6d50099816
* Rewrite interpreter generically This change re-implements the Cranelift interpreter to use generic values; this makes it possible to do abstract interpretation of Cranelift instructions. In doing so, the interpretation state is extracted from the `Interpreter` structure and is accessed via a `State` trait; this makes it possible to not only more clearly observe the interpreter's state but also to interpret using a dummy state (e.g. `ImmutableRegisterState`). This addition made it possible to implement more of the Cranelift instructions (~70%, ignoring the x86-specific instructions). * Replace macros with closures
43 lines
1.5 KiB
Rust
43 lines
1.5 KiB
Rust
//! The [InstructionContext] trait describes a Cranelift instruction; a default implementation is
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//! provided with [DfgInstructionContext]
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use cranelift_codegen::ir::{DataFlowGraph, Inst, InstructionData, Type, Value};
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/// Exposes the necessary information for understanding a single Cranelift instruction. It would be
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/// nice if [InstructionData] contained everything necessary for interpreting the instruction, but
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/// Cranelift's current design requires looking at other structures. A default implementation using
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/// a reference to a [DataFlowGraph] is provided in [DfgInstructionContext].
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pub trait InstructionContext {
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fn data(&self) -> InstructionData;
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fn args(&self) -> &[Value];
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fn type_of(&self, v: Value) -> Option<Type>;
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fn controlling_type(&self) -> Option<Type>;
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}
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/// Since [InstructionContext] is likely used within a Cranelift context in which a [DataFlowGraph]
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/// is available, a default implementation is provided--[DfgInstructionContext].
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pub struct DfgInstructionContext<'a>(Inst, &'a DataFlowGraph);
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impl<'a> DfgInstructionContext<'a> {
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pub fn new(inst: Inst, dfg: &'a DataFlowGraph) -> Self {
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Self(inst, dfg)
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}
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}
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impl InstructionContext for DfgInstructionContext<'_> {
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fn data(&self) -> InstructionData {
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self.1[self.0].clone()
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}
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fn args(&self) -> &[Value] {
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self.1.inst_args(self.0)
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}
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fn type_of(&self, v: Value) -> Option<Type> {
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Some(self.1.value_type(v))
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}
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fn controlling_type(&self) -> Option<Type> {
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Some(self.1.ctrl_typevar(self.0))
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}
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}
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