clang-tools-extra/clangd/Diagnostics.h

   1 //===--- Diagnostics.h -------------------------------------------*- 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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_DIAGNOSTICS_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_DIAGNOSTICS_H
  11
  12 #include "Protocol.h"
  13 #include "clang/Basic/Diagnostic.h"
  14 #include "clang/Basic/LangOptions.h"
  15 #include "clang/Basic/SourceLocation.h"
  16 #include "llvm/ADT/ArrayRef.h"
  17 #include "llvm/ADT/DenseSet.h"
  18 #include "llvm/ADT/SmallVector.h"
  19 #include "llvm/ADT/StringSet.h"
  20 #include "llvm/Support/JSON.h"
  21 #include "llvm/Support/SourceMgr.h"
  22 #include <cassert>
  23 #include <functional>
  24 #include <memory>
  25 #include <optional>
  26 #include <string>
  27 #include <utility>
  28 #include <vector>
  29
  30 namespace clang {
  31 namespace tidy {
  32 class ClangTidyContext;
  33 } // namespace tidy
  34 namespace clangd {
  35
  36 struct ClangdDiagnosticOptions {
  37   /// If true, Clangd uses an LSP extension to embed the fixes with the
  38   /// diagnostics that are sent to the client.
  39   bool EmbedFixesInDiagnostics = false;
  40
  41   /// If true, Clangd uses the relatedInformation field to include other
  42   /// locations (in particular attached notes).
  43   /// Otherwise, these are flattened into the diagnostic message.
  44   bool EmitRelatedLocations = false;
  45
  46   /// If true, Clangd uses an LSP extension to send the diagnostic's
  47   /// category to the client. The category typically describes the compilation
  48   /// stage during which the issue was produced, e.g. "Semantic Issue" or "Parse
  49   /// Issue".
  50   bool SendDiagnosticCategory = false;
  51
  52   /// If true, Clangd will add a number of available fixes to the diagnostic's
  53   /// message.
  54   bool DisplayFixesCount = true;
  55 };
  56
  57 /// Contains basic information about a diagnostic.
  58 struct DiagBase {
  59   std::string Message;
  60   // Intended to be used only in error messages.
  61   // May be relative, absolute or even artificially constructed.
  62   std::string File;
  63   // Absolute path to containing file, if available.
  64   std::optional<std::string> AbsFile;
  65
  66   clangd::Range Range;
  67   DiagnosticsEngine::Level Severity = DiagnosticsEngine::Note;
  68   std::string Category;
  69   // Since File is only descriptive, we store a separate flag to distinguish
  70   // diags from the main file.
  71   bool InsideMainFile = false;
  72   unsigned ID = 0; // e.g. member of clang::diag, or clang-tidy assigned ID.
  73   // Feature modules can make use of this field to propagate data from a
  74   // diagnostic to a CodeAction request. Each module should only append to the
  75   // list.
  76   llvm::json::Object OpaqueData;
  77 };
  78 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const DiagBase &D);
  79
  80 /// Represents a single fix-it that editor can apply to fix the error.
  81 struct Fix {
  82   /// Message for the fix-it.
  83   std::string Message;
  84   /// TextEdits from clang's fix-its. Must be non-empty.
  85   llvm::SmallVector<TextEdit, 1> Edits;
  86
  87   /// Annotations for the Edits.
  88   llvm::SmallVector<std::pair<ChangeAnnotationIdentifier, ChangeAnnotation>>
  89       Annotations;
  90 };
  91 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Fix &F);
  92
  93 /// Represents a note for the diagnostic. Severity of notes can only be 'note'
  94 /// or 'remark'.
  95 struct Note : DiagBase {};
  96
  97 /// A top-level diagnostic that may have Notes and Fixes.
  98 struct Diag : DiagBase {
  99   std::string Name; // if ID was recognized.
 100   // The source of this diagnostic.
 101   enum DiagSource {
 102     Unknown,
 103     Clang,
 104     ClangTidy,
 105     Clangd,
 106     ClangdConfig,
 107   } Source = Unknown;
 108   /// Elaborate on the problem, usually pointing to a related piece of code.
 109   std::vector<Note> Notes;
 110   /// *Alternative* fixes for this diagnostic, one should be chosen.
 111   std::vector<Fix> Fixes;
 112   llvm::SmallVector<DiagnosticTag, 1> Tags;
 113 };
 114 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Diag &D);
 115
 116 Diag toDiag(const llvm::SMDiagnostic &, Diag::DiagSource Source);
 117
 118 /// Conversion to LSP diagnostics. Formats the error message of each diagnostic
 119 /// to include all its notes. Notes inside main file are also provided as
 120 /// separate diagnostics with their corresponding fixits. Notes outside main
 121 /// file do not have a corresponding LSP diagnostic, but can still be included
 122 /// as part of their main diagnostic's message.
 123 void toLSPDiags(
 124     const Diag &D, const URIForFile &File, const ClangdDiagnosticOptions &Opts,
 125     llvm::function_ref<void(clangd::Diagnostic, llvm::ArrayRef<Fix>)> OutFn);
 126
 127 /// Convert from clang diagnostic level to LSP severity.
 128 int getSeverity(DiagnosticsEngine::Level L);
 129
 130 /// Returns a URI providing more information about a particular diagnostic.
 131 std::optional<std::string> getDiagnosticDocURI(Diag::DiagSource, unsigned ID,
 132                                                llvm::StringRef Name);
 133
 134 /// StoreDiags collects the diagnostics that can later be reported by
 135 /// clangd. It groups all notes for a diagnostic into a single Diag
 136 /// and filters out diagnostics that don't mention the main file (i.e. neither
 137 /// the diag itself nor its notes are in the main file).
 138 class StoreDiags : public DiagnosticConsumer {
 139 public:
 140   // The ClangTidyContext populates Source and Name for clang-tidy diagnostics.
 141   std::vector<Diag> take(const clang::tidy::ClangTidyContext *Tidy = nullptr);
 142
 143   void BeginSourceFile(const LangOptions &Opts,
 144                        const Preprocessor *PP) override;
 145   void EndSourceFile() override;
 146   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
 147                         const clang::Diagnostic &Info) override;
 148
 149   /// When passed a main diagnostic, returns fixes to add to it.
 150   /// When passed a note diagnostic, returns fixes to replace it with.
 151   using DiagFixer = std::function<std::vector<Fix>(DiagnosticsEngine::Level,
 152                                                    const clang::Diagnostic &)>;
 153   using LevelAdjuster = std::function<DiagnosticsEngine::Level(
 154       DiagnosticsEngine::Level, const clang::Diagnostic &)>;
 155   using DiagCallback =
 156       std::function<void(const clang::Diagnostic &, clangd::Diag &)>;
 157   /// If set, possibly adds fixes for diagnostics using \p Fixer.
 158   void contributeFixes(DiagFixer Fixer) { this->Fixer = Fixer; }
 159   /// If set, this allows the client of this class to adjust the level of
 160   /// diagnostics, such as promoting warnings to errors, or ignoring
 161   /// diagnostics.
 162   void setLevelAdjuster(LevelAdjuster Adjuster) { this->Adjuster = Adjuster; }
 163   /// Invokes a callback every time a diagnostics is completely formed. Handler
 164   /// of the callback can also mutate the diagnostic.
 165   void setDiagCallback(DiagCallback CB) { DiagCB = std::move(CB); }
 166
 167 private:
 168   void flushLastDiag();
 169
 170   DiagFixer Fixer = nullptr;
 171   LevelAdjuster Adjuster = nullptr;
 172   DiagCallback DiagCB = nullptr;
 173   std::vector<Diag> Output;
 174   std::optional<LangOptions> LangOpts;
 175   std::optional<Diag> LastDiag;
 176   std::optional<FullSourceLoc> LastDiagLoc;  // Valid only when LastDiag is set.
 177   bool LastDiagOriginallyError = false;      // Valid only when LastDiag is set.
 178   SourceManager *OrigSrcMgr = nullptr;
 179
 180   llvm::DenseSet<std::pair<unsigned, unsigned>> IncludedErrorLocations;
 181 };
 182
 183 /// Determine whether a (non-clang-tidy) diagnostic is suppressed by config.
 184 bool isBuiltinDiagnosticSuppressed(unsigned ID,
 185                                    const llvm::StringSet<> &Suppressed,
 186                                    const LangOptions &);
 187 /// Take a user-specified diagnostic code, and convert it to a normalized form
 188 /// stored in the config and consumed by isBuiltinDiagnosticsSuppressed.
 189 ///
 190 /// (This strips err_ and -W prefix so we can match with or without them.)
 191 llvm::StringRef normalizeSuppressedCode(llvm::StringRef);
 192
 193 } // namespace clangd
 194 } // namespace clang
 195
 196 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_DIAGNOSTICS_H