wazabin-qcode 0.4.0

//! Static immutable providers for qcode IR reads.
//!
//! [`ModuleView`] resolves any function body in an unchanged [`Context`].
//! [`BodyView`] resolves exactly one body plus shared data and published
//! interfaces. Both implement [`QCodeView`], which is deliberately read-only.

use jstd::registry::Registry;

use crate::{
    context::{Context, Shared},
    types::TypeId,
    value::{
        BasicBlock, BlockId, BlockParamRef, BlockRef, FunctionBody, FunctionId, FunctionRef,
        Instruction, InstructionRef, Temp, TempId, TempRef, TempSpace, TempSpaceId, TempSpaceRef,
        ValueId,
        block::{EdgeData, EdgeId},
        block_param::{BlockParam, BlockParamId},
        function::FunctionInterface,
        insn::InstructionId,
    },
};

/// Read-only resolution capability shared by module and single-body views.
///
/// The explicit lifetimes let provider-generic refs return data with the
/// provider's underlying borrow lifetime, rather than tying results to a short
/// borrow of the thin provider value.
pub trait QCodeView<'ctx, 'str>: Copy
where
    'str: 'ctx,
{
    fn shared(self) -> &'ctx Shared<'str>;
    fn interface(self, id: FunctionId) -> &'ctx FunctionInterface<'str>;
    fn function(self, id: FunctionId) -> &'ctx FunctionBody<'str>;

    /// The single function this view is scoped to, if any. A whole-module view
    /// returns `None` (it may read every function); a function-pass [`BodyView`]
    /// returns its owner, so callers can avoid a cross-function read that the
    /// locality guard would panic on (e.g. rendering a foreign `SymbolicRef::Block`
    /// falls back to the numeric form instead of resolving its name).
    fn owner(self) -> Option<FunctionId> {
        None
    }

    fn instruction(self, id: InstructionId) -> &'ctx Instruction<'str> {
        &self.function(id.func).insns[id.local]
    }

    fn contains_instruction(self, id: InstructionId) -> bool {
        self.function(id.func).insns.contains(id.local)
    }

    fn block(self, id: BlockId) -> &'ctx BasicBlock<'str> {
        &self.function(id.func).blocks[id.local]
    }

    fn contains_block(self, id: BlockId) -> bool {
        self.function(id.func).blocks.contains(id.local)
    }

    fn block_param(self, id: BlockParamId) -> &'ctx BlockParam<'str> {
        &self.function(id.func).params[id.local]
    }

    fn contains_block_param(self, id: BlockParamId) -> bool {
        self.function(id.func).params.contains(id.local)
    }

    fn edge(self, function: FunctionId, id: EdgeId) -> &'ctx EdgeData {
        &self.function(function).edges[id]
    }

    #[track_caller]
    fn temp_space(self, id: TempSpaceId) -> &'ctx TempSpace {
        debug_assert!(
            self.contains_temp_space(id),
            "missing temporary space {id:?} in function {:?}",
            id.func
        );
        &self.function(id.func).temp_spaces[id.local]
    }

    fn contains_temp_space(self, id: TempSpaceId) -> bool {
        usize::from(id.local) < self.function(id.func).temp_spaces.len()
    }

    #[track_caller]
    fn temp(self, id: TempId) -> &'ctx Temp<'str> {
        debug_assert!(
            self.contains_temp(id),
            "missing temporary {id:?} in function {:?}",
            id.func
        );
        &self.function(id.func).temps[id.local]
    }

    fn contains_temp(self, id: TempId) -> bool {
        usize::from(id.local) < self.function(id.func).temps.len()
    }

    fn type_of(self, id: ValueId) -> TypeId {
        let shared = self.shared();
        match id {
            ValueId::Literal(id) => shared.values.literals[id].type_id,
            ValueId::Bytes(id) => shared.values.bytes[id].type_id,
            ValueId::Instruction(id) => self.instruction(id).type_id,
            ValueId::BlockParam(id) => self.block_param(id).type_id,
            ValueId::Varnode(id) => shared
                .values
                .varnode_types
                .get(&id)
                .copied()
                .unwrap_or_else(|| {
                    shared
                        .types
                        .get_or_make_int(shared.values.varnodes[id].size_bytes())
                }),
            ValueId::Temp(id) => shared.types.get_or_make_int(self.temp(id).size),
            ValueId::Poison(id) => shared.values.poisons[id].type_id,
            ValueId::BasicBlock(_) | ValueId::Function(_) => shared.types.get_or_make_int(0),
        }
    }

    fn stored_type_of(self, id: ValueId) -> Option<TypeId> {
        let shared = self.shared();
        match id {
            ValueId::Literal(id) => Some(shared.values.literals[id].type_id),
            ValueId::Bytes(id) => Some(shared.values.bytes[id].type_id),
            ValueId::Instruction(id) => Some(self.instruction(id).type_id),
            ValueId::BlockParam(id) => Some(self.block_param(id).type_id),
            ValueId::Varnode(id) => shared.values.varnode_types.get(&id).copied(),
            ValueId::Poison(id) => Some(shared.values.poisons[id].type_id),
            ValueId::Temp(_) => None,
            ValueId::BasicBlock(_) | ValueId::Function(_) => None,
        }
    }

    fn block_ref(self, id: BlockId) -> BlockRef<'str, 'ctx, Self>
    where
        Self: Sized,
    {
        let _ = self.block(id);
        BlockRef::new(self, id)
    }

    fn insn_ref(self, id: InstructionId) -> InstructionRef<'str, 'ctx, Self>
    where
        Self: Sized,
    {
        let _ = self.instruction(id);
        InstructionRef::new(self, id)
    }

    fn param_ref(self, id: BlockParamId) -> BlockParamRef<'str, 'ctx, Self>
    where
        Self: Sized,
    {
        let _ = self.block_param(id);
        BlockParamRef::new(self, id)
    }

    fn function_ref(self, id: FunctionId) -> FunctionRef<'str, 'ctx, Self>
    where
        Self: Sized,
    {
        let _ = self.function(id);
        FunctionRef::new(self, id)
    }

    fn temp_space_ref(self, id: TempSpaceId) -> TempSpaceRef<'str, 'ctx, Self>
    where
        Self: Sized,
    {
        let _ = self.temp_space(id);
        TempSpaceRef::new(self, id)
    }

    fn temp_ref(self, id: TempId) -> TempRef<'str, 'ctx, Self>
    where
        Self: Sized,
    {
        let _ = self.temp(id);
        TempRef::new(self, id)
    }
}

/// Whole-module immutable provider.
#[derive(Clone, Copy)]
pub struct ModuleView<'ctx, 'str> {
    context: &'ctx Context<'str>,
}

impl<'ctx, 'str> ModuleView<'ctx, 'str> {
    pub fn new(context: &'ctx Context<'str>) -> Self {
        Self { context }
    }

    /// Whole-context access is intentionally module-only and absent from
    /// [`QCodeView`] / [`BodyView`].
    pub fn context(self) -> &'ctx Context<'str> {
        self.context
    }
}

impl<'ctx, 'str: 'ctx> QCodeView<'ctx, 'str> for ModuleView<'ctx, 'str> {
    fn shared(self) -> &'ctx Shared<'str> {
        &self.context.shared
    }

    fn interface(self, id: FunctionId) -> &'ctx FunctionInterface<'str> {
        &self.context.interfaces[id]
    }

    fn function(self, id: FunctionId) -> &'ctx FunctionBody<'str> {
        &self.context.bodies[id]
    }
}

/// Single-body immutable provider used by function passes.
#[derive(Clone, Copy)]
pub struct BodyView<'ctx, 'str> {
    body: &'ctx FunctionBody<'str>,
    shared: &'ctx Shared<'str>,
    interfaces: &'ctx Registry<FunctionId, FunctionInterface<'str>>,
}

impl<'ctx, 'str> BodyView<'ctx, 'str> {
    pub fn new(
        body: &'ctx FunctionBody<'str>,
        shared: &'ctx Shared<'str>,
        interfaces: &'ctx Registry<FunctionId, FunctionInterface<'str>>,
    ) -> Self {
        // Block ownership is derived from the storing arena (a rostered block
        // lives in `body`'s own arena by construction), so there is no
        // reattribution state left to scan for here.
        Self {
            body,
            shared,
            interfaces,
        }
    }

    pub fn function_id(self) -> FunctionId {
        self.body.id()
    }
}

impl<'ctx, 'str: 'ctx> QCodeView<'ctx, 'str> for BodyView<'ctx, 'str> {
    fn shared(self) -> &'ctx Shared<'str> {
        self.shared
    }

    fn interface(self, id: FunctionId) -> &'ctx FunctionInterface<'str> {
        &self.interfaces[id]
    }

    fn function(self, id: FunctionId) -> &'ctx FunctionBody<'str> {
        let owner = self.body.id();
        assert!(
            id == owner,
            "A function pass running on `{}` ({owner:?}) attempted to read `{}` ({id:?})",
            self.interfaces[owner].name,
            self.interfaces[id].name,
        );
        self.body
    }

    fn owner(self) -> Option<FunctionId> {
        Some(self.body.id())
    }
}

#[cfg(test)]
mod tests {
    use crate::{
        context::Context,
        space::{LocalMemorySpaceId, MemorySpaceId},
        value::{
            BasicBlock, FunctionBody, LocalValueId, Temp, TempSpace, ValueId, ValueRef,
            insn::{InstructionRef, Load, Mnemonic, Unary, Unop},
        },
    };

    use super::*;

    #[test]
    fn module_and_body_views_resolve_identical_local_data() {
        let mut ctx = Context::new();
        let function = FunctionBody::make(&mut ctx, "f".into()).unwrap().id;
        let block = BasicBlock::make(&mut ctx, function).id;
        let value = ctx.get_const(7, 8).id();
        let insn = ctx.builder(block).push_return(value).id;

        let module = ModuleView::new(&ctx);
        let body = BodyView::new(&ctx.bodies[function], &ctx.shared, &ctx.interfaces);

        assert_eq!(module.block(block).address, body.block(block).address);
        assert!(std::ptr::eq(
            module.instruction(insn),
            body.instruction(insn)
        ));
        assert_eq!(
            module.type_of(ValueId::Instruction(insn)),
            body.type_of(ValueId::Instruction(insn))
        );
        assert_eq!(module.insn_ref(insn).id, body.insn_ref(insn).id);
        assert_eq!(
            module.insn_ref(insn).as_statement().to_string(),
            body.insn_ref(insn).as_statement().to_string()
        );
        assert_eq!(
            module
                .function_ref(function)
                .iter()
                .map(|block| block.id)
                .collect::<Vec<_>>(),
            body.function_ref(function)
                .iter()
                .map(|block| block.id)
                .collect::<Vec<_>>()
        );
        assert_eq!(
            ValueRef::from_view(module, ValueId::Instruction(insn)).to_string(),
            ValueRef::from_view(body, ValueId::Instruction(insn)).to_string()
        );
    }

    #[test]
    fn body_view_reads_foreign_interfaces_but_not_foreign_bodies() {
        let mut ctx = Context::new();
        let own = FunctionBody::make(&mut ctx, "own".into()).unwrap().id;
        let foreign = FunctionBody::make(&mut ctx, "foreign".into()).unwrap().id;
        let view = BodyView::new(&ctx.bodies[own], &ctx.shared, &ctx.interfaces);

        assert_eq!(view.interface(foreign).name.as_ref(), "foreign");
        let panic = match std::panic::catch_unwind(|| view.function(foreign)) {
            Ok(_) => panic!("foreign body read unexpectedly succeeded"),
            Err(panic) => panic,
        };
        let message = panic
            .downcast_ref::<String>()
            .map(String::as_str)
            .or_else(|| panic.downcast_ref::<&str>().copied())
            .expect("BodyView panic should carry a string message");
        assert_eq!(
            message,
            format!(
                "A function pass running on `own` ({own:?}) attempted to read `foreign` ({foreign:?})"
            )
        );
    }

    #[test]
    fn body_view_rejects_foreign_composite_ids() {
        let mut ctx = Context::new();
        let own = FunctionBody::make(&mut ctx, "own".into()).unwrap().id;
        let foreign = FunctionBody::make(&mut ctx, "foreign".into()).unwrap().id;
        let block = BasicBlock::make(&mut ctx, foreign).id;
        let view = BodyView::new(&ctx.bodies[own], &ctx.shared, &ctx.interfaces);

        assert!(std::panic::catch_unwind(|| view.block(block)).is_err());
    }

    #[test]
    fn temporary_ids_are_qualified_by_their_body() {
        let mut ctx = Context::new();
        let first = FunctionBody::make(&mut ctx, "first".into()).unwrap().id;
        let second = FunctionBody::make(&mut ctx, "second".into()).unwrap().id;

        let first_space = ctx.bodies[first].push_temp_space(TempSpace::new(None, 1, 8));
        let second_space = ctx.bodies[second].push_temp_space(TempSpace::new(None, 1, 8));
        assert_eq!(first_space.local, second_space.local);
        assert_ne!(first_space, second_space);

        let first_temp = ctx.bodies[first].push_temp(Temp::new(0x20, 4, first_space.local));
        let second_temp = ctx.bodies[second].push_temp(Temp::new(0x20, 4, second_space.local));
        assert_eq!(first_temp.local, second_temp.local);
        assert_ne!(first_temp, second_temp);

        let module = ModuleView::new(&ctx);
        assert_eq!(module.temp_ref(first_temp).space().id, first_space);
        assert_eq!(module.temp_ref(second_temp).space().id, second_space);

        let body = BodyView::new(&ctx.bodies[first], &ctx.shared, &ctx.interfaces);
        assert_eq!(body.temp_ref(first_temp).size(), 4);
        assert!(std::panic::catch_unwind(|| body.temp(second_temp)).is_err());
        assert!(std::panic::catch_unwind(|| body.temp_space(second_space)).is_err());
    }

    #[test]
    fn temporary_arena_ids_survive_context_round_trip() {
        let mut ctx = Context::new();
        let function = FunctionBody::make(&mut ctx, "roundtrip".into()).unwrap().id;
        let space = ctx.bodies[function].push_temp_space(TempSpace::new(Some("local"), 1, 8));
        let temp = ctx.bodies[function].push_temp(Temp::new(0x30, 2, space.local));

        let bytes = bincode::serde::encode_to_vec(&ctx, bincode::config::standard()).unwrap();
        let (restored, consumed): (Context<'static>, _) =
            bincode::serde::decode_from_slice(&bytes, bincode::config::standard()).unwrap();
        assert_eq!(consumed, bytes.len());

        let view = ModuleView::new(&restored);
        assert_eq!(view.temp_space_ref(space).name(), Some("local"));
        assert_eq!(view.temp_ref(temp).address(), 0x30);
        assert_eq!(view.temp_ref(temp).space().id, space);
    }

    #[test]
    fn temporary_names_are_body_local_and_qualified_at_lookup() {
        let mut ctx = Context::new();
        let first = FunctionBody::make(&mut ctx, "first".into()).unwrap().id;
        let second = FunctionBody::make(&mut ctx, "second".into()).unwrap().id;
        let first_space = ctx.bodies[first].push_temp_space(TempSpace::new(None, 1, 8));
        let second_space = ctx.bodies[second].push_temp_space(TempSpace::new(None, 1, 8));
        let first_temp = ctx.bodies[first]
            .push_temp(Temp::new(0x20, 4, first_space.local).with_name("scratch".into()));
        let second_temp = ctx.bodies[second]
            .push_temp(Temp::new(0x20, 4, second_space.local).with_name("scratch".into()));

        assert_eq!(first_temp.local, second_temp.local);
        assert_eq!(
            ctx.bodies[first].names.get("scratch"),
            Some(LocalValueId::Temp(first_temp.local))
        );
        assert_eq!(
            FunctionBody::from_id(&ctx, first).local_named("scratch"),
            Some(ValueId::Temp(first_temp))
        );
        assert_eq!(
            FunctionBody::from_id(&ctx, second).local_named("scratch"),
            Some(ValueId::Temp(second_temp))
        );
        assert_eq!(ctx.get_named("scratch"), None);
    }

    #[test]
    fn temporary_values_and_spaces_render_and_preserve_qualified_provenance() {
        let mut ctx = Context::new();
        let function = FunctionBody::make(&mut ctx, "temporary_ir".into())
            .unwrap()
            .id;
        let space = ctx.bodies[function].push_temp_space(TempSpace::new(Some("scratch"), 1, 8));
        let temp = ctx.bodies[function].push_temp(Temp::new(0x20, 8, space.local));
        ctx.bodies[function].temps[temp.local].label = Some(9);

        let pointer_type = ctx
            .shared
            .types
            .get_or_make_space_address(8, MemorySpaceId::Temp(space));
        let pointer = InstructionRef::from_mnemonic_with_type(
            &mut ctx,
            function,
            Mnemonic::Unop(Unary {
                op: Unop::IntNot,
                src: ValueId::Temp(temp).localize(function),
            }),
            pointer_type,
        )
        .id;
        let load_type = ctx.shared.types.get_or_make_int(4);
        let load = InstructionRef::from_mnemonic_with_type(
            &mut ctx,
            function,
            Mnemonic::Load(Load {
                space: LocalMemorySpaceId::Temp(space.local),
                ptr: ValueId::Instruction(pointer).localize(function),
                size: 4,
            }),
            load_type,
        )
        .id;

        let view = ModuleView::new(&ctx);
        assert_eq!(
            view.insn_ref(pointer).memory_space(),
            Some(MemorySpaceId::Temp(space))
        );
        assert_eq!(
            view.shared()
                .types
                .size_of(view.type_of(ValueId::Temp(temp))),
            8
        );
        assert_eq!(view.temp_ref(temp).to_string(), "v9");
        assert_eq!(
            view.insn_ref(load).as_statement().to_string(),
            "i32 %tmp1 = load($temp0:4, i64 %tmp0);"
        );
    }
}