//===- Synthesis.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 "clang/Basic/TokenKinds.h"

#include "clang/Tooling/Syntax/BuildTree.h"

#include "clang/Tooling/Syntax/Tree.h"

#include "clang/Tooling/Syntax/Tokens.h"

#include "clang/Tooling/Syntax/TokenBufferTokenManager.h"

using namespace clang;

/// Exposes private syntax tree APIs required to implement node synthesis.

/// Should not be used for anything else.

class clang::syntax::FactoryImpl {

public:

  static void setCanModify(syntax::Node *N) { N->CanModify = true; }

  static void prependChildLowLevel(syntax::Tree *T, syntax::Node *Child,

                                   syntax::NodeRole R) {

    T->prependChildLowLevel(Child, R);

  }

  static void appendChildLowLevel(syntax::Tree *T, syntax::Node *Child,

                                  syntax::NodeRole R) {

    T->appendChildLowLevel(Child, R);

  }

  static std::pair<FileID, ArrayRef<Token>>

  lexBuffer(TokenBufferTokenManager &TBTM,

            std::unique_ptr<llvm::MemoryBuffer> Buffer) {

    return TBTM.lexBuffer(std::move(Buffer));

  }

};

// FIXME: `createLeaf` is based on `syntax::tokenize` internally, as such it

// doesn't support digraphs or line continuations.

syntax::Leaf *clang::syntax::createLeaf(syntax::Arena &A,

                                        TokenBufferTokenManager &TBTM,

                                        tok::TokenKind K, StringRef Spelling) {

  auto Tokens =

      FactoryImpl::lexBuffer(TBTM, llvm::MemoryBuffer::getMemBufferCopy(Spelling))

          .second;

  assert(Tokens.size() == 1);

  assert(Tokens.front().kind() == K &&

         "spelling is not lexed into the expected kind of token");

  auto *Leaf = new (A.getAllocator()) syntax::Leaf(

    reinterpret_cast<TokenManager::Key>(Tokens.begin()));

  syntax::FactoryImpl::setCanModify(Leaf);

  Leaf->assertInvariants();

  return Leaf;

}

syntax::Leaf *clang::syntax::createLeaf(syntax::Arena &A,

                                        TokenBufferTokenManager &TBTM,

                                        tok::TokenKind K) {

  const auto *Spelling = tok::getPunctuatorSpelling(K);

  if (!Spelling)

    Spelling = tok::getKeywordSpelling(K);

  assert(Spelling &&

         "Cannot infer the spelling of the token from its token kind.");

  return createLeaf(A, TBTM, K, Spelling);

}

namespace {

// Allocates the concrete syntax `Tree` according to its `NodeKind`.

syntax::Tree *allocateTree(syntax::Arena &A, syntax::NodeKind Kind) {

  switch (Kind) {

  case syntax::NodeKind::Leaf:

    assert(false);

    break;

  case syntax::NodeKind::TranslationUnit:

    return new (A.getAllocator()) syntax::TranslationUnit;

  case syntax::NodeKind::UnknownExpression:

    return new (A.getAllocator()) syntax::UnknownExpression;

  case syntax::NodeKind::ParenExpression:

    return new (A.getAllocator()) syntax::ParenExpression;

  case syntax::NodeKind::ThisExpression:

    return new (A.getAllocator()) syntax::ThisExpression;

  case syntax::NodeKind::IntegerLiteralExpression:

    return new (A.getAllocator()) syntax::IntegerLiteralExpression;

  case syntax::NodeKind::CharacterLiteralExpression:

    return new (A.getAllocator()) syntax::CharacterLiteralExpression;

  case syntax::NodeKind::FloatingLiteralExpression:

    return new (A.getAllocator()) syntax::FloatingLiteralExpression;

  case syntax::NodeKind::StringLiteralExpression:

    return new (A.getAllocator()) syntax::StringLiteralExpression;

  case syntax::NodeKind::BoolLiteralExpression:

    return new (A.getAllocator()) syntax::BoolLiteralExpression;

  case syntax::NodeKind::CxxNullPtrExpression:

    return new (A.getAllocator()) syntax::CxxNullPtrExpression;

  case syntax::NodeKind::IntegerUserDefinedLiteralExpression:

    return new (A.getAllocator()) syntax::IntegerUserDefinedLiteralExpression;

  case syntax::NodeKind::FloatUserDefinedLiteralExpression:

    return new (A.getAllocator()) syntax::FloatUserDefinedLiteralExpression;

  case syntax::NodeKind::CharUserDefinedLiteralExpression:

    return new (A.getAllocator()) syntax::CharUserDefinedLiteralExpression;

  case syntax::NodeKind::StringUserDefinedLiteralExpression:

    return new (A.getAllocator()) syntax::StringUserDefinedLiteralExpression;

  case syntax::NodeKind::PrefixUnaryOperatorExpression:

    return new (A.getAllocator()) syntax::PrefixUnaryOperatorExpression;

  case syntax::NodeKind::PostfixUnaryOperatorExpression:

    return new (A.getAllocator()) syntax::PostfixUnaryOperatorExpression;

  case syntax::NodeKind::BinaryOperatorExpression:

    return new (A.getAllocator()) syntax::BinaryOperatorExpression;

  case syntax::NodeKind::UnqualifiedId:

    return new (A.getAllocator()) syntax::UnqualifiedId;

  case syntax::NodeKind::IdExpression:

    return new (A.getAllocator()) syntax::IdExpression;

  case syntax::NodeKind::CallExpression:

    return new (A.getAllocator()) syntax::CallExpression;

  case syntax::NodeKind::UnknownStatement:

    return new (A.getAllocator()) syntax::UnknownStatement;

  case syntax::NodeKind::DeclarationStatement:

    return new (A.getAllocator()) syntax::DeclarationStatement;

  case syntax::NodeKind::EmptyStatement:

    return new (A.getAllocator()) syntax::EmptyStatement;

  case syntax::NodeKind::SwitchStatement:

    return new (A.getAllocator()) syntax::SwitchStatement;

  case syntax::NodeKind::CaseStatement:

    return new (A.getAllocator()) syntax::CaseStatement;

  case syntax::NodeKind::DefaultStatement:

    return new (A.getAllocator()) syntax::DefaultStatement;

  case syntax::NodeKind::IfStatement:

    return new (A.getAllocator()) syntax::IfStatement;

  case syntax::NodeKind::ForStatement:

    return new (A.getAllocator()) syntax::ForStatement;

  case syntax::NodeKind::WhileStatement:

    return new (A.getAllocator()) syntax::WhileStatement;

  case syntax::NodeKind::ContinueStatement:

    return new (A.getAllocator()) syntax::ContinueStatement;

  case syntax::NodeKind::BreakStatement:

    return new (A.getAllocator()) syntax::BreakStatement;

  case syntax::NodeKind::ReturnStatement:

    return new (A.getAllocator()) syntax::ReturnStatement;

  case syntax::NodeKind::RangeBasedForStatement:

    return new (A.getAllocator()) syntax::RangeBasedForStatement;

  case syntax::NodeKind::ExpressionStatement:

    return new (A.getAllocator()) syntax::ExpressionStatement;

  case syntax::NodeKind::CompoundStatement:

    return new (A.getAllocator()) syntax::CompoundStatement;

  case syntax::NodeKind::UnknownDeclaration:

    return new (A.getAllocator()) syntax::UnknownDeclaration;

  case syntax::NodeKind::EmptyDeclaration:

    return new (A.getAllocator()) syntax::EmptyDeclaration;

  case syntax::NodeKind::StaticAssertDeclaration:

    return new (A.getAllocator()) syntax::StaticAssertDeclaration;

  case syntax::NodeKind::LinkageSpecificationDeclaration:

    return new (A.getAllocator()) syntax::LinkageSpecificationDeclaration;

  case syntax::NodeKind::SimpleDeclaration:

    return new (A.getAllocator()) syntax::SimpleDeclaration;

  case syntax::NodeKind::TemplateDeclaration:

    return new (A.getAllocator()) syntax::TemplateDeclaration;

  case syntax::NodeKind::ExplicitTemplateInstantiation:

    return new (A.getAllocator()) syntax::ExplicitTemplateInstantiation;

  case syntax::NodeKind::NamespaceDefinition:

    return new (A.getAllocator()) syntax::NamespaceDefinition;

  case syntax::NodeKind::NamespaceAliasDefinition:

    return new (A.getAllocator()) syntax::NamespaceAliasDefinition;

  case syntax::NodeKind::UsingNamespaceDirective:

    return new (A.getAllocator()) syntax::UsingNamespaceDirective;

  case syntax::NodeKind::UsingDeclaration:

    return new (A.getAllocator()) syntax::UsingDeclaration;

  case syntax::NodeKind::TypeAliasDeclaration:

    return new (A.getAllocator()) syntax::TypeAliasDeclaration;

  case syntax::NodeKind::SimpleDeclarator:

    return new (A.getAllocator()) syntax::SimpleDeclarator;

  case syntax::NodeKind::ParenDeclarator:

    return new (A.getAllocator()) syntax::ParenDeclarator;

  case syntax::NodeKind::ArraySubscript:

    return new (A.getAllocator()) syntax::ArraySubscript;

  case syntax::NodeKind::TrailingReturnType:

    return new (A.getAllocator()) syntax::TrailingReturnType;

  case syntax::NodeKind::ParametersAndQualifiers:

    return new (A.getAllocator()) syntax::ParametersAndQualifiers;

  case syntax::NodeKind::MemberPointer:

    return new (A.getAllocator()) syntax::MemberPointer;

  case syntax::NodeKind::GlobalNameSpecifier:

    return new (A.getAllocator()) syntax::GlobalNameSpecifier;

  case syntax::NodeKind::DecltypeNameSpecifier:

    return new (A.getAllocator()) syntax::DecltypeNameSpecifier;

  case syntax::NodeKind::IdentifierNameSpecifier:

    return new (A.getAllocator()) syntax::IdentifierNameSpecifier;

  case syntax::NodeKind::SimpleTemplateNameSpecifier:

    return new (A.getAllocator()) syntax::SimpleTemplateNameSpecifier;

  case syntax::NodeKind::NestedNameSpecifier:

    return new (A.getAllocator()) syntax::NestedNameSpecifier;

  case syntax::NodeKind::MemberExpression:

    return new (A.getAllocator()) syntax::MemberExpression;

  case syntax::NodeKind::CallArguments:

    return new (A.getAllocator()) syntax::CallArguments;

  case syntax::NodeKind::ParameterDeclarationList:

    return new (A.getAllocator()) syntax::ParameterDeclarationList;

  case syntax::NodeKind::DeclaratorList:

    return new (A.getAllocator()) syntax::DeclaratorList;

  }

  llvm_unreachable("unknown node kind");

}

} // namespace

syntax::Tree *clang::syntax::createTree(

    syntax::Arena &A,

    ArrayRef<std::pair<syntax::Node *, syntax::NodeRole>> Children,

    syntax::NodeKind K) {

  auto *T = allocateTree(A, K);

  FactoryImpl::setCanModify(T);

  for (const auto &Child : Children)

    FactoryImpl::appendChildLowLevel(T, Child.first, Child.second);

  T->assertInvariants();

  return T;

}

syntax::Node *clang::syntax::deepCopyExpandingMacros(syntax::Arena &A,

                                                    TokenBufferTokenManager &TBTM,

                                                     const syntax::Node *N) {

  if (const auto *L = dyn_cast<syntax::Leaf>(N))

    // `L->getToken()` gives us the expanded token, thus we implicitly expand

    // any macros here.

    return createLeaf(A, TBTM, TBTM.getToken(L->getTokenKey())->kind(),

                       TBTM.getText(L->getTokenKey()));

  const auto *T = cast<syntax::Tree>(N);

  std::vector<std::pair<syntax::Node *, syntax::NodeRole>> Children;

  for (const auto *Child = T->getFirstChild(); Child;

       Child = Child->getNextSibling())

    Children.push_back({deepCopyExpandingMacros(A, TBTM, Child), Child->getRole()});

  return createTree(A, Children, N->getKind());

}

syntax::EmptyStatement *clang::syntax::createEmptyStatement(syntax::Arena &A,  TokenBufferTokenManager &TBTM) {

  return cast<EmptyStatement>(

      createTree(A, {{createLeaf(A, TBTM, tok::semi), NodeRole::Unknown}},

                 NodeKind::EmptyStatement));

}