instance.hh

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#ifndef WASMTIME_INSTANCE_HH
#define WASMTIME_INSTANCE_HH
 
#include <wasmtime/extern.hh>
#include <wasmtime/func.hh>
#include <wasmtime/global.hh>
#include <wasmtime/instance.h>
#include <wasmtime/memory.hh>
#include <wasmtime/module.hh>
#include <wasmtime/store.hh>
#include <wasmtime/table.hh>
#include <wasmtime/tag.hh>
 
namespace wasmtime {
 
class Instance {
  friend class Linker;
  friend class Caller;
 
  wasmtime_instance_t instance;
 
public:
  Instance(wasmtime_instance_t instance) : instance(instance) {}
 
  static TrapResult<Instance> create(Store::Context cx, const Module &m,
                                     const std::vector<Extern> &imports) {
    std::vector<wasmtime_extern_t> raw_imports;
    for (const auto &item : imports) {
      raw_imports.push_back(wasmtime_extern_t{});
      auto &last = raw_imports.back();
      detail::cvt_extern(item, last);
    }
    wasmtime_instance_t instance;
    wasm_trap_t *trap = nullptr;
    auto *error = wasmtime_instance_new(cx.ptr, m.capi(), raw_imports.data(),
                                        raw_imports.size(), &instance, &trap);
    if (error != nullptr) {
      return TrapError(Error(error));
    }
    if (trap != nullptr) {
      return TrapError(Trap(trap));
    }
    return Instance(instance);
  }
 
  std::optional<Extern> get(Store::Context cx, std::string_view name) {
    wasmtime_extern_t e;
    if (!wasmtime_instance_export_get(cx.ptr, &instance, name.data(),
                                      name.size(), &e)) {
      return std::nullopt;
    }
    return detail::cvt_extern(e);
  }
 
  std::optional<std::pair<std::string_view, Extern>> get(Store::Context cx,
                                                         size_t idx) {
    wasmtime_extern_t e;
    // I'm not sure why clang-tidy thinks this is using va_list or anything
    // related to that...
    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    char *name = nullptr;
    size_t len = 0;
    if (!wasmtime_instance_export_nth(cx.ptr, &instance, idx, &name, &len,
                                      &e)) {
      return std::nullopt;
    }
    std::string_view n(name, len);
    return std::pair(n, detail::cvt_extern(e));
  }
};
 
} // namespace wasmtime
 
#endif // WASMTIME_INSTANCE_HH