1//===- Tree.cpp -----------------------------------------------*- C++ -*-=====//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8#include "clang/Tooling/Syntax/Tree.h"
9#include "clang/Basic/TokenKinds.h"
10#include "clang/Tooling/Syntax/Nodes.h"
11#include "llvm/ADT/ArrayRef.h"
12#include "llvm/ADT/STLExtras.h"
13#include "llvm/Support/Casting.h"
14#include <cassert>
15
16using namespace clang;
17
18namespace {
19static void traverse(const syntax::Node *N,
20                     llvm::function_ref<void(const syntax::Node *)> Visit) {
21  if (auto *T = dyn_cast<syntax::Tree>(N)) {
22    for (auto *C = T->firstChild(); C; C = C->nextSibling())
23      traverse(C, Visit);
24  }
25  Visit(N);
26}
27static void traverse(syntax::Node *N,
28                     llvm::function_ref<void(syntax::Node *)> Visit) {
29  traverse(static_cast<const syntax::Node *>(N), [&](const syntax::Node *N) {
30    Visit(const_cast<syntax::Node *>(N));
31  });
32}
33} // namespace
34
35syntax::Arena::Arena(SourceManager &SourceMgr, const LangOptions &LangOpts,
36                     TokenBuffer Tokens)
37    : SourceMgr(SourceMgr), LangOpts(LangOpts), Tokens(std::move(Tokens)) {}
38
39const clang::syntax::TokenBuffer &syntax::Arena::tokenBuffer() const {
40  return Tokens;
41}
42
43std::pair<FileID, llvm::ArrayRef<syntax::Token>>
44syntax::Arena::lexBuffer(std::unique_ptr<llvm::MemoryBuffer> Input) {
45  auto FID = SourceMgr.createFileID(std::move(Input));
46  auto It = ExtraTokens.try_emplace(FID, tokenize(FID, SourceMgr, LangOpts));
47  assert(It.second && "duplicate FileID");
48  return {FID, It.first->second};
49}
50
51syntax::Leaf::Leaf(const syntax::Token *Tok) : Node(NodeKind::Leaf), Tok(Tok) {
52  assert(Tok != nullptr);
53}
54
55bool syntax::Leaf::classof(const Node *N) {
56  return N->kind() == NodeKind::Leaf;
57}
58
59syntax::Node::Node(NodeKind Kind)
60    : Parent(nullptr), NextSibling(nullptr), Kind(static_cast<unsigned>(Kind)),
61      Role(static_cast<unsigned>(NodeRole::Detached)), Original(false),
62      CanModify(false) {}
63
64bool syntax::Node::isDetached() const { return role() == NodeRole::Detached; }
65
66bool syntax::Tree::classof(const Node *N) { return N->kind() > NodeKind::Leaf; }
67
68void syntax::Tree::prependChildLowLevel(Node *Child, NodeRole Role) {
69  assert(Child->Parent == nullptr);
70  assert(Child->NextSibling == nullptr);
71  assert(Child->role() == NodeRole::Detached);
72  assert(Role != NodeRole::Detached);
73
74  Child->Parent = this;
75  Child->NextSibling = this->FirstChild;
76  Child->Role = static_cast<unsigned>(Role);
77  this->FirstChild = Child;
78}
79
80void syntax::Tree::replaceChildRangeLowLevel(Node *BeforeBegin, Node *End,
81                                             Node *New) {
82  assert(!BeforeBegin || BeforeBegin->Parent == this);
83
84#ifndef NDEBUG
85  for (auto *N = New; N; N = N->nextSibling()) {
86    assert(N->Parent == nullptr);
87    assert(N->role() != NodeRole::Detached && "Roles must be set");
88    // FIXME: sanity-check the role.
89  }
90#endif
91
92  // Detach old nodes.
93  for (auto *N = !BeforeBegin ? FirstChild : BeforeBegin->nextSibling();
94       N != End;) {
95    auto *Next = N->NextSibling;
96
97    N->Role = static_cast<unsigned>(NodeRole::Detached);
98    N->Parent = nullptr;
99    N->NextSibling = nullptr;
100    if (N->Original)
101      traverse(N, [&](Node *C) { C->Original = false; });
102
103    N = Next;
104  }
105
106  // Attach new nodes.
107  if (BeforeBegin)
108    BeforeBegin->NextSibling = New ? New : End;
109  else
110    FirstChild = New ? New : End;
111
112  if (New) {
113    auto *Last = New;
114    for (auto *N = New; N != nullptr; N = N->nextSibling()) {
115      Last = N;
116      N->Parent = this;
117    }
118    Last->NextSibling = End;
119  }
120
121  // Mark the node as modified.
122  for (auto *T = this; T && T->Original; T = T->Parent)
123    T->Original = false;
124}
125
126namespace {
127static void dumpTokens(llvm::raw_ostream &OS, ArrayRef<syntax::Token> Tokens,
128                       const SourceManager &SM) {
129  assert(!Tokens.empty());
130  bool First = true;
131  for (const auto &T : Tokens) {
132    if (!First)
133      OS << " ";
134    else
135      First = false;
136    // Handle 'eof' separately, calling text() on it produces an empty string.
137    if (T.kind() == tok::eof) {
138      OS << "<eof>";
139      continue;
140    }
141    OS << T.text(SM);
142  }
143}
144
145static void dumpTree(llvm::raw_ostream &OS, const syntax::Node *N,
146                     const syntax::Arena &A, std::vector<bool> IndentMask) {
147  std::string Marks;
148  if (!N->isOriginal())
149    Marks += "M";
150  if (N->role() == syntax::NodeRole::Detached)
151    Marks += "*"; // FIXME: find a nice way to print other roles.
152  if (!N->canModify())
153    Marks += "I";
154  if (!Marks.empty())
155    OS << Marks << ": ";
156
157  if (auto *L = llvm::dyn_cast<syntax::Leaf>(N)) {
158    dumpTokens(OS, *L->token(), A.sourceManager());
159    OS << "\n";
160    return;
161  }
162
163  auto *T = llvm::cast<syntax::Tree>(N);
164  OS << T->kind() << "\n";
165
166  for (auto It = T->firstChild(); It != nullptr; It = It->nextSibling()) {
167    for (bool Filled : IndentMask) {
168      if (Filled)
169        OS << "| ";
170      else
171        OS << "  ";
172    }
173    if (!It->nextSibling()) {
174      OS << "`-";
175      IndentMask.push_back(false);
176    } else {
177      OS << "|-";
178      IndentMask.push_back(true);
179    }
180    dumpTree(OS, It, A, IndentMask);
181    IndentMask.pop_back();
182  }
183}
184} // namespace
185
186std::string syntax::Node::dump(const Arena &A) const {
187  std::string Str;
188  llvm::raw_string_ostream OS(Str);
189  dumpTree(OS, this, A, /*IndentMask=*/{});
190  return std::move(OS.str());
191}
192
193std::string syntax::Node::dumpTokens(const Arena &A) const {
194  std::string Storage;
195  llvm::raw_string_ostream OS(Storage);
196  traverse(this, [&](const syntax::Node *N) {
197    auto *L = llvm::dyn_cast<syntax::Leaf>(N);
198    if (!L)
199      return;
200    ::dumpTokens(OS, *L->token(), A.sourceManager());
201    OS << " ";
202  });
203  return OS.str();
204}
205
206void syntax::Node::assertInvariants() const {
207#ifndef NDEBUG
208  if (isDetached())
209    assert(parent() == nullptr);
210  else
211    assert(parent() != nullptr);
212
213  auto *T = dyn_cast<Tree>(this);
214  if (!T)
215    return;
216  for (auto *C = T->firstChild(); C; C = C->nextSibling()) {
217    if (T->isOriginal())
218      assert(C->isOriginal());
219    assert(!C->isDetached());
220    assert(C->parent() == T);
221  }
222#endif
223}
224
225void syntax::Node::assertInvariantsRecursive() const {
226#ifndef NDEBUG
227  traverse(this, [&](const syntax::Node *N) { N->assertInvariants(); });
228#endif
229}
230
231syntax::Leaf *syntax::Tree::firstLeaf() {
232  auto *T = this;
233  while (auto *C = T->firstChild()) {
234    if (auto *L = dyn_cast<syntax::Leaf>(C))
235      return L;
236    T = cast<syntax::Tree>(C);
237  }
238  return nullptr;
239}
240
241syntax::Leaf *syntax::Tree::lastLeaf() {
242  auto *T = this;
243  while (auto *C = T->firstChild()) {
244    // Find the last child.
245    while (auto *Next = C->nextSibling())
246      C = Next;
247
248    if (auto *L = dyn_cast<syntax::Leaf>(C))
249      return L;
250    T = cast<syntax::Tree>(C);
251  }
252  return nullptr;
253}
254
255syntax::Node *syntax::Tree::findChild(NodeRole R) {
256  for (auto *C = FirstChild; C; C = C->nextSibling()) {
257    if (C->role() == R)
258      return C;
259  }
260  return nullptr;
261}
262