fix(parser): handle single-line functions in parseWast

[Owanesh]

Closes #4

wasmParser/parser.py -- finalize single-line functions immediately

After matching (func ...), check if func_bracketNum == 0. If so, the function has no body and should be finalized on the spot:

parsedSection["Function"][funcID] = ss.FUNCTION(type=funcType)

# Handle single-line functions where brackets balance on one line
# e.g. (func $stub (type $t0) (param $p0 i32))
if func_bracketNum == 0:
    funcHeaderStr = ''.join([h[0].strip() for h in funcHeaderLine])
    params = parse_param_local_blocks(funcHeaderStr, RE_PARAM)
    locals_ = parse_param_local_blocks(funcHeaderStr, RE_LOCAL)
    has_result = re.search(RE_RESULT, funcHeaderStr)
    result = has_result.group(1) if has_result is not None else None

    parsedSection["Function"][funcID].param = params
    parsedSection["Function"][funcID].result = result
    parsedSection["Function"][funcID].local = locals_
    parsedSection["Function"][funcID].header = funcHeaderLine
    parsedSection["Function"][funcID].body = []

    funcHeaderArea = False
    funcHeaderLine = list()

This prevents the header from leaking into the next function's header list.

strategies/code_perturbation.py -- skip empty-body functions in opaque_predicate_insertion

Extend the guard to also skip functions with an empty body (no instructions means no blocks to insert predicates into):

if function.body is None or len(function.body) == 0:
    continue

After fix

swamped obfuscate repro.wasm -o out.wasm -s opaque_predicate_insertion --seed 42 --ratio 0.5
# [+] Done! Output: out.wasm

The generated WAT now correctly preserves empty-body functions untouched and only inserts predicates into functions that have actual control-flow blocks:

  (func $f0 (type $t0) (param $p0 i32))              ;; untouched
(func $real (type $t1) ... (local $wadelocal i32)     ;; correctly modified
    ...
  (func $f2 (type $t2))                               ;; untouched
(func $real2 (type $t1) ... (local $wadelocal i32)    ;; correctly modified