1 //===--- TextDiagnostic.h - Text Diagnostic Pretty-Printing -----*- 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 // This is a utility class that provides support for textual pretty-printing of
10 // diagnostics. It is used to implement the different code paths which require
11 // such functionality in a consistent way.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_FRONTEND_TEXTDIAGNOSTIC_H
16 #define LLVM_CLANG_FRONTEND_TEXTDIAGNOSTIC_H
17 
18 #include "clang/Frontend/DiagnosticRenderer.h"
19 
20 namespace clang {
21 
22 /// Class to encapsulate the logic for formatting and printing a textual
23 /// diagnostic message.
24 ///
25 /// This class provides an interface for building and emitting a textual
26 /// diagnostic, including all of the macro backtraces, caret diagnostics, FixIt
27 /// Hints, and code snippets. In the presence of macros this involves
28 /// a recursive process, synthesizing notes for each macro expansion.
29 ///
30 /// The purpose of this class is to isolate the implementation of printing
31 /// beautiful text diagnostics from any particular interfaces. The Clang
32 /// DiagnosticClient is implemented through this class as is diagnostic
33 /// printing coming out of libclang.
34 class TextDiagnostic : public DiagnosticRenderer {
35   raw_ostream &OS;
36 
37 public:
38   TextDiagnostic(raw_ostream &OS,
39                  const LangOptions &LangOpts,
40                  DiagnosticOptions *DiagOpts);
41 
42   ~TextDiagnostic() override;
43 
44   /// Print the diagonstic level to a raw_ostream.
45   ///
46   /// This is a static helper that handles colorizing the level and formatting
47   /// it into an arbitrary output stream. This is used internally by the
48   /// TextDiagnostic emission code, but it can also be used directly by
49   /// consumers that don't have a source manager or other state that the full
50   /// TextDiagnostic logic requires.
51   static void printDiagnosticLevel(raw_ostream &OS,
52                                    DiagnosticsEngine::Level Level,
53                                    bool ShowColors);
54 
55   /// Pretty-print a diagnostic message to a raw_ostream.
56   ///
57   /// This is a static helper to handle the line wrapping, colorizing, and
58   /// rendering of a diagnostic message to a particular ostream. It is
59   /// publicly visible so that clients which do not have sufficient state to
60   /// build a complete TextDiagnostic object can still get consistent
61   /// formatting of their diagnostic messages.
62   ///
63   /// \param OS Where the message is printed
64   /// \param IsSupplemental true if this is a continuation note diagnostic
65   /// \param Message The text actually printed
66   /// \param CurrentColumn The starting column of the first line, accounting
67   ///                      for any prefix.
68   /// \param Columns The number of columns to use in line-wrapping, 0 disables
69   ///                all line-wrapping.
70   /// \param ShowColors Enable colorizing of the message.
71   static void printDiagnosticMessage(raw_ostream &OS, bool IsSupplemental,
72                                      StringRef Message, unsigned CurrentColumn,
73                                      unsigned Columns, bool ShowColors);
74 
75 protected:
76   void emitDiagnosticMessage(FullSourceLoc Loc, PresumedLoc PLoc,
77                              DiagnosticsEngine::Level Level, StringRef Message,
78                              ArrayRef<CharSourceRange> Ranges,
79                              DiagOrStoredDiag D) override;
80 
81   void emitDiagnosticLoc(FullSourceLoc Loc, PresumedLoc PLoc,
82                          DiagnosticsEngine::Level Level,
83                          ArrayRef<CharSourceRange> Ranges) override;
84 
85   void emitCodeContext(FullSourceLoc Loc, DiagnosticsEngine::Level Level,
86                        SmallVectorImpl<CharSourceRange> &Ranges,
87                        ArrayRef<FixItHint> Hints) override {
88     emitSnippetAndCaret(Loc, Level, Ranges, Hints);
89   }
90 
91   void emitIncludeLocation(FullSourceLoc Loc, PresumedLoc PLoc) override;
92 
93   void emitImportLocation(FullSourceLoc Loc, PresumedLoc PLoc,
94                           StringRef ModuleName) override;
95 
96   void emitBuildingModuleLocation(FullSourceLoc Loc, PresumedLoc PLoc,
97                                   StringRef ModuleName) override;
98 
99 private:
100   void emitFilename(StringRef Filename, const SourceManager &SM);
101 
102   void emitSnippetAndCaret(FullSourceLoc Loc, DiagnosticsEngine::Level Level,
103                            SmallVectorImpl<CharSourceRange> &Ranges,
104                            ArrayRef<FixItHint> Hints);
105 
106   void emitSnippet(StringRef SourceLine, unsigned MaxLineNoDisplayWidth,
107                    unsigned LineNo);
108 
109   void emitParseableFixits(ArrayRef<FixItHint> Hints, const SourceManager &SM);
110 };
111 
112 } // end namespace clang
113 
114 #endif
115