1#include <iostream>
2#include <fstream>
3#include <cstdlib>
4#include <string>
5#include <cinttypes>
6
7#include "wasm.hh"
8
9// A function to be called from Wasm code.
10auto callback(
11  const wasm::Val args[], wasm::Val results[]
12) -> wasm::own<wasm::Trap> {
13  std::cout << "Calling back..." << std::endl;
14  std::cout << "> " << args[0].i32();
15  std::cout << " " << args[1].i64();
16  std::cout << " " << args[2].i64();
17  std::cout << " " << args[3].i32() << std::endl;
18  results[0] = args[3].copy();
19  results[1] = args[1].copy();
20  results[2] = args[2].copy();
21  results[3] = args[0].copy();
22  return nullptr;
23}
24
25
26void run() {
27  // Initialize.
28  std::cout << "Initializing..." << std::endl;
29  auto engine = wasm::Engine::make();
30  auto store_ = wasm::Store::make(engine.get());
31  auto store = store_.get();
32
33  // Load binary.
34  std::cout << "Loading binary..." << std::endl;
35  std::ifstream file("multi.wasm");
36  file.seekg(0, std::ios_base::end);
37  auto file_size = file.tellg();
38  file.seekg(0);
39  auto binary = wasm::vec<byte_t>::make_uninitialized(file_size);
40  file.read(binary.get(), file_size);
41  file.close();
42  if (file.fail()) {
43    std::cout << "> Error loading module!" << std::endl;
44    exit(1);
45  }
46
47  // Compile.
48  std::cout << "Compiling module..." << std::endl;
49  auto module = wasm::Module::make(store, binary);
50  if (!module) {
51    std::cout << "> Error compiling module!" << std::endl;
52    exit(1);
53  }
54
55  // Create external print functions.
56  std::cout << "Creating callback..." << std::endl;
57  auto tuple = wasm::ownvec<wasm::ValType>::make(
58    wasm::ValType::make(wasm::I32),
59    wasm::ValType::make(wasm::I64),
60    wasm::ValType::make(wasm::I64),
61    wasm::ValType::make(wasm::I32)
62  );
63  auto callback_type =
64    wasm::FuncType::make(tuple.deep_copy(), tuple.deep_copy());
65  auto callback_func = wasm::Func::make(store, callback_type.get(), callback);
66
67  // Instantiate.
68  std::cout << "Instantiating module..." << std::endl;
69  wasm::Extern* imports[] = {callback_func.get()};
70  auto instance = wasm::Instance::make(store, module.get(), imports);
71  if (!instance) {
72    std::cout << "> Error instantiating module!" << std::endl;
73    exit(1);
74  }
75
76  // Extract export.
77  std::cout << "Extracting export..." << std::endl;
78  auto exports = instance->exports();
79  if (exports.size() == 0 || exports[0]->kind() != wasm::EXTERN_FUNC || !exports[0]->func()) {
80    std::cout << "> Error accessing export!" << std::endl;
81    exit(1);
82  }
83  auto run_func = exports[0]->func();
84
85  // Call.
86  std::cout << "Calling export..." << std::endl;
87  wasm::Val args[] = {
88    wasm::Val::i32(1), wasm::Val::i64(2), wasm::Val::i64(3), wasm::Val::i32(4)
89  };
90  wasm::Val results[4];
91  if (wasm::own<wasm::Trap> trap = run_func->call(args, results)) {
92    std::cout << "> Error calling function! " << trap->message().get() << std::endl;
93    exit(1);
94  }
95
96  // Print result.
97  std::cout << "Printing result..." << std::endl;
98  std::cout << "> " << results[0].i32();
99  std::cout << " " << results[1].i64();
100  std::cout << " " << results[2].i64();
101  std::cout << " " << results[3].i32() << std::endl;
102
103  assert(results[0].i32() == 4);
104  assert(results[1].i64() == 3);
105  assert(results[2].i64() == 2);
106  assert(results[3].i32() == 1);
107
108  // Shut down.
109  std::cout << "Shutting down..." << std::endl;
110}
111
112
113int main(int argc, const char* argv[]) {
114  run();
115  std::cout << "Done." << std::endl;
116  return 0;
117}
118
119