cure-java-simplify

The Java rule pack of cure: 30 Java-specific semantic-preserving simplification rules (64 with the engine's 34 built-ins) over cure-java-ast, driven to a fixed point by cure-engine.

The point is not compression — it is making decompiled code read like hand-written code: fold constants and opaque predicates, inline copies, kill dead stores and compiler register noise, recover StringBuilder statement chains, dissolve control-flow-flattening state machines, evaluate literal-only JDK calls, and restore idiomatic shapes (try-with-resources, string switch).

use cure_engine::Config;
use cure_java_parser::parse;
use cure_java_print::print_unit;
use cure_java_simplify::simplify_unit;

let src = "class B { void n() { int x = 1 + 2; boolean c = (x > 2) && true;
            if (c) { System.out.println(\"y\" + 1); } return; } }";
let mut out = parse(src);
let report = simplify_unit(&mut out.ast, &mut out.unit, &Config::default());
println!("{} edits", report.edits);
println!("{}", print_unit(&out.ast, &out.unit));
// class B {
//     void n() {
//         System.out.println("y1");
//     }
// }

Correctness methodology

Every rule is gated by effect analysis (evaluation order, short-circuiting, and side-effect sequences are preserved) and validated in three layers: property testing against an interpreter, differential testing against real javac/java runs (byte-identical stdout/exit codes/exception signatures), and whole-corpus idempotency (second pass makes zero edits). See the verification section of the repository README.

Notable rules: cff_recover (control-flow flattening recovery), literal_eval (partial evaluation of literal-only JDK calls), string_builder_statements (statement-level builder-chain recovery), store_kill (dominating-path dead-store kill), xor_noise, twr_recover / string_switch_recover (decompiler shape restoration). Full catalog in the repository README.

License: MIT. Zero runtime dependencies.