505 lines
17 KiB
C++
505 lines
17 KiB
C++
//===--- Quality.cpp ---------------------------------------------*- C++-*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "Quality.h"
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#include "AST.h"
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#include "FileDistance.h"
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#include "SourceCode.h"
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#include "URI.h"
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#include "index/Symbol.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/Decl.h"
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#include "clang/AST/DeclCXX.h"
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#include "clang/AST/DeclTemplate.h"
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#include "clang/AST/DeclVisitor.h"
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#include "clang/Basic/CharInfo.h"
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#include "clang/Basic/SourceManager.h"
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#include "clang/Sema/CodeCompleteConsumer.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/FormatVariadic.h"
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#include "llvm/Support/MathExtras.h"
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#include "llvm/Support/raw_ostream.h"
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#include <algorithm>
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#include <cmath>
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namespace clang {
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namespace clangd {
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static bool isReserved(llvm::StringRef Name) {
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// FIXME: Should we exclude _Bool and others recognized by the standard?
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return Name.size() >= 2 && Name[0] == '_' &&
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(isUppercase(Name[1]) || Name[1] == '_');
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}
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static bool hasDeclInMainFile(const Decl &D) {
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auto &SourceMgr = D.getASTContext().getSourceManager();
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for (auto *Redecl : D.redecls()) {
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if (isInsideMainFile(Redecl->getLocation(), SourceMgr))
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return true;
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}
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return false;
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}
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static bool hasUsingDeclInMainFile(const CodeCompletionResult &R) {
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const auto &Context = R.Declaration->getASTContext();
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const auto &SourceMgr = Context.getSourceManager();
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if (R.ShadowDecl) {
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if (isInsideMainFile(R.ShadowDecl->getLocation(), SourceMgr))
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return true;
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}
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return false;
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}
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static SymbolQualitySignals::SymbolCategory categorize(const NamedDecl &ND) {
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if (const auto *FD = dyn_cast<FunctionDecl>(&ND)) {
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if (FD->isOverloadedOperator())
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return SymbolQualitySignals::Operator;
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}
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class Switch
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: public ConstDeclVisitor<Switch, SymbolQualitySignals::SymbolCategory> {
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public:
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#define MAP(DeclType, Category) \
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SymbolQualitySignals::SymbolCategory Visit##DeclType(const DeclType *) { \
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return SymbolQualitySignals::Category; \
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}
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MAP(NamespaceDecl, Namespace);
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MAP(NamespaceAliasDecl, Namespace);
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MAP(TypeDecl, Type);
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MAP(TypeAliasTemplateDecl, Type);
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MAP(ClassTemplateDecl, Type);
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MAP(CXXConstructorDecl, Constructor);
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MAP(CXXDestructorDecl, Destructor);
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MAP(ValueDecl, Variable);
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MAP(VarTemplateDecl, Variable);
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MAP(FunctionDecl, Function);
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MAP(FunctionTemplateDecl, Function);
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MAP(Decl, Unknown);
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#undef MAP
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};
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return Switch().Visit(&ND);
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}
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static SymbolQualitySignals::SymbolCategory
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categorize(const CodeCompletionResult &R) {
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if (R.Declaration)
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return categorize(*R.Declaration);
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if (R.Kind == CodeCompletionResult::RK_Macro)
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return SymbolQualitySignals::Macro;
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// Everything else is a keyword or a pattern. Patterns are mostly keywords
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// too, except a few which we recognize by cursor kind.
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switch (R.CursorKind) {
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case CXCursor_CXXMethod:
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return SymbolQualitySignals::Function;
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case CXCursor_ModuleImportDecl:
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return SymbolQualitySignals::Namespace;
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case CXCursor_MacroDefinition:
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return SymbolQualitySignals::Macro;
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case CXCursor_TypeRef:
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return SymbolQualitySignals::Type;
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case CXCursor_MemberRef:
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return SymbolQualitySignals::Variable;
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case CXCursor_Constructor:
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return SymbolQualitySignals::Constructor;
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default:
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return SymbolQualitySignals::Keyword;
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}
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}
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static SymbolQualitySignals::SymbolCategory
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categorize(const index::SymbolInfo &D) {
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switch (D.Kind) {
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case index::SymbolKind::Namespace:
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case index::SymbolKind::NamespaceAlias:
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return SymbolQualitySignals::Namespace;
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case index::SymbolKind::Macro:
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return SymbolQualitySignals::Macro;
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case index::SymbolKind::Enum:
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case index::SymbolKind::Struct:
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case index::SymbolKind::Class:
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case index::SymbolKind::Protocol:
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case index::SymbolKind::Extension:
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case index::SymbolKind::Union:
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case index::SymbolKind::TypeAlias:
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return SymbolQualitySignals::Type;
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case index::SymbolKind::Function:
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case index::SymbolKind::ClassMethod:
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case index::SymbolKind::InstanceMethod:
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case index::SymbolKind::StaticMethod:
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case index::SymbolKind::InstanceProperty:
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case index::SymbolKind::ClassProperty:
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case index::SymbolKind::StaticProperty:
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case index::SymbolKind::ConversionFunction:
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return SymbolQualitySignals::Function;
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case index::SymbolKind::Destructor:
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return SymbolQualitySignals::Destructor;
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case index::SymbolKind::Constructor:
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return SymbolQualitySignals::Constructor;
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case index::SymbolKind::Variable:
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case index::SymbolKind::Field:
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case index::SymbolKind::EnumConstant:
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case index::SymbolKind::Parameter:
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return SymbolQualitySignals::Variable;
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case index::SymbolKind::Using:
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case index::SymbolKind::Module:
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case index::SymbolKind::Unknown:
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return SymbolQualitySignals::Unknown;
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}
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llvm_unreachable("Unknown index::SymbolKind");
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}
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static bool isInstanceMember(const NamedDecl *ND) {
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if (!ND)
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return false;
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if (const auto *TP = dyn_cast<FunctionTemplateDecl>(ND))
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ND = TP->TemplateDecl::getTemplatedDecl();
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if (const auto *CM = dyn_cast<CXXMethodDecl>(ND))
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return !CM->isStatic();
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return isa<FieldDecl>(ND); // Note that static fields are VarDecl.
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}
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static bool isInstanceMember(const index::SymbolInfo &D) {
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switch (D.Kind) {
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case index::SymbolKind::InstanceMethod:
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case index::SymbolKind::InstanceProperty:
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case index::SymbolKind::Field:
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return true;
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default:
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return false;
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}
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}
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void SymbolQualitySignals::merge(const CodeCompletionResult &SemaCCResult) {
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Deprecated |= (SemaCCResult.Availability == CXAvailability_Deprecated);
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Category = categorize(SemaCCResult);
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if (SemaCCResult.Declaration) {
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ImplementationDetail |= isImplementationDetail(SemaCCResult.Declaration);
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if (auto *ID = SemaCCResult.Declaration->getIdentifier())
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ReservedName = ReservedName || isReserved(ID->getName());
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} else if (SemaCCResult.Kind == CodeCompletionResult::RK_Macro)
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ReservedName = ReservedName || isReserved(SemaCCResult.Macro->getName());
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}
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void SymbolQualitySignals::merge(const Symbol &IndexResult) {
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Deprecated |= (IndexResult.Flags & Symbol::Deprecated);
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ImplementationDetail |= (IndexResult.Flags & Symbol::ImplementationDetail);
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References = std::max(IndexResult.References, References);
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Category = categorize(IndexResult.SymInfo);
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ReservedName = ReservedName || isReserved(IndexResult.Name);
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}
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float SymbolQualitySignals::evaluate() const {
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float Score = 1;
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// This avoids a sharp gradient for tail symbols, and also neatly avoids the
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// question of whether 0 references means a bad symbol or missing data.
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if (References >= 10) {
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// Use a sigmoid style boosting function, which flats out nicely for large
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// numbers (e.g. 2.58 for 1M refererences).
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// The following boosting function is equivalent to:
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// m = 0.06
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// f = 12.0
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// boost = f * sigmoid(m * std::log(References)) - 0.5 * f + 0.59
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// Sample data points: (10, 1.00), (100, 1.41), (1000, 1.82),
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// (10K, 2.21), (100K, 2.58), (1M, 2.94)
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float S = std::pow(References, -0.06);
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Score *= 6.0 * (1 - S) / (1 + S) + 0.59;
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}
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if (Deprecated)
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Score *= 0.1f;
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if (ReservedName)
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Score *= 0.1f;
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if (ImplementationDetail)
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Score *= 0.2f;
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switch (Category) {
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case Keyword: // Often relevant, but misses most signals.
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Score *= 4; // FIXME: important keywords should have specific boosts.
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break;
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case Type:
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case Function:
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case Variable:
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Score *= 1.1f;
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break;
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case Namespace:
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Score *= 0.8f;
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break;
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case Macro:
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case Destructor:
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case Operator:
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Score *= 0.5f;
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break;
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case Constructor: // No boost constructors so they are after class types.
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case Unknown:
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break;
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}
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return Score;
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}
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llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
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const SymbolQualitySignals &S) {
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OS << llvm::formatv("=== Symbol quality: {0}\n", S.evaluate());
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OS << llvm::formatv("\tReferences: {0}\n", S.References);
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OS << llvm::formatv("\tDeprecated: {0}\n", S.Deprecated);
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OS << llvm::formatv("\tReserved name: {0}\n", S.ReservedName);
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OS << llvm::formatv("\tCategory: {0}\n", static_cast<int>(S.Category));
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return OS;
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}
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static SymbolRelevanceSignals::AccessibleScope
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computeScope(const NamedDecl *D) {
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// Injected "Foo" within the class "Foo" has file scope, not class scope.
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const DeclContext *DC = D->getDeclContext();
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if (auto *R = dyn_cast_or_null<RecordDecl>(D))
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if (R->isInjectedClassName())
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DC = DC->getParent();
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// Class constructor should have the same scope as the class.
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if (isa<CXXConstructorDecl>(D))
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DC = DC->getParent();
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bool InClass = false;
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for (; !DC->isFileContext(); DC = DC->getParent()) {
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if (DC->isFunctionOrMethod())
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return SymbolRelevanceSignals::FunctionScope;
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InClass = InClass || DC->isRecord();
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}
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if (InClass)
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return SymbolRelevanceSignals::ClassScope;
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// This threshold could be tweaked, e.g. to treat module-visible as global.
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if (D->getLinkageInternal() < ExternalLinkage)
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return SymbolRelevanceSignals::FileScope;
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return SymbolRelevanceSignals::GlobalScope;
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}
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void SymbolRelevanceSignals::merge(const Symbol &IndexResult) {
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SymbolURI = IndexResult.CanonicalDeclaration.FileURI;
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SymbolScope = IndexResult.Scope;
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IsInstanceMember |= isInstanceMember(IndexResult.SymInfo);
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if (!(IndexResult.Flags & Symbol::VisibleOutsideFile)) {
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Scope = AccessibleScope::FileScope;
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}
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}
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void SymbolRelevanceSignals::merge(const CodeCompletionResult &SemaCCResult) {
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if (SemaCCResult.Availability == CXAvailability_NotAvailable ||
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SemaCCResult.Availability == CXAvailability_NotAccessible)
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Forbidden = true;
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if (SemaCCResult.Declaration) {
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SemaSaysInScope = true;
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// We boost things that have decls in the main file. We give a fixed score
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// for all other declarations in sema as they are already included in the
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// translation unit.
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float DeclProximity = (hasDeclInMainFile(*SemaCCResult.Declaration) ||
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hasUsingDeclInMainFile(SemaCCResult))
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? 1.0
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: 0.6;
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SemaFileProximityScore = std::max(DeclProximity, SemaFileProximityScore);
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IsInstanceMember |= isInstanceMember(SemaCCResult.Declaration);
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InBaseClass |= SemaCCResult.InBaseClass;
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}
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// Declarations are scoped, others (like macros) are assumed global.
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if (SemaCCResult.Declaration)
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Scope = std::min(Scope, computeScope(SemaCCResult.Declaration));
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NeedsFixIts = !SemaCCResult.FixIts.empty();
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}
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static std::pair<float, unsigned> uriProximity(llvm::StringRef SymbolURI,
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URIDistance *D) {
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if (!D || SymbolURI.empty())
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return {0.f, 0u};
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unsigned Distance = D->distance(SymbolURI);
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// Assume approximately default options are used for sensible scoring.
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return {std::exp(Distance * -0.4f / FileDistanceOptions().UpCost), Distance};
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}
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static float scopeBoost(ScopeDistance &Distance,
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llvm::Optional<llvm::StringRef> SymbolScope) {
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if (!SymbolScope)
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return 1;
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auto D = Distance.distance(*SymbolScope);
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if (D == FileDistance::Unreachable)
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return 0.6f;
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return std::max(0.65, 2.0 * std::pow(0.6, D / 2.0));
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}
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static llvm::Optional<llvm::StringRef>
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wordMatching(llvm::StringRef Name, const llvm::StringSet<> *ContextWords) {
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if (ContextWords)
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for (const auto& Word : ContextWords->keys())
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if (Name.contains_lower(Word))
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return Word;
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return llvm::None;
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}
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float SymbolRelevanceSignals::evaluate() const {
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float Score = 1;
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if (Forbidden)
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return 0;
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Score *= NameMatch;
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// File proximity scores are [0,1] and we translate them into a multiplier in
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// the range from 1 to 3.
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Score *= 1 + 2 * std::max(uriProximity(SymbolURI, FileProximityMatch).first,
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SemaFileProximityScore);
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if (ScopeProximityMatch)
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// Use a constant scope boost for sema results, as scopes of sema results
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// can be tricky (e.g. class/function scope). Set to the max boost as we
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// don't load top-level symbols from the preamble and sema results are
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// always in the accessible scope.
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Score *=
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SemaSaysInScope ? 2.0 : scopeBoost(*ScopeProximityMatch, SymbolScope);
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if (wordMatching(Name, ContextWords))
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Score *= 1.5;
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// Symbols like local variables may only be referenced within their scope.
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// Conversely if we're in that scope, it's likely we'll reference them.
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if (Query == CodeComplete) {
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// The narrower the scope where a symbol is visible, the more likely it is
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// to be relevant when it is available.
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switch (Scope) {
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case GlobalScope:
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break;
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case FileScope:
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Score *= 1.5f;
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break;
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case ClassScope:
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Score *= 2;
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break;
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case FunctionScope:
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Score *= 4;
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break;
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}
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} else {
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// For non-completion queries, the wider the scope where a symbol is
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// visible, the more likely it is to be relevant.
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switch (Scope) {
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case GlobalScope:
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break;
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case FileScope:
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Score *= 0.5f;
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break;
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default:
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// TODO: Handle other scopes as we start to use them for index results.
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break;
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}
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}
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if (TypeMatchesPreferred)
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Score *= 5.0;
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// Penalize non-instance members when they are accessed via a class instance.
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if (!IsInstanceMember &&
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(Context == CodeCompletionContext::CCC_DotMemberAccess ||
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Context == CodeCompletionContext::CCC_ArrowMemberAccess)) {
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Score *= 0.2f;
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}
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if (InBaseClass)
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Score *= 0.5f;
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// Penalize for FixIts.
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if (NeedsFixIts)
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Score *= 0.5f;
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return Score;
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}
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llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
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const SymbolRelevanceSignals &S) {
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OS << llvm::formatv("=== Symbol relevance: {0}\n", S.evaluate());
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OS << llvm::formatv("\tName: {0}\n", S.Name);
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OS << llvm::formatv("\tName match: {0}\n", S.NameMatch);
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if (S.ContextWords)
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OS << llvm::formatv(
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"\tMatching context word: {0}\n",
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wordMatching(S.Name, S.ContextWords).getValueOr("<none>"));
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OS << llvm::formatv("\tForbidden: {0}\n", S.Forbidden);
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OS << llvm::formatv("\tNeedsFixIts: {0}\n", S.NeedsFixIts);
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OS << llvm::formatv("\tIsInstanceMember: {0}\n", S.IsInstanceMember);
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OS << llvm::formatv("\tContext: {0}\n", getCompletionKindString(S.Context));
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OS << llvm::formatv("\tQuery type: {0}\n", static_cast<int>(S.Query));
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OS << llvm::formatv("\tScope: {0}\n", static_cast<int>(S.Scope));
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OS << llvm::formatv("\tSymbol URI: {0}\n", S.SymbolURI);
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OS << llvm::formatv("\tSymbol scope: {0}\n",
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S.SymbolScope ? *S.SymbolScope : "<None>");
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if (S.FileProximityMatch) {
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auto Score = uriProximity(S.SymbolURI, S.FileProximityMatch);
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OS << llvm::formatv("\tIndex URI proximity: {0} (distance={1})\n",
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Score.first, Score.second);
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}
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OS << llvm::formatv("\tSema file proximity: {0}\n", S.SemaFileProximityScore);
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OS << llvm::formatv("\tSema says in scope: {0}\n", S.SemaSaysInScope);
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if (S.ScopeProximityMatch)
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OS << llvm::formatv("\tIndex scope boost: {0}\n",
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scopeBoost(*S.ScopeProximityMatch, S.SymbolScope));
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OS << llvm::formatv(
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"\tType matched preferred: {0} (Context type: {1}, Symbol type: {2}\n",
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S.TypeMatchesPreferred, S.HadContextType, S.HadSymbolType);
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return OS;
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}
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float evaluateSymbolAndRelevance(float SymbolQuality, float SymbolRelevance) {
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return SymbolQuality * SymbolRelevance;
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}
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// Produces an integer that sorts in the same order as F.
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// That is: a < b <==> encodeFloat(a) < encodeFloat(b).
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static uint32_t encodeFloat(float F) {
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static_assert(std::numeric_limits<float>::is_iec559, "");
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constexpr uint32_t TopBit = ~(~uint32_t{0} >> 1);
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// Get the bits of the float. Endianness is the same as for integers.
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uint32_t U = llvm::FloatToBits(F);
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// IEEE 754 floats compare like sign-magnitude integers.
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if (U & TopBit) // Negative float.
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return 0 - U; // Map onto the low half of integers, order reversed.
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return U + TopBit; // Positive floats map onto the high half of integers.
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}
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std::string sortText(float Score, llvm::StringRef Name) {
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// We convert -Score to an integer, and hex-encode for readability.
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// Example: [0.5, "foo"] -> "41000000foo"
|
|
std::string S;
|
|
llvm::raw_string_ostream OS(S);
|
|
llvm::write_hex(OS, encodeFloat(-Score), llvm::HexPrintStyle::Lower,
|
|
/*Width=*/2 * sizeof(Score));
|
|
OS << Name;
|
|
OS.flush();
|
|
return S;
|
|
}
|
|
|
|
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
|
|
const SignatureQualitySignals &S) {
|
|
OS << llvm::formatv("=== Signature Quality:\n");
|
|
OS << llvm::formatv("\tNumber of parameters: {0}\n", S.NumberOfParameters);
|
|
OS << llvm::formatv("\tNumber of optional parameters: {0}\n",
|
|
S.NumberOfOptionalParameters);
|
|
OS << llvm::formatv("\tKind: {0}\n", S.Kind);
|
|
return OS;
|
|
}
|
|
|
|
} // namespace clangd
|
|
} // namespace clang
|