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RewriteBuffer.h
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1 //===- RewriteBuffer.h - Buffer 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 #ifndef LLVM_CLANG_REWRITE_CORE_REWRITEBUFFER_H
10 #define LLVM_CLANG_REWRITE_CORE_REWRITEBUFFER_H
11 
12 #include "clang/Basic/LLVM.h"
15 #include "llvm/ADT/StringRef.h"
16 
17 namespace clang {
18 
19 /// RewriteBuffer - As code is rewritten, SourceBuffer's from the original
20 /// input with modifications get a new RewriteBuffer associated with them. The
21 /// RewriteBuffer captures the modified text itself as well as information used
22 /// to map between SourceLocation's in the original input and offsets in the
23 /// RewriteBuffer. For example, if text is inserted into the buffer, any
24 /// locations after the insertion point have to be mapped.
26  friend class Rewriter;
27 
28  /// Deltas - Keep track of all the deltas in the source code due to insertions
29  /// and deletions.
30  DeltaTree Deltas;
31 
32  RewriteRope Buffer;
33 
34 public:
36 
37  iterator begin() const { return Buffer.begin(); }
38  iterator end() const { return Buffer.end(); }
39  unsigned size() const { return Buffer.size(); }
40 
41  /// Initialize - Start this rewrite buffer out with a copy of the unmodified
42  /// input buffer.
43  void Initialize(const char *BufStart, const char *BufEnd) {
44  Buffer.assign(BufStart, BufEnd);
45  }
46  void Initialize(StringRef Input) {
47  Initialize(Input.begin(), Input.end());
48  }
49 
50  /// Write to \p Stream the result of applying all changes to the
51  /// original buffer.
52  /// Note that it isn't safe to use this function to overwrite memory mapped
53  /// files in-place (PR17960). Consider using a higher-level utility such as
54  /// Rewriter::overwriteChangedFiles() instead.
55  ///
56  /// The original buffer is not actually changed.
57  raw_ostream &write(raw_ostream &Stream) const;
58 
59  /// RemoveText - Remove the specified text.
60  void RemoveText(unsigned OrigOffset, unsigned Size,
61  bool removeLineIfEmpty = false);
62 
63  /// InsertText - Insert some text at the specified point, where the offset in
64  /// the buffer is specified relative to the original SourceBuffer. The
65  /// text is inserted after the specified location.
66  void InsertText(unsigned OrigOffset, StringRef Str,
67  bool InsertAfter = true);
68 
69 
70  /// InsertTextBefore - Insert some text before the specified point, where the
71  /// offset in the buffer is specified relative to the original
72  /// SourceBuffer. The text is inserted before the specified location. This is
73  /// method is the same as InsertText with "InsertAfter == false".
74  void InsertTextBefore(unsigned OrigOffset, StringRef Str) {
75  InsertText(OrigOffset, Str, false);
76  }
77 
78  /// InsertTextAfter - Insert some text at the specified point, where the
79  /// offset in the buffer is specified relative to the original SourceBuffer.
80  /// The text is inserted after the specified location.
81  void InsertTextAfter(unsigned OrigOffset, StringRef Str) {
82  InsertText(OrigOffset, Str);
83  }
84 
85  /// ReplaceText - This method replaces a range of characters in the input
86  /// buffer with a new string. This is effectively a combined "remove/insert"
87  /// operation.
88  void ReplaceText(unsigned OrigOffset, unsigned OrigLength,
89  StringRef NewStr);
90 
91 private:
92  /// getMappedOffset - Given an offset into the original SourceBuffer that this
93  /// RewriteBuffer is based on, map it into the offset space of the
94  /// RewriteBuffer. If AfterInserts is true and if the OrigOffset indicates a
95  /// position where text is inserted, the location returned will be after any
96  /// inserted text at the position.
97  unsigned getMappedOffset(unsigned OrigOffset,
98  bool AfterInserts = false) const{
99  return Deltas.getDeltaAt(2*OrigOffset+AfterInserts)+OrigOffset;
100  }
101 
102  /// AddInsertDelta - When an insertion is made at a position, this
103  /// method is used to record that information.
104  void AddInsertDelta(unsigned OrigOffset, int Change) {
105  return Deltas.AddDelta(2*OrigOffset, Change);
106  }
107 
108  /// AddReplaceDelta - When a replacement/deletion is made at a position, this
109  /// method is used to record that information.
110  void AddReplaceDelta(unsigned OrigOffset, int Change) {
111  return Deltas.AddDelta(2*OrigOffset+1, Change);
112  }
113 };
114 
115 } // namespace clang
116 
117 #endif // LLVM_CLANG_REWRITE_CORE_REWRITEBUFFER_H
void AddDelta(unsigned FileIndex, int Delta)
AddDelta - When a change is made that shifts around the text buffer, this method is used to record th...
Definition: DeltaTree.cpp:455
void Initialize(StringRef Input)
Definition: RewriteBuffer.h:46
RewriteRope - A powerful string class.
Definition: RewriteRope.h:166
void Initialize(const char *BufStart, const char *BufEnd)
Initialize - Start this rewrite buffer out with a copy of the unmodified input buffer.
Definition: RewriteBuffer.h:43
RewriteBuffer - As code is rewritten, SourceBuffer's from the original input with modifications get a...
Definition: RewriteBuffer.h:25
iterator end() const
Definition: RewriteBuffer.h:38
RopePieceBTree::iterator const_iterator
Definition: RewriteRope.h:180
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
iterator end() const
Definition: RewriteRope.h:183
iterator begin() const
Definition: RewriteRope.h:182
void InsertTextAfter(unsigned OrigOffset, StringRef Str)
InsertTextAfter - Insert some text at the specified point, where the offset in the buffer is specifie...
Definition: RewriteBuffer.h:81
int getDeltaAt(unsigned FileIndex) const
getDeltaAt - Return the accumulated delta at the specified file offset.
Definition: DeltaTree.cpp:408
void InsertText(unsigned OrigOffset, StringRef Str, bool InsertAfter=true)
InsertText - Insert some text at the specified point, where the offset in the buffer is specified rel...
Definition: Rewriter.cpp:104
iterator begin() const
Definition: RewriteBuffer.h:37
DeltaTree - a multiway search tree (BTree) structure with some fancy features.
Definition: DeltaTree.h:25
void ReplaceText(unsigned OrigOffset, unsigned OrigLength, StringRef NewStr)
ReplaceText - This method replaces a range of characters in the input buffer with a new string...
Definition: Rewriter.cpp:119
raw_ostream & write(raw_ostream &Stream) const
Write to Stream the result of applying all changes to the original buffer.
Definition: Rewriter.cpp:37
unsigned size() const
Definition: RewriteRope.h:184
void RemoveText(unsigned OrigOffset, unsigned Size, bool removeLineIfEmpty=false)
RemoveText - Remove the specified text.
Definition: Rewriter.cpp:61
void InsertTextBefore(unsigned OrigOffset, StringRef Str)
InsertTextBefore - Insert some text before the specified point, where the offset in the buffer is spe...
Definition: RewriteBuffer.h:74
Dataflow Directional Tag Classes.
RopePieceBTreeIterator - This class provides read-only forward iteration over bytes that are in a Rop...
Definition: RewriteRope.h:86
void assign(const char *Start, const char *End)
Definition: RewriteRope.h:190
unsigned size() const
Definition: RewriteBuffer.h:39
Rewriter - This is the main interface to the rewrite buffers.
Definition: Rewriter.h:32