1//===--- SemanticHighlighting.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
9#include "SemanticHighlighting.h"
10#include "Config.h"
11#include "FindTarget.h"
12#include "ParsedAST.h"
13#include "Protocol.h"
14#include "SourceCode.h"
15#include "support/Logger.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/Decl.h"
18#include "clang/AST/DeclCXX.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/DeclTemplate.h"
21#include "clang/AST/DeclarationName.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/AST/RecursiveASTVisitor.h"
24#include "clang/AST/Type.h"
25#include "clang/AST/TypeLoc.h"
26#include "clang/Basic/LangOptions.h"
27#include "clang/Basic/SourceLocation.h"
28#include "clang/Basic/SourceManager.h"
29#include "clang/Sema/HeuristicResolver.h"
30#include "clang/Tooling/Syntax/Tokens.h"
31#include "llvm/ADT/STLExtras.h"
32#include "llvm/ADT/StringRef.h"
33#include "llvm/Support/Casting.h"
34#include "llvm/Support/Error.h"
35#include <algorithm>
36#include <optional>
37
38namespace clang {
39namespace clangd {
40namespace {
41
42/// Get the last Position on a given line.
43llvm::Expected<Position> endOfLine(llvm::StringRef Code, int Line) {
44 auto StartOfLine = positionToOffset(Code, P: Position{.line: Line, .character: 0});
45 if (!StartOfLine)
46 return StartOfLine.takeError();
47 StringRef LineText = Code.drop_front(N: *StartOfLine).take_until(F: [](char C) {
48 return C == '\n';
49 });
50 return Position{.line: Line, .character: static_cast<int>(lspLength(Code: LineText))};
51}
52
53/// Some names are not written in the source code and cannot be highlighted,
54/// e.g. anonymous classes. This function detects those cases.
55bool canHighlightName(DeclarationName Name) {
56 switch (Name.getNameKind()) {
57 case DeclarationName::Identifier: {
58 auto *II = Name.getAsIdentifierInfo();
59 return II && !II->getName().empty();
60 }
61 case DeclarationName::CXXConstructorName:
62 case DeclarationName::CXXDestructorName:
63 return true;
64 case DeclarationName::ObjCZeroArgSelector:
65 case DeclarationName::ObjCOneArgSelector:
66 case DeclarationName::ObjCMultiArgSelector:
67 // Multi-arg selectors need special handling, and we handle 0/1 arg
68 // selectors there too.
69 return false;
70 case DeclarationName::CXXConversionFunctionName:
71 case DeclarationName::CXXOperatorName:
72 case DeclarationName::CXXDeductionGuideName:
73 case DeclarationName::CXXLiteralOperatorName:
74 case DeclarationName::CXXUsingDirective:
75 return false;
76 }
77 llvm_unreachable("invalid name kind");
78}
79
80bool isUniqueDefinition(const NamedDecl *Decl) {
81 if (auto *Func = dyn_cast<FunctionDecl>(Val: Decl))
82 return Func->isThisDeclarationADefinition();
83 if (auto *Klass = dyn_cast<CXXRecordDecl>(Val: Decl))
84 return Klass->isThisDeclarationADefinition();
85 if (auto *Iface = dyn_cast<ObjCInterfaceDecl>(Val: Decl))
86 return Iface->isThisDeclarationADefinition();
87 if (auto *Proto = dyn_cast<ObjCProtocolDecl>(Val: Decl))
88 return Proto->isThisDeclarationADefinition();
89 if (auto *Var = dyn_cast<VarDecl>(Val: Decl))
90 return Var->isThisDeclarationADefinition();
91 return isa<TemplateTypeParmDecl>(Val: Decl) ||
92 isa<NonTypeTemplateParmDecl>(Val: Decl) ||
93 isa<TemplateTemplateParmDecl>(Val: Decl) || isa<ObjCCategoryDecl>(Val: Decl) ||
94 isa<ObjCImplDecl>(Val: Decl);
95}
96
97std::optional<HighlightingKind> kindForType(const Type *TP,
98 const HeuristicResolver *Resolver);
99std::optional<HighlightingKind> kindForDecl(const NamedDecl *D,
100 const HeuristicResolver *Resolver) {
101 if (auto *USD = dyn_cast<UsingShadowDecl>(Val: D)) {
102 if (auto *Target = USD->getTargetDecl())
103 D = Target;
104 }
105 if (auto *TD = dyn_cast<TemplateDecl>(Val: D)) {
106 if (auto *Templated = TD->getTemplatedDecl())
107 D = Templated;
108 }
109 if (auto *TD = dyn_cast<TypedefNameDecl>(Val: D)) {
110 // We try to highlight typedefs as their underlying type.
111 if (auto K =
112 kindForType(TP: TD->getUnderlyingType().getTypePtrOrNull(), Resolver))
113 return K;
114 // And fallback to a generic kind if this fails.
115 return HighlightingKind::Typedef;
116 }
117 // We highlight class decls, constructor decls and destructor decls as
118 // `Class` type. The destructor decls are handled in `VisitTagTypeLoc` (we
119 // will visit a TypeLoc where the underlying Type is a CXXRecordDecl).
120 if (auto *RD = llvm::dyn_cast<RecordDecl>(Val: D)) {
121 // We don't want to highlight lambdas like classes.
122 if (RD->isLambda())
123 return std::nullopt;
124 return HighlightingKind::Class;
125 }
126 if (isa<ClassTemplateDecl, RecordDecl, CXXConstructorDecl, ObjCInterfaceDecl,
127 ObjCImplementationDecl>(Val: D))
128 return HighlightingKind::Class;
129 if (isa<ObjCProtocolDecl>(Val: D))
130 return HighlightingKind::Interface;
131 if (isa<ObjCCategoryDecl, ObjCCategoryImplDecl>(Val: D))
132 return HighlightingKind::Namespace;
133 if (auto *MD = dyn_cast<CXXMethodDecl>(Val: D))
134 return MD->isStatic() ? HighlightingKind::StaticMethod
135 : HighlightingKind::Method;
136 if (auto *OMD = dyn_cast<ObjCMethodDecl>(Val: D))
137 return OMD->isClassMethod() ? HighlightingKind::StaticMethod
138 : HighlightingKind::Method;
139 if (isa<FieldDecl, IndirectFieldDecl, ObjCPropertyDecl>(Val: D))
140 return HighlightingKind::Field;
141 if (isa<EnumDecl>(Val: D))
142 return HighlightingKind::Enum;
143 if (isa<EnumConstantDecl>(Val: D))
144 return HighlightingKind::EnumConstant;
145 if (isa<ParmVarDecl>(Val: D))
146 return HighlightingKind::Parameter;
147 if (auto *VD = dyn_cast<VarDecl>(Val: D)) {
148 if (isa<ImplicitParamDecl>(Val: VD)) // e.g. ObjC Self
149 return std::nullopt;
150 return VD->isStaticDataMember()
151 ? HighlightingKind::StaticField
152 : VD->isLocalVarDecl() ? HighlightingKind::LocalVariable
153 : HighlightingKind::Variable;
154 }
155 if (const auto *BD = dyn_cast<BindingDecl>(Val: D))
156 return BD->getDeclContext()->isFunctionOrMethod()
157 ? HighlightingKind::LocalVariable
158 : HighlightingKind::Variable;
159 if (isa<FunctionDecl>(Val: D))
160 return HighlightingKind::Function;
161 if (isa<NamespaceDecl>(Val: D) || isa<NamespaceAliasDecl>(Val: D) ||
162 isa<UsingDirectiveDecl>(Val: D))
163 return HighlightingKind::Namespace;
164 if (isa<TemplateTemplateParmDecl>(Val: D) || isa<TemplateTypeParmDecl>(Val: D) ||
165 isa<NonTypeTemplateParmDecl>(Val: D))
166 return HighlightingKind::TemplateParameter;
167 if (isa<ConceptDecl>(Val: D))
168 return HighlightingKind::Concept;
169 if (isa<LabelDecl>(Val: D))
170 return HighlightingKind::Label;
171 if (const auto *UUVD = dyn_cast<UnresolvedUsingValueDecl>(Val: D)) {
172 auto Targets = Resolver->resolveUsingValueDecl(UUVD);
173 if (!Targets.empty() && Targets[0] != UUVD) {
174 return kindForDecl(D: Targets[0], Resolver);
175 }
176 return HighlightingKind::Unknown;
177 }
178 return std::nullopt;
179}
180std::optional<HighlightingKind> kindForType(const Type *TP,
181 const HeuristicResolver *Resolver) {
182 if (!TP)
183 return std::nullopt;
184 if (TP->isBuiltinType()) // Builtins are special, they do not have decls.
185 return HighlightingKind::Primitive;
186 if (auto *TD = dyn_cast<TemplateTypeParmType>(Val: TP))
187 return kindForDecl(TD->getDecl(), Resolver);
188 if (isa<ObjCObjectPointerType>(Val: TP))
189 return HighlightingKind::Class;
190 if (auto *TD = TP->getAsTagDecl())
191 return kindForDecl(TD, Resolver);
192 return std::nullopt;
193}
194
195// Whether T is const in a loose sense - is a variable with this type readonly?
196bool isConst(QualType T) {
197 if (T.isNull())
198 return false;
199 T = T.getNonReferenceType();
200 if (T.isConstQualified())
201 return true;
202 if (const auto *AT = T->getAsArrayTypeUnsafe())
203 return isConst(AT->getElementType());
204 if (isConst(T: T->getPointeeType()))
205 return true;
206 return false;
207}
208
209// Whether D is const in a loose sense (should it be highlighted as such?)
210// FIXME: This is separate from whether *a particular usage* can mutate D.
211// We may want V in V.size() to be readonly even if V is mutable.
212bool isConst(const Decl *D) {
213 if (llvm::isa<EnumConstantDecl>(Val: D) || llvm::isa<NonTypeTemplateParmDecl>(Val: D))
214 return true;
215 if (llvm::isa<FieldDecl>(Val: D) || llvm::isa<VarDecl>(Val: D) ||
216 llvm::isa<MSPropertyDecl>(Val: D) || llvm::isa<BindingDecl>(Val: D)) {
217 if (isConst(T: llvm::cast<ValueDecl>(Val: D)->getType()))
218 return true;
219 }
220 if (const auto *OCPD = llvm::dyn_cast<ObjCPropertyDecl>(Val: D)) {
221 if (OCPD->isReadOnly())
222 return true;
223 }
224 if (const auto *MPD = llvm::dyn_cast<MSPropertyDecl>(Val: D)) {
225 if (!MPD->hasSetter())
226 return true;
227 }
228 if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(Val: D)) {
229 if (CMD->isConst())
230 return true;
231 }
232 return false;
233}
234
235// "Static" means many things in C++, only some get the "static" modifier.
236//
237// Meanings that do:
238// - Members associated with the class rather than the instance.
239// This is what 'static' most often means across languages.
240// - static local variables
241// These are similarly "detached from their context" by the static keyword.
242// In practice, these are rarely used inside classes, reducing confusion.
243//
244// Meanings that don't:
245// - Namespace-scoped variables, which have static storage class.
246// This is implicit, so the keyword "static" isn't so strongly associated.
247// If we want a modifier for these, "global scope" is probably the concept.
248// - Namespace-scoped variables/functions explicitly marked "static".
249// There the keyword changes *linkage* , which is a totally different concept.
250// If we want to model this, "file scope" would be a nice modifier.
251//
252// This is confusing, and maybe we should use another name, but because "static"
253// is a standard LSP modifier, having one with that name has advantages.
254bool isStatic(const Decl *D) {
255 if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(Val: D))
256 return CMD->isStatic();
257 if (const VarDecl *VD = llvm::dyn_cast<VarDecl>(Val: D))
258 return VD->isStaticDataMember() || VD->isStaticLocal();
259 if (const auto *OPD = llvm::dyn_cast<ObjCPropertyDecl>(Val: D))
260 return OPD->isClassProperty();
261 if (const auto *OMD = llvm::dyn_cast<ObjCMethodDecl>(Val: D))
262 return OMD->isClassMethod();
263 return false;
264}
265
266bool isAbstract(const Decl *D) {
267 if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(Val: D))
268 return CMD->isPureVirtual();
269 if (const auto *CRD = llvm::dyn_cast<CXXRecordDecl>(Val: D))
270 return CRD->hasDefinition() && CRD->isAbstract();
271 return false;
272}
273
274bool isVirtual(const Decl *D) {
275 if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(Val: D))
276 return CMD->isVirtual();
277 return false;
278}
279
280bool isDependent(const Decl *D) {
281 if (isa<UnresolvedUsingValueDecl>(Val: D))
282 return true;
283 return false;
284}
285
286/// Returns true if `Decl` is considered to be from a default/system library.
287/// This currently checks the systemness of the file by include type, although
288/// different heuristics may be used in the future (e.g. sysroot paths).
289bool isDefaultLibrary(const Decl *D) {
290 SourceLocation Loc = D->getLocation();
291 if (!Loc.isValid())
292 return false;
293 return D->getASTContext().getSourceManager().isInSystemHeader(Loc);
294}
295
296bool isDefaultLibrary(const Type *T) {
297 if (!T)
298 return false;
299 const Type *Underlying = T->getPointeeOrArrayElementType();
300 if (Underlying->isBuiltinType())
301 return true;
302 if (auto *TD = dyn_cast<TemplateTypeParmType>(Val: Underlying))
303 return isDefaultLibrary(TD->getDecl());
304 if (auto *TD = Underlying->getAsTagDecl())
305 return isDefaultLibrary(TD);
306 return false;
307}
308
309// For a macro usage `DUMP(foo)`, we want:
310// - DUMP --> "macro"
311// - foo --> "variable".
312SourceLocation getHighlightableSpellingToken(SourceLocation L,
313 const SourceManager &SM) {
314 if (L.isFileID())
315 return SM.isWrittenInMainFile(Loc: L) ? L : SourceLocation{};
316 // Tokens expanded from the macro body contribute no highlightings.
317 if (!SM.isMacroArgExpansion(Loc: L))
318 return {};
319 // Tokens expanded from macro args are potentially highlightable.
320 return getHighlightableSpellingToken(L: SM.getImmediateSpellingLoc(Loc: L), SM);
321}
322
323unsigned evaluateHighlightPriority(const HighlightingToken &Tok) {
324 enum HighlightPriority { Dependent = 0, Resolved = 1 };
325 return (Tok.Modifiers & (1 << uint32_t(HighlightingModifier::DependentName)))
326 ? Dependent
327 : Resolved;
328}
329
330// Sometimes we get multiple tokens at the same location:
331//
332// - findExplicitReferences() returns a heuristic result for a dependent name
333// (e.g. Method) and CollectExtraHighlighting returning a fallback dependent
334// highlighting (e.g. Unknown+Dependent).
335// - macro arguments are expanded multiple times and have different roles
336// - broken code recovery produces several AST nodes at the same location
337//
338// We should either resolve these to a single token, or drop them all.
339// Our heuristics are:
340//
341// - token kinds that come with "dependent-name" modifiers are less reliable
342// (these tend to be vague, like Type or Unknown)
343// - if we have multiple equally reliable kinds, drop token rather than guess
344// - take the union of modifiers from all tokens
345//
346// In particular, heuristically resolved dependent names get their heuristic
347// kind, plus the dependent modifier.
348std::optional<HighlightingToken> resolveConflict(const HighlightingToken &A,
349 const HighlightingToken &B) {
350 unsigned Priority1 = evaluateHighlightPriority(Tok: A);
351 unsigned Priority2 = evaluateHighlightPriority(Tok: B);
352 if (Priority1 == Priority2 && A.Kind != B.Kind)
353 return std::nullopt;
354 auto Result = Priority1 > Priority2 ? A : B;
355 Result.Modifiers = A.Modifiers | B.Modifiers;
356 return Result;
357}
358std::optional<HighlightingToken>
359resolveConflict(ArrayRef<HighlightingToken> Tokens) {
360 if (Tokens.size() == 1)
361 return Tokens[0];
362
363 assert(Tokens.size() >= 2);
364 std::optional<HighlightingToken> Winner =
365 resolveConflict(A: Tokens[0], B: Tokens[1]);
366 for (size_t I = 2; Winner && I < Tokens.size(); ++I)
367 Winner = resolveConflict(A: *Winner, B: Tokens[I]);
368 return Winner;
369}
370
371/// Filter to remove particular kinds of highlighting tokens and modifiers from
372/// the output.
373class HighlightingFilter {
374public:
375 HighlightingFilter() {
376 for (auto &Active : ActiveKindLookup)
377 Active = true;
378
379 ActiveModifiersMask = ~0;
380 }
381
382 void disableKind(HighlightingKind Kind) {
383 ActiveKindLookup[static_cast<size_t>(Kind)] = false;
384 }
385
386 void disableModifier(HighlightingModifier Modifier) {
387 ActiveModifiersMask &= ~(1 << static_cast<uint32_t>(Modifier));
388 }
389
390 bool isHighlightKindActive(HighlightingKind Kind) const {
391 return ActiveKindLookup[static_cast<size_t>(Kind)];
392 }
393
394 uint32_t maskModifiers(uint32_t Modifiers) const {
395 return Modifiers & ActiveModifiersMask;
396 }
397
398 static HighlightingFilter fromCurrentConfig() {
399 const Config &C = Config::current();
400 HighlightingFilter Filter;
401 for (const auto &Kind : C.SemanticTokens.DisabledKinds)
402 if (auto K = highlightingKindFromString(Name: Kind))
403 Filter.disableKind(Kind: *K);
404 for (const auto &Modifier : C.SemanticTokens.DisabledModifiers)
405 if (auto M = highlightingModifierFromString(Name: Modifier))
406 Filter.disableModifier(Modifier: *M);
407
408 return Filter;
409 }
410
411private:
412 bool ActiveKindLookup[static_cast<size_t>(HighlightingKind::LastKind) + 1];
413 uint32_t ActiveModifiersMask;
414};
415
416/// Consumes source locations and maps them to text ranges for highlightings.
417class HighlightingsBuilder {
418public:
419 HighlightingsBuilder(const ParsedAST &AST, const HighlightingFilter &Filter)
420 : TB(AST.getTokens()), SourceMgr(AST.getSourceManager()),
421 LangOpts(AST.getLangOpts()), Filter(Filter),
422 Resolver(AST.getHeuristicResolver()) {}
423
424 HighlightingToken &addToken(SourceLocation Loc, HighlightingKind Kind) {
425 auto Range = getRangeForSourceLocation(Loc);
426 if (!Range)
427 return InvalidHighlightingToken;
428
429 return addToken(R: *Range, Kind);
430 }
431
432 // Most of this function works around
433 // https://github.com/clangd/clangd/issues/871.
434 void addAngleBracketTokens(SourceLocation LLoc, SourceLocation RLoc) {
435 if (!LLoc.isValid() || !RLoc.isValid())
436 return;
437
438 auto LRange = getRangeForSourceLocation(Loc: LLoc);
439 if (!LRange)
440 return;
441
442 // RLoc might be pointing at a virtual buffer when it's part of a `>>`
443 // token.
444 RLoc = SourceMgr.getFileLoc(Loc: RLoc);
445 // Make sure token is part of the main file.
446 RLoc = getHighlightableSpellingToken(L: RLoc, SM: SourceMgr);
447 if (!RLoc.isValid())
448 return;
449
450 const auto *RTok = TB.spelledTokenContaining(Loc: RLoc);
451 // Handle `>>`. RLoc is either part of `>>` or a spelled token on its own
452 // `>`. If it's the former, slice to have length of 1, if latter use the
453 // token as-is.
454 if (!RTok || RTok->kind() == tok::greatergreater) {
455 Position Begin = sourceLocToPosition(SM: SourceMgr, Loc: RLoc);
456 Position End = sourceLocToPosition(SM: SourceMgr, Loc: RLoc.getLocWithOffset(Offset: 1));
457 addToken(R: *LRange, Kind: HighlightingKind::Bracket);
458 addToken(R: {.start: Begin, .end: End}, Kind: HighlightingKind::Bracket);
459 return;
460 }
461
462 // Easy case, we have the `>` token directly available.
463 if (RTok->kind() == tok::greater) {
464 if (auto RRange = getRangeForSourceLocation(Loc: RLoc)) {
465 addToken(R: *LRange, Kind: HighlightingKind::Bracket);
466 addToken(R: *RRange, Kind: HighlightingKind::Bracket);
467 }
468 return;
469 }
470 }
471
472 HighlightingToken &addToken(Range R, HighlightingKind Kind) {
473 if (!Filter.isHighlightKindActive(Kind))
474 return InvalidHighlightingToken;
475
476 HighlightingToken HT;
477 HT.R = std::move(R);
478 HT.Kind = Kind;
479 Tokens.push_back(x: std::move(HT));
480 return Tokens.back();
481 }
482
483 void addExtraModifier(SourceLocation Loc, HighlightingModifier Modifier) {
484 if (auto Range = getRangeForSourceLocation(Loc))
485 ExtraModifiers[*Range].push_back(Elt: Modifier);
486 }
487
488 std::vector<HighlightingToken> collect(ParsedAST &AST) && {
489 // Initializer lists can give duplicates of tokens, therefore all tokens
490 // must be deduplicated.
491 llvm::sort(C&: Tokens);
492 auto Last = std::unique(first: Tokens.begin(), last: Tokens.end());
493 Tokens.erase(first: Last, last: Tokens.end());
494
495 // Macros can give tokens that have the same source range but conflicting
496 // kinds. In this case all tokens sharing this source range should be
497 // removed.
498 std::vector<HighlightingToken> NonConflicting;
499 NonConflicting.reserve(n: Tokens.size());
500 for (ArrayRef<HighlightingToken> TokRef = Tokens; !TokRef.empty();) {
501 ArrayRef<HighlightingToken> Conflicting =
502 TokRef.take_while(Pred: [&](const HighlightingToken &T) {
503 // TokRef is guaranteed at least one element here because otherwise
504 // this predicate would never fire.
505 return T.R == TokRef.front().R;
506 });
507 if (auto Resolved = resolveConflict(Tokens: Conflicting)) {
508 // Apply extra collected highlighting modifiers
509 auto Modifiers = ExtraModifiers.find(x: Resolved->R);
510 if (Modifiers != ExtraModifiers.end()) {
511 for (HighlightingModifier Mod : Modifiers->second) {
512 Resolved->addModifier(M: Mod);
513 }
514 }
515
516 Resolved->Modifiers = Filter.maskModifiers(Modifiers: Resolved->Modifiers);
517 NonConflicting.push_back(x: *Resolved);
518 }
519 // TokRef[Conflicting.size()] is the next token with a different range (or
520 // the end of the Tokens).
521 TokRef = TokRef.drop_front(N: Conflicting.size());
522 }
523
524 if (!Filter.isHighlightKindActive(Kind: HighlightingKind::InactiveCode))
525 return NonConflicting;
526
527 const auto &SM = AST.getSourceManager();
528 StringRef MainCode = SM.getBufferOrFake(FID: SM.getMainFileID()).getBuffer();
529
530 // Merge token stream with "inactive line" markers.
531 std::vector<HighlightingToken> WithInactiveLines;
532 auto SortedInactiveRegions = getInactiveRegions(AST);
533 llvm::sort(C&: SortedInactiveRegions);
534 auto It = NonConflicting.begin();
535 for (const Range &R : SortedInactiveRegions) {
536 // Create one token for each line in the inactive range, so it works
537 // with line-based diffing.
538 assert(R.start.line <= R.end.line);
539 for (int Line = R.start.line; Line <= R.end.line; ++Line) {
540 // Copy tokens before the inactive line
541 for (; It != NonConflicting.end() && It->R.start.line < Line; ++It)
542 WithInactiveLines.push_back(x: std::move(*It));
543 // Add a token for the inactive line itself.
544 auto EndOfLine = endOfLine(Code: MainCode, Line);
545 if (EndOfLine) {
546 HighlightingToken HT;
547 WithInactiveLines.emplace_back();
548 WithInactiveLines.back().Kind = HighlightingKind::InactiveCode;
549 WithInactiveLines.back().R.start.line = Line;
550 WithInactiveLines.back().R.end = *EndOfLine;
551 } else {
552 elog(Fmt: "Failed to determine end of line: {0}", Vals: EndOfLine.takeError());
553 }
554
555 // Skip any other tokens on the inactive line. e.g.
556 // `#ifndef Foo` is considered as part of an inactive region when Foo is
557 // defined, and there is a Foo macro token.
558 // FIXME: we should reduce the scope of the inactive region to not
559 // include the directive itself.
560 while (It != NonConflicting.end() && It->R.start.line == Line)
561 ++It;
562 }
563 }
564 // Copy tokens after the last inactive line
565 for (; It != NonConflicting.end(); ++It)
566 WithInactiveLines.push_back(x: std::move(*It));
567 return WithInactiveLines;
568 }
569
570 const HeuristicResolver *getResolver() const { return Resolver; }
571
572private:
573 std::optional<Range> getRangeForSourceLocation(SourceLocation Loc) {
574 Loc = getHighlightableSpellingToken(L: Loc, SM: SourceMgr);
575 if (Loc.isInvalid())
576 return std::nullopt;
577 // We might have offsets in the main file that don't correspond to any
578 // spelled tokens.
579 const auto *Tok = TB.spelledTokenContaining(Loc);
580 if (!Tok)
581 return std::nullopt;
582 return halfOpenToRange(SM: SourceMgr,
583 R: Tok->range(SM: SourceMgr).toCharRange(SM: SourceMgr));
584 }
585
586 const syntax::TokenBuffer &TB;
587 const SourceManager &SourceMgr;
588 const LangOptions &LangOpts;
589 HighlightingFilter Filter;
590 std::vector<HighlightingToken> Tokens;
591 std::map<Range, llvm::SmallVector<HighlightingModifier, 1>> ExtraModifiers;
592 const HeuristicResolver *Resolver;
593 // returned from addToken(InvalidLoc)
594 HighlightingToken InvalidHighlightingToken;
595};
596
597std::optional<HighlightingModifier> scopeModifier(const NamedDecl *D) {
598 const DeclContext *DC = D->getDeclContext();
599 // Injected "Foo" within the class "Foo" has file scope, not class scope.
600 if (auto *R = dyn_cast_or_null<RecordDecl>(Val: D))
601 if (R->isInjectedClassName())
602 DC = DC->getParent();
603 // Lambda captures are considered function scope, not class scope.
604 if (llvm::isa<FieldDecl>(Val: D))
605 if (const auto *RD = llvm::dyn_cast<RecordDecl>(Val: DC))
606 if (RD->isLambda())
607 return HighlightingModifier::FunctionScope;
608 // Walk up the DeclContext hierarchy until we find something interesting.
609 for (; !DC->isFileContext(); DC = DC->getParent()) {
610 if (DC->isFunctionOrMethod())
611 return HighlightingModifier::FunctionScope;
612 if (DC->isRecord())
613 return HighlightingModifier::ClassScope;
614 }
615 // Some template parameters (e.g. those for variable templates) don't have
616 // meaningful DeclContexts. That doesn't mean they're global!
617 if (DC->isTranslationUnit() && D->isTemplateParameter())
618 return std::nullopt;
619 // ExternalLinkage threshold could be tweaked, e.g. module-visible as global.
620 if (llvm::to_underlying(E: D->getLinkageInternal()) <
621 llvm::to_underlying(E: Linkage::External))
622 return HighlightingModifier::FileScope;
623 return HighlightingModifier::GlobalScope;
624}
625
626std::optional<HighlightingModifier> scopeModifier(const Type *T) {
627 if (!T)
628 return std::nullopt;
629 if (T->isBuiltinType())
630 return HighlightingModifier::GlobalScope;
631 if (auto *TD = dyn_cast<TemplateTypeParmType>(Val: T))
632 return scopeModifier(TD->getDecl());
633 if (auto *TD = T->getAsTagDecl())
634 return scopeModifier(TD);
635 return std::nullopt;
636}
637
638/// Produces highlightings, which are not captured by findExplicitReferences,
639/// e.g. highlights dependent names and 'auto' as the underlying type.
640class CollectExtraHighlightings
641 : public RecursiveASTVisitor<CollectExtraHighlightings> {
642 using Base = RecursiveASTVisitor<CollectExtraHighlightings>;
643
644public:
645 CollectExtraHighlightings(HighlightingsBuilder &H) : H(H) {}
646
647 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
648 highlightMutableReferenceArguments(E->getConstructor(),
649 {E->getArgs(), E->getNumArgs()});
650
651 return true;
652 }
653
654 bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
655 if (Init->isMemberInitializer())
656 if (auto *Member = Init->getMember())
657 highlightMutableReferenceArgument(T: Member->getType(), Arg: Init->getInit());
658 return Base::TraverseConstructorInitializer(Init);
659 }
660
661 bool TraverseTypeConstraint(const TypeConstraint *C) {
662 if (auto *Args = C->getTemplateArgsAsWritten())
663 H.addAngleBracketTokens(LLoc: Args->getLAngleLoc(), RLoc: Args->getRAngleLoc());
664 return Base::TraverseTypeConstraint(C);
665 }
666
667 bool VisitPredefinedExpr(PredefinedExpr *E) {
668 H.addToken(Loc: E->getLocation(), Kind: HighlightingKind::LocalVariable)
669 .addModifier(M: HighlightingModifier::Static)
670 .addModifier(M: HighlightingModifier::Readonly)
671 .addModifier(M: HighlightingModifier::FunctionScope);
672 return true;
673 }
674
675 bool VisitConceptSpecializationExpr(ConceptSpecializationExpr *E) {
676 if (auto *Args = E->getTemplateArgsAsWritten())
677 H.addAngleBracketTokens(LLoc: Args->getLAngleLoc(), RLoc: Args->getRAngleLoc());
678 return true;
679 }
680
681 bool VisitTemplateDecl(TemplateDecl *D) {
682 if (auto *TPL = D->getTemplateParameters())
683 H.addAngleBracketTokens(LLoc: TPL->getLAngleLoc(), RLoc: TPL->getRAngleLoc());
684 return true;
685 }
686
687 bool VisitTagDecl(TagDecl *D) {
688 for (unsigned i = 0; i < D->getNumTemplateParameterLists(); ++i) {
689 if (auto *TPL = D->getTemplateParameterList(i))
690 H.addAngleBracketTokens(LLoc: TPL->getLAngleLoc(), RLoc: TPL->getRAngleLoc());
691 }
692 return true;
693 }
694
695 bool
696 VisitClassTemplateSpecializationDecl(ClassTemplateSpecializationDecl *D) {
697 if (auto *Args = D->getTemplateArgsAsWritten())
698 H.addAngleBracketTokens(LLoc: Args->getLAngleLoc(), RLoc: Args->getRAngleLoc());
699 return true;
700 }
701
702 bool VisitClassTemplatePartialSpecializationDecl(
703 ClassTemplatePartialSpecializationDecl *D) {
704 if (auto *TPL = D->getTemplateParameters())
705 H.addAngleBracketTokens(LLoc: TPL->getLAngleLoc(), RLoc: TPL->getRAngleLoc());
706 return true;
707 }
708
709 bool VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D) {
710 if (auto *Args = D->getTemplateArgsAsWritten())
711 H.addAngleBracketTokens(LLoc: Args->getLAngleLoc(), RLoc: Args->getRAngleLoc());
712 return true;
713 }
714
715 bool VisitVarTemplatePartialSpecializationDecl(
716 VarTemplatePartialSpecializationDecl *D) {
717 if (auto *TPL = D->getTemplateParameters())
718 H.addAngleBracketTokens(LLoc: TPL->getLAngleLoc(), RLoc: TPL->getRAngleLoc());
719 return true;
720 }
721
722 bool VisitDeclRefExpr(DeclRefExpr *E) {
723 H.addAngleBracketTokens(LLoc: E->getLAngleLoc(), RLoc: E->getRAngleLoc());
724 return true;
725 }
726 bool VisitMemberExpr(MemberExpr *E) {
727 H.addAngleBracketTokens(LLoc: E->getLAngleLoc(), RLoc: E->getRAngleLoc());
728 return true;
729 }
730
731 bool VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc L) {
732 H.addAngleBracketTokens(LLoc: L.getLAngleLoc(), RLoc: L.getRAngleLoc());
733 return true;
734 }
735
736 bool VisitFunctionDecl(FunctionDecl *D) {
737 if (D->isOverloadedOperator()) {
738 const auto AddOpDeclToken = [&](SourceLocation Loc) {
739 auto &Token = H.addToken(Loc, Kind: HighlightingKind::Operator)
740 .addModifier(M: HighlightingModifier::Declaration);
741 if (D->isThisDeclarationADefinition())
742 Token.addModifier(M: HighlightingModifier::Definition);
743 };
744 const auto Range = D->getNameInfo().getCXXOperatorNameRange();
745 AddOpDeclToken(Range.getBegin());
746 const auto Kind = D->getOverloadedOperator();
747 if (Kind == OO_Call || Kind == OO_Subscript)
748 AddOpDeclToken(Range.getEnd());
749 }
750 if (auto *Args = D->getTemplateSpecializationArgsAsWritten())
751 H.addAngleBracketTokens(LLoc: Args->getLAngleLoc(), RLoc: Args->getRAngleLoc());
752 return true;
753 }
754
755 bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
756 const auto AddOpToken = [&](SourceLocation Loc) {
757 H.addToken(Loc, Kind: HighlightingKind::Operator)
758 .addModifier(M: HighlightingModifier::UserDefined);
759 };
760 AddOpToken(E->getOperatorLoc());
761 const auto Kind = E->getOperator();
762 if (Kind == OO_Call || Kind == OO_Subscript) {
763 if (auto *Callee = E->getCallee())
764 AddOpToken(Callee->getBeginLoc());
765 }
766 return true;
767 }
768
769 bool VisitUnaryOperator(UnaryOperator *Op) {
770 auto &Token = H.addToken(Loc: Op->getOperatorLoc(), Kind: HighlightingKind::Operator);
771 if (Op->getSubExpr()->isTypeDependent())
772 Token.addModifier(M: HighlightingModifier::UserDefined);
773 return true;
774 }
775
776 bool VisitBinaryOperator(BinaryOperator *Op) {
777 auto &Token = H.addToken(Loc: Op->getOperatorLoc(), Kind: HighlightingKind::Operator);
778 if (Op->getLHS()->isTypeDependent() || Op->getRHS()->isTypeDependent())
779 Token.addModifier(M: HighlightingModifier::UserDefined);
780 return true;
781 }
782
783 bool VisitConditionalOperator(ConditionalOperator *Op) {
784 H.addToken(Op->getQuestionLoc(), HighlightingKind::Operator);
785 H.addToken(Op->getColonLoc(), HighlightingKind::Operator);
786 return true;
787 }
788
789 bool VisitCXXNewExpr(CXXNewExpr *E) {
790 auto &Token = H.addToken(Loc: E->getBeginLoc(), Kind: HighlightingKind::Operator);
791 if (isa_and_present<CXXMethodDecl>(Val: E->getOperatorNew()))
792 Token.addModifier(M: HighlightingModifier::UserDefined);
793 return true;
794 }
795
796 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
797 auto &Token = H.addToken(Loc: E->getBeginLoc(), Kind: HighlightingKind::Operator);
798 if (isa_and_present<CXXMethodDecl>(Val: E->getOperatorDelete()))
799 Token.addModifier(M: HighlightingModifier::UserDefined);
800 return true;
801 }
802
803 bool VisitCXXNamedCastExpr(CXXNamedCastExpr *E) {
804 const auto &B = E->getAngleBrackets();
805 H.addAngleBracketTokens(LLoc: B.getBegin(), RLoc: B.getEnd());
806 return true;
807 }
808
809 bool VisitCallExpr(CallExpr *E) {
810 // Highlighting parameters passed by non-const reference does not really
811 // make sense for literals...
812 if (isa<UserDefinedLiteral>(Val: E))
813 return true;
814
815 // FIXME: consider highlighting parameters of some other overloaded
816 // operators as well
817 llvm::ArrayRef<const Expr *> Args = {E->getArgs(), E->getNumArgs()};
818 if (auto *CallOp = dyn_cast<CXXOperatorCallExpr>(Val: E)) {
819 switch (CallOp->getOperator()) {
820 case OO_Call:
821 case OO_Subscript:
822 Args = Args.drop_front(); // Drop object parameter
823 break;
824 default:
825 return true;
826 }
827 }
828
829 highlightMutableReferenceArguments(
830 FD: dyn_cast_or_null<FunctionDecl>(Val: E->getCalleeDecl()), Args);
831
832 return true;
833 }
834
835 void highlightMutableReferenceArgument(QualType T, const Expr *Arg) {
836 if (!Arg)
837 return;
838
839 // Is this parameter passed by non-const pointer or reference?
840 // FIXME The condition T->idDependentType() could be relaxed a bit,
841 // e.g. std::vector<T>& is dependent but we would want to highlight it
842 bool IsRef = T->isLValueReferenceType();
843 bool IsPtr = T->isPointerType();
844 if ((!IsRef && !IsPtr) || T->getPointeeType().isConstQualified() ||
845 T->isDependentType()) {
846 return;
847 }
848
849 std::optional<SourceLocation> Location;
850
851 // FIXME Add "unwrapping" for ArraySubscriptExpr,
852 // e.g. highlight `a` in `a[i]`
853 // FIXME Handle dependent expression types
854 if (auto *IC = dyn_cast<ImplicitCastExpr>(Val: Arg))
855 Arg = IC->getSubExprAsWritten();
856 if (auto *UO = dyn_cast<UnaryOperator>(Val: Arg)) {
857 if (UO->getOpcode() == UO_AddrOf)
858 Arg = UO->getSubExpr();
859 }
860 if (auto *DR = dyn_cast<DeclRefExpr>(Val: Arg))
861 Location = DR->getLocation();
862 else if (auto *M = dyn_cast<MemberExpr>(Val: Arg))
863 Location = M->getMemberLoc();
864
865 if (Location)
866 H.addExtraModifier(Loc: *Location,
867 Modifier: IsRef ? HighlightingModifier::UsedAsMutableReference
868 : HighlightingModifier::UsedAsMutablePointer);
869 }
870
871 void
872 highlightMutableReferenceArguments(const FunctionDecl *FD,
873 llvm::ArrayRef<const Expr *const> Args) {
874 if (!FD)
875 return;
876
877 if (auto *ProtoType = FD->getType()->getAs<FunctionProtoType>()) {
878 // Iterate over the types of the function parameters.
879 // If any of them are non-const reference paramteres, add it as a
880 // highlighting modifier to the corresponding expression
881 for (size_t I = 0;
882 I < std::min(a: size_t(ProtoType->getNumParams()), b: Args.size()); ++I) {
883 highlightMutableReferenceArgument(T: ProtoType->getParamType(I), Arg: Args[I]);
884 }
885 }
886 }
887
888 bool VisitDecltypeTypeLoc(DecltypeTypeLoc L) {
889 if (auto K = kindForType(L.getTypePtr(), H.getResolver())) {
890 auto &Tok = H.addToken(L.getBeginLoc(), *K)
891 .addModifier(HighlightingModifier::Deduced);
892 if (auto Mod = scopeModifier(L.getTypePtr()))
893 Tok.addModifier(*Mod);
894 if (isDefaultLibrary(L.getTypePtr()))
895 Tok.addModifier(HighlightingModifier::DefaultLibrary);
896 }
897 return true;
898 }
899
900 bool VisitCXXDestructorDecl(CXXDestructorDecl *D) {
901 if (auto *TI = D->getNameInfo().getNamedTypeInfo()) {
902 SourceLocation Loc = TI->getTypeLoc().getBeginLoc();
903 H.addExtraModifier(Loc, Modifier: HighlightingModifier::ConstructorOrDestructor);
904 H.addExtraModifier(Loc, Modifier: HighlightingModifier::Declaration);
905 if (D->isThisDeclarationADefinition())
906 H.addExtraModifier(Loc, Modifier: HighlightingModifier::Definition);
907 }
908 return true;
909 }
910
911 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *CE) {
912 // getMethodDecl can return nullptr with member pointers, e.g.
913 // `(foo.*pointer_to_member_fun)(arg);`
914 if (auto *D = CE->getMethodDecl()) {
915 if (isa<CXXDestructorDecl>(Val: D)) {
916 if (auto *ME = dyn_cast<MemberExpr>(CE->getCallee())) {
917 if (auto *TI = ME->getMemberNameInfo().getNamedTypeInfo()) {
918 H.addExtraModifier(Loc: TI->getTypeLoc().getBeginLoc(),
919 Modifier: HighlightingModifier::ConstructorOrDestructor);
920 }
921 }
922 } else if (D->isOverloadedOperator()) {
923 if (auto *ME = dyn_cast<MemberExpr>(CE->getCallee()))
924 H.addToken(
925 ME->getMemberNameInfo().getCXXOperatorNameRange().getBegin(),
926 HighlightingKind::Operator)
927 .addModifier(HighlightingModifier::UserDefined);
928 }
929 }
930 return true;
931 }
932
933 bool VisitDeclaratorDecl(DeclaratorDecl *D) {
934 for (unsigned i = 0; i < D->getNumTemplateParameterLists(); ++i) {
935 if (auto *TPL = D->getTemplateParameterList(index: i))
936 H.addAngleBracketTokens(LLoc: TPL->getLAngleLoc(), RLoc: TPL->getRAngleLoc());
937 }
938 auto *AT = D->getType()->getContainedAutoType();
939 if (!AT)
940 return true;
941 auto K =
942 kindForType(AT->getDeducedType().getTypePtrOrNull(), H.getResolver());
943 if (!K)
944 return true;
945 auto *TSI = D->getTypeSourceInfo();
946 if (!TSI)
947 return true;
948 SourceLocation StartLoc =
949 TSI->getTypeLoc().getContainedAutoTypeLoc().getNameLoc();
950 // The AutoType may not have a corresponding token, e.g. in the case of
951 // init-captures. In this case, StartLoc overlaps with the location
952 // of the decl itself, and producing a token for the type here would result
953 // in both it and the token for the decl being dropped due to conflict.
954 if (StartLoc == D->getLocation())
955 return true;
956
957 auto &Tok =
958 H.addToken(StartLoc, *K).addModifier(HighlightingModifier::Deduced);
959 const Type *Deduced = AT->getDeducedType().getTypePtrOrNull();
960 if (auto Mod = scopeModifier(T: Deduced))
961 Tok.addModifier(*Mod);
962 if (isDefaultLibrary(T: Deduced))
963 Tok.addModifier(HighlightingModifier::DefaultLibrary);
964 return true;
965 }
966
967 // We handle objective-C selectors specially, because one reference can
968 // cover several non-contiguous tokens.
969 void highlightObjCSelector(const ArrayRef<SourceLocation> &Locs, bool Decl,
970 bool Def, bool Class, bool DefaultLibrary) {
971 HighlightingKind Kind =
972 Class ? HighlightingKind::StaticMethod : HighlightingKind::Method;
973 for (SourceLocation Part : Locs) {
974 auto &Tok =
975 H.addToken(Loc: Part, Kind).addModifier(M: HighlightingModifier::ClassScope);
976 if (Decl)
977 Tok.addModifier(M: HighlightingModifier::Declaration);
978 if (Def)
979 Tok.addModifier(M: HighlightingModifier::Definition);
980 if (Class)
981 Tok.addModifier(M: HighlightingModifier::Static);
982 if (DefaultLibrary)
983 Tok.addModifier(M: HighlightingModifier::DefaultLibrary);
984 }
985 }
986
987 bool VisitObjCMethodDecl(ObjCMethodDecl *OMD) {
988 llvm::SmallVector<SourceLocation> Locs;
989 OMD->getSelectorLocs(SelLocs&: Locs);
990 highlightObjCSelector(Locs, /*Decl=*/true,
991 Def: OMD->isThisDeclarationADefinition(),
992 Class: OMD->isClassMethod(), DefaultLibrary: isDefaultLibrary(OMD));
993 return true;
994 }
995
996 bool VisitObjCMessageExpr(ObjCMessageExpr *OME) {
997 llvm::SmallVector<SourceLocation> Locs;
998 OME->getSelectorLocs(SelLocs&: Locs);
999 bool DefaultLibrary = false;
1000 if (ObjCMethodDecl *OMD = OME->getMethodDecl())
1001 DefaultLibrary = isDefaultLibrary(OMD);
1002 highlightObjCSelector(Locs, /*Decl=*/false, /*Def=*/false,
1003 Class: OME->isClassMessage(), DefaultLibrary);
1004 return true;
1005 }
1006
1007 // Objective-C allows you to use property syntax `self.prop` as sugar for
1008 // `[self prop]` and `[self setProp:]` when there's no explicit `@property`
1009 // for `prop` as well as for class properties. We treat this like a property
1010 // even though semantically it's equivalent to a method expression.
1011 void highlightObjCImplicitPropertyRef(const ObjCMethodDecl *OMD,
1012 SourceLocation Loc) {
1013 auto &Tok = H.addToken(Loc, Kind: HighlightingKind::Field)
1014 .addModifier(M: HighlightingModifier::ClassScope);
1015 if (OMD->isClassMethod())
1016 Tok.addModifier(M: HighlightingModifier::Static);
1017 if (isDefaultLibrary(OMD))
1018 Tok.addModifier(M: HighlightingModifier::DefaultLibrary);
1019 }
1020
1021 bool VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *OPRE) {
1022 // We need to handle implicit properties here since they will appear to
1023 // reference `ObjCMethodDecl` via an implicit `ObjCMessageExpr`, so normal
1024 // highlighting will not work.
1025 if (!OPRE->isImplicitProperty())
1026 return true;
1027 // A single property expr can reference both a getter and setter, but we can
1028 // only provide a single semantic token, so prefer the getter. In most cases
1029 // the end result should be the same, although it's technically possible
1030 // that the user defines a setter for a system SDK.
1031 if (OPRE->isMessagingGetter()) {
1032 highlightObjCImplicitPropertyRef(OMD: OPRE->getImplicitPropertyGetter(),
1033 Loc: OPRE->getLocation());
1034 return true;
1035 }
1036 if (OPRE->isMessagingSetter()) {
1037 highlightObjCImplicitPropertyRef(OMD: OPRE->getImplicitPropertySetter(),
1038 Loc: OPRE->getLocation());
1039 }
1040 return true;
1041 }
1042
1043 bool VisitOverloadExpr(OverloadExpr *E) {
1044 H.addAngleBracketTokens(LLoc: E->getLAngleLoc(), RLoc: E->getRAngleLoc());
1045 if (!E->decls().empty())
1046 return true; // handled by findExplicitReferences.
1047 auto &Tok = H.addToken(Loc: E->getNameLoc(), Kind: HighlightingKind::Unknown)
1048 .addModifier(M: HighlightingModifier::DependentName);
1049 if (llvm::isa<UnresolvedMemberExpr>(Val: E))
1050 Tok.addModifier(M: HighlightingModifier::ClassScope);
1051 // other case is UnresolvedLookupExpr, scope is unknown.
1052 return true;
1053 }
1054
1055 bool VisitCXXDependentScopeMemberExpr(CXXDependentScopeMemberExpr *E) {
1056 H.addToken(Loc: E->getMemberNameInfo().getLoc(), Kind: HighlightingKind::Unknown)
1057 .addModifier(M: HighlightingModifier::DependentName)
1058 .addModifier(M: HighlightingModifier::ClassScope);
1059 H.addAngleBracketTokens(LLoc: E->getLAngleLoc(), RLoc: E->getRAngleLoc());
1060 return true;
1061 }
1062
1063 bool VisitDependentScopeDeclRefExpr(DependentScopeDeclRefExpr *E) {
1064 H.addToken(Loc: E->getNameInfo().getLoc(), Kind: HighlightingKind::Unknown)
1065 .addModifier(M: HighlightingModifier::DependentName)
1066 .addModifier(M: HighlightingModifier::ClassScope);
1067 H.addAngleBracketTokens(LLoc: E->getLAngleLoc(), RLoc: E->getRAngleLoc());
1068 return true;
1069 }
1070
1071 bool VisitAttr(Attr *A) {
1072 switch (A->getKind()) {
1073 case attr::Override:
1074 case attr::Final:
1075 H.addToken(Loc: A->getLocation(), Kind: HighlightingKind::Modifier);
1076 break;
1077 default:
1078 break;
1079 }
1080 return true;
1081 }
1082
1083 bool VisitDependentNameTypeLoc(DependentNameTypeLoc L) {
1084 H.addToken(Loc: L.getNameLoc(), Kind: HighlightingKind::Type)
1085 .addModifier(M: HighlightingModifier::DependentName)
1086 .addModifier(M: HighlightingModifier::ClassScope);
1087 return true;
1088 }
1089
1090 bool VisitDependentTemplateSpecializationTypeLoc(
1091 DependentTemplateSpecializationTypeLoc L) {
1092 H.addToken(Loc: L.getTemplateNameLoc(), Kind: HighlightingKind::Type)
1093 .addModifier(M: HighlightingModifier::DependentName)
1094 .addModifier(M: HighlightingModifier::ClassScope);
1095 H.addAngleBracketTokens(LLoc: L.getLAngleLoc(), RLoc: L.getRAngleLoc());
1096 return true;
1097 }
1098
1099 bool TraverseTemplateArgumentLoc(TemplateArgumentLoc L) {
1100 // Handle template template arguments only (other arguments are handled by
1101 // their Expr, TypeLoc etc values).
1102 if (L.getArgument().getKind() != TemplateArgument::Template &&
1103 L.getArgument().getKind() != TemplateArgument::TemplateExpansion)
1104 return RecursiveASTVisitor::TraverseTemplateArgumentLoc(ArgLoc: L);
1105
1106 TemplateName N = L.getArgument().getAsTemplateOrTemplatePattern();
1107 switch (N.getKind()) {
1108 case TemplateName::OverloadedTemplate:
1109 // Template template params must always be class templates.
1110 // Don't bother to try to work out the scope here.
1111 H.addToken(Loc: L.getTemplateNameLoc(), Kind: HighlightingKind::Class);
1112 break;
1113 case TemplateName::DependentTemplate:
1114 case TemplateName::AssumedTemplate:
1115 H.addToken(Loc: L.getTemplateNameLoc(), Kind: HighlightingKind::Class)
1116 .addModifier(M: HighlightingModifier::DependentName);
1117 break;
1118 case TemplateName::Template:
1119 case TemplateName::QualifiedTemplate:
1120 case TemplateName::SubstTemplateTemplateParm:
1121 case TemplateName::SubstTemplateTemplateParmPack:
1122 case TemplateName::UsingTemplate:
1123 case TemplateName::DeducedTemplate:
1124 // Names that could be resolved to a TemplateDecl are handled elsewhere.
1125 break;
1126 }
1127 return RecursiveASTVisitor::TraverseTemplateArgumentLoc(ArgLoc: L);
1128 }
1129
1130 // findExplicitReferences will walk nested-name-specifiers and
1131 // find anything that can be resolved to a Decl. However, non-leaf
1132 // components of nested-name-specifiers which are dependent names
1133 // (kind "Identifier") cannot be resolved to a decl, so we visit
1134 // them here.
1135 bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc Q) {
1136 if (NestedNameSpecifier *NNS = Q.getNestedNameSpecifier()) {
1137 if (NNS->getKind() == NestedNameSpecifier::Identifier)
1138 H.addToken(Loc: Q.getLocalBeginLoc(), Kind: HighlightingKind::Type)
1139 .addModifier(M: HighlightingModifier::DependentName)
1140 .addModifier(M: HighlightingModifier::ClassScope);
1141 }
1142 return RecursiveASTVisitor::TraverseNestedNameSpecifierLoc(NNS: Q);
1143 }
1144
1145private:
1146 HighlightingsBuilder &H;
1147};
1148} // namespace
1149
1150std::vector<HighlightingToken>
1151getSemanticHighlightings(ParsedAST &AST, bool IncludeInactiveRegionTokens) {
1152 auto &C = AST.getASTContext();
1153 HighlightingFilter Filter = HighlightingFilter::fromCurrentConfig();
1154 if (!IncludeInactiveRegionTokens)
1155 Filter.disableKind(Kind: HighlightingKind::InactiveCode);
1156 // Add highlightings for AST nodes.
1157 HighlightingsBuilder Builder(AST, Filter);
1158 // Highlight 'decltype' and 'auto' as their underlying types.
1159 CollectExtraHighlightings(Builder).TraverseAST(AST&: C);
1160 // Highlight all decls and references coming from the AST.
1161 findExplicitReferences(
1162 AST: C,
1163 Out: [&](ReferenceLoc R) {
1164 for (const NamedDecl *Decl : R.Targets) {
1165 if (!canHighlightName(Name: Decl->getDeclName()))
1166 continue;
1167 auto Kind = kindForDecl(D: Decl, Resolver: AST.getHeuristicResolver());
1168 if (!Kind)
1169 continue;
1170 auto &Tok = Builder.addToken(Loc: R.NameLoc, Kind: *Kind);
1171
1172 // The attribute tests don't want to look at the template.
1173 if (auto *TD = dyn_cast<TemplateDecl>(Val: Decl)) {
1174 if (auto *Templated = TD->getTemplatedDecl())
1175 Decl = Templated;
1176 }
1177 if (auto Mod = scopeModifier(D: Decl))
1178 Tok.addModifier(M: *Mod);
1179 if (isConst(Decl))
1180 Tok.addModifier(M: HighlightingModifier::Readonly);
1181 if (isStatic(Decl))
1182 Tok.addModifier(M: HighlightingModifier::Static);
1183 if (isAbstract(Decl))
1184 Tok.addModifier(M: HighlightingModifier::Abstract);
1185 if (isVirtual(Decl))
1186 Tok.addModifier(M: HighlightingModifier::Virtual);
1187 if (isDependent(Decl))
1188 Tok.addModifier(M: HighlightingModifier::DependentName);
1189 if (isDefaultLibrary(Decl))
1190 Tok.addModifier(M: HighlightingModifier::DefaultLibrary);
1191 if (Decl->isDeprecated())
1192 Tok.addModifier(M: HighlightingModifier::Deprecated);
1193 if (isa<CXXConstructorDecl>(Val: Decl))
1194 Tok.addModifier(M: HighlightingModifier::ConstructorOrDestructor);
1195 if (R.IsDecl) {
1196 // Do not treat an UnresolvedUsingValueDecl as a declaration.
1197 // It's more common to think of it as a reference to the
1198 // underlying declaration.
1199 if (!isa<UnresolvedUsingValueDecl>(Val: Decl))
1200 Tok.addModifier(M: HighlightingModifier::Declaration);
1201 if (isUniqueDefinition(Decl))
1202 Tok.addModifier(M: HighlightingModifier::Definition);
1203 }
1204 }
1205 },
1206 Resolver: AST.getHeuristicResolver());
1207 // Add highlightings for macro references.
1208 auto AddMacro = [&](const MacroOccurrence &M) {
1209 auto &T = Builder.addToken(R: M.toRange(SM: C.getSourceManager()),
1210 Kind: HighlightingKind::Macro);
1211 T.addModifier(M: HighlightingModifier::GlobalScope);
1212 if (M.IsDefinition)
1213 T.addModifier(M: HighlightingModifier::Declaration);
1214 };
1215 for (const auto &SIDToRefs : AST.getMacros().MacroRefs)
1216 for (const auto &M : SIDToRefs.second)
1217 AddMacro(M);
1218 for (const auto &M : AST.getMacros().UnknownMacros)
1219 AddMacro(M);
1220
1221 return std::move(Builder).collect(AST);
1222}
1223
1224llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, HighlightingKind K) {
1225 switch (K) {
1226 case HighlightingKind::Variable:
1227 return OS << "Variable";
1228 case HighlightingKind::LocalVariable:
1229 return OS << "LocalVariable";
1230 case HighlightingKind::Parameter:
1231 return OS << "Parameter";
1232 case HighlightingKind::Function:
1233 return OS << "Function";
1234 case HighlightingKind::Method:
1235 return OS << "Method";
1236 case HighlightingKind::StaticMethod:
1237 return OS << "StaticMethod";
1238 case HighlightingKind::Field:
1239 return OS << "Field";
1240 case HighlightingKind::StaticField:
1241 return OS << "StaticField";
1242 case HighlightingKind::Class:
1243 return OS << "Class";
1244 case HighlightingKind::Interface:
1245 return OS << "Interface";
1246 case HighlightingKind::Enum:
1247 return OS << "Enum";
1248 case HighlightingKind::EnumConstant:
1249 return OS << "EnumConstant";
1250 case HighlightingKind::Typedef:
1251 return OS << "Typedef";
1252 case HighlightingKind::Type:
1253 return OS << "Type";
1254 case HighlightingKind::Unknown:
1255 return OS << "Unknown";
1256 case HighlightingKind::Namespace:
1257 return OS << "Namespace";
1258 case HighlightingKind::TemplateParameter:
1259 return OS << "TemplateParameter";
1260 case HighlightingKind::Concept:
1261 return OS << "Concept";
1262 case HighlightingKind::Primitive:
1263 return OS << "Primitive";
1264 case HighlightingKind::Macro:
1265 return OS << "Macro";
1266 case HighlightingKind::Modifier:
1267 return OS << "Modifier";
1268 case HighlightingKind::Operator:
1269 return OS << "Operator";
1270 case HighlightingKind::Bracket:
1271 return OS << "Bracket";
1272 case HighlightingKind::Label:
1273 return OS << "Label";
1274 case HighlightingKind::InactiveCode:
1275 return OS << "InactiveCode";
1276 }
1277 llvm_unreachable("invalid HighlightingKind");
1278}
1279std::optional<HighlightingKind>
1280highlightingKindFromString(llvm::StringRef Name) {
1281 static llvm::StringMap<HighlightingKind> Lookup = {
1282 {"Variable", HighlightingKind::Variable},
1283 {"LocalVariable", HighlightingKind::LocalVariable},
1284 {"Parameter", HighlightingKind::Parameter},
1285 {"Function", HighlightingKind::Function},
1286 {"Method", HighlightingKind::Method},
1287 {"StaticMethod", HighlightingKind::StaticMethod},
1288 {"Field", HighlightingKind::Field},
1289 {"StaticField", HighlightingKind::StaticField},
1290 {"Class", HighlightingKind::Class},
1291 {"Interface", HighlightingKind::Interface},
1292 {"Enum", HighlightingKind::Enum},
1293 {"EnumConstant", HighlightingKind::EnumConstant},
1294 {"Typedef", HighlightingKind::Typedef},
1295 {"Type", HighlightingKind::Type},
1296 {"Unknown", HighlightingKind::Unknown},
1297 {"Namespace", HighlightingKind::Namespace},
1298 {"TemplateParameter", HighlightingKind::TemplateParameter},
1299 {"Concept", HighlightingKind::Concept},
1300 {"Primitive", HighlightingKind::Primitive},
1301 {"Macro", HighlightingKind::Macro},
1302 {"Modifier", HighlightingKind::Modifier},
1303 {"Operator", HighlightingKind::Operator},
1304 {"Bracket", HighlightingKind::Bracket},
1305 {"InactiveCode", HighlightingKind::InactiveCode},
1306 };
1307
1308 auto It = Lookup.find(Key: Name);
1309 return It != Lookup.end() ? std::make_optional(t&: It->getValue()) : std::nullopt;
1310}
1311llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, HighlightingModifier K) {
1312 switch (K) {
1313 case HighlightingModifier::Declaration:
1314 return OS << "decl"; // abbreviation for common case
1315 case HighlightingModifier::Definition:
1316 return OS << "def"; // abbrevation for common case
1317 case HighlightingModifier::ConstructorOrDestructor:
1318 return OS << "constrDestr";
1319 default:
1320 return OS << toSemanticTokenModifier(Modifier: K);
1321 }
1322}
1323std::optional<HighlightingModifier>
1324highlightingModifierFromString(llvm::StringRef Name) {
1325 static llvm::StringMap<HighlightingModifier> Lookup = {
1326 {"Declaration", HighlightingModifier::Declaration},
1327 {"Definition", HighlightingModifier::Definition},
1328 {"Deprecated", HighlightingModifier::Deprecated},
1329 {"Deduced", HighlightingModifier::Deduced},
1330 {"Readonly", HighlightingModifier::Readonly},
1331 {"Static", HighlightingModifier::Static},
1332 {"Abstract", HighlightingModifier::Abstract},
1333 {"Virtual", HighlightingModifier::Virtual},
1334 {"DependentName", HighlightingModifier::DependentName},
1335 {"DefaultLibrary", HighlightingModifier::DefaultLibrary},
1336 {"UsedAsMutableReference", HighlightingModifier::UsedAsMutableReference},
1337 {"UsedAsMutablePointer", HighlightingModifier::UsedAsMutablePointer},
1338 {"ConstructorOrDestructor",
1339 HighlightingModifier::ConstructorOrDestructor},
1340 {"UserDefined", HighlightingModifier::UserDefined},
1341 {"FunctionScope", HighlightingModifier::FunctionScope},
1342 {"ClassScope", HighlightingModifier::ClassScope},
1343 {"FileScope", HighlightingModifier::FileScope},
1344 {"GlobalScope", HighlightingModifier::GlobalScope},
1345 };
1346
1347 auto It = Lookup.find(Key: Name);
1348 return It != Lookup.end() ? std::make_optional(t&: It->getValue()) : std::nullopt;
1349}
1350
1351bool operator==(const HighlightingToken &L, const HighlightingToken &R) {
1352 return std::tie(args: L.R, args: L.Kind, args: L.Modifiers) ==
1353 std::tie(args: R.R, args: R.Kind, args: R.Modifiers);
1354}
1355bool operator<(const HighlightingToken &L, const HighlightingToken &R) {
1356 return std::tie(args: L.R, args: L.Kind, args: L.Modifiers) <
1357 std::tie(args: R.R, args: R.Kind, args: R.Modifiers);
1358}
1359
1360std::vector<SemanticToken>
1361toSemanticTokens(llvm::ArrayRef<HighlightingToken> Tokens,
1362 llvm::StringRef Code) {
1363 assert(llvm::is_sorted(Tokens));
1364 std::vector<SemanticToken> Result;
1365 // In case we split a HighlightingToken into multiple tokens (e.g. because it
1366 // was spanning multiple lines), this tracks the last one. This prevents
1367 // having a copy all the time.
1368 HighlightingToken Scratch;
1369 const HighlightingToken *Last = nullptr;
1370 for (const HighlightingToken &Tok : Tokens) {
1371 Result.emplace_back();
1372 SemanticToken *Out = &Result.back();
1373 // deltaStart/deltaLine are relative if possible.
1374 if (Last) {
1375 assert(Tok.R.start.line >= Last->R.end.line);
1376 Out->deltaLine = Tok.R.start.line - Last->R.end.line;
1377 if (Out->deltaLine == 0) {
1378 assert(Tok.R.start.character >= Last->R.start.character);
1379 Out->deltaStart = Tok.R.start.character - Last->R.start.character;
1380 } else {
1381 Out->deltaStart = Tok.R.start.character;
1382 }
1383 } else {
1384 Out->deltaLine = Tok.R.start.line;
1385 Out->deltaStart = Tok.R.start.character;
1386 }
1387 Out->tokenType = static_cast<unsigned>(Tok.Kind);
1388 Out->tokenModifiers = Tok.Modifiers;
1389 Last = &Tok;
1390
1391 if (Tok.R.end.line == Tok.R.start.line) {
1392 Out->length = Tok.R.end.character - Tok.R.start.character;
1393 } else {
1394 // If the token spans a line break, split it into multiple pieces for each
1395 // line.
1396 // This is slow, but multiline tokens are rare.
1397 // FIXME: There's a client capability for supporting multiline tokens,
1398 // respect that.
1399 auto TokStartOffset = llvm::cantFail(ValOrErr: positionToOffset(Code, P: Tok.R.start));
1400 // Note that the loop doesn't cover the last line, which has a special
1401 // length.
1402 for (int I = Tok.R.start.line; I < Tok.R.end.line; ++I) {
1403 auto LineEnd = Code.find(C: '\n', From: TokStartOffset);
1404 assert(LineEnd != Code.npos);
1405 Out->length = LineEnd - TokStartOffset;
1406 // Token continues on next line, right after the line break.
1407 TokStartOffset = LineEnd + 1;
1408 Result.emplace_back();
1409 Out = &Result.back();
1410 *Out = Result[Result.size() - 2];
1411 // New token starts at the first column of the next line.
1412 Out->deltaLine = 1;
1413 Out->deltaStart = 0;
1414 }
1415 // This is the token on last line.
1416 Out->length = Tok.R.end.character;
1417 // Update the start location for last token, as that's used in the
1418 // relative delta calculation for following tokens.
1419 Scratch = *Last;
1420 Scratch.R.start.line = Tok.R.end.line;
1421 Scratch.R.start.character = 0;
1422 Last = &Scratch;
1423 }
1424 }
1425 return Result;
1426}
1427llvm::StringRef toSemanticTokenType(HighlightingKind Kind) {
1428 switch (Kind) {
1429 case HighlightingKind::Variable:
1430 case HighlightingKind::LocalVariable:
1431 case HighlightingKind::StaticField:
1432 return "variable";
1433 case HighlightingKind::Parameter:
1434 return "parameter";
1435 case HighlightingKind::Function:
1436 return "function";
1437 case HighlightingKind::Method:
1438 return "method";
1439 case HighlightingKind::StaticMethod:
1440 // FIXME: better method with static modifier?
1441 return "function";
1442 case HighlightingKind::Field:
1443 return "property";
1444 case HighlightingKind::Class:
1445 return "class";
1446 case HighlightingKind::Interface:
1447 return "interface";
1448 case HighlightingKind::Enum:
1449 return "enum";
1450 case HighlightingKind::EnumConstant:
1451 return "enumMember";
1452 case HighlightingKind::Typedef:
1453 case HighlightingKind::Type:
1454 return "type";
1455 case HighlightingKind::Unknown:
1456 return "unknown"; // nonstandard
1457 case HighlightingKind::Namespace:
1458 return "namespace";
1459 case HighlightingKind::TemplateParameter:
1460 return "typeParameter";
1461 case HighlightingKind::Concept:
1462 return "concept"; // nonstandard
1463 case HighlightingKind::Primitive:
1464 return "type";
1465 case HighlightingKind::Macro:
1466 return "macro";
1467 case HighlightingKind::Modifier:
1468 return "modifier";
1469 case HighlightingKind::Operator:
1470 return "operator";
1471 case HighlightingKind::Bracket:
1472 return "bracket";
1473 case HighlightingKind::Label:
1474 return "label";
1475 case HighlightingKind::InactiveCode:
1476 return "comment";
1477 }
1478 llvm_unreachable("unhandled HighlightingKind");
1479}
1480
1481llvm::StringRef toSemanticTokenModifier(HighlightingModifier Modifier) {
1482 switch (Modifier) {
1483 case HighlightingModifier::Declaration:
1484 return "declaration";
1485 case HighlightingModifier::Definition:
1486 return "definition";
1487 case HighlightingModifier::Deprecated:
1488 return "deprecated";
1489 case HighlightingModifier::Readonly:
1490 return "readonly";
1491 case HighlightingModifier::Static:
1492 return "static";
1493 case HighlightingModifier::Deduced:
1494 return "deduced"; // nonstandard
1495 case HighlightingModifier::Abstract:
1496 return "abstract";
1497 case HighlightingModifier::Virtual:
1498 return "virtual";
1499 case HighlightingModifier::DependentName:
1500 return "dependentName"; // nonstandard
1501 case HighlightingModifier::DefaultLibrary:
1502 return "defaultLibrary";
1503 case HighlightingModifier::UsedAsMutableReference:
1504 return "usedAsMutableReference"; // nonstandard
1505 case HighlightingModifier::UsedAsMutablePointer:
1506 return "usedAsMutablePointer"; // nonstandard
1507 case HighlightingModifier::ConstructorOrDestructor:
1508 return "constructorOrDestructor"; // nonstandard
1509 case HighlightingModifier::UserDefined:
1510 return "userDefined"; // nonstandard
1511 case HighlightingModifier::FunctionScope:
1512 return "functionScope"; // nonstandard
1513 case HighlightingModifier::ClassScope:
1514 return "classScope"; // nonstandard
1515 case HighlightingModifier::FileScope:
1516 return "fileScope"; // nonstandard
1517 case HighlightingModifier::GlobalScope:
1518 return "globalScope"; // nonstandard
1519 }
1520 llvm_unreachable("unhandled HighlightingModifier");
1521}
1522
1523std::vector<SemanticTokensEdit>
1524diffTokens(llvm::ArrayRef<SemanticToken> Old,
1525 llvm::ArrayRef<SemanticToken> New) {
1526 // For now, just replace everything from the first-last modification.
1527 // FIXME: use a real diff instead, this is bad with include-insertion.
1528
1529 unsigned Offset = 0;
1530 while (!Old.empty() && !New.empty() && Old.front() == New.front()) {
1531 ++Offset;
1532 Old = Old.drop_front();
1533 New = New.drop_front();
1534 }
1535 while (!Old.empty() && !New.empty() && Old.back() == New.back()) {
1536 Old = Old.drop_back();
1537 New = New.drop_back();
1538 }
1539
1540 if (Old.empty() && New.empty())
1541 return {};
1542 SemanticTokensEdit Edit;
1543 Edit.startToken = Offset;
1544 Edit.deleteTokens = Old.size();
1545 Edit.tokens = New;
1546 return {std::move(Edit)};
1547}
1548
1549std::vector<Range> getInactiveRegions(ParsedAST &AST) {
1550 std::vector<Range> SkippedRanges(std::move(AST.getMacros().SkippedRanges));
1551 const auto &SM = AST.getSourceManager();
1552 StringRef MainCode = SM.getBufferOrFake(FID: SM.getMainFileID()).getBuffer();
1553 std::vector<Range> InactiveRegions;
1554 for (const Range &Skipped : SkippedRanges) {
1555 Range Inactive = Skipped;
1556 // Sometimes, SkippedRanges contains a range ending at position 0
1557 // of a line. Clients that apply whole-line styles will treat that
1558 // line as inactive which is not desirable, so adjust the ending
1559 // position to be the end of the previous line.
1560 if (Inactive.end.character == 0 && Inactive.end.line > 0) {
1561 --Inactive.end.line;
1562 }
1563 // Exclude the directive lines themselves from the range.
1564 if (Inactive.end.line >= Inactive.start.line + 2) {
1565 ++Inactive.start.line;
1566 --Inactive.end.line;
1567 } else {
1568 // range would be empty, e.g. #endif on next line after #ifdef
1569 continue;
1570 }
1571 // Since we've adjusted the ending line, we need to recompute the
1572 // column to reflect the end of that line.
1573 if (auto EndOfLine = endOfLine(Code: MainCode, Line: Inactive.end.line)) {
1574 Inactive.end = *EndOfLine;
1575 } else {
1576 elog(Fmt: "Failed to determine end of line: {0}", Vals: EndOfLine.takeError());
1577 continue;
1578 }
1579 InactiveRegions.push_back(x: Inactive);
1580 }
1581 return InactiveRegions;
1582}
1583
1584} // namespace clangd
1585} // namespace clang
1586