAsync,
    /// Swift error parameter.
    SwiftError,
    /// Swift self parameter (the `self` argument).
    SwiftSelf,
    /// Swift error parameter variant 2.
    SwiftError2,
}

impl ParamAttrKind {
    /// Parse a parameter attribute from its LLVM assembly string representation.
    ///
    /// @llvm_behavior: Recognizes standard parameter attribute names
    /// including those with numeric arguments like "align 8" or
    /// "dereferenceable(16)". Returns `None` for unrecognized strings.
    pub fn from_string(s: &str) -> Option<Self> {
        // Handle attributes with arguments: "align 8", "dereferenceable(16)", etc.
        if let Some(rest) = s.strip_prefix("align ") {
            return rest.parse::<u32>().ok().map(ParamAttrKind::Align);
        }
        if let Some(rest) = s.strip_prefix("alignstack ") {
            return rest.parse::<u32>().ok().map(ParamAttrKind::Align);
        }
        if let Some(rest) = s.strip_prefix("dereferenceable(") {
            if let Some(val_str) = rest.strip_suffix(')') {
                return val_str
                    .parse::<u64>()
                    .ok()
                    .map(ParamAttrKind::Dereferenceable);
            }
        }
        if let Some(rest) = s.strip_prefix("dereferenceable_or_null(") {
            if let Some(val_str) = rest.strip_suffix(')') {
                return val_str
                    .parse::<u64>()
                    .ok()
                    .map(ParamAttrKind::DereferenceableOrNull);
            }
        }

        // Simple keyword attributes
        match s {
            "zeroext" => Some(ParamAttrKind::ZeroExt),
            "signext" => Some(ParamAttrKind::SignExt),
            "noalias" => Some(ParamAttrKind::NoAlias),
            "nocapture" => Some(ParamAttrKind::NoCapture),
            "nofree" => Some(ParamAttrKind::NoFree),
            "nonnull" => Some(ParamAttrKind::NonNull),
            "readonly" => Some(ParamAttrKind::ReadOnly),
            "writeonly" => Some(ParamAttrKind::WriteOnly),
            "inreg" => Some(ParamAttrKind::InReg),
            "returned" => Some(ParamAttrKind::Returned),
            "immarg" => Some(ParamAttrKind::ImmArg),
            "sext" => Some(ParamAttrKind::SExt),
            "noundef" => Some(ParamAttrKind::NoUndef),
            "nest" => Some(ParamAttrKind::Nest),
            "allocptr" => Some(ParamAttrKind::AllocPtr),
            "initialexec" => Some(ParamAttrKind::InitialExec),
            "swiftasync" => Some(ParamAttrKind::SwiftAsync),
            "swifterror" => Some(ParamAttrKind::SwiftError),
            "swiftself" => Some(ParamAttrKind::SwiftSelf),
            "swifterror2" => Some(ParamAttrKind::SwiftError2),
            s if s.starts_with("nofpclass(") => {
                let inner = &s["nofpclass(".len()..s.len() - 1];
                inner.parse::<u32>().ok().map(ParamAttrKind::NoFPClass)
            }
            s if s.starts_with("range(") => {
                let inner = &s["range(".len()..s.len() - 1];
                let parts: Vec<&str> = inner.split(',').collect();
                let min = parts[0].trim().parse::<u64>().ok()?;
                let max = if parts.len() > 1 {
                    parts[1].trim().parse::<u64>().ok()?
                } else {
                    min
                };
                Some(ParamAttrKind::Range(min, max))
            }
            _ => None,
        }
    }

    /// Convert this parameter attribute to its LLVM assembly string representation.
    ///
    /// @llvm_behavior: Produces the canonical attribute string, including
    /// numeric arguments where applicable.
    pub fn to_string(&self) -> String {
        match self {
            ParamAttrKind::ZeroExt => "zeroext".to_string(),
            ParamAttrKind::SignExt => "signext".to_string(),
            ParamAttrKind::NoAlias => "noalias".to_string(),
            ParamAttrKind::NoCapture => "nocapture".to_string(),
            ParamAttrKind::NoFree => "nofree".to_string(),
            ParamAttrKind::NonNull => "nonnull".to_string(),
            ParamAttrKind::ReadOnly => "readonly".to_string(),
            ParamAttrKind::WriteOnly => "writeonly".to_string(),
            ParamAttrKind::Dereferenceable(n) => format!("dereferenceable({})", n),
            ParamAttrKind::DereferenceableOrNull(n) => format!("dereferenceable_or_null({})", n),
            ParamAttrKind::Align(n) => format!("align {}", n),
            ParamAttrKind::ByVal(_) => "byval".to_string(),
            ParamAttrKind::StructRet(_) => "sret".to_string(),
            ParamAttrKind::InReg => "inreg".to_string(),
            ParamAttrKind::Returned => "returned".to_string(),
            ParamAttrKind::ImmArg => "immarg".to_string(),
            ParamAttrKind::SExt => "sext".to_string(),
            ParamAttrKind::NoUndef => "noundef".to_string(),
            ParamAttrKind::ByRef(_) => "byref".to_string(),
            ParamAttrKind::Preallocated(_) => "preallocated".to_string(),
            ParamAttrKind::InAlloca(_) => "inalloca".to_string(),
            ParamAttrKind::Nest => "nest".to_string(),
            ParamAttrKind::ElementType(_) => "elementtype".to_string(),
            ParamAttrKind::AllocPtr => "allocptr".to_string(),
            ParamAttrKind::NoFPClass(n) => format!("nofpclass({})", n),
            ParamAttrKind::Range(min, max) => format!("range({}, {})", min, max),
            ParamAttrKind::InitialExec => "initialexec".to_string(),
            ParamAttrKind::SwiftAsync => "swiftasync".to_string(),
            ParamAttrKind::SwiftError => "swifterror".to_string(),
            ParamAttrKind::SwiftSelf => "swiftself".to_string(),
            ParamAttrKind::SwiftError2 => "swifterror2".to_string(),
        }
    }

    /// Returns true if this is a type-carrying attribute (needs a Type parameter).
    pub fn is_type_attr(&self) -> bool {
        matches!(
            self,
            ParamAttrKind::ByVal(_)
                | ParamAttrKind::StructRet(_)
                | ParamAttrKind::ByRef(_)
                | ParamAttrKind::Preallocated(_)
                | ParamAttrKind::InAlloca(_)
                | ParamAttrKind::ElementType(_)
        )
    }

    /// Returns true if this is a numeric-carrying attribute.
    pub fn is_numeric_attr(&self) -> bool {
        matches!(
            self,
            ParamAttrKind::Dereferenceable(_)
                | ParamAttrKind::DereferenceableOrNull(_)
                | ParamAttrKind::Align(_)
                | ParamAttrKind::NoFPClass(_)
                | ParamAttrKind::Range(_, _)
        )
    }

    /// Returns the kind discriminant (ignoring numeric/type arguments).
    pub fn kind_discriminant(&self) -> &'static str {
        match self {
            ParamAttrKind::ZeroExt => "zeroext",
            ParamAttrKind::SignExt => "signext",
            ParamAttrKind::NoAlias => "noalias",
            ParamAttrKind::NoCapture => "nocapture",
            ParamAttrKind::NoFree => "nofree",
            ParamAttrKind::NonNull => "nonnull",
            ParamAttrKind::ReadOnly => "readonly",
            ParamAttrKind::WriteOnly => "writeonly",
            ParamAttrKind::Dereferenceable(_) => "dereferenceable",
            ParamAttrKind::DereferenceableOrNull(_) => "dereferenceable_or_null",
            ParamAttrKind::Align(_) => "align",
            ParamAttrKind::ByVal(_) => "byval",
            ParamAttrKind::StructRet(_) => "sret",
            ParamAttrKind::InReg => "inreg",
            ParamAttrKind::Returned => "returned",
            ParamAttrKind::ImmArg => "immarg",
            ParamAttrKind::SExt => "sext",
            ParamAttrKind::NoUndef => "noundef",
            ParamAttrKind::ByRef(_) => "byref",
            ParamAttrKind::Preallocated(_) => "preallocated",
            ParamAttrKind::InAlloca(_) => "inalloca",
            ParamAttrKind::Nest => "nest",
            ParamAttrKind::ElementType(_) => "elementtype",
            ParamAttrKind::AllocPtr => "allocptr",
            ParamAttrKind::NoFPClass(_) => "nofpclass",
            ParamAttrKind::Range(_, _) => "range",
            ParamAttrKind::InitialExec => "initialexec",
            ParamAttrKind::SwiftAsync => "swiftasync",
            ParamAttrKind::SwiftError => "swifterror",
            ParamAttrKind::SwiftSelf => "swiftself",
            ParamAttrKind::SwiftError2 => "swifterror2",
        }
    }
}

/// An attribute group — a collection of function attributes identified by
/// a numeric ID. Groups can be referenced from function definitions and
/// call instructions to avoid repeating attribute lists.
///
/// @llvm_behavior: Attribute groups in LLVM are identified by unsigned
/// integers and contain a list of attribute kinds. Groups are referenced
/// in IR as `#0`, `#1`, etc.
#[derive(Debug, Clone, PartialEq)]
pub struct AttrGroup {
    /// The numeric identifier for this attribute group.
    pub id: u32,
    /// The function attributes in this group.
    pub attrs: Vec<AttributeKind>,
}

impl AttrGroup {
    /// Create a new attribute group with the given ID.
    pub fn new(id: u32) -> Self {
        Self {
            id,
            attrs: Vec::new(),
        }
    }

    /// Add a function attribute to this group.
    pub fn add_attr(&mut self, attr: AttributeKind) {
        // Avoid duplicates
        if !self.attrs.contains(&attr) {
            self.attrs.push(attr);
        }
    }

    /// Remove a function attribute from this group.
    pub fn remove_attr(&mut self, attr: &AttributeKind) {
        self.attrs.retain(|a| a != attr);
    }

    /// Check if this group contains the given attribute.
    pub fn has_attr(&self, attr: &AttributeKind) -> bool {
        self.attrs.contains(attr)
    }

    /// Returns true if this group is empty.
    pub fn is_empty(&self) -> bool {
        self.attrs.is_empty()
    }

    /// Returns the number of attributes in this group.
    pub fn len(&self) -> usize {
        self.attrs.len()
    }
}

/// The complete attribute list for a function.
///
/// @llvm_behavior: A function has function-level attributes, return
/// attributes, and per-parameter attributes. This struct mirrors the
/// LLVM `AttributeList` class, holding all three categories plus
/// optional attribute groups.
#[derive(Debug, Clone, PartialEq)]
pub struct AttributeList {
    /// Function-level attributes.
    pub fn_attrs: Vec<AttributeKind>,
    /// Return value attributes.
    pub ret_attrs: Vec<ParamAttrKind>,
    /// Per-parameter attributes, indexed by parameter number.
    pub param_attrs: Vec<Vec<ParamAttrKind>>,
    /// Attribute groups referenced by ID.
    pub groups: HashMap<u32, AttrGroup>,
}

impl AttributeList {
    /// Create a new, empty attribute list.
    pub fn new() -> Self {
        Self {
            fn_attrs: Vec::new(),
            ret_attrs: Vec::new(),
            param_attrs: Vec::new(),
            groups: HashMap::new(),
        }
    }

    /// Add a function-level attribute.
    ///
    /// Duplicate attributes are silently ignored.
    pub fn add_fn_attr(&mut self, attr: AttributeKind) {
        if !self.fn_attrs.contains(&attr) {
            self.fn_attrs.push(attr);
        }
    }

    /// Remove a function-level attribute.
    pub fn remove_fn_attr(&mut self, attr: &AttributeKind) {
        self.fn_attrs.retain(|a| a != attr);
    }

    /// Add a return-value attribute.
    pub fn add_ret_attr(&mut self, attr: ParamAttrKind) {
        if !self.ret_attrs.contains(&attr) {
            self.ret_attrs.push(attr);
        }
    }

    /// Remove a return-value attribute.
    pub fn remove_ret_attr(&mut self, attr: &ParamAttrKind) {
        self.ret_attrs.retain(|a| a != attr);
    }

    /// Add a parameter attribute at the given parameter index.
    ///
    /// If the parameter vector needs to grow to accommodate the index,
    /// intermediate entries are filled with empty vectors.
    pub fn add_param_attr(&mut self, param_idx: u32, attr: ParamAttrKind) {
        let idx = param_idx as usize;
        while self.param_attrs.len() <= idx {
            self.param_attrs.push(Vec::new());
        }
        if !self.param_attrs[idx].contains(&attr) {
            self.param_attrs[idx].push(attr);
        }
    }

    /// Remove a parameter attribute at the given parameter index.
    pub fn remove_param_attr(&mut self, param_idx: u32, attr: &ParamAttrKind) {
        let idx = param_idx as usize;
        if idx < self.param_attrs.len() {
            self.param_attrs[idx].retain(|a| a != attr);
        }
    }

    /// Check if a function-level attribute is present.
    pub fn has_fn_attr(&self, kind: &AttributeKind) -> bool {
        self.fn_attrs.contains(kind)
    }

    /// Check if any function-level memory effect attribute is set.
    pub fn has_memory_attr(&self) -> bool {
        self.fn_attrs.iter().any(|a| a.is_memory_attr())
    }

    /// Check if a return-value attribute is present.
    pub fn has_ret_attr(&self, kind: &ParamAttrKind) -> bool {
        self.ret_attrs.contains(kind)
    }

    /// Get the attributes for a specific parameter index.
    ///
    /// Returns an empty slice if the index is out of bounds.
    pub fn get_param_attrs(&self, idx: u32) -> &[ParamAttrKind] {
        let idx = idx as usize;
        if idx < self.param_attrs.len() {
            &self.param_attrs[idx]
        } else {
            &[]
        }
    }

    /// Set the attributes for a specific parameter index (replaces existing).
    pub fn set_param_attrs(&mut self, param_idx: u32, attrs: Vec<ParamAttrKind>) {
        let idx = param_idx as usize;
        while self.param_attrs.len() <= idx {
            self.param_attrs.push(Vec::new());
        }
        self.param_attrs[idx] = attrs;
    }

    /// Returns the number of parameters that have attributes.
    pub fn num_param_slots(&self) -> usize {
        self.param_attrs.len()
    }

    /// Returns true if the attribute list is completely empty.
    pub fn is_empty(&self) -> bool {
        self.fn_attrs.is_empty()
            && self.ret_attrs.is_empty()
            && self.param_attrs.iter().all(|v| v.is_empty())
            && self.groups.is_empty()
    }

    // === Attribute groups ===

    /// Add an attribute group to the list.
    pub fn add_group(&mut self, group: AttrGroup) {
        self.groups.insert(group.id, group);
    }

    /// Get an attribute group by ID.
    pub fn get_group(&self, id: u32) -> Option<&AttrGroup> {
        self.groups.get(&id)
    }

    /// Remove an attribute group by ID.
    pub fn remove_group(&mut self, id: u32) {
        self.groups.remove(&id);
    }

    /// Create a group from a list of function attributes and return its ID.
    ///
    /// A new unique group ID is auto-generated.
    pub fn create_group(&mut self, attrs: Vec<AttributeKind>) -> u32 {
        let id = self.groups.len() as u32 + 1;
        let group = AttrGroup { id, attrs };
        self.groups.insert(id, group);
        id
    }

    // === Parsing ===

    /// Create an attribute list from LLVM assembly-style attribute strings.
    ///
    /// Handles both function attributes and parameter attributes.
    /// Example input: `["noinline", "nounwind", "readonly"]`
    pub fn from_fn_attr_strings(attr_strings: &[&str]) -> Self {
        let mut list = Self::new();
        for s in attr_strings {
            if let Some(attr) = AttributeKind::from_string(s) {
                list.add_fn_attr(attr);
            }
        }
        list
    }

    /// Build a complete attribute list from parsed attribute strings
    /// organized by category.
    pub fn from_parts(
        fn_attr_strs: &[&str],
        ret_attr_strs: &[&str],
        param_attr_strs: &[Vec<&str>],
    ) -> Self {
        let mut list = Self::new();
        for s in fn_attr_strs {
            if let Some(attr) = AttributeKind::from_string(s) {
                list.add_fn_attr(attr);
            }
        }
        for s in ret_attr_strs {
            if let Some(attr) = ParamAttrKind::from_string(s) {
                list.add_ret_attr(attr);
            }
        }
        for (i, attrs) in param_attr_strs.iter().enumerate() {
            for s in attrs {
                if let Some(attr) = ParamAttrKind::from_string(s) {
                    list.add_param_attr(i as u32, attr);
                }
            }
        }
        list
    }

    // === LLVM IR text emission ===

    /// Emit the function attribute list in LLVM IR assembly format.
    ///
    /// Produces output like: `noinline nounwind readnone`
    pub fn emit_fn_attr_string(&self) -> String {
        if self.fn_attrs.is_empty() {
            return String::new();
        }
        self.fn_attrs
            .iter()
            .map(|a| a.to_string())
            .collect::<Vec<_>>()
            .join(" ")
    }

    /// Emit return attributes as an LLVM IR string.
    pub fn emit_ret_attr_string(&self) -> String {
        if self.ret_attrs.is_empty() {
            return String::new();
        }
        self.ret_attrs
            .iter()
            .map(|a| a.to_string())
            .collect::<Vec<_>>()
            .join(" ")
    }

    /// Emit parameter N attributes as an LLVM IR string.
    pub fn emit_param_attr_string(&self, param_idx: u32) -> String {
        let attrs = self.get_param_attrs(param_idx);
        if attrs.is_empty() {
            return String::new();
        }
        attrs
            .iter()
            .map(|a| a.to_string())
            .collect::<Vec<_>>()
            .join(" ")
    }

    // === Combinators ===

    /// Merge another attribute list into this one.
    ///
    /// Function attributes are merged (union). Parameter attributes at
    /// the same index are merged. Groups with colliding IDs are
    /// overwritten by `other`.
    pub fn merge(&mut self, other: &AttributeList) {
        for attr in &other.fn_attrs {
            self.add_fn_attr(attr.clone());
        }
        for attr in &other.ret_attrs {
            self.add_ret_attr(attr.clone());
        }
        for (i, attrs) in other.param_attrs.iter().enumerate() {
            for attr in attrs {
                self.add_param_attr(i as u32, attr.clone());
            }
        }
        for (id, group) in &other.groups {
            self.groups.insert(*id, group.clone());
        }
    }
}

impl Default for AttributeList {
    fn default() -> Self {
        Self::new()
    }
}

// ============================================================================
// Attribute Index Constants
// ============================================================================

/// Well-known attribute index values.
/// In LLVM, `AttributeList` uses signed indices:
/// - `ReturnIndex` (0) for return value attributes
/// - `FunctionIndex` (~0, i.e., -1) for function-level attributes
/// - Parameter indices start at 1
pub struct AttrIndex;

impl AttrIndex {
    /// Index for the return value.
    pub const RETURN: u32 = 0;
    /// Index for the function itself.
    pub const FUNCTION: u32 = u32::MAX; // LLVM uses ~0U
    /// First parameter index.
    pub const FIRST_PARAM: u32 = 1;

    /// Check if an index refers to the return value.
    pub fn is_return(idx: u32) -> bool {
        idx == Self::RETURN
    }
    /// Check if an index refers to the function.
    pub fn is_function(idx: u32) -> bool {
        idx == Self::FUNCTION
    }
    /// Check if an index refers to a parameter.
    pub fn is_param(idx: u32) -> bool {
        idx != Self::RETURN && idx != Self::FUNCTION
    }
}

// ============================================================================
// AttributeSet — attributes at a single index
// ============================================================================

/// A set of attributes applied at a single position (function, return, or
/// parameter index). This is the basic building block; `AttributeList`
/// aggregates multiple `AttributeSet`s at different indices.
///
/// @llvm_behavior: Corresponds to `llvm::AttributeSet` in C++. Unlike
/// `AttributeList` which holds attributes for all positions, `AttributeSet`
/// holds attributes for exactly one index.
#[derive(Debug, Clone, PartialEq)]
pub struct AttributeSet {
    /// The index this set applies to (function, return, or param N).
    pub index: u32,
    /// Function-level attributes at this index.
    pub fn_attrs: Vec<AttributeKind>,
    /// Parameter/return attributes at this index.
    pub param_attrs: Vec<ParamAttrKind>,
}

impl AttributeSet {
    /// Create an empty attribute set for the given index.
    pub fn new(index: u32) -> Self {
        Self {
            index,
            fn_attrs: Vec::new(),
            param_attrs: Vec::new(),
        }
    }

    /// Create a set of function attributes.
    pub fn for_function(attrs: Vec<AttributeKind>) -> Self {
        Self {
            index: AttrIndex::FUNCTION,
            fn_attrs: attrs,
            param_attrs: Vec::new(),
        }
    }

    /// Create a set of return attributes.
    pub fn for_return(param_attrs: Vec<ParamAttrKind>) -> Self {
        Self {
            index: AttrIndex::RETURN,
            fn_attrs: Vec::new(),
            param_attrs,
        }
    }

    /// Create a set of parameter attributes.
    pub fn for_param(param_idx: u32, param_attrs: Vec<ParamAttrKind>) -> Self {
        Self {
            index: param_idx,
            fn_attrs: Vec::new(),
            param_attrs,
        }
    }

    /// Add a function attribute.
    pub fn add_fn_attr(&mut self, attr: AttributeKind) {
        if !self.fn_attrs.contains(&attr) {
            self.fn_attrs.push(attr);
        }
    }

    /// Add a parameter/return attribute.
    pub fn add_param_attr(&mut self, attr: ParamAttrKind) {
        if !self.param_attrs.contains(&attr) {
            self.param_attrs.push(attr);
        }
    }

    /// Check if this set contains a specific function attribute.
    pub fn has_fn_attr(&self, attr: &AttributeKind) -> bool {
        self.fn_attrs.contains(attr)
    }

    /// Check if this set contains a specific parameter attribute.
    pub fn has_param_attr(&self, attr: &ParamAttrKind) -> bool {
        self.param_attrs.contains(attr)
    }

    /// Check if a function attribute with a specific discriminant exists.
    pub fn has_fn_attr_kind(&self, name: &str) -> bool {
        self.fn_attrs
            .iter()
            .any(|a| a.to_string().starts_with(name))
    }

    /// Get the alignment from the align attribute, if present.
    pub fn get_alignment(&self) -> Option<u32> {
        self.param_attrs.iter().find_map(|a| {
            if let ParamAttrKind::Align(n) = a {
                Some(*n)
            } else {
                None
            }
        })
    }

    /// Get the dereferenceable byte count, if present.
    pub fn get_dereferenceable_bytes(&self) -> Option<u64> {
        self.param_attrs.iter().find_map(|a| {
            if let ParamAttrKind::Dereferenceable(n) = a {
                Some(*n)
            } else {
                None
            }
        })
    }

    /// Check if this set has the `nonnull` attribute.
    pub fn is_non_null(&self) -> bool {
        self.has_param_attr(&ParamAttrKind::NonNull)
    }

    /// Check if this set has the `nocapture` attribute.
    pub fn is_no_capture(&self) -> bool {
        self.has_param_attr(&ParamAttrKind::NoCapture)
    }

    /// Check if this set has the `noalias` attribute.
    pub fn is_no_alias(&self) -> bool {
        self.has_param_attr(&ParamAttrKind::NoAlias)
    }

    /// Check if this set marks a sign-extended integer.
    pub fn is_sign_ext(&self) -> bool {
        self.has_param_attr(&ParamAttrKind::SignExt) || self.has_param_attr(&ParamAttrKind::SExt)
    }

    /// Check if this set marks a zero-extended integer.
    pub fn is_zero_ext(&self) -> bool {
        self.has_param_attr(&ParamAttrKind::ZeroExt)
    }

    /// Returns the number of function attributes.
    pub fn num_fn_attrs(&self) -> usize {
        self.fn_attrs.len()
    }

    /// Returns the number of parameter/return attributes.
    pub fn num_param_attrs(&self) -> usize {
        self.param_attrs.len()
    }

    /// Returns true if this set is completely empty.
    pub fn is_empty(&self) -> bool {
        self.fn_attrs.is_empty() && self.param_attrs.is_empty()
    }

    /// Merge another AttributeSet into this one (union of attributes).
    pub fn merge(&mut self, other: &AttributeSet) {
        for attr in &other.fn_attrs {
            self.add_fn_attr(attr.clone());
        }
        for attr in &other.param_attrs {
            self.add_param_attr(attr.clone());
        }
    }

    /// Emit this attribute set as an LLVM IR attribute string.
    pub fn to_llvm_string(&self) -> String {
        let mut parts = Vec::new();
        for attr in &self.fn_attrs {
            parts.push(attr.to_string());
        }
        for attr in &self.param_attrs {
            parts.push(attr.to_string());
        }
        parts.join(" ")
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    // === AttributeKind tests ===

    #[test]
    fn test_attribute_kind_from_string_standard() {
        assert_eq!(
            AttributeKind::from_string("noinline"),
            Some(AttributeKind::NoInline)
        );
        assert_eq!(
            AttributeKind::from_string("alwaysinline"),
            Some(AttributeKind::AlwaysInline)
        );
        assert_eq!(
            AttributeKind::from_string("optnone"),
            Some(AttributeKind::OptimizeNone)
        );
        assert_eq!(
            AttributeKind::from_string("readnone"),
            Some(AttributeKind::ReadNone)
        );
        assert_eq!(
            AttributeKind::from_string("readonly"),
            Some(AttributeKind::ReadOnly)
        );
        assert_eq!(
            AttributeKind::from_string("nounwind"),
            Some(AttributeKind::NoUnwind)
        );
        assert_eq!(
            AttributeKind::from_string("noreturn"),
            Some(AttributeKind::NoReturn)
        );
        assert_eq!(
            AttributeKind::from_string("cold"),
            Some(AttributeKind::Cold)
        );
        assert_eq!(AttributeKind::from_string("hot"), Some(AttributeKind::Hot));
    }

    #[test]
    fn test_attribute_kind_from_string_memory_aliases() {
        assert_eq!(
            AttributeKind::from_string("memory(none)"),
            Some(AttributeKind::ReadNone)
        );
        assert_eq!(
            AttributeKind::from_string("memory(read)"),
            Some(AttributeKind::ReadOnly)
        );
        assert_eq!(
            AttributeKind::from_string("memory(write)"),
            Some(AttributeKind::WriteOnly)
        );
    }

    #[test]
    fn test_attribute_kind_from_string_sanitizers() {
        assert_eq!(
            AttributeKind::from_string("sanitize_address"),
            Some(AttributeKind::SanitizeAddress)
        );
        assert_eq!(
            AttributeKind::from_string("sanitize_thread"),
            Some(AttributeKind::SanitizeThread)
        );
        assert_eq!(
            AttributeKind::from_string("sanitize_memory"),
            Some(AttributeKind::SanitizeMemory)
        );
        assert_eq!(
            AttributeKind::from_string("nosanitize"),
            Some(AttributeKind::NoSanitize)
        );
    }

    #[test]
    fn test_attribute_kind_from_string_security() {
        assert_eq!(AttributeKind::from_string("ssp"), Some(AttributeKind::Ssp));
        assert_eq!(
            AttributeKind::from_string("sspreq"),
            Some(AttributeKind::SspReq)
        );
        assert_eq!(
            AttributeKind::from_string("sspstrong"),
            Some(AttributeKind::SspStrong)
        );
        assert_eq!(
            AttributeKind::from_string("shadowcallstack"),
            Some(AttributeKind::ShadowCallStack)
        );
        assert_eq!(
            AttributeKind::from_string("nocf_check"),
            Some(AttributeKind::NoCfCheck)
        );
    }

    #[test]
    fn test_attribute_kind_from_string_unknown() {
        assert_eq!(AttributeKind::from_string("nonexistent"), None);
        assert_eq!(AttributeKind::from_string(""), None);
    }

    #[test]
    fn test_attribute_kind_to_string_roundtrip() {
        let attrs = vec![
            AttributeKind::NoInline,
            AttributeKind::AlwaysInline,
            AttributeKind::ReadNone,
            AttributeKind::NoUnwind,
            AttributeKind::NoReturn,
            AttributeKind::Cold,
            AttributeKind::Hot,
        ];
        for attr in attrs {
            let s = attr.to_string();
            let parsed = AttributeKind::from_string(&s);
            assert!(
                parsed.is_some(),
                "Failed roundtrip for {:?} via string '{}'",
                attr,
                s
            );
        }
    }

    #[test]
    fn test_attribute_kind_is_memory_attr() {
        assert!(AttributeKind::ReadNone.is_memory_attr());
        assert!(AttributeKind::ReadOnly.is_memory_attr());
        assert!(AttributeKind::WriteOnly.is_memory_attr());
        assert!(AttributeKind::ArgMemOnly.is_memory_attr());
        assert!(AttributeKind::InaccessibleMemOnly.is_memory_attr());
        assert!(!AttributeKind::NoInline.is_memory_attr());
        assert!(!AttributeKind::Cold.is_memory_attr());
    }

    #[test]
    fn test_attribute_kind_is_sanitizer_attr() {
        assert!(AttributeKind::SanitizeAddress.is_sanitizer_attr());
        assert!(AttributeKind::SanitizeThread.is_sanitizer_attr());
        assert!(AttributeKind::NoSanitize.is_sanitizer_attr());
        assert!(!AttributeKind::NoInline.is_sanitizer_attr());
    }

    #[test]
    fn test_attribute_kind_is_security_attr() {
        assert!(AttributeKind::Ssp.is_security_attr());
        assert!(AttributeKind::SspReq.is_security_attr());
        assert!(AttributeKind::ShadowCallStack.is_security_attr());
        assert!(!AttributeKind::NoInline.is_security_attr());
    }

    // === ParamAttrKind tests ===

    #[test]
    fn test_param_attr_kind_from_string_simple() {
        assert_eq!(
            ParamAttrKind::from_string("zeroext"),
            Some(ParamAttrKind::ZeroExt)
        );
        assert_eq!(
            ParamAttrKind::from_string("signext"),
            Some(ParamAttrKind::SignExt)
        );
        assert_eq!(
            ParamAttrKind::from_string("noalias"),
            Some(ParamAttrKind::NoAlias)
        );
        assert_eq!(
            ParamAttrKind::from_string("nocapture"),
            Some(ParamAttrKind::NoCapture)
        );
        assert_eq!(
            ParamAttrKind::from_string("nonnull"),
            Some(ParamAttrKind::NonNull)
        );
        assert_eq!(
            ParamAttrKind::from_string("inreg"),
            Some(ParamAttrKind::InReg)
        );
        assert_eq!(
            ParamAttrKind::from_string("returned"),
            Some(ParamAttrKind::Returned)
        );
        assert_eq!(
            ParamAttrKind::from_string("immarg"),
            Some(ParamAttrKind::ImmArg)
        );
        assert_eq!(
            ParamAttrKind::from_string("noundef"),
            Some(ParamAttrKind::NoUndef)
        );
    }

    #[test]
    fn test_param_attr_kind_from_string_numeric() {
        assert_eq!(
            ParamAttrKind::from_string("align 8"),
            Some(ParamAttrKind::Align(8))
        );
        assert_eq!(
            ParamAttrKind::from_string("align 16"),
            Some(ParamAttrKind::Align(16))
        );
        assert_eq!(
            ParamAttrKind::from_string("dereferenceable(32)"),
            Some(ParamAttrKind::Dereferenceable(32))
        );
        assert_eq!(
            ParamAttrKind::from_string("dereferenceable_or_null(64)"),
            Some(ParamAttrKind::DereferenceableOrNull(64))
        );
    }

    #[test]
    fn test_param_attr_kind_from_string_invalid() {
        assert_eq!(ParamAttrKind::from_string("notanattr"), None);
        assert_eq!(ParamAttrKind::from_string("align"), None);
        assert_eq!(ParamAttrKind::from_string("align abc"), None);
    }

    #[test]
    fn test_param_attr_kind_to_string_roundtrip_simple() {
        let attrs = vec![
            ParamAttrKind::ZeroExt,
            ParamAttrKind::SignExt,
            ParamAttrKind::NoAlias,
            ParamAttrKind::NoCapture,
            ParamAttrKind::NonNull,
            ParamAttrKind::InReg,
            ParamAttrKind::Returned,
        ];
        for attr in attrs {
            let s = attr.to_string();
            let parsed = ParamAttrKind::from_string(&s);
            assert_eq!(
                Some(attr.clone()),
                parsed,
                "Failed roundtrip via string '{}'",
                s
            );
        }
    }

    #[test]
    fn test_param_attr_kind_to_string_numeric() {
        assert_eq!(ParamAttrKind::Align(8).to_string(), "align 8");
        assert_eq!(
            ParamAttrKind::Dereferenceable(16).to_string(),
            "dereferenceable(16)"
        );
        assert_eq!(
            ParamAttrKind::DereferenceableOrNull(32).to_string(),
            "dereferenceable_or_null(32)"
        );
    }

    #[test]
    fn test_param_attr_kind_is_type_attr() {
        assert!(!ParamAttrKind::ZeroExt.is_type_attr());
        assert!(!ParamAttrKind::Align(8).is_type_attr());
        // ByVal, StructRet, ByRef, Preallocated need types to construct,
        // so we skip creating them in a no-std-friendly test.
    }

    #[test]
    fn test_param_attr_kind_kind_discriminant() {
        assert_eq!(ParamAttrKind::ZeroExt.kind_discriminant(), "zeroext");
        assert_eq!(ParamAttrKind::Align(8).kind_discriminant(), "align");
        assert_eq!(
            ParamAttrKind::Dereferenceable(4).kind_discriminant(),
            "dereferenceable"
        );
    }

    // === AttrGroup tests ===

    #[test]
    fn test_attr_group_new() {
        let group = AttrGroup::new(42);
        assert_eq!(group.id, 42);
        assert!(group.is_empty());
        assert_eq!(group.len(), 0);
    }

    #[test]
    fn test_attr_group_add_and_check() {
        let mut group = AttrGroup::new(1);
        group.add_attr(AttributeKind::NoInline);
        group.add_attr(AttributeKind::NoUnwind);
        assert_eq!(group.len(), 2);
        assert!(group.has_attr(&AttributeKind::NoInline));
        assert!(group.has_attr(&AttributeKind::NoUnwind));
        assert!(!group.has_attr(&AttributeKind::Cold));
    }

    #[test]
    fn test_attr_group_remove() {
        let mut group = AttrGroup::new(1);
        group.add_attr(AttributeKind::NoInline);
        group.add_attr(AttributeKind::NoUnwind);
        group.remove_attr(&AttributeKind::NoInline);
        assert_eq!(group.len(), 1);
        assert!(!group.has_attr(&AttributeKind::NoInline));
        assert!(group.has_attr(&AttributeKind::NoUnwind));
    }

    #[test]
    fn test_attr_group_no_duplicates() {
        let mut group = AttrGroup::new(1);
        group.add_attr(AttributeKind::NoInline);
        group.add_attr(AttributeKind::NoInline);
        assert_eq!(group.len(), 1);
    }

    // === AttributeList tests ===

    #[test]
    fn test_attribute_list_new_empty() {
        let list = AttributeList::new();
        assert!(list.is_empty());
        assert_eq!(list.fn_attrs.len(), 0);
        assert_eq!(list.ret_attrs.len(), 0);
        assert_eq!(list.num_param_slots(), 0);
    }

    #[test]
    fn test_attribute_list_add_fn_attrs() {
        let mut list = AttributeList::new();
        list.add_fn_attr(AttributeKind::NoInline);
        list.add_fn_attr(AttributeKind::ReadNone);
        assert!(list.has_fn_attr(&AttributeKind::NoInline));
        assert!(list.has_fn_attr(&AttributeKind::ReadNone));
        assert!(!list.has_fn_attr(&AttributeKind::Cold));
    }

    #[test]
    fn test_attribute_list_add_param_attr() {
        let mut list = AttributeList::new();
        list.add_param_attr(0, ParamAttrKind::ZeroExt);
        list.add_param_attr(0, ParamAttrKind::NonNull);
        list.add_param_attr(1, ParamAttrKind::SignExt);

        let p0 = list.get_param_attrs(0);
        assert_eq!(p0.len(), 2);
        assert!(p0.contains(&ParamAttrKind::ZeroExt));
        assert!(p0.contains(&ParamAttrKind::NonNull));

        let p1 = list.get_param_attrs(1);
        assert_eq!(p1.len(), 1);
        assert!(p1.contains(&ParamAttrKind::SignExt));

        let p2 = list.get_param_attrs(2);
        assert!(p2.is_empty());
    }

    #[test]
    fn test_attribute_list_merge() {
        let mut list1 = AttributeList::new();
        list1.add_fn_attr(AttributeKind::NoInline);
        list1.add_param_attr(0, ParamAttrKind::ZeroExt);

        let mut list2 = AttributeList::new();
        list2.add_fn_attr(AttributeKind::NoUnwind);
        list2.add_param_attr(0, ParamAttrKind::NonNull);
        list2.add_param_attr(1, ParamAttrKind::SignExt);

        list1.merge(&list2);

        assert!(list1.has_fn_attr(&AttributeKind::NoInline));
        assert!(list1.has_fn_attr(&AttributeKind::NoUnwind));

        let p0 = list1.get_param_attrs(0);
        assert_eq!(p0.len(), 2);
        assert!(p0.contains(&ParamAttrKind::ZeroExt));
        assert!(p0.contains(&ParamAttrKind::NonNull));

        let p1 = list1.get_param_attrs(1);
        assert_eq!(p1.len(), 1);
        assert!(p1.contains(&ParamAttrKind::SignExt));
    }

    #[test]
    fn test_attribute_list_from_parts() {
        let list = AttributeList::from_parts(
            &["noinline", "nounwind"],
            &["zeroext"],
            &[vec!["nocapture", "nonnull"], vec!["signext"]],
        );

        assert!(list.has_fn_attr(&AttributeKind::NoInline));
        assert!(list.has_fn_attr(&AttributeKind::NoUnwind));
        assert!(list.has_ret_attr(&ParamAttrKind::ZeroExt));

        let p0 = list.get_param_attrs(0);
        assert!(p0.contains(&ParamAttrKind::NoCapture));
        assert!(p0.contains(&ParamAttrKind::NonNull));

        let p1 = list.get_param_attrs(1);
        assert!(p1.contains(&ParamAttrKind::SignExt));
    }

    #[test]
    fn test_attribute_list_emit_fn_attr_string() {
        let mut list = AttributeList::new();
        list.add_fn_attr(AttributeKind::NoInline);
        list.add_fn_attr(AttributeKind::ReadNone);
        let s = list.emit_fn_attr_string();
        assert!(s.contains("noinline"));
        assert!(s.contains("readnone"));
    }

    #[test]
    fn test_attribute_list_groups() {
        let mut list = AttributeList::new();
        let id = list.create_group(vec![AttributeKind::NoInline, AttributeKind::ReadNone]);

        let group = list.get_group(id);
        assert!(group.is_some());
        let group = group.unwrap();
        assert_eq!(group.id, id);
        assert!(group.has_attr(&AttributeKind::NoInline));
        assert!(group.has_attr(&AttributeKind::ReadNone));

        list.remove_group(id);
        assert!(list.get_group(id).is_none());
    }

    #[test]
    fn test_attribute_list_string_attribute() {
        let attr =
            AttributeKind::StringAttribute("my_custom_attr".to_string(), "some_value".to_string());
        let s = attr.to_string();
        assert!(s.contains("my_custom_attr"));
        assert!(s.contains("some_value"));
    }

    #[test]
    fn test_attribute_kind_minsize_and_optforsize() {
        let mut list = AttributeList::new();
        list.add_fn_attr(AttributeKind::Minsize);
        list.add_fn_attr(AttributeKind::OptimizeForSize);
        assert!(list.has_fn_attr(&AttributeKind::Minsize));
        assert!(list.has_fn_attr(&AttributeKind::OptimizeForSize));
    }

    #[test]
    fn test_param_attr_no_duplicates() {
        let mut list = AttributeList::new();
        list.add_param_attr(0, ParamAttrKind::NoAlias);
        list.add_param_attr(0, ParamAttrKind::NoAlias);
        assert_eq!(list.get_param_attrs(0).len(), 1);
    }

    #[test]
    fn test_attribute_list_default() {
        let list = AttributeList::default();
        assert!(list.is_empty());
    }

    #[test]
    fn test_attribute_kind_no_sync_no_free() {
        assert_eq!(
            AttributeKind::from_string("nosync"),
            Some(AttributeKind::NoSync)
        );
        assert_eq!(
            AttributeKind::from_string("nofree"),
            Some(AttributeKind::NoFree)
        );
        assert_eq!(
            AttributeKind::from_string("norecurse"),
            Some(AttributeKind::NoRecurse)
        );
        assert_eq!(
            AttributeKind::from_string("noduplicate"),
            Some(AttributeKind::NoDuplicate)
        );
    }

    #[test]
    fn test_attribute_kind_willreturn() {
        assert_eq!(
            AttributeKind::from_string("willreturn"),
            Some(AttributeKind::WillReturn)
        );
        assert_eq!(AttributeKind::WillReturn.to_string(), "willreturn");
    }

    #[test]
    fn test_attribute_kind_null_pointer_is_valid() {
        let attr = AttributeKind::NullPointerIsValid;
        assert_eq!(attr.to_string(), "null_pointer_is_valid");
        assert_eq!(
            AttributeKind::from_string("null_pointer_is_valid"),
            Some(AttributeKind::NullPointerIsValid)
        );
    }
}