xref: /llvm-project/clang-tools-extra/clangd/FindSymbols.cpp (revision b0c070e2637935030ecd36777f22542bf371ef8c)
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/IndexSymbol.h"
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/StringRef.h"
23 #include <limits>
24 #include <optional>
25 #include <tuple>
26 
27 #define DEBUG_TYPE "FindSymbols"
28 
29 namespace clang {
30 namespace clangd {
31 
32 namespace {
33 using ScoredSymbolInfo = std::pair<float, SymbolInformation>;
34 struct ScoredSymbolGreater {
35   bool operator()(const ScoredSymbolInfo &L, const ScoredSymbolInfo &R) {
36     if (L.first != R.first)
37       return L.first > R.first;
38     return L.second.name < R.second.name; // Earlier name is better.
39   }
40 };
41 
42 // Returns true if \p Query can be found as a sub-sequence inside \p Scope.
43 bool approximateScopeMatch(llvm::StringRef Scope, llvm::StringRef Query) {
44   assert(Scope.empty() || Scope.ends_with("::"));
45   assert(Query.empty() || Query.ends_with("::"));
46   while (!Scope.empty() && !Query.empty()) {
47     auto Colons = Scope.find("::");
48     assert(Colons != llvm::StringRef::npos);
49 
50     llvm::StringRef LeadingSpecifier = Scope.slice(0, Colons + 2);
51     Scope = Scope.slice(Colons + 2, llvm::StringRef::npos);
52     Query.consume_front(LeadingSpecifier);
53   }
54   return Query.empty();
55 }
56 
57 } // namespace
58 
59 llvm::Expected<Location> indexToLSPLocation(const SymbolLocation &Loc,
60                                             llvm::StringRef TUPath) {
61   auto Path = URI::resolve(Loc.FileURI, TUPath);
62   if (!Path)
63     return error("Could not resolve path for file '{0}': {1}", Loc.FileURI,
64                  Path.takeError());
65   Location L;
66   L.uri = URIForFile::canonicalize(*Path, TUPath);
67   Position Start, End;
68   Start.line = Loc.Start.line();
69   Start.character = Loc.Start.column();
70   End.line = Loc.End.line();
71   End.character = Loc.End.column();
72   L.range = {Start, End};
73   return L;
74 }
75 
76 llvm::Expected<Location> symbolToLocation(const Symbol &Sym,
77                                           llvm::StringRef TUPath) {
78   // Prefer the definition over e.g. a function declaration in a header
79   return indexToLSPLocation(
80       Sym.Definition ? Sym.Definition : Sym.CanonicalDeclaration, TUPath);
81 }
82 
83 llvm::Expected<std::vector<SymbolInformation>>
84 getWorkspaceSymbols(llvm::StringRef Query, int Limit,
85                     const SymbolIndex *const Index, llvm::StringRef HintPath) {
86   std::vector<SymbolInformation> Result;
87   if (!Index)
88     return Result;
89 
90   // Lookup for qualified names are performed as:
91   // - Exact namespaces are boosted by the index.
92   // - Approximate matches are (sub-scope match) included via AnyScope logic.
93   // - Non-matching namespaces (no sub-scope match) are post-filtered.
94   auto Names = splitQualifiedName(Query);
95 
96   FuzzyFindRequest Req;
97   Req.Query = std::string(Names.second);
98 
99   // FuzzyFind doesn't want leading :: qualifier.
100   auto HasLeadingColons = Names.first.consume_front("::");
101   // Limit the query to specific namespace if it is fully-qualified.
102   Req.AnyScope = !HasLeadingColons;
103   // Boost symbols from desired namespace.
104   if (HasLeadingColons || !Names.first.empty())
105     Req.Scopes = {std::string(Names.first)};
106   if (Limit) {
107     Req.Limit = Limit;
108     // If we are boosting a specific scope allow more results to be retrieved,
109     // since some symbols from preferred namespaces might not make the cut.
110     if (Req.AnyScope && !Req.Scopes.empty())
111       *Req.Limit *= 5;
112   }
113   TopN<ScoredSymbolInfo, ScoredSymbolGreater> Top(
114       Req.Limit.value_or(std::numeric_limits<size_t>::max()));
115   FuzzyMatcher Filter(Req.Query);
116 
117   Index->fuzzyFind(Req, [HintPath, &Top, &Filter, AnyScope = Req.AnyScope,
118                          ReqScope = Names.first](const Symbol &Sym) {
119     llvm::StringRef Scope = Sym.Scope;
120     // Fuzzyfind might return symbols from irrelevant namespaces if query was
121     // not fully-qualified, drop those.
122     if (AnyScope && !approximateScopeMatch(Scope, ReqScope))
123       return;
124 
125     auto Loc = symbolToLocation(Sym, HintPath);
126     if (!Loc) {
127       log("Workspace symbols: {0}", Loc.takeError());
128       return;
129     }
130 
131     SymbolQualitySignals Quality;
132     Quality.merge(Sym);
133     SymbolRelevanceSignals Relevance;
134     Relevance.Name = Sym.Name;
135     Relevance.Query = SymbolRelevanceSignals::Generic;
136     // If symbol and request scopes do not match exactly, apply a penalty.
137     Relevance.InBaseClass = AnyScope && Scope != ReqScope;
138     if (auto NameMatch = Filter.match(Sym.Name))
139       Relevance.NameMatch = *NameMatch;
140     else {
141       log("Workspace symbol: {0} didn't match query {1}", Sym.Name,
142           Filter.pattern());
143       return;
144     }
145     Relevance.merge(Sym);
146     auto QualScore = Quality.evaluateHeuristics();
147     auto RelScore = Relevance.evaluateHeuristics();
148     auto Score = evaluateSymbolAndRelevance(QualScore, RelScore);
149     dlog("FindSymbols: {0}{1} = {2}\n{3}{4}\n", Sym.Scope, Sym.Name, Score,
150          Quality, Relevance);
151 
152     SymbolInformation Info;
153     Info.name = (Sym.Name + Sym.TemplateSpecializationArgs).str();
154     Info.kind = indexSymbolKindToSymbolKind(Sym.SymInfo.Kind);
155     Info.location = *Loc;
156     Scope.consume_back("::");
157     Info.containerName = Scope.str();
158 
159     // Exposed score excludes fuzzy-match component, for client-side re-ranking.
160     Info.score = Relevance.NameMatch > std::numeric_limits<float>::epsilon()
161                      ? Score / Relevance.NameMatch
162                      : QualScore;
163     Top.push({Score, std::move(Info)});
164   });
165   for (auto &R : std::move(Top).items())
166     Result.push_back(std::move(R.second));
167   return Result;
168 }
169 
170 namespace {
171 std::string getSymbolName(ASTContext &Ctx, const NamedDecl &ND) {
172   // Print `MyClass(Category)` instead of `Category` and `MyClass()` instead
173   // of `anonymous`.
174   if (const auto *Container = dyn_cast<ObjCContainerDecl>(&ND))
175     return printObjCContainer(*Container);
176   // Differentiate between class and instance methods: print `-foo` instead of
177   // `foo` and `+sharedInstance` instead of `sharedInstance`.
178   if (const auto *Method = dyn_cast<ObjCMethodDecl>(&ND)) {
179     std::string Name;
180     llvm::raw_string_ostream OS(Name);
181 
182     OS << (Method->isInstanceMethod() ? '-' : '+');
183     Method->getSelector().print(OS);
184 
185     return Name;
186   }
187   return printName(Ctx, ND);
188 }
189 
190 std::string getSymbolDetail(ASTContext &Ctx, const NamedDecl &ND) {
191   PrintingPolicy P(Ctx.getPrintingPolicy());
192   P.SuppressScope = true;
193   P.SuppressUnwrittenScope = true;
194   P.AnonymousTagLocations = false;
195   P.PolishForDeclaration = true;
196   std::string Detail;
197   llvm::raw_string_ostream OS(Detail);
198   if (ND.getDescribedTemplateParams()) {
199     OS << "template ";
200   }
201   if (const auto *VD = dyn_cast<ValueDecl>(&ND)) {
202     // FIXME: better printing for dependent type
203     if (isa<CXXConstructorDecl>(VD)) {
204       std::string ConstructorType = VD->getType().getAsString(P);
205       // Print constructor type as "(int)" instead of "void (int)".
206       llvm::StringRef WithoutVoid = ConstructorType;
207       WithoutVoid.consume_front("void ");
208       OS << WithoutVoid;
209     } else if (!isa<CXXDestructorDecl>(VD)) {
210       VD->getType().print(OS, P);
211     }
212   } else if (const auto *TD = dyn_cast<TagDecl>(&ND)) {
213     OS << TD->getKindName();
214   } else if (isa<TypedefNameDecl>(&ND)) {
215     OS << "type alias";
216   } else if (isa<ConceptDecl>(&ND)) {
217     OS << "concept";
218   }
219   return std::move(OS.str());
220 }
221 
222 std::optional<DocumentSymbol> declToSym(ASTContext &Ctx, const NamedDecl &ND) {
223   auto &SM = Ctx.getSourceManager();
224 
225   SourceLocation BeginLoc = ND.getBeginLoc();
226   SourceLocation EndLoc = ND.getEndLoc();
227   const auto SymbolRange =
228       toHalfOpenFileRange(SM, Ctx.getLangOpts(), {BeginLoc, EndLoc});
229   if (!SymbolRange)
230     return std::nullopt;
231 
232   index::SymbolInfo SymInfo = index::getSymbolInfo(&ND);
233   // FIXME: This is not classifying constructors, destructors and operators
234   // correctly.
235   SymbolKind SK = indexSymbolKindToSymbolKind(SymInfo.Kind);
236 
237   DocumentSymbol SI;
238   SI.name = getSymbolName(Ctx, ND);
239   SI.kind = SK;
240   SI.deprecated = ND.isDeprecated();
241   SI.range = Range{sourceLocToPosition(SM, SymbolRange->getBegin()),
242                    sourceLocToPosition(SM, SymbolRange->getEnd())};
243   SI.detail = getSymbolDetail(Ctx, ND);
244 
245   SourceLocation NameLoc = ND.getLocation();
246   SourceLocation FallbackNameLoc;
247   if (NameLoc.isMacroID()) {
248     if (isSpelledInSource(NameLoc, SM)) {
249       // Prefer the spelling loc, but save the expansion loc as a fallback.
250       FallbackNameLoc = SM.getExpansionLoc(NameLoc);
251       NameLoc = SM.getSpellingLoc(NameLoc);
252     } else {
253       NameLoc = SM.getExpansionLoc(NameLoc);
254     }
255   }
256   auto ComputeSelectionRange = [&](SourceLocation L) -> Range {
257     Position NameBegin = sourceLocToPosition(SM, L);
258     Position NameEnd = sourceLocToPosition(
259         SM, Lexer::getLocForEndOfToken(L, 0, SM, Ctx.getLangOpts()));
260     return Range{NameBegin, NameEnd};
261   };
262 
263   SI.selectionRange = ComputeSelectionRange(NameLoc);
264   if (!SI.range.contains(SI.selectionRange) && FallbackNameLoc.isValid()) {
265     // 'selectionRange' must be contained in 'range'. In cases where clang
266     // reports unrelated ranges, we first try falling back to the expansion
267     // loc for the selection range.
268     SI.selectionRange = ComputeSelectionRange(FallbackNameLoc);
269   }
270   if (!SI.range.contains(SI.selectionRange)) {
271     // If the containment relationship still doesn't hold, throw away
272     // 'range' and use 'selectionRange' for both.
273     SI.range = SI.selectionRange;
274   }
275   return SI;
276 }
277 
278 /// A helper class to build an outline for the parse AST. It traverses the AST
279 /// directly instead of using RecursiveASTVisitor (RAV) for three main reasons:
280 ///    - there is no way to keep RAV from traversing subtrees we are not
281 ///      interested in. E.g. not traversing function locals or implicit template
282 ///      instantiations.
283 ///    - it's easier to combine results of recursive passes,
284 ///    - visiting decls is actually simple, so we don't hit the complicated
285 ///      cases that RAV mostly helps with (types, expressions, etc.)
286 class DocumentOutline {
287   // A DocumentSymbol we're constructing.
288   // We use this instead of DocumentSymbol directly so that we can keep track
289   // of the nodes we insert for macros.
290   class SymBuilder {
291     std::vector<SymBuilder> Children;
292     DocumentSymbol Symbol; // Symbol.children is empty, use Children instead.
293     // Macro expansions that this node or its parents are associated with.
294     // (Thus we will never create further children for these expansions).
295     llvm::SmallVector<SourceLocation> EnclosingMacroLoc;
296 
297   public:
298     DocumentSymbol build() && {
299       for (SymBuilder &C : Children) {
300         Symbol.children.push_back(std::move(C).build());
301         // Expand range to ensure children nest properly, which editors expect.
302         // This can fix some edge-cases in the AST, but is vital for macros.
303         // A macro expansion "contains" AST node if it covers the node's primary
304         // location, but it may not span the node's whole range.
305         Symbol.range.start =
306             std::min(Symbol.range.start, Symbol.children.back().range.start);
307         Symbol.range.end =
308             std::max(Symbol.range.end, Symbol.children.back().range.end);
309       }
310       return std::move(Symbol);
311     }
312 
313     // Add a symbol as a child of the current one.
314     SymBuilder &addChild(DocumentSymbol S) {
315       Children.emplace_back();
316       Children.back().EnclosingMacroLoc = EnclosingMacroLoc;
317       Children.back().Symbol = std::move(S);
318       return Children.back();
319     }
320 
321     // Get an appropriate container for children of this symbol that were
322     // expanded from a macro (whose spelled name is Tok).
323     //
324     // This may return:
325     //  - a macro symbol child of this (either new or previously created)
326     //  - this scope itself, if it *is* the macro symbol or is nested within it
327     SymBuilder &inMacro(const syntax::Token &Tok, const SourceManager &SM,
328                         std::optional<syntax::TokenBuffer::Expansion> Exp) {
329       if (llvm::is_contained(EnclosingMacroLoc, Tok.location()))
330         return *this;
331       // If there's an existing child for this macro, we expect it to be last.
332       if (!Children.empty() && !Children.back().EnclosingMacroLoc.empty() &&
333           Children.back().EnclosingMacroLoc.back() == Tok.location())
334         return Children.back();
335 
336       DocumentSymbol Sym;
337       Sym.name = Tok.text(SM).str();
338       Sym.kind = SymbolKind::Null; // There's no suitable kind!
339       Sym.range = Sym.selectionRange =
340           halfOpenToRange(SM, Tok.range(SM).toCharRange(SM));
341 
342       // FIXME: Exp is currently unavailable for nested expansions.
343       if (Exp) {
344         // Full range covers the macro args.
345         Sym.range = halfOpenToRange(SM, CharSourceRange::getCharRange(
346                                             Exp->Spelled.front().location(),
347                                             Exp->Spelled.back().endLocation()));
348         // Show macro args as detail.
349         llvm::raw_string_ostream OS(Sym.detail);
350         const syntax::Token *Prev = nullptr;
351         for (const auto &Tok : Exp->Spelled.drop_front()) {
352           // Don't dump arbitrarily long macro args.
353           if (OS.tell() > 80) {
354             OS << " ...)";
355             break;
356           }
357           if (Prev && Prev->endLocation() != Tok.location())
358             OS << ' ';
359           OS << Tok.text(SM);
360           Prev = &Tok;
361         }
362       }
363       SymBuilder &Child = addChild(std::move(Sym));
364       Child.EnclosingMacroLoc.push_back(Tok.location());
365       return Child;
366     }
367   };
368 
369 public:
370   DocumentOutline(ParsedAST &AST) : AST(AST) {}
371 
372   /// Builds the document outline for the generated AST.
373   std::vector<DocumentSymbol> build() {
374     SymBuilder Root;
375     for (auto &TopLevel : AST.getLocalTopLevelDecls())
376       traverseDecl(TopLevel, Root);
377     return std::move(std::move(Root).build().children);
378   }
379 
380 private:
381   enum class VisitKind { No, OnlyDecl, OnlyChildren, DeclAndChildren };
382 
383   void traverseDecl(Decl *D, SymBuilder &Parent) {
384     // Skip symbols which do not originate from the main file.
385     if (!isInsideMainFile(D->getLocation(), AST.getSourceManager()))
386       return;
387 
388     if (auto *Templ = llvm::dyn_cast<TemplateDecl>(D)) {
389       // TemplatedDecl might be null, e.g. concepts.
390       if (auto *TD = Templ->getTemplatedDecl())
391         D = TD;
392     }
393 
394     VisitKind Visit = shouldVisit(D);
395     if (Visit == VisitKind::No)
396       return;
397 
398     if (Visit == VisitKind::OnlyChildren)
399       return traverseChildren(D, Parent);
400 
401     auto *ND = llvm::cast<NamedDecl>(D);
402     auto Sym = declToSym(AST.getASTContext(), *ND);
403     if (!Sym)
404       return;
405     SymBuilder &MacroParent = possibleMacroContainer(D->getLocation(), Parent);
406     SymBuilder &Child = MacroParent.addChild(std::move(*Sym));
407 
408     if (Visit == VisitKind::OnlyDecl)
409       return;
410 
411     assert(Visit == VisitKind::DeclAndChildren && "Unexpected VisitKind");
412     traverseChildren(ND, Child);
413   }
414 
415   // Determines where a decl should appear in the DocumentSymbol hierarchy.
416   //
417   // This is usually a direct child of the relevant AST parent.
418   // But we may also insert nodes for macros. Given:
419   //   #define DECLARE_INT(V) int v;
420   //   namespace a { DECLARE_INT(x) }
421   // We produce:
422   //   Namespace a
423   //     Macro DECLARE_INT(x)
424   //       Variable x
425   //
426   // In the absence of macros, this method simply returns Parent.
427   // Otherwise it may return a macro expansion node instead.
428   // Each macro only has at most one node in the hierarchy, even if it expands
429   // to multiple decls.
430   SymBuilder &possibleMacroContainer(SourceLocation TargetLoc,
431                                      SymBuilder &Parent) {
432     const auto &SM = AST.getSourceManager();
433     // Look at the path of macro-callers from the token to the main file.
434     // Note that along these paths we see the "outer" macro calls first.
435     SymBuilder *CurParent = &Parent;
436     for (SourceLocation Loc = TargetLoc; Loc.isMacroID();
437          Loc = SM.getImmediateMacroCallerLoc(Loc)) {
438       // Find the virtual macro body that our token is being substituted into.
439       FileID MacroBody;
440       if (SM.isMacroArgExpansion(Loc)) {
441         // Loc is part of a macro arg being substituted into a macro body.
442         MacroBody = SM.getFileID(SM.getImmediateExpansionRange(Loc).getBegin());
443       } else {
444         // Loc is already in the macro body.
445         MacroBody = SM.getFileID(Loc);
446       }
447       // The macro body is being substituted for a macro expansion, whose
448       // first token is the name of the macro.
449       SourceLocation MacroName =
450           SM.getSLocEntry(MacroBody).getExpansion().getExpansionLocStart();
451       // Only include the macro expansion in the outline if it was written
452       // directly in the main file, rather than expanded from another macro.
453       if (!MacroName.isValid() || !MacroName.isFileID())
454         continue;
455       // All conditions satisfied, add the macro.
456       if (auto *Tok = AST.getTokens().spelledTokenContaining(MacroName))
457         CurParent = &CurParent->inMacro(
458             *Tok, SM, AST.getTokens().expansionStartingAt(Tok));
459     }
460     return *CurParent;
461   }
462 
463   void traverseChildren(Decl *D, SymBuilder &Builder) {
464     auto *Scope = llvm::dyn_cast<DeclContext>(D);
465     if (!Scope)
466       return;
467     for (auto *C : Scope->decls())
468       traverseDecl(C, Builder);
469   }
470 
471   VisitKind shouldVisit(Decl *D) {
472     if (D->isImplicit())
473       return VisitKind::No;
474 
475     if (llvm::isa<LinkageSpecDecl>(D) || llvm::isa<ExportDecl>(D))
476       return VisitKind::OnlyChildren;
477 
478     if (!llvm::isa<NamedDecl>(D))
479       return VisitKind::No;
480 
481     if (auto *Func = llvm::dyn_cast<FunctionDecl>(D)) {
482       // Some functions are implicit template instantiations, those should be
483       // ignored.
484       if (auto *Info = Func->getTemplateSpecializationInfo()) {
485         if (!Info->isExplicitInstantiationOrSpecialization())
486           return VisitKind::No;
487       }
488       // Only visit the function itself, do not visit the children (i.e.
489       // function parameters, etc.)
490       return VisitKind::OnlyDecl;
491     }
492     // Handle template instantiations. We have three cases to consider:
493     //   - explicit instantiations, e.g. 'template class std::vector<int>;'
494     //     Visit the decl itself (it's present in the code), but not the
495     //     children.
496     //   - implicit instantiations, i.e. not written by the user.
497     //     Do not visit at all, they are not present in the code.
498     //   - explicit specialization, e.g. 'template <> class vector<bool> {};'
499     //     Visit both the decl and its children, both are written in the code.
500     if (auto *TemplSpec = llvm::dyn_cast<ClassTemplateSpecializationDecl>(D)) {
501       if (TemplSpec->isExplicitInstantiationOrSpecialization())
502         return TemplSpec->isExplicitSpecialization()
503                    ? VisitKind::DeclAndChildren
504                    : VisitKind::OnlyDecl;
505       return VisitKind::No;
506     }
507     if (auto *TemplSpec = llvm::dyn_cast<VarTemplateSpecializationDecl>(D)) {
508       if (TemplSpec->isExplicitInstantiationOrSpecialization())
509         return TemplSpec->isExplicitSpecialization()
510                    ? VisitKind::DeclAndChildren
511                    : VisitKind::OnlyDecl;
512       return VisitKind::No;
513     }
514     // For all other cases, visit both the children and the decl.
515     return VisitKind::DeclAndChildren;
516   }
517 
518   ParsedAST &AST;
519 };
520 
521 struct PragmaMarkSymbol {
522   DocumentSymbol DocSym;
523   bool IsGroup;
524 };
525 
526 /// Merge in `PragmaMarkSymbols`, sorted ascending by range, into the given
527 /// `DocumentSymbol` tree.
528 void mergePragmas(DocumentSymbol &Root, ArrayRef<PragmaMarkSymbol> Pragmas) {
529   while (!Pragmas.empty()) {
530     // We'll figure out where the Pragmas.front() should go.
531     PragmaMarkSymbol P = std::move(Pragmas.front());
532     Pragmas = Pragmas.drop_front();
533     DocumentSymbol *Cur = &Root;
534     while (Cur->range.contains(P.DocSym.range)) {
535       bool Swapped = false;
536       for (auto &C : Cur->children) {
537         // We assume at most 1 child can contain the pragma (as pragmas are on
538         // a single line, and children have disjoint ranges).
539         if (C.range.contains(P.DocSym.range)) {
540           Cur = &C;
541           Swapped = true;
542           break;
543         }
544       }
545       // Cur is the parent of P since none of the children contain P.
546       if (!Swapped)
547         break;
548     }
549     // Pragma isn't a group so we can just insert it and we are done.
550     if (!P.IsGroup) {
551       Cur->children.emplace_back(std::move(P.DocSym));
552       continue;
553     }
554     // Pragma is a group, so we need to figure out where it terminates:
555     // - If the next Pragma is not contained in Cur, P owns all of its
556     //   parent's children which occur after P.
557     // - If the next pragma is contained in Cur but actually belongs to one
558     //   of the parent's children, we temporarily skip over it and look at
559     //   the next pragma to decide where we end.
560     // - Otherwise nest all of its parent's children which occur after P but
561     //   before the next pragma.
562     bool TerminatedByNextPragma = false;
563     for (auto &NextPragma : Pragmas) {
564       // If we hit a pragma outside of Cur, the rest will be outside as well.
565       if (!Cur->range.contains(NextPragma.DocSym.range))
566         break;
567 
568       // NextPragma cannot terminate P if it is nested inside a child, look for
569       // the next one.
570       if (llvm::any_of(Cur->children, [&NextPragma](const auto &Child) {
571             return Child.range.contains(NextPragma.DocSym.range);
572           }))
573         continue;
574 
575       // Pragma owns all the children between P and NextPragma
576       auto It = llvm::partition(Cur->children,
577                                 [&P, &NextPragma](const auto &S) -> bool {
578                                   return !(P.DocSym.range < S.range &&
579                                            S.range < NextPragma.DocSym.range);
580                                 });
581       P.DocSym.children.assign(make_move_iterator(It),
582                                make_move_iterator(Cur->children.end()));
583       Cur->children.erase(It, Cur->children.end());
584       TerminatedByNextPragma = true;
585       break;
586     }
587     if (!TerminatedByNextPragma) {
588       // P is terminated by the end of current symbol, hence it owns all the
589       // children after P.
590       auto It = llvm::partition(Cur->children, [&P](const auto &S) -> bool {
591         return !(P.DocSym.range < S.range);
592       });
593       P.DocSym.children.assign(make_move_iterator(It),
594                                make_move_iterator(Cur->children.end()));
595       Cur->children.erase(It, Cur->children.end());
596     }
597     // Update the range for P to cover children and append to Cur.
598     for (DocumentSymbol &Sym : P.DocSym.children)
599       unionRanges(P.DocSym.range, Sym.range);
600     Cur->children.emplace_back(std::move(P.DocSym));
601   }
602 }
603 
604 PragmaMarkSymbol markToSymbol(const PragmaMark &P) {
605   StringRef Name = StringRef(P.Trivia).trim();
606   bool IsGroup = false;
607   // "-\s+<group name>" or "<name>" after an initial trim. The former is
608   // considered a group, the latter just a mark. Like Xcode, we don't consider
609   // `-Foo` to be a group (space(s) after the `-` is required).
610   //
611   // We need to include a name here, otherwise editors won't properly render the
612   // symbol.
613   StringRef MaybeGroupName = Name;
614   if (MaybeGroupName.consume_front("-") &&
615       (MaybeGroupName.ltrim() != MaybeGroupName || MaybeGroupName.empty())) {
616     Name = MaybeGroupName.empty() ? "(unnamed group)" : MaybeGroupName.ltrim();
617     IsGroup = true;
618   } else if (Name.empty()) {
619     Name = "(unnamed mark)";
620   }
621   DocumentSymbol Sym;
622   Sym.name = Name.str();
623   Sym.kind = SymbolKind::File;
624   Sym.range = P.Rng;
625   Sym.selectionRange = P.Rng;
626   return {Sym, IsGroup};
627 }
628 
629 std::vector<DocumentSymbol> collectDocSymbols(ParsedAST &AST) {
630   std::vector<DocumentSymbol> Syms = DocumentOutline(AST).build();
631 
632   const auto &PragmaMarks = AST.getMarks();
633   if (PragmaMarks.empty())
634     return Syms;
635 
636   std::vector<PragmaMarkSymbol> Pragmas;
637   Pragmas.reserve(PragmaMarks.size());
638   for (const auto &P : PragmaMarks)
639     Pragmas.push_back(markToSymbol(P));
640   Range EntireFile = {
641       {0, 0},
642       {std::numeric_limits<int>::max(), std::numeric_limits<int>::max()}};
643   DocumentSymbol Root;
644   Root.children = std::move(Syms);
645   Root.range = EntireFile;
646   mergePragmas(Root, llvm::ArrayRef(Pragmas));
647   return Root.children;
648 }
649 
650 } // namespace
651 
652 llvm::Expected<std::vector<DocumentSymbol>> getDocumentSymbols(ParsedAST &AST) {
653   return collectDocSymbols(AST);
654 }
655 
656 } // namespace clangd
657 } // namespace clang
658