[clang-tools-extra] r372008 - [clangd] Simplify semantic highlighting visitor
Ilya Biryukov via cfe-commits
cfe-commits at lists.llvm.org
Mon Sep 16 09:16:03 PDT 2019
Author: ibiryukov
Date: Mon Sep 16 09:16:03 2019
New Revision: 372008
URL: http://llvm.org/viewvc/llvm-project?rev=372008&view=rev
Log:
[clangd] Simplify semantic highlighting visitor
Summary:
- Functions to compute highlighting kinds for things are separated from
the ones that add highlighting tokens.
This keeps each of them more focused on what they're doing: getting
locations and figuring out the kind of the entity, correspondingly.
- Less special cases in visitor for various nodes.
This change is an NFC.
Reviewers: hokein
Reviewed By: hokein
Subscribers: MaskRay, jkorous, arphaman, kadircet, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67341
Modified:
clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp
Modified: clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp?rev=372008&r1=372007&r2=372008&view=diff
==============================================================================
--- clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp (original)
+++ clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp Mon Sep 16 09:16:03 2019
@@ -14,6 +14,7 @@
#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"
@@ -24,6 +25,77 @@ 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> {
@@ -70,66 +142,30 @@ public:
bool VisitNamespaceAliasDecl(NamespaceAliasDecl *NAD) {
// The target namespace of an alias can not be found in any other way.
- addToken(NAD->getTargetNameLoc(), HighlightingKind::Namespace);
+ addToken(NAD->getTargetNameLoc(), NAD->getAliasedNamespace());
return true;
}
bool VisitMemberExpr(MemberExpr *ME) {
- const auto *MD = ME->getMemberDecl();
- if (isa<CXXDestructorDecl>(MD))
- // When calling the destructor manually like: AAA::~A(); The ~ is a
- // MemberExpr. Other methods should still be highlighted though.
- return true;
- if (isa<CXXConversionDecl>(MD))
- // The MemberLoc is invalid for C++ conversion operators. We do not
- // attempt to add tokens with invalid locations.
- return true;
- addToken(ME->getMemberLoc(), MD);
+ if (canHighlightName(ME->getMemberNameInfo().getName()))
+ addToken(ME->getMemberLoc(), ME->getMemberDecl());
return true;
}
bool VisitNamedDecl(NamedDecl *ND) {
- // UsingDirectiveDecl's namespaces do not show up anywhere else in the
- // Visit/Traverse mehods. But they should also be highlighted as a
- // namespace.
- if (const auto *UD = dyn_cast<UsingDirectiveDecl>(ND)) {
- addToken(UD->getIdentLocation(), HighlightingKind::Namespace);
- return true;
- }
-
- // Constructors' TypeLoc has a TypePtr that is a FunctionProtoType. It has
- // no tag decl and therefore constructors must be gotten as NamedDecls
- // instead.
- if (ND->getDeclName().getNameKind() ==
- DeclarationName::CXXConstructorName) {
+ if (canHighlightName(ND->getDeclName()))
addToken(ND->getLocation(), ND);
- return true;
- }
-
- if (ND->getDeclName().getNameKind() != DeclarationName::Identifier)
- return true;
-
- addToken(ND->getLocation(), ND);
return true;
}
bool VisitDeclRefExpr(DeclRefExpr *Ref) {
- if (Ref->getNameInfo().getName().getNameKind() !=
- DeclarationName::Identifier)
- // Only want to highlight identifiers.
- return true;
-
- addToken(Ref->getLocation(), Ref->getDecl());
- return true;
- }
-
- bool VisitTypedefNameDecl(TypedefNameDecl *TD) {
- addTokenForTypedef(TD->getLocation(), TD);
+ if (canHighlightName(Ref->getNameInfo().getName()))
+ addToken(Ref->getLocation(), Ref->getDecl());
return true;
}
bool VisitTypedefTypeLoc(TypedefTypeLoc TL) {
- addTokenForTypedef(TL.getBeginLoc(), TL.getTypedefNameDecl());
+ addToken(TL.getBeginLoc(), TL.getTypedefNameDecl());
return true;
}
@@ -140,22 +176,29 @@ public:
return true;
}
- bool VisitTypeLoc(TypeLoc &TL) {
- // This check is for not getting two entries when there are anonymous
- // structs. It also makes us not highlight certain namespace qualifiers
- // twice. For elaborated types the actual type is highlighted as an inner
- // TypeLoc.
- if (TL.getTypeLocClass() != TypeLoc::TypeLocClass::Elaborated)
- addType(TL.getBeginLoc(), TL.getTypePtr());
+ 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 (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier())
+ if (auto *NNS = NNSLoc.getNestedNameSpecifier()) {
if (NNS->getKind() == NestedNameSpecifier::Namespace ||
NNS->getKind() == NestedNameSpecifier::NamespaceAlias)
addToken(NNSLoc.getLocalBeginLoc(), HighlightingKind::Namespace);
-
+ }
return RecursiveASTVisitor<
HighlightingTokenCollector>::TraverseNestedNameSpecifierLoc(NNSLoc);
}
@@ -168,127 +211,21 @@ public:
}
bool VisitDeclaratorDecl(DeclaratorDecl *D) {
- if ((!D->getTypeSourceInfo()))
+ // Highlight 'auto' with its underlying type.
+ auto *AT = D->getType()->getContainedAutoType();
+ if (!AT)
return true;
-
- if (auto *AT = D->getType()->getContainedAutoType()) {
- const auto Deduced = AT->getDeducedType();
- if (!Deduced.isNull())
- addType(D->getTypeSpecStartLoc(), Deduced.getTypePtr());
- }
+ auto K = kindForType(AT->getDeducedType().getTypePtrOrNull());
+ if (!K)
+ return true;
+ addToken(D->getTypeSpecStartLoc(), *K);
return true;
}
private:
- void addTokenForTypedef(SourceLocation Loc, const TypedefNameDecl *TD) {
- auto *TSI = TD->getTypeSourceInfo();
- if (!TSI)
- return;
- // Try to highlight as underlying type.
- if (addType(Loc, TSI->getType().getTypePtrOrNull()))
- return;
- // Fallback to the typedef highlighting kind.
- addToken(Loc, HighlightingKind::Typedef);
- }
-
- bool addType(SourceLocation Loc, const Type *TP) {
- if (!TP)
- return false;
- if (TP->isBuiltinType()) {
- // Builtins must be special cased as they do not have a TagDecl.
- addToken(Loc, HighlightingKind::Primitive);
- return true;
- }
- if (auto *TD = dyn_cast<TemplateTypeParmType>(TP)) {
- // TemplateTypeParmType also do not have a TagDecl.
- addToken(Loc, TD->getDecl());
- return true;
- }
- if (auto *TD = TP->getAsTagDecl()) {
- addToken(Loc, TD);
- return true;
- }
- return false;
- }
-
- void addToken(SourceLocation Loc, const NamedDecl *D) {
- if (D->getDeclName().isIdentifier() && D->getName().empty())
- // Don't add symbols that don't have any length.
- return;
- // 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 (isa<ClassTemplateDecl>(D)) {
- addToken(Loc, HighlightingKind::Class);
- return;
- }
- if (isa<RecordDecl>(D)) {
- addToken(Loc, HighlightingKind::Class);
- return;
- }
- if (isa<CXXConstructorDecl>(D)) {
- addToken(Loc, HighlightingKind::Class);
- return;
- }
- if (auto *MD = dyn_cast<CXXMethodDecl>(D)) {
- addToken(Loc, MD->isStatic() ? HighlightingKind::StaticMethod
- : HighlightingKind::Method);
- return;
- }
- if (isa<FieldDecl>(D)) {
- addToken(Loc, HighlightingKind::Field);
- return;
- }
- if (isa<EnumDecl>(D)) {
- addToken(Loc, HighlightingKind::Enum);
- return;
- }
- if (isa<EnumConstantDecl>(D)) {
- addToken(Loc, HighlightingKind::EnumConstant);
- return;
- }
- if (isa<ParmVarDecl>(D)) {
- addToken(Loc, HighlightingKind::Parameter);
- return;
- }
- if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
- addToken(Loc, VD->isStaticDataMember()
- ? HighlightingKind::StaticField
- : VD->isLocalVarDecl() ? HighlightingKind::LocalVariable
- : HighlightingKind::Variable);
- return;
- }
- if (isa<BindingDecl>(D)) {
- addToken(Loc, HighlightingKind::Variable);
- return;
- }
- if (isa<FunctionDecl>(D)) {
- addToken(Loc, HighlightingKind::Function);
- return;
- }
- if (isa<NamespaceDecl>(D)) {
- addToken(Loc, HighlightingKind::Namespace);
- return;
- }
- if (isa<NamespaceAliasDecl>(D)) {
- addToken(Loc, HighlightingKind::Namespace);
- return;
- }
- if (isa<TemplateTemplateParmDecl>(D)) {
- addToken(Loc, HighlightingKind::TemplateParameter);
- return;
- }
- if (isa<TemplateTypeParmDecl>(D)) {
- addToken(Loc, HighlightingKind::TemplateParameter);
- return;
- }
- if (isa<NonTypeTemplateParmDecl>(D)) {
- addToken(Loc, HighlightingKind::TemplateParameter);
- return;
- }
- }
-
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)).
@@ -298,8 +235,8 @@ private:
}
// 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)
+ // 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))
@@ -314,6 +251,11 @@ private:
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.
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