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 
16 using namespace clang;
17 
18 namespace {
19 static 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 }
27 static 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 
35 syntax::Arena::Arena(SourceManager &SourceMgr, const LangOptions &LangOpts,
36                      TokenBuffer Tokens)
37     : SourceMgr(SourceMgr), LangOpts(LangOpts), Tokens(std::move(Tokens)) {}
38 
39 const clang::syntax::TokenBuffer &syntax::Arena::tokenBuffer() const {
40   return Tokens;
41 }
42 
43 std::pair<FileID, llvm::ArrayRef<syntax::Token>>
44 syntax::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 
51 syntax::Leaf::Leaf(const syntax::Token *Tok) : Node(NodeKind::Leaf), Tok(Tok) {
52   assert(Tok != nullptr);
53 }
54 
55 bool syntax::Leaf::classof(const Node *N) {
56   return N->kind() == NodeKind::Leaf;
57 }
58 
59 syntax::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 
64 bool syntax::Node::isDetached() const { return role() == NodeRole::Detached; }
65 
66 bool syntax::Tree::classof(const Node *N) { return N->kind() > NodeKind::Leaf; }
67 
68 void 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 
80 void 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 
126 namespace {
127 static 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 
145 static 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 
186 std::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 
193 std::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 
206 void 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 
225 void syntax::Node::assertInvariantsRecursive() const {
226 #ifndef NDEBUG
227   traverse(this, [&](const syntax::Node *N) { N->assertInvariants(); });
228 #endif
229 }
230 
231 syntax::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 
241 syntax::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 
255 syntax::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