clang-tools  17.0.0git
Quality.h
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1 //===--- Quality.h - Ranking alternatives for ambiguous queries --*- 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 /// Some operations such as code completion produce a set of candidates.
10 /// Usually the user can choose between them, but we should put the best options
11 /// at the top (they're easier to select, and more likely to be seen).
12 ///
13 /// This file defines building blocks for ranking candidates.
14 /// It's used by the features directly and also in the implementation of
15 /// indexes, as indexes also need to heuristically limit their results.
16 ///
17 /// The facilities here are:
18 /// - retrieving scoring signals from e.g. indexes, AST, CodeCompletionString
19 /// These are structured in a way that they can be debugged, and are fairly
20 /// consistent regardless of the source.
21 /// - compute scores from scoring signals. These are suitable for sorting.
22 /// - sorting utilities like the TopN container.
23 /// These could be split up further to isolate dependencies if we care.
24 ///
25 //===----------------------------------------------------------------------===//
26 
27 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
28 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
29 
30 #include "FileDistance.h"
31 #include "clang/Sema/CodeCompleteConsumer.h"
32 #include "llvm/ADT/StringRef.h"
33 #include "llvm/ADT/StringSet.h"
34 #include <algorithm>
35 #include <functional>
36 #include <optional>
37 #include <vector>
38 
39 namespace llvm {
40 class raw_ostream;
41 } // namespace llvm
42 
43 namespace clang {
44 class CodeCompletionResult;
45 
46 namespace clangd {
47 struct ASTSignals;
48 struct Symbol;
49 class URIDistance;
50 
51 // Signals structs are designed to be aggregated from 0 or more sources.
52 // A default instance has neutral signals, and sources are merged into it.
53 // They can be dumped for debugging, and evaluate()d into a score.
54 
55 /// Attributes of a symbol that affect how much we like it.
57  bool Deprecated = false;
58  bool ReservedName = false; // __foo, _Foo are usually implementation details.
59  // FIXME: make these findable once user types _.
60  bool ImplementationDetail = false;
61  unsigned References = 0;
62 
64  Unknown = 0,
74  } Category = Unknown;
75 
76  void merge(const CodeCompletionResult &SemaCCResult);
77  void merge(const Symbol &IndexResult);
78 
79  // Condense these signals down to a single number, higher is better.
80  float evaluateHeuristics() const;
81 };
82 llvm::raw_ostream &operator<<(llvm::raw_ostream &,
83  const SymbolQualitySignals &);
84 
85 /// Attributes of a symbol-query pair that affect how much we like it.
87  /// The name of the symbol (for ContextWords). Must be explicitly assigned.
88  llvm::StringRef Name;
89  /// 0-1+ fuzzy-match score for unqualified name. Must be explicitly assigned.
90  float NameMatch = 1;
91  /// Lowercase words relevant to the context (e.g. near the completion point).
92  llvm::StringSet<>* ContextWords = nullptr;
93  bool Forbidden = false; // Unavailable (e.g const) or inaccessible (private).
94  /// Whether fixits needs to be applied for that completion or not.
95  bool NeedsFixIts = false;
96  bool InBaseClass = false; // A member from base class of the accessed class.
97 
99  /// These are used to calculate proximity between the index symbol and the
100  /// query.
101  llvm::StringRef SymbolURI;
102  /// FIXME: unify with index proximity score - signals should be
103  /// source-independent.
104  /// Proximity between best declaration and the query. [0-1], 1 is closest.
106 
107  // Scope proximity is only considered (both index and sema) when this is set.
109  std::optional<llvm::StringRef> SymbolScope;
110  // A symbol from sema should be accessible from the current scope.
111  bool SemaSaysInScope = false;
112 
113  // An approximate measure of where we expect the symbol to be used.
119  } Scope = GlobalScope;
120 
121  enum QueryType {
124  } Query = Generic;
125 
126  CodeCompletionContext::Kind Context = CodeCompletionContext::CCC_Other;
127 
128  // Whether symbol is an instance member of a class.
129  bool IsInstanceMember = false;
130 
131  // Whether clang provided a preferred type in the completion context.
132  bool HadContextType = false;
133  // Whether a source completion item or a symbol had a type information.
134  bool HadSymbolType = false;
135  // Whether the item matches the type expected in the completion context.
136  bool TypeMatchesPreferred = false;
137 
138  /// Length of the unqualified partial name of Symbol typed in
139  /// CompletionPrefix.
140  unsigned FilterLength = 0;
141 
142  const ASTSignals *MainFileSignals = nullptr;
143  /// Number of references to the candidate in the main file.
144  unsigned MainFileRefs = 0;
145  /// Number of unique symbols in the main file which belongs to candidate's
146  /// namespace. This indicates how relevant the namespace is in the current
147  /// file.
148  unsigned ScopeRefsInFile = 0;
149 
150  /// Set of derived signals computed by calculateDerivedSignals(). Must not be
151  /// set explicitly.
152  struct DerivedSignals {
153  /// Whether Name contains some word from context.
154  bool NameMatchesContext = false;
155  /// Min distance between SymbolURI and all the headers included by the TU.
157  /// Min distance between SymbolScope and all the available scopes.
159  };
160 
162 
163  void merge(const CodeCompletionResult &SemaResult);
164  void merge(const Symbol &IndexResult);
165  void computeASTSignals(const CodeCompletionResult &SemaResult);
166 
167  // Condense these signals down to a single number, higher is better.
168  float evaluateHeuristics() const;
169 };
170 llvm::raw_ostream &operator<<(llvm::raw_ostream &,
171  const SymbolRelevanceSignals &);
172 
173 /// Combine symbol quality and relevance into a single score.
174 float evaluateSymbolAndRelevance(float SymbolQuality, float SymbolRelevance);
175 
176 /// Same semantics as CodeComplete::Score. Quality score and Relevance score
177 /// have been removed since DecisionForest cannot assign individual scores to
178 /// Quality and Relevance signals.
180  float Total = 0.f;
181  float ExcludingName = 0.f;
182 };
183 
186  const SymbolRelevanceSignals &Relevance, float Base);
187 
188 /// TopN<T> is a lossy container that preserves only the "best" N elements.
189 template <typename T, typename Compare = std::greater<T>> class TopN {
190 public:
191  using value_type = T;
192  TopN(size_t N, Compare Greater = Compare())
193  : N(N), Greater(std::move(Greater)) {}
194 
195  // Adds a candidate to the set.
196  // Returns true if a candidate was dropped to get back under N.
197  bool push(value_type &&V) {
198  bool Dropped = false;
199  if (Heap.size() >= N) {
200  Dropped = true;
201  if (N > 0 && Greater(V, Heap.front())) {
202  std::pop_heap(Heap.begin(), Heap.end(), Greater);
203  Heap.back() = std::move(V);
204  std::push_heap(Heap.begin(), Heap.end(), Greater);
205  }
206  } else {
207  Heap.push_back(std::move(V));
208  std::push_heap(Heap.begin(), Heap.end(), Greater);
209  }
210  assert(Heap.size() <= N);
211  assert(std::is_heap(Heap.begin(), Heap.end(), Greater));
212  return Dropped;
213  }
214 
215  // Returns candidates from best to worst.
216  std::vector<value_type> items() && {
217  std::sort_heap(Heap.begin(), Heap.end(), Greater);
218  assert(Heap.size() <= N);
219  return std::move(Heap);
220  }
221 
222 private:
223  const size_t N;
224  std::vector<value_type> Heap; // Min-heap, comparator is Greater.
225  Compare Greater;
226 };
227 
228 /// Returns a string that sorts in the same order as (-Score, Tiebreak), for
229 /// LSP. (The highest score compares smallest so it sorts at the top).
230 std::string sortText(float Score, llvm::StringRef Tiebreak = "");
231 
233  uint32_t NumberOfParameters = 0;
235  CodeCompleteConsumer::OverloadCandidate::CandidateKind Kind =
236  CodeCompleteConsumer::OverloadCandidate::CandidateKind::CK_Function;
237 };
238 llvm::raw_ostream &operator<<(llvm::raw_ostream &,
239  const SignatureQualitySignals &);
240 
241 } // namespace clangd
242 } // namespace clang
243 
244 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_QUALITY_H
clang::clangd::SymbolRelevanceSignals::merge
void merge(const CodeCompletionResult &SemaResult)
Definition: Quality.cpp:325
clang::clangd::SymbolQualitySignals::Deprecated
bool Deprecated
Definition: Quality.h:57
clang::clangd::SymbolQualitySignals::ImplementationDetail
bool ImplementationDetail
Definition: Quality.h:60
Base
std::unique_ptr< GlobalCompilationDatabase > Base
Definition: GlobalCompilationDatabaseTests.cpp:85
llvm
Some operations such as code completion produce a set of candidates.
Definition: YAMLGenerator.cpp:34
clang::clangd::SymbolRelevanceSignals::Scope
enum clang::clangd::SymbolRelevanceSignals::AccessibleScope Scope
clang::clangd::SymbolRelevanceSignals::SymbolScope
std::optional< llvm::StringRef > SymbolScope
Definition: Quality.h:109
clang::clangd::SymbolRelevanceSignals::Query
enum clang::clangd::SymbolRelevanceSignals::QueryType Query
clang::clangd::TopN::items
std::vector< value_type > items() &&
Definition: Quality.h:216
clang::clangd::SymbolRelevanceSignals::HadSymbolType
bool HadSymbolType
Definition: Quality.h:134
clang::clangd::SymbolRelevanceSignals::FilterLength
unsigned FilterLength
Length of the unqualified partial name of Symbol typed in CompletionPrefix.
Definition: Quality.h:140
clang::clangd::SignatureQualitySignals
Definition: Quality.h:232
IndexResult
const Symbol * IndexResult
Definition: CodeComplete.cpp:208
clang::clangd::evaluateSymbolAndRelevance
float evaluateSymbolAndRelevance(float SymbolQuality, float SymbolRelevance)
Combine symbol quality and relevance into a single score.
Definition: Quality.cpp:530
clang::clangd::SymbolRelevanceSignals::SymbolURI
llvm::StringRef SymbolURI
These are used to calculate proximity between the index symbol and the query.
Definition: Quality.h:101
clang::clangd::TopN::TopN
TopN(size_t N, Compare Greater=Compare())
Definition: Quality.h:192
clang::clangd::SymbolQualitySignals::Variable
@ Variable
Definition: Quality.h:65
clang::clangd::DecisionForestScores
Same semantics as CodeComplete::Score.
Definition: Quality.h:179
clang::clangd::SymbolQualitySignals::Unknown
@ Unknown
Definition: Quality.h:64
clang::clangd::SymbolRelevanceSignals::FunctionScope
@ FunctionScope
Definition: Quality.h:115
Kind
BindArgumentKind Kind
Definition: AvoidBindCheck.cpp:57
clang::clangd::SymbolRelevanceSignals::DerivedSignals::FileProximityDistance
unsigned FileProximityDistance
Min distance between SymbolURI and all the headers included by the TU.
Definition: Quality.h:156
clang::clangd::SymbolRelevanceSignals::evaluateHeuristics
float evaluateHeuristics() const
Definition: Quality.cpp:395
clang::clangd::SymbolQualitySignals::ReservedName
bool ReservedName
Definition: Quality.h:58
clang::clangd::DecisionForestScores::ExcludingName
float ExcludingName
Definition: Quality.h:181
clang::clangd::ScopeDistance
Support lookups like FileDistance, but the lookup keys are symbol scopes.
Definition: FileDistance.h:112
clang::clangd::SymbolQualitySignals
Attributes of a symbol that affect how much we like it.
Definition: Quality.h:56
clang::clangd::SymbolRelevanceSignals::computeASTSignals
void computeASTSignals(const CodeCompletionResult &SemaResult)
Definition: Quality.cpp:299
clang::clangd::SymbolRelevanceSignals::ScopeRefsInFile
unsigned ScopeRefsInFile
Number of unique symbols in the main file which belongs to candidate's namespace.
Definition: Quality.h:148
clang::clangd::SymbolRelevanceSignals::Forbidden
bool Forbidden
Definition: Quality.h:93
clang::clangd::SignatureQualitySignals::NumberOfOptionalParameters
uint32_t NumberOfOptionalParameters
Definition: Quality.h:234
clang::clangd::SymbolRelevanceSignals::AccessibleScope
AccessibleScope
Definition: Quality.h:114
clang::clangd::TopN::push
bool push(value_type &&V)
Definition: Quality.h:197
FileDistance.h
Score
std::optional< float > Score
Definition: FuzzyMatchTests.cpp:48
clang::clangd::SymbolQualitySignals::Constructor
@ Constructor
Definition: Quality.h:69
clang::clangd::TopN
TopN<T> is a lossy container that preserves only the "best" N elements.
Definition: Quality.h:189
clang::clangd::SymbolQualitySignals::References
unsigned References
Definition: Quality.h:61
Quality
SignatureQualitySignals Quality
Definition: CodeComplete.cpp:934
clang::clangd::TopN::value_type
T value_type
Definition: Quality.h:191
clang::clangd::SymbolQualitySignals::Destructor
@ Destructor
Definition: Quality.h:70
SemaResult
const CodeCompletionResult * SemaResult
Definition: CodeComplete.cpp:207
clang::clangd::Symbol
The class presents a C++ symbol, e.g.
Definition: Symbol.h:39
clang::clangd::SymbolRelevanceSignals::HadContextType
bool HadContextType
Definition: Quality.h:132
clang::clangd::SignatureQualitySignals::NumberOfParameters
uint32_t NumberOfParameters
Definition: Quality.h:233
clang::clangd::evaluateDecisionForest
DecisionForestScores evaluateDecisionForest(const SymbolQualitySignals &Quality, const SymbolRelevanceSignals &Relevance, float Base)
Definition: DecisionForest.cpp:18
clang::clangd::SymbolRelevanceSignals::SemaFileProximityScore
float SemaFileProximityScore
FIXME: unify with index proximity score - signals should be source-independent.
Definition: Quality.h:105
clang::clangd::SymbolQualitySignals::Function
@ Function
Definition: Quality.h:68
clang::clangd::SymbolRelevanceSignals::FileProximityMatch
URIDistance * FileProximityMatch
Definition: Quality.h:98
clang::clangd::operator<<
llvm::raw_ostream & operator<<(llvm::raw_ostream &OS, const CodeCompletion &C)
Definition: CodeComplete.cpp:2244
clang::clangd::SymbolRelevanceSignals::TypeMatchesPreferred
bool TypeMatchesPreferred
Definition: Quality.h:136
clang::clangd::SymbolRelevanceSignals::ScopeProximityMatch
ScopeDistance * ScopeProximityMatch
Definition: Quality.h:108
clang::clangd::SymbolRelevanceSignals::Name
llvm::StringRef Name
The name of the symbol (for ContextWords). Must be explicitly assigned.
Definition: Quality.h:88
clang::clangd::SymbolRelevanceSignals::DerivedSignals
Set of derived signals computed by calculateDerivedSignals().
Definition: Quality.h:152
clang::clangd::URIDistance
Definition: FileDistance.h:88
clang::clangd::SymbolRelevanceSignals::DerivedSignals::NameMatchesContext
bool NameMatchesContext
Whether Name contains some word from context.
Definition: Quality.h:154
clang::clangd::SymbolQualitySignals::Namespace
@ Namespace
Definition: Quality.h:71
clang::clangd::ASTSignals
Signals derived from a valid AST of a file.
Definition: ASTSignals.h:27
clang::clangd::SymbolRelevanceSignals::IsInstanceMember
bool IsInstanceMember
Definition: Quality.h:129
clang::clangd::SymbolRelevanceSignals::MainFileSignals
const ASTSignals * MainFileSignals
Definition: Quality.h:142
clang::clangd::SymbolRelevanceSignals::SemaSaysInScope
bool SemaSaysInScope
Definition: Quality.h:111
clang::clangd::SymbolQualitySignals::Keyword
@ Keyword
Definition: Quality.h:72
clang::clangd::SymbolRelevanceSignals::NeedsFixIts
bool NeedsFixIts
Whether fixits needs to be applied for that completion or not.
Definition: Quality.h:95
clang::clangd::sortText
std::string sortText(float Score, llvm::StringRef Name)
Returns a string that sorts in the same order as (-Score, Tiebreak), for LSP.
Definition: Quality.cpp:548
clang::clangd::SymbolQualitySignals::Macro
@ Macro
Definition: Quality.h:66
clang::clangd::SymbolRelevanceSignals::MainFileRefs
unsigned MainFileRefs
Number of references to the candidate in the main file.
Definition: Quality.h:144
clang::clangd::SymbolRelevanceSignals::ClassScope
@ ClassScope
Definition: Quality.h:116
clang::clangd::SymbolQualitySignals::Operator
@ Operator
Definition: Quality.h:73
clang::clangd::SymbolRelevanceSignals::calculateDerivedSignals
DerivedSignals calculateDerivedSignals() const
Definition: Quality.cpp:381
clang::clangd::SymbolQualitySignals::Type
@ Type
Definition: Quality.h:67
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
clang::clangd::SymbolQualitySignals::SymbolCategory
SymbolCategory
Definition: Quality.h:63
clang::clangd::SymbolQualitySignals::evaluateHeuristics
float evaluateHeuristics() const
Definition: Quality.cpp:196
clang::clangd::SymbolRelevanceSignals::ContextWords
llvm::StringSet * ContextWords
Lowercase words relevant to the context (e.g. near the completion point).
Definition: Quality.h:92
clang::clangd::SignatureQualitySignals::Kind
CodeCompleteConsumer::OverloadCandidate::CandidateKind Kind
Definition: Quality.h:235
clang::clangd::SymbolQualitySignals::Category
enum clang::clangd::SymbolQualitySignals::SymbolCategory Category
clang::clangd::SymbolRelevanceSignals::DerivedSignals::ScopeProximityDistance
unsigned ScopeProximityDistance
Min distance between SymbolScope and all the available scopes.
Definition: Quality.h:158
clang::clangd::SymbolRelevanceSignals::Generic
@ Generic
Definition: Quality.h:123
clang::clangd::SymbolRelevanceSignals::NameMatch
float NameMatch
0-1+ fuzzy-match score for unqualified name. Must be explicitly assigned.
Definition: Quality.h:90
clang::clangd::DecisionForestScores::Total
float Total
Definition: Quality.h:180
clang::clangd::SymbolRelevanceSignals::CodeComplete
@ CodeComplete
Definition: Quality.h:122
clang::clangd::SymbolRelevanceSignals::InBaseClass
bool InBaseClass
Definition: Quality.h:96
clang::clangd::SymbolRelevanceSignals::GlobalScope
@ GlobalScope
Definition: Quality.h:118
clang::clangd::SymbolRelevanceSignals
Attributes of a symbol-query pair that affect how much we like it.
Definition: Quality.h:86
clang::clangd::Context
A context is an immutable container for per-request data that must be propagated through layers that ...
Definition: Context.h:69
clang::clangd::SymbolRelevanceSignals::QueryType
QueryType
Definition: Quality.h:121
clang::clangd::FileDistance::Unreachable
static constexpr unsigned Unreachable
Definition: FileDistance.h:69
clang::clangd::SymbolRelevanceSignals::FileScope
@ FileScope
Definition: Quality.h:117
clang::clangd::SymbolQualitySignals::merge
void merge(const CodeCompletionResult &SemaCCResult)
Definition: Quality.cpp:175