//===-- ModelInjector.cpp ---------------------------------------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "ModelInjector.h"

#include "clang/AST/Decl.h"

#include "clang/Basic/IdentifierTable.h"

#include "clang/Basic/LangStandard.h"

#include "clang/Basic/Stack.h"

#include "clang/AST/DeclObjC.h"

#include "clang/Frontend/ASTUnit.h"

#include "clang/Frontend/CompilerInstance.h"

#include "clang/Frontend/FrontendAction.h"

#include "clang/Lex/Preprocessor.h"

#include "clang/Serialization/ASTReader.h"

#include "clang/StaticAnalyzer/Frontend/FrontendActions.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/Support/CrashRecoveryContext.h"

#include "llvm/Support/FileSystem.h"

#include <utility>

using namespace clang;

using namespace ento;

ModelInjector::ModelInjector(CompilerInstance &CI) : CI(CI) {}

Stmt *ModelInjector::getBody(const FunctionDecl *D) {

  onBodySynthesis(D);

  return Bodies[D->getName()];

}

Stmt *ModelInjector::getBody(const ObjCMethodDecl *D) {

  onBodySynthesis(D);

  return Bodies[D->getName()];

}

void ModelInjector::onBodySynthesis(const NamedDecl *D) {

  // FIXME: what about overloads? Declarations can be used as keys but what

  // about file name index? Mangled names may not be suitable for that either.

  if (Bodies.count(D->getName()) != 0)

    return;

  SourceManager &SM = CI.getSourceManager();

  FileID mainFileID = SM.getMainFileID();

  llvm::StringRef modelPath = CI.getAnalyzerOpts().ModelPath;

  llvm::SmallString<128> fileName;

  if (!modelPath.empty())

    fileName =

        llvm::StringRef(modelPath.str() + "/" + D->getName().str() + ".model");

  else

    fileName = llvm::StringRef(D->getName().str() + ".model");

  if (!llvm::sys::fs::exists(fileName.str())) {

    Bodies[D->getName()] = nullptr;

    return;

  }

  auto Invocation = std::make_shared<CompilerInvocation>(CI.getInvocation());

  FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();

  InputKind IK = Language::CXX; // FIXME

  FrontendOpts.Inputs.clear();

  FrontendOpts.Inputs.emplace_back(fileName, IK);

  FrontendOpts.DisableFree = true;

  Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;

  // Modules are parsed by a separate CompilerInstance, so this code mimics that

  // behavior for models

  CompilerInstance Instance(CI.getPCHContainerOperations());

  Instance.setInvocation(std::move(Invocation));

  Instance.createDiagnostics(

      new ForwardingDiagnosticConsumer(CI.getDiagnosticClient()),

      /*ShouldOwnClient=*/true);

  Instance.getDiagnostics().setSourceManager(&SM);

  // The instance wants to take ownership, however DisableFree frontend option

  // is set to true to avoid double free issues

  Instance.setFileManager(&CI.getFileManager());

  Instance.setSourceManager(&SM);

  Instance.setPreprocessor(CI.getPreprocessorPtr());

  Instance.setASTContext(&CI.getASTContext());

  Instance.getPreprocessor().InitializeForModelFile();

  ParseModelFileAction parseModelFile(Bodies);

  llvm::CrashRecoveryContext CRC;

  CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(parseModelFile); },

                        DesiredStackSize);

  Instance.getPreprocessor().FinalizeForModelFile();

  Instance.resetAndLeakSourceManager();

  Instance.resetAndLeakFileManager();

  Instance.resetAndLeakPreprocessor();

  // The preprocessor enters to the main file id when parsing is started, so

  // the main file id is changed to the model file during parsing and it needs

  // to be reset to the former main file id after parsing of the model file

  // is done.

  SM.setMainFileID(mainFileID);

}