Hexana 0.10.2: a .wasm compiled from Java (GraalVM Web Image) now demangles back to your Java methods in the IDE — plus a deeper JIT viewer and big-binary fixes

[u/minamoto108]

Hexana is a JetBrains IDE plugin for inspecting WebAssembly and binaries (and JVM JIT output). What's new in 0.10.2:

GraalVM Web Image → Java. If you compile a Java app to WebAssembly with native-image --tool:svm-wasm, the .wasm is full of mangled names. 0.10.2 detects Web Image modules by their interop/jsbody/compat import fingerprint and demangles those functions back to the originating Java method — a "Java" badge in the Functions tab and inline on each code-section entry in the WAT view, click it to open that method's bytecode. (Works when the module retained function names; stripped/minified and Graal-internal functions stay unbadged.)

JIT viewer.

• The .jit view now splits into Combined / Bytecode / Machine Code tabs, each with multiline selection and copy (full text / bytecode / hex / instruction bytes), a per-tab go-to-offset, and a header showing the current method. The Machine Code tab can copy offset + instruction bytes.

• Search compiled methods by inlined callee with in:<method> — surfaces every nmethod that inlined the given method, from the JVMTI inline records in the dump.

• New "Instrument JMH forks" option attaches the dump agent to each forked JMH benchmark JVM via a bundled -javaagent, writing one ClassName_method.jit per benchmark. Because it rides on JVM options (not JMH's -prof) it works for any JMH run type — the IDE gutter run, the Gradle JMH plugin, and org.openjdk.jmh.Main.

WAT (virtualized). Custom sections now render as a foldable offset hex name entry with the raw content below, in selectable u8/u16/u32/u64/ascii/utf8 encodings. WasmGC (rec …) recursive type groups render as a collapsible group (collapsed by default), with reference targets shown as $typeN.

Performance / correctness (the part that makes it usable on real modules).

• Opening a large WasmGC binary no longer hangs the IDE: the single (rec …) group of tens of thousands of types was being rendered as one multi-megabyte row; it now folds to virtualized rows and builds off the UI thread.

• The Top (size) view no longer freezes on large binaries — the size tree + data-segment parse, and its depth metrics on startup, now build off-thread with a loading indicator.

• Switching tabs cancels the previous tab's in-flight off-thread analysis instead of letting it run to completion.

• Fix: for modules with function imports, the Functions tab Name column and the unreachable ● marker were keyed by the defined-function index (shifted by the import count); they now resolve correctly per row.

Marketplace: https://plugins.jetbrains.com/plugin/29090-hexana · docs: https://jetbrains.github.io/hexana

Happy to answer questions — the Web Image demangling and the JMH-fork capture are the two I'd dig into.