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/BitVector.h"
12#include "llvm/Support/raw_ostream.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>(Val: N)) {
22 for (const syntax::Node &C : T->getChildren())
23 traverse(N: &C, Visit);
24 }
25 Visit(N);
26}
27static void traverse(syntax::Node *N,
28 llvm::function_ref<void(syntax::Node *)> Visit) {
29 traverse(N: static_cast<const syntax::Node *>(N), Visit: [&](const syntax::Node *N) {
30 Visit(const_cast<syntax::Node *>(N));
31 });
32}
33} // namespace
34
35syntax::Leaf::Leaf(syntax::TokenManager::Key K) : Node(NodeKind::Leaf), K(K) {}
36
37syntax::Node::Node(NodeKind Kind)
38 : Parent(nullptr), NextSibling(nullptr), PreviousSibling(nullptr),
39 Kind(static_cast<unsigned>(Kind)), Role(0), Original(false),
40 CanModify(false) {
41 this->setRole(NodeRole::Detached);
42}
43
44bool syntax::Node::isDetached() const {
45 return getRole() == NodeRole::Detached;
46}
47
48void syntax::Node::setRole(NodeRole NR) {
49 this->Role = static_cast<unsigned>(NR);
50}
51
52void syntax::Tree::appendChildLowLevel(Node *Child, NodeRole Role) {
53 assert(Child->getRole() == NodeRole::Detached);
54 assert(Role != NodeRole::Detached);
55
56 Child->setRole(Role);
57 appendChildLowLevel(Child);
58}
59
60void syntax::Tree::appendChildLowLevel(Node *Child) {
61 assert(Child->Parent == nullptr);
62 assert(Child->NextSibling == nullptr);
63 assert(Child->PreviousSibling == nullptr);
64 assert(Child->getRole() != NodeRole::Detached);
65
66 Child->Parent = this;
67 if (this->LastChild) {
68 Child->PreviousSibling = this->LastChild;
69 this->LastChild->NextSibling = Child;
70 } else
71 this->FirstChild = Child;
72
73 this->LastChild = Child;
74}
75
76void syntax::Tree::prependChildLowLevel(Node *Child, NodeRole Role) {
77 assert(Child->getRole() == NodeRole::Detached);
78 assert(Role != NodeRole::Detached);
79
80 Child->setRole(Role);
81 prependChildLowLevel(Child);
82}
83
84void syntax::Tree::prependChildLowLevel(Node *Child) {
85 assert(Child->Parent == nullptr);
86 assert(Child->NextSibling == nullptr);
87 assert(Child->PreviousSibling == nullptr);
88 assert(Child->getRole() != NodeRole::Detached);
89
90 Child->Parent = this;
91 if (this->FirstChild) {
92 Child->NextSibling = this->FirstChild;
93 this->FirstChild->PreviousSibling = Child;
94 } else
95 this->LastChild = Child;
96
97 this->FirstChild = Child;
98}
99
100void syntax::Tree::replaceChildRangeLowLevel(Node *Begin, Node *End,
101 Node *New) {
102 assert((!Begin || Begin->Parent == this) &&
103 "`Begin` is not a child of `this`.");
104 assert((!End || End->Parent == this) && "`End` is not a child of `this`.");
105 assert(canModify() && "Cannot modify `this`.");
106
107#ifndef NDEBUG
108 for (auto *N = New; N; N = N->NextSibling) {
109 assert(N->Parent == nullptr);
110 assert(N->getRole() != NodeRole::Detached && "Roles must be set");
111 // FIXME: validate the role.
112 }
113
114 auto Reachable = [](Node *From, Node *N) {
115 if (!N)
116 return true;
117 for (auto *It = From; It; It = It->NextSibling)
118 if (It == N)
119 return true;
120 return false;
121 };
122 assert(Reachable(FirstChild, Begin) && "`Begin` is not reachable.");
123 assert(Reachable(Begin, End) && "`End` is not after `Begin`.");
124#endif
125
126 if (!New && Begin == End)
127 return;
128
129 // Mark modification.
130 for (auto *T = this; T && T->Original; T = T->Parent)
131 T->Original = false;
132
133 // Save the node before the range to be removed. Later we insert the `New`
134 // range after this node.
135 auto *BeforeBegin = Begin ? Begin->PreviousSibling : LastChild;
136
137 // Detach old nodes.
138 for (auto *N = Begin; N != End;) {
139 auto *Next = N->NextSibling;
140
141 N->setRole(NodeRole::Detached);
142 N->Parent = nullptr;
143 N->NextSibling = nullptr;
144 N->PreviousSibling = nullptr;
145 if (N->Original)
146 traverse(N, Visit: [](Node *C) { C->Original = false; });
147
148 N = Next;
149 }
150
151 // Attach new range.
152 auto *&NewFirst = BeforeBegin ? BeforeBegin->NextSibling : FirstChild;
153 auto *&NewLast = End ? End->PreviousSibling : LastChild;
154
155 if (!New) {
156 NewFirst = End;
157 NewLast = BeforeBegin;
158 return;
159 }
160
161 New->PreviousSibling = BeforeBegin;
162 NewFirst = New;
163
164 Node *LastInNew;
165 for (auto *N = New; N != nullptr; N = N->NextSibling) {
166 LastInNew = N;
167 N->Parent = this;
168 }
169 LastInNew->NextSibling = End;
170 NewLast = LastInNew;
171}
172
173namespace {
174static void dumpNode(raw_ostream &OS, const syntax::Node *N,
175 const syntax::TokenManager &TM, llvm::BitVector IndentMask) {
176 auto DumpExtraInfo = [&OS](const syntax::Node *N) {
177 if (N->getRole() != syntax::NodeRole::Unknown)
178 OS << " " << N->getRole();
179 if (!N->isOriginal())
180 OS << " synthesized";
181 if (!N->canModify())
182 OS << " unmodifiable";
183 };
184
185 assert(N);
186 if (const auto *L = dyn_cast<syntax::Leaf>(Val: N)) {
187 OS << "'";
188 OS << TM.getText(K: L->getTokenKey());
189 OS << "'";
190 DumpExtraInfo(N);
191 OS << "\n";
192 return;
193 }
194
195 const auto *T = cast<syntax::Tree>(Val: N);
196 OS << T->getKind();
197 DumpExtraInfo(N);
198 OS << "\n";
199
200 for (const syntax::Node &It : T->getChildren()) {
201 for (unsigned Idx = 0; Idx < IndentMask.size(); ++Idx) {
202 if (IndentMask[Idx])
203 OS << "| ";
204 else
205 OS << " ";
206 }
207 if (!It.getNextSibling()) {
208 OS << "`-";
209 IndentMask.push_back(Val: false);
210 } else {
211 OS << "|-";
212 IndentMask.push_back(Val: true);
213 }
214 dumpNode(OS, N: &It, TM, IndentMask);
215 IndentMask.pop_back();
216 }
217}
218} // namespace
219
220std::string syntax::Node::dump(const TokenManager &TM) const {
221 std::string Str;
222 llvm::raw_string_ostream OS(Str);
223 dumpNode(OS, N: this, TM, /*IndentMask=*/{});
224 return std::move(OS.str());
225}
226
227std::string syntax::Node::dumpTokens(const TokenManager &TM) const {
228 std::string Storage;
229 llvm::raw_string_ostream OS(Storage);
230 traverse(N: this, Visit: [&](const syntax::Node *N) {
231 if (const auto *L = dyn_cast<syntax::Leaf>(Val: N)) {
232 OS << TM.getText(K: L->getTokenKey());
233 OS << " ";
234 }
235 });
236 return Storage;
237}
238
239void syntax::Node::assertInvariants() const {
240#ifndef NDEBUG
241 if (isDetached())
242 assert(getParent() == nullptr);
243 else
244 assert(getParent() != nullptr);
245
246 const auto *T = dyn_cast<Tree>(Val: this);
247 if (!T)
248 return;
249 for (const Node &C : T->getChildren()) {
250 if (T->isOriginal())
251 assert(C.isOriginal());
252 assert(!C.isDetached());
253 assert(C.getParent() == T);
254 const auto *Next = C.getNextSibling();
255 assert(!Next || &C == Next->getPreviousSibling());
256 if (!C.getNextSibling())
257 assert(&C == T->getLastChild() &&
258 "Last child is reachable by advancing from the first child.");
259 }
260
261 const auto *L = dyn_cast<List>(Val: T);
262 if (!L)
263 return;
264 for (const Node &C : T->getChildren()) {
265 assert(C.getRole() == NodeRole::ListElement ||
266 C.getRole() == NodeRole::ListDelimiter);
267 if (C.getRole() == NodeRole::ListDelimiter) {
268 assert(isa<Leaf>(C));
269 // FIXME: re-enable it when there is way to retrieve token kind in Leaf.
270 // assert(cast<Leaf>(C).getToken()->kind() == L->getDelimiterTokenKind());
271 }
272 }
273
274#endif
275}
276
277void syntax::Node::assertInvariantsRecursive() const {
278#ifndef NDEBUG
279 traverse(N: this, Visit: [&](const syntax::Node *N) { N->assertInvariants(); });
280#endif
281}
282
283const syntax::Leaf *syntax::Tree::findFirstLeaf() const {
284 for (const Node &C : getChildren()) {
285 if (const auto *L = dyn_cast<syntax::Leaf>(Val: &C))
286 return L;
287 if (const auto *L = cast<syntax::Tree>(Val: C).findFirstLeaf())
288 return L;
289 }
290 return nullptr;
291}
292
293const syntax::Leaf *syntax::Tree::findLastLeaf() const {
294 for (const auto *C = getLastChild(); C; C = C->getPreviousSibling()) {
295 if (const auto *L = dyn_cast<syntax::Leaf>(Val: C))
296 return L;
297 if (const auto *L = cast<syntax::Tree>(Val: C)->findLastLeaf())
298 return L;
299 }
300 return nullptr;
301}
302
303const syntax::Node *syntax::Tree::findChild(NodeRole R) const {
304 for (const Node &C : getChildren()) {
305 if (C.getRole() == R)
306 return &C;
307 }
308 return nullptr;
309}
310
311std::vector<syntax::List::ElementAndDelimiter<syntax::Node>>
312syntax::List::getElementsAsNodesAndDelimiters() {
313 if (!getFirstChild())
314 return {};
315
316 std::vector<syntax::List::ElementAndDelimiter<Node>> Children;
317 syntax::Node *ElementWithoutDelimiter = nullptr;
318 for (Node &C : getChildren()) {
319 switch (C.getRole()) {
320 case syntax::NodeRole::ListElement: {
321 if (ElementWithoutDelimiter) {
322 Children.push_back(x: {.element: ElementWithoutDelimiter, .delimiter: nullptr});
323 }
324 ElementWithoutDelimiter = &C;
325 break;
326 }
327 case syntax::NodeRole::ListDelimiter: {
328 Children.push_back(x: {.element: ElementWithoutDelimiter, .delimiter: cast<syntax::Leaf>(Val: &C)});
329 ElementWithoutDelimiter = nullptr;
330 break;
331 }
332 default:
333 llvm_unreachable(
334 "A list can have only elements and delimiters as children.");
335 }
336 }
337
338 switch (getTerminationKind()) {
339 case syntax::List::TerminationKind::Separated: {
340 Children.push_back(x: {.element: ElementWithoutDelimiter, .delimiter: nullptr});
341 break;
342 }
343 case syntax::List::TerminationKind::Terminated:
344 case syntax::List::TerminationKind::MaybeTerminated: {
345 if (ElementWithoutDelimiter) {
346 Children.push_back(x: {.element: ElementWithoutDelimiter, .delimiter: nullptr});
347 }
348 break;
349 }
350 }
351
352 return Children;
353}
354
355// Almost the same implementation of `getElementsAsNodesAndDelimiters` but
356// ignoring delimiters
357std::vector<syntax::Node *> syntax::List::getElementsAsNodes() {
358 if (!getFirstChild())
359 return {};
360
361 std::vector<syntax::Node *> Children;
362 syntax::Node *ElementWithoutDelimiter = nullptr;
363 for (Node &C : getChildren()) {
364 switch (C.getRole()) {
365 case syntax::NodeRole::ListElement: {
366 if (ElementWithoutDelimiter) {
367 Children.push_back(x: ElementWithoutDelimiter);
368 }
369 ElementWithoutDelimiter = &C;
370 break;
371 }
372 case syntax::NodeRole::ListDelimiter: {
373 Children.push_back(x: ElementWithoutDelimiter);
374 ElementWithoutDelimiter = nullptr;
375 break;
376 }
377 default:
378 llvm_unreachable("A list has only elements or delimiters.");
379 }
380 }
381
382 switch (getTerminationKind()) {
383 case syntax::List::TerminationKind::Separated: {
384 Children.push_back(x: ElementWithoutDelimiter);
385 break;
386 }
387 case syntax::List::TerminationKind::Terminated:
388 case syntax::List::TerminationKind::MaybeTerminated: {
389 if (ElementWithoutDelimiter) {
390 Children.push_back(x: ElementWithoutDelimiter);
391 }
392 break;
393 }
394 }
395
396 return Children;
397}
398
399clang::tok::TokenKind syntax::List::getDelimiterTokenKind() const {
400 switch (this->getKind()) {
401 case NodeKind::NestedNameSpecifier:
402 return clang::tok::coloncolon;
403 case NodeKind::CallArguments:
404 case NodeKind::ParameterDeclarationList:
405 case NodeKind::DeclaratorList:
406 return clang::tok::comma;
407 default:
408 llvm_unreachable("This is not a subclass of List, thus "
409 "getDelimiterTokenKind() cannot be called");
410 }
411}
412
413syntax::List::TerminationKind syntax::List::getTerminationKind() const {
414 switch (this->getKind()) {
415 case NodeKind::NestedNameSpecifier:
416 return TerminationKind::Terminated;
417 case NodeKind::CallArguments:
418 case NodeKind::ParameterDeclarationList:
419 case NodeKind::DeclaratorList:
420 return TerminationKind::Separated;
421 default:
422 llvm_unreachable("This is not a subclass of List, thus "
423 "getTerminationKind() cannot be called");
424 }
425}
426
427bool syntax::List::canBeEmpty() const {
428 switch (this->getKind()) {
429 case NodeKind::NestedNameSpecifier:
430 return false;
431 case NodeKind::CallArguments:
432 return true;
433 case NodeKind::ParameterDeclarationList:
434 return true;
435 case NodeKind::DeclaratorList:
436 return true;
437 default:
438 llvm_unreachable("This is not a subclass of List, thus canBeEmpty() "
439 "cannot be called");
440 }
441}
442

source code of clang/lib/Tooling/Syntax/Tree.cpp