Redline: trampolines must be precomputed at build time; the Cranelift bridge must not be a runtime dependency

[andreaTP]

Both native machines (JffiNativeMachine and the Panama NativeMachine) compile their ABI trampolines in the constructor, i.e. once per instance:

try (var bridge = new CraneliftBridge()) {   // Instance.builder(Cranelift.load())...build()
    bridge.init(RedlineTarget.detectHost()...triple());
    var trampolines = bridge.compileTrampolines(compiledCode, funcTypesByBody, importTypes, importStubAddrs, ...);

CraneliftBridge() instantiates the Cranelift compiler (the 2.5 MB cranelift_bridge.wasm, on the bytecode compiler) every time. The build-time output (NativeCodeSerializer) only contains the function bodies, no trampolines. Measured with quickjs4j (Endive 1.1.0, javy module): 0.8–2.9 s and ~+26 MB RSS per Instance, versus ~0.1 s for the build-time compiled bytecode. Anything that creates instances regularly (camel-quickjs recycles an engine every few thousand evaluations) is dominated by this.

Expected design: everything is precomputed at build time. The runners only load and link, and redline-bridge-experimental (the Cranelift compiler) must not be a runtime dependency of redline-runner-experimental / redline-runner-jffi-experimental at all; today both declare it in compile scope.

Concretely:

• the build-time compiler emits the entry trampolines, import trampolines, internal stub trampolines and memmove/memset trampolines next to the function bodies (one set per target), in the .native payload;
• the per-instance addresses they embed today (import closure stubs, watchdog/memgrow stubs, memmove/memset) are either read indirectly from the ctx buffer / function table, so the trampolines are position-independent, or patched at load time through a small relocation table in the payload;
• the runners drop the dependency on the bridge; the bridge stays a build-time-only artifact.

🤖 Generated with Claude Code

[andreaTP]

The cranelift compiler shouldn't be instantiated at runtime, nor it should be available on the classpath.