// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#include <google/protobuf/text_format.h>
#include <libprotobuf_mutator/src/libfuzzer/libfuzzer_macro.h>

#include "common/fuzzing/carbon.pb.h"
#include "executable_semantics/fuzzing/fuzzer_util.h"
#include "executable_semantics/interpreter/exec_program.h"
#include "executable_semantics/syntax/parse.h"
#include "executable_semantics/syntax/prelude.h"
#include "llvm/Support/raw_ostream.h"

namespace Carbon {

// Parses and executes a fuzzer-generated program.
void ParseAndExecute(const Fuzzing::CompilationUnit& compilation_unit) {
  const std::string source = ProtoToCarbonWithMain(compilation_unit);

  Arena arena;
  ErrorOr<AST> ast = ParseFromString(&arena, "Fuzzer.carbon", source,
                                     /*trace=*/false);
  if (!ast.ok()) {
    llvm::errs() << "Parsing failed: " << ast.error().message() << "\n";
    return;
  }
  AddPrelude("executable_semantics/data/prelude.carbon", &arena,
             &ast->declarations);
  const ErrorOr<int> result = ExecProgram(&arena, *ast, /*trace=*/false);
  if (!result.ok()) {
    llvm::errs() << "Execution failed: " << result.error().message() << "\n";
    return;
  }
  llvm::outs() << "Executed OK: " << *result << "\n";
}

}  // namespace Carbon

DEFINE_TEXT_PROTO_FUZZER(const Carbon::Fuzzing::Carbon& input) {
  Carbon::ParseAndExecute(input.compilation_unit());
}