xref: /llvm-project/clang-tools-extra/clangd/FindSymbols.cpp (revision ba06ac8b45ca2ad047131fb9cc9af922cb913ea1)
1 //===--- FindSymbols.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 "FindSymbols.h"
9 
10 #include "AST.h"
11 #include "FuzzyMatch.h"
12 #include "ParsedAST.h"
13 #include "Quality.h"
14 #include "SourceCode.h"
15 #include "index/Index.h"
16 #include "support/Logger.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/Index/IndexDataConsumer.h"
19 #include "clang/Index/IndexSymbol.h"
20 #include "clang/Index/IndexingAction.h"
21 #include "llvm/ADT/ArrayRef.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/ADT/StringRef.h"
25 #include "llvm/Support/FormatVariadic.h"
26 #include "llvm/Support/Path.h"
27 #include "llvm/Support/ScopedPrinter.h"
28 #include <limits>
29 #include <tuple>
30 
31 #define DEBUG_TYPE "FindSymbols"
32 
33 namespace clang {
34 namespace clangd {
35 
36 namespace {
37 using ScoredSymbolInfo = std::pair<float, SymbolInformation>;
38 struct ScoredSymbolGreater {
39   bool operator()(const ScoredSymbolInfo &L, const ScoredSymbolInfo &R) {
40     if (L.first != R.first)
41       return L.first > R.first;
42     return L.second.name < R.second.name; // Earlier name is better.
43   }
44 };
45 
46 // Returns true if \p Query can be found as a sub-sequence inside \p Scope.
47 bool approximateScopeMatch(llvm::StringRef Scope, llvm::StringRef Query) {
48   assert(Scope.empty() || Scope.endswith("::"));
49   assert(Query.empty() || Query.endswith("::"));
50   while (!Scope.empty() && !Query.empty()) {
51     auto Colons = Scope.find("::");
52     assert(Colons != llvm::StringRef::npos);
53 
54     llvm::StringRef LeadingSpecifier = Scope.slice(0, Colons + 2);
55     Scope = Scope.slice(Colons + 2, llvm::StringRef::npos);
56     Query.consume_front(LeadingSpecifier);
57   }
58   return Query.empty();
59 }
60 
61 } // namespace
62 
63 llvm::Expected<Location> indexToLSPLocation(const SymbolLocation &Loc,
64                                             llvm::StringRef TUPath) {
65   auto Path = URI::resolve(Loc.FileURI, TUPath);
66   if (!Path)
67     return error("Could not resolve path for file '{0}': {1}", Loc.FileURI,
68                  Path.takeError());
69   Location L;
70   L.uri = URIForFile::canonicalize(*Path, TUPath);
71   Position Start, End;
72   Start.line = Loc.Start.line();
73   Start.character = Loc.Start.column();
74   End.line = Loc.End.line();
75   End.character = Loc.End.column();
76   L.range = {Start, End};
77   return L;
78 }
79 
80 llvm::Expected<Location> symbolToLocation(const Symbol &Sym,
81                                           llvm::StringRef TUPath) {
82   // Prefer the definition over e.g. a function declaration in a header
83   return indexToLSPLocation(
84       Sym.Definition ? Sym.Definition : Sym.CanonicalDeclaration, TUPath);
85 }
86 
87 llvm::Expected<std::vector<SymbolInformation>>
88 getWorkspaceSymbols(llvm::StringRef Query, int Limit,
89                     const SymbolIndex *const Index, llvm::StringRef HintPath) {
90   std::vector<SymbolInformation> Result;
91   if (!Index)
92     return Result;
93 
94   // Lookup for qualified names are performed as:
95   // - Exact namespaces are boosted by the index.
96   // - Approximate matches are (sub-scope match) included via AnyScope logic.
97   // - Non-matching namespaces (no sub-scope match) are post-filtered.
98   auto Names = splitQualifiedName(Query);
99 
100   FuzzyFindRequest Req;
101   Req.Query = std::string(Names.second);
102 
103   // FuzzyFind doesn't want leading :: qualifier.
104   auto HasLeadingColons = Names.first.consume_front("::");
105   // Limit the query to specific namespace if it is fully-qualified.
106   Req.AnyScope = !HasLeadingColons;
107   // Boost symbols from desired namespace.
108   if (HasLeadingColons || !Names.first.empty())
109     Req.Scopes = {std::string(Names.first)};
110   if (Limit) {
111     Req.Limit = Limit;
112     // If we are boosting a specific scope allow more results to be retrieved,
113     // since some symbols from preferred namespaces might not make the cut.
114     if (Req.AnyScope && !Req.Scopes.empty())
115       *Req.Limit *= 5;
116   }
117   TopN<ScoredSymbolInfo, ScoredSymbolGreater> Top(
118       Req.Limit ? *Req.Limit : std::numeric_limits<size_t>::max());
119   FuzzyMatcher Filter(Req.Query);
120 
121   Index->fuzzyFind(Req, [HintPath, &Top, &Filter, AnyScope = Req.AnyScope,
122                          ReqScope = Names.first](const Symbol &Sym) {
123     llvm::StringRef Scope = Sym.Scope;
124     // Fuzzyfind might return symbols from irrelevant namespaces if query was
125     // not fully-qualified, drop those.
126     if (AnyScope && !approximateScopeMatch(Scope, ReqScope))
127       return;
128 
129     auto Loc = symbolToLocation(Sym, HintPath);
130     if (!Loc) {
131       log("Workspace symbols: {0}", Loc.takeError());
132       return;
133     }
134 
135     SymbolQualitySignals Quality;
136     Quality.merge(Sym);
137     SymbolRelevanceSignals Relevance;
138     Relevance.Name = Sym.Name;
139     Relevance.Query = SymbolRelevanceSignals::Generic;
140     // If symbol and request scopes do not match exactly, apply a penalty.
141     Relevance.InBaseClass = AnyScope && Scope != ReqScope;
142     if (auto NameMatch = Filter.match(Sym.Name))
143       Relevance.NameMatch = *NameMatch;
144     else {
145       log("Workspace symbol: {0} didn't match query {1}", Sym.Name,
146           Filter.pattern());
147       return;
148     }
149     Relevance.merge(Sym);
150     auto QualScore = Quality.evaluateHeuristics();
151     auto RelScore = Relevance.evaluateHeuristics();
152     auto Score = evaluateSymbolAndRelevance(QualScore, RelScore);
153     dlog("FindSymbols: {0}{1} = {2}\n{3}{4}\n", Sym.Scope, Sym.Name, Score,
154          Quality, Relevance);
155 
156     SymbolInformation Info;
157     Info.name = (Sym.Name + Sym.TemplateSpecializationArgs).str();
158     Info.kind = indexSymbolKindToSymbolKind(Sym.SymInfo.Kind);
159     Info.location = *Loc;
160     Scope.consume_back("::");
161     Info.containerName = Scope.str();
162 
163     // Exposed score excludes fuzzy-match component, for client-side re-ranking.
164     Info.score = Relevance.NameMatch > std::numeric_limits<float>::epsilon()
165                      ? Score / Relevance.NameMatch
166                      : QualScore;
167     Top.push({Score, std::move(Info)});
168   });
169   for (auto &R : std::move(Top).items())
170     Result.push_back(std::move(R.second));
171   return Result;
172 }
173 
174 namespace {
175 std::string getSymbolName(ASTContext &Ctx, const NamedDecl &ND) {
176   // Print `MyClass(Category)` instead of `Category` and `MyClass()` instead
177   // of `anonymous`.
178   if (const auto *Container = dyn_cast<ObjCContainerDecl>(&ND))
179     return printObjCContainer(*Container);
180   // Differentiate between class and instance methods: print `-foo` instead of
181   // `foo` and `+sharedInstance` instead of `sharedInstance`.
182   if (const auto *Method = dyn_cast<ObjCMethodDecl>(&ND)) {
183     std::string Name;
184     llvm::raw_string_ostream OS(Name);
185 
186     OS << (Method->isInstanceMethod() ? '-' : '+');
187     Method->getSelector().print(OS);
188 
189     OS.flush();
190     return Name;
191   }
192   return printName(Ctx, ND);
193 }
194 
195 std::string getSymbolDetail(ASTContext &Ctx, const NamedDecl &ND) {
196   PrintingPolicy P(Ctx.getPrintingPolicy());
197   P.SuppressScope = true;
198   P.SuppressUnwrittenScope = true;
199   P.AnonymousTagLocations = false;
200   P.PolishForDeclaration = true;
201   std::string Detail;
202   llvm::raw_string_ostream OS(Detail);
203   if (ND.getDescribedTemplateParams()) {
204     OS << "template ";
205   }
206   if (const auto *VD = dyn_cast<ValueDecl>(&ND)) {
207     // FIXME: better printing for dependent type
208     if (isa<CXXConstructorDecl>(VD)) {
209       std::string ConstructorType = VD->getType().getAsString(P);
210       // Print constructor type as "(int)" instead of "void (int)".
211       llvm::StringRef WithoutVoid = ConstructorType;
212       WithoutVoid.consume_front("void ");
213       OS << WithoutVoid;
214     } else if (!isa<CXXDestructorDecl>(VD)) {
215       VD->getType().print(OS, P);
216     }
217   } else if (const auto *TD = dyn_cast<TagDecl>(&ND)) {
218     OS << TD->getKindName();
219   } else if (isa<TypedefNameDecl>(&ND)) {
220     OS << "type alias";
221   } else if (isa<ConceptDecl>(&ND)) {
222     OS << "concept";
223   }
224   return std::move(OS.str());
225 }
226 
227 llvm::Optional<DocumentSymbol> declToSym(ASTContext &Ctx, const NamedDecl &ND) {
228   auto &SM = Ctx.getSourceManager();
229 
230   SourceLocation BeginLoc = SM.getSpellingLoc(SM.getFileLoc(ND.getBeginLoc()));
231   SourceLocation EndLoc = SM.getSpellingLoc(SM.getFileLoc(ND.getEndLoc()));
232   const auto SymbolRange =
233       toHalfOpenFileRange(SM, Ctx.getLangOpts(), {BeginLoc, EndLoc});
234   if (!SymbolRange)
235     return llvm::None;
236 
237   index::SymbolInfo SymInfo = index::getSymbolInfo(&ND);
238   // FIXME: This is not classifying constructors, destructors and operators
239   // correctly.
240   SymbolKind SK = indexSymbolKindToSymbolKind(SymInfo.Kind);
241 
242   DocumentSymbol SI;
243   SI.name = getSymbolName(Ctx, ND);
244   SI.kind = SK;
245   SI.deprecated = ND.isDeprecated();
246   SI.range = Range{sourceLocToPosition(SM, SymbolRange->getBegin()),
247                    sourceLocToPosition(SM, SymbolRange->getEnd())};
248   SI.detail = getSymbolDetail(Ctx, ND);
249 
250   SourceLocation NameLoc = ND.getLocation();
251   SourceLocation FallbackNameLoc;
252   if (NameLoc.isMacroID()) {
253     if (isSpelledInSource(NameLoc, SM)) {
254       // Prefer the spelling loc, but save the expansion loc as a fallback.
255       FallbackNameLoc = SM.getExpansionLoc(NameLoc);
256       NameLoc = SM.getSpellingLoc(NameLoc);
257     } else {
258       NameLoc = SM.getExpansionLoc(NameLoc);
259     }
260   }
261   auto ComputeSelectionRange = [&](SourceLocation L) -> Range {
262     Position NameBegin = sourceLocToPosition(SM, L);
263     Position NameEnd = sourceLocToPosition(
264         SM, Lexer::getLocForEndOfToken(L, 0, SM, Ctx.getLangOpts()));
265     return Range{NameBegin, NameEnd};
266   };
267 
268   SI.selectionRange = ComputeSelectionRange(NameLoc);
269   if (!SI.range.contains(SI.selectionRange) && FallbackNameLoc.isValid()) {
270     // 'selectionRange' must be contained in 'range'. In cases where clang
271     // reports unrelated ranges, we first try falling back to the expansion
272     // loc for the selection range.
273     SI.selectionRange = ComputeSelectionRange(FallbackNameLoc);
274   }
275   if (!SI.range.contains(SI.selectionRange)) {
276     // If the containment relationship still doesn't hold, throw away
277     // 'range' and use 'selectionRange' for both.
278     SI.range = SI.selectionRange;
279   }
280   return SI;
281 }
282 
283 /// A helper class to build an outline for the parse AST. It traverses the AST
284 /// directly instead of using RecursiveASTVisitor (RAV) for three main reasons:
285 ///    - there is no way to keep RAV from traversing subtrees we are not
286 ///      interested in. E.g. not traversing function locals or implicit template
287 ///      instantiations.
288 ///    - it's easier to combine results of recursive passes,
289 ///    - visiting decls is actually simple, so we don't hit the complicated
290 ///      cases that RAV mostly helps with (types, expressions, etc.)
291 class DocumentOutline {
292   // A DocumentSymbol we're constructing.
293   // We use this instead of DocumentSymbol directly so that we can keep track
294   // of the nodes we insert for macros.
295   class SymBuilder {
296     std::vector<SymBuilder> Children;
297     DocumentSymbol Symbol; // Symbol.children is empty, use Children instead.
298     // Macro expansions that this node or its parents are associated with.
299     // (Thus we will never create further children for these expansions).
300     llvm::SmallVector<SourceLocation> EnclosingMacroLoc;
301 
302   public:
303     DocumentSymbol build() && {
304       for (SymBuilder &C : Children) {
305         Symbol.children.push_back(std::move(C).build());
306         // Expand range to ensure children nest properly, which editors expect.
307         // This can fix some edge-cases in the AST, but is vital for macros.
308         // A macro expansion "contains" AST node if it covers the node's primary
309         // location, but it may not span the node's whole range.
310         Symbol.range.start =
311             std::min(Symbol.range.start, Symbol.children.back().range.start);
312         Symbol.range.end =
313             std::max(Symbol.range.end, Symbol.children.back().range.end);
314       }
315       return std::move(Symbol);
316     }
317 
318     // Add a symbol as a child of the current one.
319     SymBuilder &addChild(DocumentSymbol S) {
320       Children.emplace_back();
321       Children.back().EnclosingMacroLoc = EnclosingMacroLoc;
322       Children.back().Symbol = std::move(S);
323       return Children.back();
324     }
325 
326     // Get an appropriate container for children of this symbol that were
327     // expanded from a macro (whose spelled name is Tok).
328     //
329     // This may return:
330     //  - a macro symbol child of this (either new or previously created)
331     //  - this scope itself, if it *is* the macro symbol or is nested within it
332     SymBuilder &inMacro(const syntax::Token &Tok, const SourceManager &SM,
333                         llvm::Optional<syntax::TokenBuffer::Expansion> Exp) {
334       if (llvm::is_contained(EnclosingMacroLoc, Tok.location()))
335         return *this;
336       // If there's an existing child for this macro, we expect it to be last.
337       if (!Children.empty() && !Children.back().EnclosingMacroLoc.empty() &&
338           Children.back().EnclosingMacroLoc.back() == Tok.location())
339         return Children.back();
340 
341       DocumentSymbol Sym;
342       Sym.name = Tok.text(SM).str();
343       Sym.kind = SymbolKind::Null; // There's no suitable kind!
344       Sym.range = Sym.selectionRange =
345           halfOpenToRange(SM, Tok.range(SM).toCharRange(SM));
346 
347       // FIXME: Exp is currently unavailable for nested expansions.
348       if (Exp) {
349         // Full range covers the macro args.
350         Sym.range = halfOpenToRange(SM, CharSourceRange::getCharRange(
351                                             Exp->Spelled.front().location(),
352                                             Exp->Spelled.back().endLocation()));
353         // Show macro args as detail.
354         llvm::raw_string_ostream OS(Sym.detail);
355         const syntax::Token *Prev = nullptr;
356         for (const auto &Tok : Exp->Spelled.drop_front()) {
357           // Don't dump arbitrarily long macro args.
358           if (OS.tell() > 80) {
359             OS << " ...)";
360             break;
361           }
362           if (Prev && Prev->endLocation() != Tok.location())
363             OS << ' ';
364           OS << Tok.text(SM);
365           Prev = &Tok;
366         }
367       }
368       SymBuilder &Child = addChild(std::move(Sym));
369       Child.EnclosingMacroLoc.push_back(Tok.location());
370       return Child;
371     }
372   };
373 
374 public:
375   DocumentOutline(ParsedAST &AST) : AST(AST) {}
376 
377   /// Builds the document outline for the generated AST.
378   std::vector<DocumentSymbol> build() {
379     SymBuilder Root;
380     for (auto &TopLevel : AST.getLocalTopLevelDecls())
381       traverseDecl(TopLevel, Root);
382     return std::move(std::move(Root).build().children);
383   }
384 
385 private:
386   enum class VisitKind { No, OnlyDecl, OnlyChildren, DeclAndChildren };
387 
388   void traverseDecl(Decl *D, SymBuilder &Parent) {
389     // Skip symbols which do not originate from the main file.
390     if (!isInsideMainFile(D->getLocation(), AST.getSourceManager()))
391       return;
392 
393     if (auto *Templ = llvm::dyn_cast<TemplateDecl>(D)) {
394       // TemplatedDecl might be null, e.g. concepts.
395       if (auto *TD = Templ->getTemplatedDecl())
396         D = TD;
397     }
398 
399     VisitKind Visit = shouldVisit(D);
400     if (Visit == VisitKind::No)
401       return;
402 
403     if (Visit == VisitKind::OnlyChildren)
404       return traverseChildren(D, Parent);
405 
406     auto *ND = llvm::cast<NamedDecl>(D);
407     auto Sym = declToSym(AST.getASTContext(), *ND);
408     if (!Sym)
409       return;
410     SymBuilder &MacroParent = possibleMacroContainer(D->getLocation(), Parent);
411     SymBuilder &Child = MacroParent.addChild(std::move(*Sym));
412 
413     if (Visit == VisitKind::OnlyDecl)
414       return;
415 
416     assert(Visit == VisitKind::DeclAndChildren && "Unexpected VisitKind");
417     traverseChildren(ND, Child);
418   }
419 
420   // Determines where a decl should appear in the DocumentSymbol hierarchy.
421   //
422   // This is usually a direct child of the relevant AST parent.
423   // But we may also insert nodes for macros. Given:
424   //   #define DECLARE_INT(V) int v;
425   //   namespace a { DECLARE_INT(x) }
426   // We produce:
427   //   Namespace a
428   //     Macro DECLARE_INT(x)
429   //       Variable x
430   //
431   // In the absence of macros, this method simply returns Parent.
432   // Otherwise it may return a macro expansion node instead.
433   // Each macro only has at most one node in the hierarchy, even if it expands
434   // to multiple decls.
435   SymBuilder &possibleMacroContainer(SourceLocation TargetLoc,
436                                      SymBuilder &Parent) {
437     const auto &SM = AST.getSourceManager();
438     // Look at the path of macro-callers from the token to the main file.
439     // Note that along these paths we see the "outer" macro calls first.
440     SymBuilder *CurParent = &Parent;
441     for (SourceLocation Loc = TargetLoc; Loc.isMacroID();
442          Loc = SM.getImmediateMacroCallerLoc(Loc)) {
443       // Find the virtual macro body that our token is being substituted into.
444       FileID MacroBody;
445       if (SM.isMacroArgExpansion(Loc)) {
446         // Loc is part of a macro arg being substituted into a macro body.
447         MacroBody = SM.getFileID(SM.getImmediateExpansionRange(Loc).getBegin());
448       } else {
449         // Loc is already in the macro body.
450         MacroBody = SM.getFileID(Loc);
451       }
452       // The macro body is being substituted for a macro expansion, whose
453       // first token is the name of the macro.
454       SourceLocation MacroName =
455           SM.getSLocEntry(MacroBody).getExpansion().getExpansionLocStart();
456       // Only include the macro expansion in the outline if it was written
457       // directly in the main file, rather than expanded from another macro.
458       if (!MacroName.isValid() || !MacroName.isFileID())
459         continue;
460       // All conditions satisfied, add the macro.
461       if (auto *Tok = AST.getTokens().spelledTokenAt(MacroName))
462         CurParent = &CurParent->inMacro(
463             *Tok, SM, AST.getTokens().expansionStartingAt(Tok));
464     }
465     return *CurParent;
466   }
467 
468   void traverseChildren(Decl *D, SymBuilder &Builder) {
469     auto *Scope = llvm::dyn_cast<DeclContext>(D);
470     if (!Scope)
471       return;
472     for (auto *C : Scope->decls())
473       traverseDecl(C, Builder);
474   }
475 
476   VisitKind shouldVisit(Decl *D) {
477     if (D->isImplicit())
478       return VisitKind::No;
479 
480     if (llvm::isa<LinkageSpecDecl>(D) || llvm::isa<ExportDecl>(D))
481       return VisitKind::OnlyChildren;
482 
483     if (!llvm::isa<NamedDecl>(D))
484       return VisitKind::No;
485 
486     if (auto Func = llvm::dyn_cast<FunctionDecl>(D)) {
487       // Some functions are implicit template instantiations, those should be
488       // ignored.
489       if (auto *Info = Func->getTemplateSpecializationInfo()) {
490         if (!Info->isExplicitInstantiationOrSpecialization())
491           return VisitKind::No;
492       }
493       // Only visit the function itself, do not visit the children (i.e.
494       // function parameters, etc.)
495       return VisitKind::OnlyDecl;
496     }
497     // Handle template instantiations. We have three cases to consider:
498     //   - explicit instantiations, e.g. 'template class std::vector<int>;'
499     //     Visit the decl itself (it's present in the code), but not the
500     //     children.
501     //   - implicit instantiations, i.e. not written by the user.
502     //     Do not visit at all, they are not present in the code.
503     //   - explicit specialization, e.g. 'template <> class vector<bool> {};'
504     //     Visit both the decl and its children, both are written in the code.
505     if (auto *TemplSpec = llvm::dyn_cast<ClassTemplateSpecializationDecl>(D)) {
506       if (TemplSpec->isExplicitInstantiationOrSpecialization())
507         return TemplSpec->isExplicitSpecialization()
508                    ? VisitKind::DeclAndChildren
509                    : VisitKind::OnlyDecl;
510       return VisitKind::No;
511     }
512     if (auto *TemplSpec = llvm::dyn_cast<VarTemplateSpecializationDecl>(D)) {
513       if (TemplSpec->isExplicitInstantiationOrSpecialization())
514         return TemplSpec->isExplicitSpecialization()
515                    ? VisitKind::DeclAndChildren
516                    : VisitKind::OnlyDecl;
517       return VisitKind::No;
518     }
519     // For all other cases, visit both the children and the decl.
520     return VisitKind::DeclAndChildren;
521   }
522 
523   ParsedAST &AST;
524 };
525 
526 struct PragmaMarkSymbol {
527   DocumentSymbol DocSym;
528   bool IsGroup;
529 };
530 
531 /// Merge in `PragmaMarkSymbols`, sorted ascending by range, into the given
532 /// `DocumentSymbol` tree.
533 void mergePragmas(DocumentSymbol &Root, ArrayRef<PragmaMarkSymbol> Pragmas) {
534   while (!Pragmas.empty()) {
535     // We'll figure out where the Pragmas.front() should go.
536     PragmaMarkSymbol P = std::move(Pragmas.front());
537     Pragmas = Pragmas.drop_front();
538     DocumentSymbol *Cur = &Root;
539     while (Cur->range.contains(P.DocSym.range)) {
540       bool Swapped = false;
541       for (auto &C : Cur->children) {
542         // We assume at most 1 child can contain the pragma (as pragmas are on
543         // a single line, and children have disjoint ranges).
544         if (C.range.contains(P.DocSym.range)) {
545           Cur = &C;
546           Swapped = true;
547           break;
548         }
549       }
550       // Cur is the parent of P since none of the children contain P.
551       if (!Swapped)
552         break;
553     }
554     // Pragma isn't a group so we can just insert it and we are done.
555     if (!P.IsGroup) {
556       Cur->children.emplace_back(std::move(P.DocSym));
557       continue;
558     }
559     // Pragma is a group, so we need to figure out where it terminates:
560     // - If the next Pragma is not contained in Cur, P owns all of its
561     //   parent's children which occur after P.
562     // - If the next pragma is contained in Cur but actually belongs to one
563     //   of the parent's children, we temporarily skip over it and look at
564     //   the next pragma to decide where we end.
565     // - Otherwise nest all of its parent's children which occur after P but
566     //   before the next pragma.
567     bool TerminatedByNextPragma = false;
568     for (auto &NextPragma : Pragmas) {
569       // If we hit a pragma outside of Cur, the rest will be outside as well.
570       if (!Cur->range.contains(NextPragma.DocSym.range))
571         break;
572 
573       // NextPragma cannot terminate P if it is nested inside a child, look for
574       // the next one.
575       if (llvm::any_of(Cur->children, [&NextPragma](const auto &Child) {
576             return Child.range.contains(NextPragma.DocSym.range);
577           }))
578         continue;
579 
580       // Pragma owns all the children between P and NextPragma
581       auto It = llvm::partition(Cur->children,
582                                 [&P, &NextPragma](const auto &S) -> bool {
583                                   return !(P.DocSym.range < S.range &&
584                                            S.range < NextPragma.DocSym.range);
585                                 });
586       P.DocSym.children.assign(make_move_iterator(It),
587                                make_move_iterator(Cur->children.end()));
588       Cur->children.erase(It, Cur->children.end());
589       TerminatedByNextPragma = true;
590       break;
591     }
592     if (!TerminatedByNextPragma) {
593       // P is terminated by the end of current symbol, hence it owns all the
594       // children after P.
595       auto It = llvm::partition(Cur->children, [&P](const auto &S) -> bool {
596         return !(P.DocSym.range < S.range);
597       });
598       P.DocSym.children.assign(make_move_iterator(It),
599                                make_move_iterator(Cur->children.end()));
600       Cur->children.erase(It, Cur->children.end());
601     }
602     // Update the range for P to cover children and append to Cur.
603     for (DocumentSymbol &Sym : P.DocSym.children)
604       unionRanges(P.DocSym.range, Sym.range);
605     Cur->children.emplace_back(std::move(P.DocSym));
606   }
607 }
608 
609 PragmaMarkSymbol markToSymbol(const PragmaMark &P) {
610   StringRef Name = StringRef(P.Trivia).trim();
611   bool IsGroup = false;
612   // "-\s+<group name>" or "<name>" after an initial trim. The former is
613   // considered a group, the latter just a mark. Like Xcode, we don't consider
614   // `-Foo` to be a group (space(s) after the `-` is required).
615   //
616   // We need to include a name here, otherwise editors won't properly render the
617   // symbol.
618   StringRef MaybeGroupName = Name;
619   if (MaybeGroupName.consume_front("-") &&
620       (MaybeGroupName.ltrim() != MaybeGroupName || MaybeGroupName.empty())) {
621     Name = MaybeGroupName.empty() ? "(unnamed group)" : MaybeGroupName.ltrim();
622     IsGroup = true;
623   } else if (Name.empty()) {
624     Name = "(unnamed mark)";
625   }
626   DocumentSymbol Sym;
627   Sym.name = Name.str();
628   Sym.kind = SymbolKind::File;
629   Sym.range = P.Rng;
630   Sym.selectionRange = P.Rng;
631   return {Sym, IsGroup};
632 }
633 
634 std::vector<DocumentSymbol> collectDocSymbols(ParsedAST &AST) {
635   std::vector<DocumentSymbol> Syms = DocumentOutline(AST).build();
636 
637   const auto &PragmaMarks = AST.getMarks();
638   if (PragmaMarks.empty())
639     return Syms;
640 
641   std::vector<PragmaMarkSymbol> Pragmas;
642   Pragmas.reserve(PragmaMarks.size());
643   for (const auto &P : PragmaMarks)
644     Pragmas.push_back(markToSymbol(P));
645   Range EntireFile = {
646       {0, 0},
647       {std::numeric_limits<int>::max(), std::numeric_limits<int>::max()}};
648   DocumentSymbol Root;
649   Root.children = std::move(Syms);
650   Root.range = EntireFile;
651   mergePragmas(Root, llvm::makeArrayRef(Pragmas));
652   return Root.children;
653 }
654 
655 } // namespace
656 
657 llvm::Expected<std::vector<DocumentSymbol>> getDocumentSymbols(ParsedAST &AST) {
658   return collectDocSymbols(AST);
659 }
660 
661 } // namespace clangd
662 } // namespace clang
663