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Rewriter.h
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1 //===- Rewriter.h - Code rewriting interface --------------------*- 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 file defines the Rewriter class, which is used for code
10 // transformations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_REWRITE_CORE_REWRITER_H
15 #define LLVM_CLANG_REWRITE_CORE_REWRITER_H
16 
17 #include "clang/Basic/LLVM.h"
20 #include "llvm/ADT/StringRef.h"
21 #include <map>
22 #include <string>
23 
24 namespace clang {
25 
26 class LangOptions;
27 class SourceManager;
28 
29 /// Rewriter - This is the main interface to the rewrite buffers. Its primary
30 /// job is to dispatch high-level requests to the low-level RewriteBuffers that
31 /// are involved.
32 class Rewriter {
33  SourceManager *SourceMgr = nullptr;
34  const LangOptions *LangOpts = nullptr;
35  std::map<FileID, RewriteBuffer> RewriteBuffers;
36 
37 public:
38  struct RewriteOptions {
39  /// Given a source range, true to include previous inserts at the
40  /// beginning of the range as part of the range itself (true by default).
42 
43  /// Given a source range, true to include previous inserts at the
44  /// end of the range as part of the range itself (true by default).
46 
47  /// If true and removing some text leaves a blank line
48  /// also remove the empty line (false by default).
49  ///
50  /// FIXME: This sometimes corrupts the file's rewrite buffer due to
51  /// incorrect indexing in the implementation (see the FIXME in
52  /// clang::RewriteBuffer::RemoveText). Moreover, it's inefficient because
53  /// it must scan the buffer from the beginning to find the start of the
54  /// line. When feasible, it's better for the caller to check for a blank
55  /// line and then, if found, expand the removal range to include it.
56  /// Checking for a blank line is easy if, for example, the caller can
57  /// guarantee this is the first edit of a line. In that case, it can just
58  /// scan before and after the removal range until the next newline or
59  /// begin/end of the input.
60  bool RemoveLineIfEmpty = false;
61 
63  };
64 
65  using buffer_iterator = std::map<FileID, RewriteBuffer>::iterator;
66  using const_buffer_iterator = std::map<FileID, RewriteBuffer>::const_iterator;
67 
68  explicit Rewriter() = default;
69  explicit Rewriter(SourceManager &SM, const LangOptions &LO)
70  : SourceMgr(&SM), LangOpts(&LO) {}
71 
73  SourceMgr = &SM;
74  LangOpts = &LO;
75  }
76 
77  SourceManager &getSourceMgr() const { return *SourceMgr; }
78  const LangOptions &getLangOpts() const { return *LangOpts; }
79 
80  /// isRewritable - Return true if this location is a raw file location, which
81  /// is rewritable. Locations from macros, etc are not rewritable.
82  static bool isRewritable(SourceLocation Loc) {
83  return Loc.isFileID();
84  }
85 
86  /// getRangeSize - Return the size in bytes of the specified range if they
87  /// are in the same file. If not, this returns -1.
88  int getRangeSize(SourceRange Range,
89  RewriteOptions opts = RewriteOptions()) const;
90  int getRangeSize(const CharSourceRange &Range,
91  RewriteOptions opts = RewriteOptions()) const;
92 
93  /// getRewrittenText - Return the rewritten form of the text in the specified
94  /// range. If the start or end of the range was unrewritable or if they are
95  /// in different buffers, this returns an empty string.
96  ///
97  /// Note that this method is not particularly efficient.
98  std::string getRewrittenText(CharSourceRange Range) const;
99 
100  /// getRewrittenText - Return the rewritten form of the text in the specified
101  /// range. If the start or end of the range was unrewritable or if they are
102  /// in different buffers, this returns an empty string.
103  ///
104  /// Note that this method is not particularly efficient.
105  std::string getRewrittenText(SourceRange Range) const {
107  }
108 
109  /// InsertText - Insert the specified string at the specified location in the
110  /// original buffer. This method returns true (and does nothing) if the input
111  /// location was not rewritable, false otherwise.
112  ///
113  /// \param indentNewLines if true new lines in the string are indented
114  /// using the indentation of the source line in position \p Loc.
115  bool InsertText(SourceLocation Loc, StringRef Str,
116  bool InsertAfter = true, bool indentNewLines = false);
117 
118  /// InsertTextAfter - Insert the specified string at the specified location in
119  /// the original buffer. This method returns true (and does nothing) if
120  /// the input location was not rewritable, false otherwise. Text is
121  /// inserted after any other text that has been previously inserted
122  /// at the some point (the default behavior for InsertText).
123  bool InsertTextAfter(SourceLocation Loc, StringRef Str) {
124  return InsertText(Loc, Str);
125  }
126 
127  /// Insert the specified string after the token in the
128  /// specified location.
129  bool InsertTextAfterToken(SourceLocation Loc, StringRef Str);
130 
131  /// InsertText - Insert the specified string at the specified location in the
132  /// original buffer. This method returns true (and does nothing) if the input
133  /// location was not rewritable, false otherwise. Text is
134  /// inserted before any other text that has been previously inserted
135  /// at the some point.
136  bool InsertTextBefore(SourceLocation Loc, StringRef Str) {
137  return InsertText(Loc, Str, false);
138  }
139 
140  /// RemoveText - Remove the specified text region.
141  bool RemoveText(SourceLocation Start, unsigned Length,
142  RewriteOptions opts = RewriteOptions());
143 
144  /// Remove the specified text region.
146  RewriteOptions opts = RewriteOptions()) {
147  return RemoveText(range.getBegin(), getRangeSize(range, opts), opts);
148  }
149 
150  /// Remove the specified text region.
152  return RemoveText(range.getBegin(), getRangeSize(range, opts), opts);
153  }
154 
155  /// ReplaceText - This method replaces a range of characters in the input
156  /// buffer with a new string. This is effectively a combined "remove/insert"
157  /// operation.
158  bool ReplaceText(SourceLocation Start, unsigned OrigLength,
159  StringRef NewStr);
160 
161  /// ReplaceText - This method replaces a range of characters in the input
162  /// buffer with a new string. This is effectively a combined "remove/insert"
163  /// operation.
164  bool ReplaceText(CharSourceRange range, StringRef NewStr) {
165  return ReplaceText(range.getBegin(), getRangeSize(range), NewStr);
166  }
167 
168  /// ReplaceText - This method replaces a range of characters in the input
169  /// buffer with a new string. This is effectively a combined "remove/insert"
170  /// operation.
171  bool ReplaceText(SourceRange range, StringRef NewStr) {
172  return ReplaceText(range.getBegin(), getRangeSize(range), NewStr);
173  }
174 
175  /// ReplaceText - This method replaces a range of characters in the input
176  /// buffer with a new string. This is effectively a combined "remove/insert"
177  /// operation.
178  bool ReplaceText(SourceRange range, SourceRange replacementRange);
179 
180  /// Increase indentation for the lines between the given source range.
181  /// To determine what the indentation should be, 'parentIndent' is used
182  /// that should be at a source location with an indentation one degree
183  /// lower than the given range.
184  bool IncreaseIndentation(CharSourceRange range, SourceLocation parentIndent);
185  bool IncreaseIndentation(SourceRange range, SourceLocation parentIndent) {
187  parentIndent);
188  }
189 
190  /// getEditBuffer - This is like getRewriteBufferFor, but always returns a
191  /// buffer, and allows you to write on it directly. This is useful if you
192  /// want efficient low-level access to apis for scribbling on one specific
193  /// FileID's buffer.
195 
196  /// getRewriteBufferFor - Return the rewrite buffer for the specified FileID.
197  /// If no modification has been made to it, return null.
199  std::map<FileID, RewriteBuffer>::const_iterator I =
200  RewriteBuffers.find(FID);
201  return I == RewriteBuffers.end() ? nullptr : &I->second;
202  }
203 
204  // Iterators over rewrite buffers.
205  buffer_iterator buffer_begin() { return RewriteBuffers.begin(); }
206  buffer_iterator buffer_end() { return RewriteBuffers.end(); }
207  const_buffer_iterator buffer_begin() const { return RewriteBuffers.begin(); }
208  const_buffer_iterator buffer_end() const { return RewriteBuffers.end(); }
209 
210  /// overwriteChangedFiles - Save all changed files to disk.
211  ///
212  /// Returns true if any files were not saved successfully.
213  /// Outputs diagnostics via the source manager's diagnostic engine
214  /// in case of an error.
215  bool overwriteChangedFiles();
216 
217 private:
218  unsigned getLocationOffsetAndFileID(SourceLocation Loc, FileID &FID) const;
219 };
220 
221 } // namespace clang
222 
223 #endif // LLVM_CLANG_REWRITE_CORE_REWRITER_H
bool IncreaseIndentation(CharSourceRange range, SourceLocation parentIndent)
Increase indentation for the lines between the given source range.
Definition: Rewriter.cpp:344
std::map< FileID, RewriteBuffer >::const_iterator const_buffer_iterator
Definition: Rewriter.h:66
const_buffer_iterator buffer_end() const
Definition: Rewriter.h:208
static CharSourceRange getTokenRange(SourceRange R)
bool RemoveText(SourceLocation Start, unsigned Length, RewriteOptions opts=RewriteOptions())
RemoveText - Remove the specified text region.
Definition: Rewriter.cpp:308
RangeSelector range(RangeSelector Begin, RangeSelector End)
Selects from the start of Begin and to the end of End.
RewriteBuffer & getEditBuffer(FileID FID)
getEditBuffer - This is like getRewriteBufferFor, but always returns a buffer, and allows you to writ...
Definition: Rewriter.cpp:240
RewriteBuffer - As code is rewritten, SourceBuffer&#39;s from the original input with modifications get a...
Definition: RewriteBuffer.h:25
std::string getRewrittenText(CharSourceRange Range) const
getRewrittenText - Return the rewritten form of the text in the specified range.
Definition: Rewriter.cpp:184
iterator end() const
Definition: RewriteBuffer.h:38
SourceLocation getBegin() const
bool ReplaceText(SourceLocation Start, unsigned OrigLength, StringRef NewStr)
ReplaceText - This method replaces a range of characters in the input buffer with a new string...
Definition: Rewriter.cpp:320
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:49
std::string getRewrittenText(SourceRange Range) const
getRewrittenText - Return the rewritten form of the text in the specified range.
Definition: Rewriter.h:105
Rewriter(SourceManager &SM, const LangOptions &LO)
Definition: Rewriter.h:69
SourceManager & getSourceMgr() const
Definition: Rewriter.h:77
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
Rewriter()=default
buffer_iterator buffer_end()
Definition: Rewriter.h:206
Represents a character-granular source range.
bool RemoveText(SourceRange range, RewriteOptions opts=RewriteOptions())
Remove the specified text region.
Definition: Rewriter.h:151
bool IncreaseIndentation(SourceRange range, SourceLocation parentIndent)
Definition: Rewriter.h:185
int getRangeSize(SourceRange Range, RewriteOptions opts=RewriteOptions()) const
getRangeSize - Return the size in bytes of the specified range if they are in the same file...
Definition: Rewriter.cpp:175
bool overwriteChangedFiles()
overwriteChangedFiles - Save all changed files to disk.
Definition: Rewriter.cpp:465
const SourceManager & SM
Definition: Format.cpp:1667
const_buffer_iterator buffer_begin() const
Definition: Rewriter.h:207
void setSourceMgr(SourceManager &SM, const LangOptions &LO)
Definition: Rewriter.h:72
Encodes a location in the source.
bool InsertTextAfter(SourceLocation Loc, StringRef Str)
InsertTextAfter - Insert the specified string at the specified location in the original buffer...
Definition: Rewriter.h:123
const RewriteBuffer * getRewriteBufferFor(FileID FID) const
getRewriteBufferFor - Return the rewrite buffer for the specified FileID.
Definition: Rewriter.h:198
bool ReplaceText(SourceRange range, StringRef NewStr)
ReplaceText - This method replaces a range of characters in the input buffer with a new string...
Definition: Rewriter.h:171
bool InsertText(SourceLocation Loc, StringRef Str, bool InsertAfter=true, bool indentNewLines=false)
InsertText - Insert the specified string at the specified location in the original buffer...
Definition: Rewriter.cpp:255
bool RemoveLineIfEmpty
If true and removing some text leaves a blank line also remove the empty line (false by default)...
Definition: Rewriter.h:60
std::map< FileID, RewriteBuffer >::iterator buffer_iterator
Definition: Rewriter.h:65
bool InsertTextBefore(SourceLocation Loc, StringRef Str)
InsertText - Insert the specified string at the specified location in the original buffer...
Definition: Rewriter.h:136
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
Dataflow Directional Tag Classes.
bool RemoveText(CharSourceRange range, RewriteOptions opts=RewriteOptions())
Remove the specified text region.
Definition: Rewriter.h:145
const LangOptions & getLangOpts() const
Definition: Rewriter.h:78
bool IncludeInsertsAtBeginOfRange
Given a source range, true to include previous inserts at the beginning of the range as part of the r...
Definition: Rewriter.h:41
buffer_iterator buffer_begin()
Definition: Rewriter.h:205
Rewriter - This is the main interface to the rewrite buffers.
Definition: Rewriter.h:32
Defines the clang::SourceLocation class and associated facilities.
static bool isRewritable(SourceLocation Loc)
isRewritable - Return true if this location is a raw file location, which is rewritable.
Definition: Rewriter.h:82
bool ReplaceText(CharSourceRange range, StringRef NewStr)
ReplaceText - This method replaces a range of characters in the input buffer with a new string...
Definition: Rewriter.h:164
A trivial tuple used to represent a source range.
bool InsertTextAfterToken(SourceLocation Loc, StringRef Str)
Insert the specified string after the token in the specified location.
Definition: Rewriter.cpp:296
SourceLocation getBegin() const
This class handles loading and caching of source files into memory.
bool IncludeInsertsAtEndOfRange
Given a source range, true to include previous inserts at the end of the range as part of the range i...
Definition: Rewriter.h:45