v8/third_party/wasm-api/example/hello.cc
Jakob Kummerow 3b45da47cd [wasm-c-api] Roll 70a2889: Remove template meta-programming
This change is very mechanical:
own<Foo*> → own<Foo>
vec<Foo*> → ownvec<Foo>
As usual, everything in third_party/ is straight-up copied from upstream.

Change-Id: If5fabda99e2b281da6f2e71ce23a2f5b68aaac86
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1760815
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63263}
2019-08-20 09:35:35 +00:00

92 lines
2.4 KiB
C++

#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <cinttypes>
#include "wasm.hh"
// A function to be called from Wasm code.
auto hello_callback(
const wasm::Val args[], wasm::Val results[]
) -> wasm::own<wasm::Trap> {
std::cout << "Calling back..." << std::endl;
std::cout << "> Hello world!" << std::endl;
return nullptr;
}
void run() {
// Initialize.
std::cout << "Initializing..." << std::endl;
auto engine = wasm::Engine::make();
auto store_ = wasm::Store::make(engine.get());
auto store = store_.get();
// Load binary.
std::cout << "Loading binary..." << std::endl;
std::ifstream file("hello.wasm");
file.seekg(0, std::ios_base::end);
auto file_size = file.tellg();
file.seekg(0);
auto binary = wasm::vec<byte_t>::make_uninitialized(file_size);
file.read(binary.get(), file_size);
file.close();
if (file.fail()) {
std::cout << "> Error loading module!" << std::endl;
exit(1);
}
// Compile.
std::cout << "Compiling module..." << std::endl;
auto module = wasm::Module::make(store, binary);
if (!module) {
std::cout << "> Error compiling module!" << std::endl;
exit(1);
}
// Create external print functions.
std::cout << "Creating callback..." << std::endl;
auto hello_type = wasm::FuncType::make(
wasm::ownvec<wasm::ValType>::make(), wasm::ownvec<wasm::ValType>::make()
);
auto hello_func = wasm::Func::make(store, hello_type.get(), hello_callback);
// Instantiate.
std::cout << "Instantiating module..." << std::endl;
wasm::Extern* imports[] = {hello_func.get()};
auto instance = wasm::Instance::make(store, module.get(), imports);
if (!instance) {
std::cout << "> Error instantiating module!" << std::endl;
exit(1);
}
// Extract export.
std::cout << "Extracting export..." << std::endl;
auto exports = instance->exports();
if (exports.size() == 0 || exports[0]->kind() != wasm::EXTERN_FUNC || !exports[0]->func()) {
std::cout << "> Error accessing export!" << std::endl;
exit(1);
}
auto run_func = exports[0]->func();
// Call.
std::cout << "Calling export..." << std::endl;
if (run_func->call()) {
std::cout << "> Error calling function!" << std::endl;
exit(1);
}
// Shut down.
std::cout << "Shutting down..." << std::endl;
}
int main(int argc, const char* argv[]) {
run();
std::cout << "Done." << std::endl;
return 0;
}