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/Optional.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringSet.h"
21 #include "llvm/Support/JSON.h"
22 #include "llvm/Support/SourceMgr.h"
23 #include <cassert>
24 #include <functional>
25 #include <memory>
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   llvm::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 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Fix &F);
88 
89 /// Represents a note for the diagnostic. Severity of notes can only be 'note'
90 /// or 'remark'.
91 struct Note : DiagBase {};
92 
93 /// A top-level diagnostic that may have Notes and Fixes.
94 struct Diag : DiagBase {
95   std::string Name; // if ID was recognized.
96   // The source of this diagnostic.
97   enum DiagSource {
98     Unknown,
99     Clang,
100     ClangTidy,
101     Clangd,
102     ClangdConfig,
103   } Source = Unknown;
104   /// Elaborate on the problem, usually pointing to a related piece of code.
105   std::vector<Note> Notes;
106   /// *Alternative* fixes for this diagnostic, one should be chosen.
107   std::vector<Fix> Fixes;
108   llvm::SmallVector<DiagnosticTag, 1> Tags;
109 };
110 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Diag &D);
111 
112 Diag toDiag(const llvm::SMDiagnostic &, Diag::DiagSource Source);
113 
114 /// Conversion to LSP diagnostics. Formats the error message of each diagnostic
115 /// to include all its notes. Notes inside main file are also provided as
116 /// separate diagnostics with their corresponding fixits. Notes outside main
117 /// file do not have a corresponding LSP diagnostic, but can still be included
118 /// as part of their main diagnostic's message.
119 void toLSPDiags(
120     const Diag &D, const URIForFile &File, const ClangdDiagnosticOptions &Opts,
121     llvm::function_ref<void(clangd::Diagnostic, llvm::ArrayRef<Fix>)> OutFn);
122 
123 /// Convert from Fix to LSP CodeAction.
124 CodeAction toCodeAction(const Fix &D, const URIForFile &File);
125 
126 /// Convert from clang diagnostic level to LSP severity.
127 int getSeverity(DiagnosticsEngine::Level L);
128 
129 /// Returns a URI providing more information about a particular diagnostic.
130 llvm::Optional<std::string> getDiagnosticDocURI(Diag::DiagSource, unsigned ID,
131                                                 llvm::StringRef Name);
132 
133 /// StoreDiags collects the diagnostics that can later be reported by
134 /// clangd. It groups all notes for a diagnostic into a single Diag
135 /// and filters out diagnostics that don't mention the main file (i.e. neither
136 /// the diag itself nor its notes are in the main file).
137 class StoreDiags : public DiagnosticConsumer {
138 public:
139   // The ClangTidyContext populates Source and Name for clang-tidy diagnostics.
140   std::vector<Diag> take(const clang::tidy::ClangTidyContext *Tidy = nullptr);
141 
142   void BeginSourceFile(const LangOptions &Opts,
143                        const Preprocessor *PP) override;
144   void EndSourceFile() override;
145   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
146                         const clang::Diagnostic &Info) override;
147 
148   /// When passed a main diagnostic, returns fixes to add to it.
149   /// When passed a note diagnostic, returns fixes to replace it with.
150   using DiagFixer = std::function<std::vector<Fix>(DiagnosticsEngine::Level,
151                                                    const clang::Diagnostic &)>;
152   using LevelAdjuster = std::function<DiagnosticsEngine::Level(
153       DiagnosticsEngine::Level, const clang::Diagnostic &)>;
154   using DiagCallback =
155       std::function<void(const clang::Diagnostic &, clangd::Diag &)>;
156   /// If set, possibly adds fixes for diagnostics using \p Fixer.
contributeFixes(DiagFixer Fixer)157   void contributeFixes(DiagFixer Fixer) { this->Fixer = Fixer; }
158   /// If set, this allows the client of this class to adjust the level of
159   /// diagnostics, such as promoting warnings to errors, or ignoring
160   /// diagnostics.
setLevelAdjuster(LevelAdjuster Adjuster)161   void setLevelAdjuster(LevelAdjuster Adjuster) { this->Adjuster = Adjuster; }
162   /// Invokes a callback every time a diagnostics is completely formed. Handler
163   /// of the callback can also mutate the diagnostic.
setDiagCallback(DiagCallback CB)164   void setDiagCallback(DiagCallback CB) { DiagCB = std::move(CB); }
165 
166 private:
167   void flushLastDiag();
168 
169   DiagFixer Fixer = nullptr;
170   LevelAdjuster Adjuster = nullptr;
171   DiagCallback DiagCB = nullptr;
172   std::vector<Diag> Output;
173   llvm::Optional<LangOptions> LangOpts;
174   llvm::Optional<Diag> LastDiag;
175   llvm::Optional<FullSourceLoc> LastDiagLoc; // Valid only when LastDiag is set.
176   bool LastDiagOriginallyError = false;      // Valid only when LastDiag is set.
177   SourceManager *OrigSrcMgr = nullptr;
178 
179   llvm::DenseSet<std::pair<unsigned, unsigned>> IncludedErrorLocations;
180 };
181 
182 /// Determine whether a (non-clang-tidy) diagnostic is suppressed by config.
183 bool isBuiltinDiagnosticSuppressed(unsigned ID,
184                                    const llvm::StringSet<> &Suppressed,
185                                    const LangOptions &);
186 /// Take a user-specified diagnostic code, and convert it to a normalized form
187 /// stored in the config and consumed by isBuiltinDiagnosticsSuppressed.
188 ///
189 /// (This strips err_ and -W prefix so we can match with or without them.)
190 llvm::StringRef normalizeSuppressedCode(llvm::StringRef);
191 
192 } // namespace clangd
193 } // namespace clang
194 
195 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_DIAGNOSTICS_H
196