| 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" |
| 13 | #include "clang/Rewrite/Core/DeltaTree.h" |
| 14 | #include "clang/Rewrite/Core/RewriteRope.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. |
| 25 | class RewriteBuffer { |
| 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: |
| 35 | using iterator = RewriteRope::const_iterator; |
| 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 |
| 118 |