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"
18#include "clang/Basic/SourceLocation.h"
19#include "clang/Rewrite/Core/RewriteBuffer.h"
20#include "llvm/ADT/StringRef.h"
21#include <map>
22#include <string>
23
24namespace clang {
25
26class LangOptions;
27class 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.
32class Rewriter {
33 SourceManager *SourceMgr = nullptr;
34 const LangOptions *LangOpts = nullptr;
35 std::map<FileID, RewriteBuffer> RewriteBuffers;
36
37public:
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).
41 bool IncludeInsertsAtBeginOfRange = true;
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).
45 bool IncludeInsertsAtEndOfRange = true;
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
62 RewriteOptions() {}
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
72 void setSourceMgr(SourceManager &SM, const LangOptions &LO) {
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 {
106 return getRewrittenText(CharSourceRange::getTokenRange(Range));
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.
145 bool RemoveText(CharSourceRange range,
146 RewriteOptions opts = RewriteOptions()) {
147 return RemoveText(range.getBegin(), getRangeSize(range, opts), opts);
148 }
149
150 /// Remove the specified text region.
151 bool RemoveText(SourceRange range, RewriteOptions opts = RewriteOptions()) {
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) {
186 return IncreaseIndentation(CharSourceRange::getTokenRange(range),
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.
194 RewriteBuffer &getEditBuffer(FileID FID);
195
196 /// getRewriteBufferFor - Return the rewrite buffer for the specified FileID.
197 /// If no modification has been made to it, return null.
198 const RewriteBuffer *getRewriteBufferFor(FileID FID) const {
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
217private:
218 unsigned getLocationOffsetAndFileID(SourceLocation Loc, FileID &FID) const;
219};
220
221} // namespace clang
222
223#endif // LLVM_CLANG_REWRITE_CORE_REWRITER_H
224