// Part of the Concrete Compiler Project, under the BSD3 License with Zama
// Exceptions. See
// https://github.com/zama-ai/concrete-compiler-internal/blob/main/LICENSE.txt
// for license information.

#include "concretelang/Conversion/Tools.h"

mlir::LogicalResult insertForwardDeclaration(mlir::Operation *op,
                                             mlir::RewriterBase &rewriter,
                                             llvm::StringRef funcName,
                                             mlir::FunctionType funcType) {
  // Looking for the `funcName` Operation
  auto module = mlir::SymbolTable::getNearestSymbolTable(op);
  auto opFunc = mlir::dyn_cast_or_null<mlir::SymbolOpInterface>(
      mlir::SymbolTable::lookupSymbolIn(module, funcName));
  if (!opFunc) {
    // Insert the forward declaration of the funcName
    mlir::OpBuilder::InsertionGuard guard(rewriter);
    rewriter.setInsertionPointToStart(&module->getRegion(0).front());

    opFunc = rewriter.create<mlir::FuncOp>(rewriter.getUnknownLoc(), funcName,
                                           funcType);
    opFunc.setPrivate();
  } else {
    // Check if the `funcName` is well a private function
    if (!opFunc.isPrivate()) {
      op->emitError() << "the function \"" << funcName
                      << "\" conflicts with the concrete C API, please rename";
      return mlir::failure();
    }
  }
  assert(mlir::SymbolTable::lookupSymbolIn(module, funcName)
             ->template hasTrait<mlir::OpTrait::FunctionLike>());
  return mlir::success();
}