// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: 2019-2024 Second State INC

#include "executor/executor.h"

#include <cstdint>

namespace WasmEdge {

namespace Executor {

// Instantiate global instance. See "include/executor/executor.h".

Expect<void> Executor::instantiate(Runtime::StackManager &StackMgr,

                                   Runtime::Instance::ModuleInstance &ModInst,

                                   const AST::GlobalSection &GlobSec) {

  // A frame with temp. module is pushed into the stack in caller.

  // Prepare pointers for compiled functions.

  ModInst.GlobalPtrs.resize(ModInst.getGlobalNum() +

                            GlobSec.getContent().size());

  // Set the global pointers of imported globals.

  for (uint32_t I = 0; I < ModInst.getGlobalNum(); ++I) {

    ModInst.GlobalPtrs[I] = &((*ModInst.getGlobal(I))->getValue());

  }

  // Iterate through the global segments to instantiate and initialize global

  // instances.

  for (const auto &GlobSeg : GlobSec.getContent()) {

    // Run initialize expression.

    EXPECTED_TRY(runExpression(StackMgr, GlobSeg.getExpr().getInstrs())

                     .map_error([](auto E) {

                       spdlog::error(ErrInfo::InfoAST(ASTNodeAttr::Expression));

                       return E;

                     }));

    // Pop result from stack.

    ValVariant InitValue = StackMgr.pop();

    // Create and add the global instance into the module instance.

    ModInst.addGlobal(GlobSeg.getGlobalType(), InitValue);

    const auto Index = ModInst.getGlobalNum() - 1;

    Runtime::Instance::GlobalInstance *GlobInst = *ModInst.getGlobal(Index);

    // Set the global pointers of instantiated globals.

    ModInst.GlobalPtrs[Index] = &(GlobInst->getValue());

  }

  return {};

}

} // namespace Executor

} // namespace WasmEdge