| //===--- SemanticHighlighting.cpp - ------------------------- ---*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "SemanticHighlighting.h" |
| #include "Logger.h" |
| #include "ParsedAST.h" |
| #include "Protocol.h" |
| #include "SourceCode.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DeclarationName.h" |
| #include "clang/AST/RecursiveASTVisitor.h" |
| #include "clang/AST/Type.h" |
| #include "clang/AST/TypeLoc.h" |
| #include "clang/Basic/SourceLocation.h" |
| #include <algorithm> |
| |
| namespace clang { |
| namespace clangd { |
| namespace { |
| |
| /// Some names are not written in the source code and cannot be highlighted, |
| /// e.g. anonymous classes. This function detects those cases. |
| bool canHighlightName(DeclarationName Name) { |
| if (Name.getNameKind() == DeclarationName::CXXConstructorName || |
| Name.getNameKind() == DeclarationName::CXXUsingDirective) |
| return true; |
| auto *II = Name.getAsIdentifierInfo(); |
| return II && !II->getName().empty(); |
| } |
| |
| llvm::Optional<HighlightingKind> kindForType(const Type *TP); |
| llvm::Optional<HighlightingKind> kindForDecl(const NamedDecl *D) { |
| if (auto *TD = dyn_cast<TypedefNameDecl>(D)) { |
| // We try to highlight typedefs as their underlying type. |
| if (auto K = kindForType(TD->getUnderlyingType().getTypePtrOrNull())) |
| return K; |
| // And fallback to a generic kind if this fails. |
| return HighlightingKind::Typedef; |
| } |
| // We highlight class decls, constructor decls and destructor decls as |
| // `Class` type. The destructor decls are handled in `VisitTypeLoc` (we |
| // will visit a TypeLoc where the underlying Type is a CXXRecordDecl). |
| if (auto *RD = llvm::dyn_cast<RecordDecl>(D)) { |
| // We don't want to highlight lambdas like classes. |
| if (RD->isLambda()) |
| return llvm::None; |
| return HighlightingKind::Class; |
| } |
| if (isa<ClassTemplateDecl>(D) || isa<RecordDecl>(D) || |
| isa<CXXConstructorDecl>(D)) |
| return HighlightingKind::Class; |
| if (auto *MD = dyn_cast<CXXMethodDecl>(D)) |
| return MD->isStatic() ? HighlightingKind::StaticMethod |
| : HighlightingKind::Method; |
| if (isa<FieldDecl>(D)) |
| return HighlightingKind::Field; |
| if (isa<EnumDecl>(D)) |
| return HighlightingKind::Enum; |
| if (isa<EnumConstantDecl>(D)) |
| return HighlightingKind::EnumConstant; |
| if (isa<ParmVarDecl>(D)) |
| return HighlightingKind::Parameter; |
| if (auto *VD = dyn_cast<VarDecl>(D)) |
| return VD->isStaticDataMember() |
| ? HighlightingKind::StaticField |
| : VD->isLocalVarDecl() ? HighlightingKind::LocalVariable |
| : HighlightingKind::Variable; |
| if (isa<BindingDecl>(D)) |
| return HighlightingKind::Variable; |
| if (isa<FunctionDecl>(D)) |
| return HighlightingKind::Function; |
| if (isa<NamespaceDecl>(D) || isa<NamespaceAliasDecl>(D) || |
| isa<UsingDirectiveDecl>(D)) |
| return HighlightingKind::Namespace; |
| if (isa<TemplateTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) || |
| isa<NonTypeTemplateParmDecl>(D)) |
| return HighlightingKind::TemplateParameter; |
| return llvm::None; |
| } |
| llvm::Optional<HighlightingKind> kindForType(const Type *TP) { |
| if (!TP) |
| return llvm::None; |
| if (TP->isBuiltinType()) // Builtins are special, they do not have decls. |
| return HighlightingKind::Primitive; |
| if (auto *TD = dyn_cast<TemplateTypeParmType>(TP)) |
| return kindForDecl(TD->getDecl()); |
| if (auto *TD = TP->getAsTagDecl()) |
| return kindForDecl(TD); |
| return llvm::None; |
| } |
| |
| // Collects all semantic tokens in an ASTContext. |
| class HighlightingTokenCollector |
| : public RecursiveASTVisitor<HighlightingTokenCollector> { |
| std::vector<HighlightingToken> Tokens; |
| ParsedAST &AST; |
| |
| public: |
| HighlightingTokenCollector(ParsedAST &AST) : AST(AST) {} |
| |
| std::vector<HighlightingToken> collectTokens() { |
| Tokens.clear(); |
| TraverseAST(AST.getASTContext()); |
| // Add highlightings for macro expansions as they are not traversed by the |
| // visitor. |
| for (SourceLocation Loc : AST.getMacros()) |
| addToken(Loc, HighlightingKind::Macro); |
| // Initializer lists can give duplicates of tokens, therefore all tokens |
| // must be deduplicated. |
| llvm::sort(Tokens); |
| auto Last = std::unique(Tokens.begin(), Tokens.end()); |
| Tokens.erase(Last, Tokens.end()); |
| // Macros can give tokens that have the same source range but conflicting |
| // kinds. In this case all tokens sharing this source range should be |
| // removed. |
| std::vector<HighlightingToken> NonConflicting; |
| NonConflicting.reserve(Tokens.size()); |
| for (ArrayRef<HighlightingToken> TokRef = Tokens; !TokRef.empty();) { |
| ArrayRef<HighlightingToken> Conflicting = |
| TokRef.take_while([&](const HighlightingToken &T) { |
| // TokRef is guaranteed at least one element here because otherwise |
| // this predicate would never fire. |
| return T.R == TokRef.front().R; |
| }); |
| // If there is exactly one token with this range it's non conflicting and |
| // should be in the highlightings. |
| if (Conflicting.size() == 1) |
| NonConflicting.push_back(TokRef.front()); |
| // TokRef[Conflicting.size()] is the next token with a different range (or |
| // the end of the Tokens). |
| TokRef = TokRef.drop_front(Conflicting.size()); |
| } |
| return NonConflicting; |
| } |
| |
| bool VisitNamespaceAliasDecl(NamespaceAliasDecl *NAD) { |
| // The target namespace of an alias can not be found in any other way. |
| addToken(NAD->getTargetNameLoc(), NAD->getAliasedNamespace()); |
| return true; |
| } |
| |
| bool VisitMemberExpr(MemberExpr *ME) { |
| if (canHighlightName(ME->getMemberNameInfo().getName())) |
| addToken(ME->getMemberLoc(), ME->getMemberDecl()); |
| return true; |
| } |
| |
| bool VisitNamedDecl(NamedDecl *ND) { |
| if (canHighlightName(ND->getDeclName())) |
| addToken(ND->getLocation(), ND); |
| return true; |
| } |
| |
| bool VisitDeclRefExpr(DeclRefExpr *Ref) { |
| if (canHighlightName(Ref->getNameInfo().getName())) |
| addToken(Ref->getLocation(), Ref->getDecl()); |
| return true; |
| } |
| |
| bool VisitTypedefTypeLoc(TypedefTypeLoc TL) { |
| addToken(TL.getBeginLoc(), TL.getTypedefNameDecl()); |
| return true; |
| } |
| |
| bool VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc TL) { |
| if (const TemplateDecl *TD = |
| TL.getTypePtr()->getTemplateName().getAsTemplateDecl()) |
| addToken(TL.getBeginLoc(), TD); |
| return true; |
| } |
| |
| bool WalkUpFromTagTypeLoc(TagTypeLoc L) { |
| if (L.isDefinition()) |
| return true; // Definition will be highligthed by VisitNamedDecl. |
| return RecursiveASTVisitor::WalkUpFromTagTypeLoc(L); |
| } |
| |
| bool WalkUpFromElaboratedTypeLoc(ElaboratedTypeLoc L) { |
| // Avoid highlighting 'struct' or 'enum' keywords. |
| return true; |
| } |
| |
| bool VisitTypeLoc(TypeLoc TL) { |
| if (auto K = kindForType(TL.getTypePtr())) |
| addToken(TL.getBeginLoc(), *K); |
| return true; |
| } |
| |
| bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNSLoc) { |
| if (auto *NNS = NNSLoc.getNestedNameSpecifier()) { |
| if (NNS->getKind() == NestedNameSpecifier::Namespace || |
| NNS->getKind() == NestedNameSpecifier::NamespaceAlias) |
| addToken(NNSLoc.getLocalBeginLoc(), HighlightingKind::Namespace); |
| } |
| return RecursiveASTVisitor< |
| HighlightingTokenCollector>::TraverseNestedNameSpecifierLoc(NNSLoc); |
| } |
| |
| bool TraverseConstructorInitializer(CXXCtorInitializer *CI) { |
| if (const FieldDecl *FD = CI->getMember()) |
| addToken(CI->getSourceLocation(), FD); |
| return RecursiveASTVisitor< |
| HighlightingTokenCollector>::TraverseConstructorInitializer(CI); |
| } |
| |
| bool VisitDeclaratorDecl(DeclaratorDecl *D) { |
| // Highlight 'auto' with its underlying type. |
| auto *AT = D->getType()->getContainedAutoType(); |
| if (!AT) |
| return true; |
| auto K = kindForType(AT->getDeducedType().getTypePtrOrNull()); |
| if (!K) |
| return true; |
| addToken(D->getTypeSpecStartLoc(), *K); |
| return true; |
| } |
| |
| private: |
| void addToken(SourceLocation Loc, HighlightingKind Kind) { |
| if (Loc.isInvalid()) |
| return; |
| const auto &SM = AST.getSourceManager(); |
| if (Loc.isMacroID()) { |
| // Only intereseted in highlighting arguments in macros (DEF_X(arg)). |
| if (!SM.isMacroArgExpansion(Loc)) |
| return; |
| Loc = SM.getSpellingLoc(Loc); |
| } |
| |
| // Non top level decls that are included from a header are not filtered by |
| // topLevelDecls. (example: method declarations being included from |
| // another file for a class from another file). |
| // There are also cases with macros where the spelling loc will not be in |
| // the main file and the highlighting would be incorrect. |
| if (!isInsideMainFile(Loc, SM)) |
| return; |
| |
| auto R = getTokenRange(SM, AST.getASTContext().getLangOpts(), Loc); |
| if (!R) { |
| // R should always have a value, if it doesn't something is very wrong. |
| elog("Tried to add semantic token with an invalid range"); |
| return; |
| } |
| |
| Tokens.push_back({Kind, R.getValue()}); |
| } |
| |
| void addToken(SourceLocation Loc, const NamedDecl *D) { |
| if (auto K = kindForDecl(D)) |
| addToken(Loc, *K); |
| } |
| }; |
| |
| // Encode binary data into base64. |
| // This was copied from compiler-rt/lib/fuzzer/FuzzerUtil.cpp. |
| // FIXME: Factor this out into llvm/Support? |
| std::string encodeBase64(const llvm::SmallVectorImpl<char> &Bytes) { |
| static const char Table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" |
| "abcdefghijklmnopqrstuvwxyz" |
| "0123456789+/"; |
| std::string Res; |
| size_t I; |
| for (I = 0; I + 2 < Bytes.size(); I += 3) { |
| uint32_t X = (Bytes[I] << 16) + (Bytes[I + 1] << 8) + Bytes[I + 2]; |
| Res += Table[(X >> 18) & 63]; |
| Res += Table[(X >> 12) & 63]; |
| Res += Table[(X >> 6) & 63]; |
| Res += Table[X & 63]; |
| } |
| if (I + 1 == Bytes.size()) { |
| uint32_t X = (Bytes[I] << 16); |
| Res += Table[(X >> 18) & 63]; |
| Res += Table[(X >> 12) & 63]; |
| Res += "=="; |
| } else if (I + 2 == Bytes.size()) { |
| uint32_t X = (Bytes[I] << 16) + (Bytes[I + 1] << 8); |
| Res += Table[(X >> 18) & 63]; |
| Res += Table[(X >> 12) & 63]; |
| Res += Table[(X >> 6) & 63]; |
| Res += "="; |
| } |
| return Res; |
| } |
| |
| void write32be(uint32_t I, llvm::raw_ostream &OS) { |
| std::array<char, 4> Buf; |
| llvm::support::endian::write32be(Buf.data(), I); |
| OS.write(Buf.data(), Buf.size()); |
| } |
| |
| void write16be(uint16_t I, llvm::raw_ostream &OS) { |
| std::array<char, 2> Buf; |
| llvm::support::endian::write16be(Buf.data(), I); |
| OS.write(Buf.data(), Buf.size()); |
| } |
| |
| // Get the highlightings on \c Line where the first entry of line is at \c |
| // StartLineIt. If it is not at \c StartLineIt an empty vector is returned. |
| ArrayRef<HighlightingToken> |
| takeLine(ArrayRef<HighlightingToken> AllTokens, |
| ArrayRef<HighlightingToken>::iterator StartLineIt, int Line) { |
| return ArrayRef<HighlightingToken>(StartLineIt, AllTokens.end()) |
| .take_while([Line](const HighlightingToken &Token) { |
| return Token.R.start.line == Line; |
| }); |
| } |
| } // namespace |
| |
| llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, HighlightingKind K) { |
| switch (K) { |
| case HighlightingKind::Variable: |
| return OS << "Variable"; |
| case HighlightingKind::LocalVariable: |
| return OS << "LocalVariable"; |
| case HighlightingKind::Parameter: |
| return OS << "Parameter"; |
| case HighlightingKind::Function: |
| return OS << "Function"; |
| case HighlightingKind::Method: |
| return OS << "Method"; |
| case HighlightingKind::StaticMethod: |
| return OS << "StaticMethod"; |
| case HighlightingKind::Field: |
| return OS << "Field"; |
| case HighlightingKind::StaticField: |
| return OS << "StaticField"; |
| case HighlightingKind::Class: |
| return OS << "Class"; |
| case HighlightingKind::Enum: |
| return OS << "Enum"; |
| case HighlightingKind::EnumConstant: |
| return OS << "EnumConstant"; |
| case HighlightingKind::Typedef: |
| return OS << "Typedef"; |
| case HighlightingKind::Namespace: |
| return OS << "Namespace"; |
| case HighlightingKind::TemplateParameter: |
| return OS << "TemplateParameter"; |
| case HighlightingKind::Primitive: |
| return OS << "Primitive"; |
| case HighlightingKind::Macro: |
| return OS << "Macro"; |
| } |
| llvm_unreachable("invalid HighlightingKind"); |
| } |
| |
| std::vector<LineHighlightings> |
| diffHighlightings(ArrayRef<HighlightingToken> New, |
| ArrayRef<HighlightingToken> Old) { |
| assert(std::is_sorted(New.begin(), New.end()) && |
| "New must be a sorted vector"); |
| assert(std::is_sorted(Old.begin(), Old.end()) && |
| "Old must be a sorted vector"); |
| |
| // FIXME: There's an edge case when tokens span multiple lines. If the first |
| // token on the line started on a line above the current one and the rest of |
| // the line is the equal to the previous one than we will remove all |
| // highlights but the ones for the token spanning multiple lines. This means |
| // that when we get into the LSP layer the only highlights that will be |
| // visible are the ones for the token spanning multiple lines. |
| // Example: |
| // EndOfMultilineToken Token Token Token |
| // If "Token Token Token" don't differ from previously the line is |
| // incorrectly removed. Suggestion to fix is to separate any multiline tokens |
| // into one token for every line it covers. This requires reading from the |
| // file buffer to figure out the length of each line though. |
| std::vector<LineHighlightings> DiffedLines; |
| // ArrayRefs to the current line in the highlightings. |
| ArrayRef<HighlightingToken> NewLine(New.begin(), |
| /*length*/ static_cast<size_t>(0)); |
| ArrayRef<HighlightingToken> OldLine(Old.begin(), |
| /*length*/ static_cast<size_t>(0)); |
| auto NewEnd = New.end(); |
| auto OldEnd = Old.end(); |
| auto NextLineNumber = [&]() { |
| int NextNew = NewLine.end() != NewEnd ? NewLine.end()->R.start.line |
| : std::numeric_limits<int>::max(); |
| int NextOld = OldLine.end() != OldEnd ? OldLine.end()->R.start.line |
| : std::numeric_limits<int>::max(); |
| return std::min(NextNew, NextOld); |
| }; |
| |
| for (int LineNumber = 0; NewLine.end() < NewEnd || OldLine.end() < OldEnd; |
| LineNumber = NextLineNumber()) { |
| NewLine = takeLine(New, NewLine.end(), LineNumber); |
| OldLine = takeLine(Old, OldLine.end(), LineNumber); |
| if (NewLine != OldLine) |
| DiffedLines.push_back({LineNumber, NewLine}); |
| } |
| |
| return DiffedLines; |
| } |
| |
| bool operator==(const HighlightingToken &L, const HighlightingToken &R) { |
| return std::tie(L.R, L.Kind) == std::tie(R.R, R.Kind); |
| } |
| bool operator<(const HighlightingToken &L, const HighlightingToken &R) { |
| return std::tie(L.R, L.Kind) < std::tie(R.R, R.Kind); |
| } |
| bool operator==(const LineHighlightings &L, const LineHighlightings &R) { |
| return std::tie(L.Line, L.Tokens) == std::tie(R.Line, R.Tokens); |
| } |
| |
| std::vector<HighlightingToken> getSemanticHighlightings(ParsedAST &AST) { |
| return HighlightingTokenCollector(AST).collectTokens(); |
| } |
| |
| std::vector<SemanticHighlightingInformation> |
| toSemanticHighlightingInformation(llvm::ArrayRef<LineHighlightings> Tokens) { |
| if (Tokens.size() == 0) |
| return {}; |
| |
| // FIXME: Tokens might be multiple lines long (block comments) in this case |
| // this needs to add multiple lines for those tokens. |
| std::vector<SemanticHighlightingInformation> Lines; |
| Lines.reserve(Tokens.size()); |
| for (const auto &Line : Tokens) { |
| llvm::SmallVector<char, 128> LineByteTokens; |
| llvm::raw_svector_ostream OS(LineByteTokens); |
| for (const auto &Token : Line.Tokens) { |
| // Writes the token to LineByteTokens in the byte format specified by the |
| // LSP proposal. Described below. |
| // |<---- 4 bytes ---->|<-- 2 bytes -->|<--- 2 bytes -->| |
| // | character | length | index | |
| |
| write32be(Token.R.start.character, OS); |
| write16be(Token.R.end.character - Token.R.start.character, OS); |
| write16be(static_cast<int>(Token.Kind), OS); |
| } |
| |
| Lines.push_back({Line.Line, encodeBase64(LineByteTokens)}); |
| } |
| |
| return Lines; |
| } |
| |
| llvm::StringRef toTextMateScope(HighlightingKind Kind) { |
| // FIXME: Add scopes for C and Objective C. |
| switch (Kind) { |
| case HighlightingKind::Function: |
| return "entity.name.function.cpp"; |
| case HighlightingKind::Method: |
| return "entity.name.function.method.cpp"; |
| case HighlightingKind::StaticMethod: |
| return "entity.name.function.method.static.cpp"; |
| case HighlightingKind::Variable: |
| return "variable.other.cpp"; |
| case HighlightingKind::LocalVariable: |
| return "variable.other.local.cpp"; |
| case HighlightingKind::Parameter: |
| return "variable.parameter.cpp"; |
| case HighlightingKind::Field: |
| return "variable.other.field.cpp"; |
| case HighlightingKind::StaticField: |
| return "variable.other.field.static.cpp"; |
| case HighlightingKind::Class: |
| return "entity.name.type.class.cpp"; |
| case HighlightingKind::Enum: |
| return "entity.name.type.enum.cpp"; |
| case HighlightingKind::EnumConstant: |
| return "variable.other.enummember.cpp"; |
| case HighlightingKind::Typedef: |
| return "entity.name.type.typedef.cpp"; |
| case HighlightingKind::Namespace: |
| return "entity.name.namespace.cpp"; |
| case HighlightingKind::TemplateParameter: |
| return "entity.name.type.template.cpp"; |
| case HighlightingKind::Primitive: |
| return "storage.type.primitive.cpp"; |
| case HighlightingKind::Macro: |
| return "entity.name.function.preprocessor.cpp"; |
| } |
| llvm_unreachable("unhandled HighlightingKind"); |
| } |
| |
| } // namespace clangd |
| } // namespace clang |