1 //===- FixItRewriter.h - Fix-It Rewriter Diagnostic Client ------*- 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 diagnostic client adaptor that performs rewrites as
10 // suggested by code modification hints attached to diagnostics. It
11 // then forwards any diagnostics to the adapted diagnostic client.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_REWRITE_FRONTEND_FIXITREWRITER_H
16 #define LLVM_CLANG_REWRITE_FRONTEND_FIXITREWRITER_H
17 
18 #include "clang/Basic/Diagnostic.h"
19 #include "clang/Basic/LLVM.h"
20 #include "clang/Basic/SourceLocation.h"
21 #include "clang/Edit/EditedSource.h"
22 #include "clang/Rewrite/Core/Rewriter.h"
23 #include <memory>
24 #include <string>
25 #include <utility>
26 #include <vector>
27 
28 namespace clang {
29 
30 class LangOptions;
31 class SourceManager;
32 
33 class FixItOptions {
34 public:
35   FixItOptions() = default;
36   virtual ~FixItOptions();
37 
38   /// This file is about to be rewritten. Return the name of the file
39   /// that is okay to write to.
40   ///
41   /// \param fd out parameter for file descriptor. After the call it may be set
42   /// to an open file descriptor for the returned filename, or it will be -1
43   /// otherwise.
44   virtual std::string RewriteFilename(const std::string &Filename, int &fd) = 0;
45 
46   /// True if files should be updated in place. RewriteFilename is only called
47   /// if this is false.
48   bool InPlace = false;
49 
50   /// Whether to abort fixing a file when not all errors could be fixed.
51   bool FixWhatYouCan = false;
52 
53   /// Whether to only fix warnings and not errors.
54   bool FixOnlyWarnings = false;
55 
56   /// If true, only pass the diagnostic to the actual diagnostic consumer
57   /// if it is an error or a fixit was applied as part of the diagnostic.
58   /// It basically silences warnings without accompanying fixits.
59   bool Silent = false;
60 };
61 
62 class FixItRewriter : public DiagnosticConsumer {
63   /// The diagnostics machinery.
64   DiagnosticsEngine &Diags;
65 
66   edit::EditedSource Editor;
67 
68   /// The rewriter used to perform the various code
69   /// modifications.
70   Rewriter Rewrite;
71 
72   /// The diagnostic client that performs the actual formatting
73   /// of error messages.
74   DiagnosticConsumer *Client;
75   std::unique_ptr<DiagnosticConsumer> Owner;
76 
77   /// Turn an input path into an output path. NULL implies overwriting
78   /// the original.
79   FixItOptions *FixItOpts;
80 
81   /// The number of rewriter failures.
82   unsigned NumFailures = 0;
83 
84   /// Whether the previous diagnostic was not passed to the consumer.
85   bool PrevDiagSilenced = false;
86 
87 public:
88   /// Initialize a new fix-it rewriter.
89   FixItRewriter(DiagnosticsEngine &Diags, SourceManager &SourceMgr,
90                 const LangOptions &LangOpts, FixItOptions *FixItOpts);
91 
92   /// Destroy the fix-it rewriter.
93   ~FixItRewriter() override;
94 
95   /// Check whether there are modifications for a given file.
IsModified(FileID ID)96   bool IsModified(FileID ID) const {
97     return Rewrite.getRewriteBufferFor(ID) != nullptr;
98   }
99 
100   using iterator = Rewriter::buffer_iterator;
101 
102   // Iteration over files with changes.
buffer_begin()103   iterator buffer_begin() { return Rewrite.buffer_begin(); }
buffer_end()104   iterator buffer_end() { return Rewrite.buffer_end(); }
105 
106   /// Write a single modified source file.
107   ///
108   /// \returns true if there was an error, false otherwise.
109   bool WriteFixedFile(FileID ID, raw_ostream &OS);
110 
111   /// Write the modified source files.
112   ///
113   /// \returns true if there was an error, false otherwise.
114   bool WriteFixedFiles(
115     std::vector<std::pair<std::string, std::string>> *RewrittenFiles = nullptr);
116 
117   /// IncludeInDiagnosticCounts - This method (whose default implementation
118   /// returns true) indicates whether the diagnostics handled by this
119   /// DiagnosticConsumer should be included in the number of diagnostics
120   /// reported by DiagnosticsEngine.
121   bool IncludeInDiagnosticCounts() const override;
122 
123   /// HandleDiagnostic - Handle this diagnostic, reporting it to the user or
124   /// capturing it to a log as needed.
125   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
126                         const Diagnostic &Info) override;
127 
128   /// Emit a diagnostic via the adapted diagnostic client.
129   void Diag(SourceLocation Loc, unsigned DiagID);
130 };
131 
132 } // namespace clang
133 
134 #endif // LLVM_CLANG_REWRITE_FRONTEND_FIXITREWRITER_H
135