Struct JitChain 

pub struct JitChain { /* private fields */ }

A finished, executable chain.

Implementations

impl JitChain

pub fn from_code(code: &[u8], pieces: usize) -> Result<JitChain, JitError>

Wrap a finished, self-contained block of machine code (no stencil pieces, no post-seal patch slots) as a runnable chain. The contiguous register-allocated region backend (compile_region_regalloc) emits its whole function as one such block, then runs it through the SAME run_with_frame ABI as a stencil chain.

pieces is the logical op count (diagnostics only); the executable is one contiguous function regardless.

pub fn patch_marked(&self, value: u64) -> Result<(), JitError>

Write value into every marked literal-pool slot (the self-call entry address, known only after layout). Errs on targets without post-seal patching (Apple Silicon MAP_JIT) — callers fall back to the table-indirect call.

pub fn has_patch_marks(&self) -> bool

Whether any slots await the self-entry patch.

pub unsafe fn entry( &self, ) -> unsafe extern "C" fn(*mut i64, *mut i64, i64, i64, i64, i64, f64, f64, f64, f64, f64, f64) -> i64

The CPS entry point: fn(base, sp) -> i64 — base is the frame (the compiled function’s register slots), sp the operand-stack top.

Safety

base must point at a frame at least as large as every patched slot index; sp must point into an operand stack with capacity for the chain’s pushes; the page must outlive every call.

pub fn run(&self) -> i64

Run the chain with an empty frame and a fresh operand stack.

pub fn run_with_frame(&self, frame: &mut [i64]) -> i64

Run the chain over the given frame (slot 0 = VM register 0, …), with a fresh operand stack. The frame is read AND written by slot stencils.

LOGOS_JIT_CANARY=1 guards the operand stack with a sentinel canary past its end: any stencil that pushes beyond the 256-slot stack (a pc/sp miscompile) trips it loudly at the source instead of silently corrupting adjacent memory. It is env-gated rather than always-on because this runs per chain — millions of times for hot recursion — so the default (and every release build) pays nothing.

pub fn bytes(&self) -> &[u8]

The mapped code+pool bytes (diagnostics/tests).

pub fn base(&self) -> u64

The runtime base address (diagnostics/tests).

pub fn piece_count(&self) -> usize

How many stencil pieces were glued (diagnostics/tests — the tail-jump economics of a lowering).

Trait Implementations

impl Debug for JitChain

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.