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 "llvm/ADT/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, llvm::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 /// llvm::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, llvm::RewriteBuffer>::iterator;
66 using const_buffer_iterator =
67 std::map<FileID, llvm::RewriteBuffer>::const_iterator;
68
69 explicit Rewriter() = default;
70 explicit Rewriter(SourceManager &SM, const LangOptions &LO)
71 : SourceMgr(&SM), LangOpts(&LO) {}
72
73 void setSourceMgr(SourceManager &SM, const LangOptions &LO) {
74 SourceMgr = &SM;
75 LangOpts = &LO;
76 }
77
78 SourceManager &getSourceMgr() const { return *SourceMgr; }
79 const LangOptions &getLangOpts() const { return *LangOpts; }
80
81 /// isRewritable - Return true if this location is a raw file location, which
82 /// is rewritable. Locations from macros, etc are not rewritable.
83 static bool isRewritable(SourceLocation Loc) {
84 return Loc.isFileID();
85 }
86
87 /// getRangeSize - Return the size in bytes of the specified range if they
88 /// are in the same file. If not, this returns -1.
89 int getRangeSize(SourceRange Range,
90 RewriteOptions opts = RewriteOptions()) const;
91 int getRangeSize(const CharSourceRange &Range,
92 RewriteOptions opts = RewriteOptions()) const;
93
94 /// getRewrittenText - Return the rewritten form of the text in the specified
95 /// range. If the start or end of the range was unrewritable or if they are
96 /// in different buffers, this returns an empty string.
97 ///
98 /// Note that this method is not particularly efficient.
99 std::string getRewrittenText(CharSourceRange Range) const;
100
101 /// getRewrittenText - Return the rewritten form of the text in the specified
102 /// range. If the start or end of the range was unrewritable or if they are
103 /// in different buffers, this returns an empty string.
104 ///
105 /// Note that this method is not particularly efficient.
106 std::string getRewrittenText(SourceRange Range) const {
107 return getRewrittenText(Range: CharSourceRange::getTokenRange(R: Range));
108 }
109
110 /// InsertText - Insert the specified string at the specified location in the
111 /// original buffer. This method returns true (and does nothing) if the input
112 /// location was not rewritable, false otherwise.
113 ///
114 /// \param indentNewLines if true new lines in the string are indented
115 /// using the indentation of the source line in position \p Loc.
116 bool InsertText(SourceLocation Loc, StringRef Str,
117 bool InsertAfter = true, bool indentNewLines = false);
118
119 /// InsertTextAfter - Insert the specified string at the specified location in
120 /// the original buffer. This method returns true (and does nothing) if
121 /// the input location was not rewritable, false otherwise. Text is
122 /// inserted after any other text that has been previously inserted
123 /// at the some point (the default behavior for InsertText).
124 bool InsertTextAfter(SourceLocation Loc, StringRef Str) {
125 return InsertText(Loc, Str);
126 }
127
128 /// Insert the specified string after the token in the
129 /// specified location.
130 bool InsertTextAfterToken(SourceLocation Loc, StringRef Str);
131
132 /// InsertText - Insert the specified string at the specified location in the
133 /// original buffer. This method returns true (and does nothing) if the input
134 /// location was not rewritable, false otherwise. Text is
135 /// inserted before any other text that has been previously inserted
136 /// at the some point.
137 bool InsertTextBefore(SourceLocation Loc, StringRef Str) {
138 return InsertText(Loc, Str, InsertAfter: false);
139 }
140
141 /// RemoveText - Remove the specified text region.
142 bool RemoveText(SourceLocation Start, unsigned Length,
143 RewriteOptions opts = RewriteOptions());
144
145 /// Remove the specified text region.
146 bool RemoveText(CharSourceRange range,
147 RewriteOptions opts = RewriteOptions()) {
148 return RemoveText(Start: range.getBegin(), Length: getRangeSize(Range: range, opts), opts);
149 }
150
151 /// Remove the specified text region.
152 bool RemoveText(SourceRange range, RewriteOptions opts = RewriteOptions()) {
153 return RemoveText(Start: range.getBegin(), Length: getRangeSize(Range: range, opts), opts);
154 }
155
156 /// ReplaceText - This method replaces a range of characters in the input
157 /// buffer with a new string. This is effectively a combined "remove/insert"
158 /// operation.
159 bool ReplaceText(SourceLocation Start, unsigned OrigLength,
160 StringRef NewStr);
161
162 /// ReplaceText - This method replaces a range of characters in the input
163 /// buffer with a new string. This is effectively a combined "remove/insert"
164 /// operation.
165 bool ReplaceText(CharSourceRange range, StringRef NewStr) {
166 return ReplaceText(Start: range.getBegin(), OrigLength: getRangeSize(Range: range), NewStr);
167 }
168
169 /// ReplaceText - This method replaces a range of characters in the input
170 /// buffer with a new string. This is effectively a combined "remove/insert"
171 /// operation.
172 bool ReplaceText(SourceRange range, StringRef NewStr) {
173 return ReplaceText(Start: range.getBegin(), OrigLength: getRangeSize(Range: range), NewStr);
174 }
175
176 /// ReplaceText - This method replaces a range of characters in the input
177 /// buffer with a new string. This is effectively a combined "remove/insert"
178 /// operation.
179 bool ReplaceText(SourceRange range, SourceRange replacementRange);
180
181 /// Increase indentation for the lines between the given source range.
182 /// To determine what the indentation should be, 'parentIndent' is used
183 /// that should be at a source location with an indentation one degree
184 /// lower than the given range.
185 bool IncreaseIndentation(CharSourceRange range, SourceLocation parentIndent);
186 bool IncreaseIndentation(SourceRange range, SourceLocation parentIndent) {
187 return IncreaseIndentation(range: CharSourceRange::getTokenRange(R: range),
188 parentIndent);
189 }
190
191 /// getEditBuffer - This is like getRewriteBufferFor, but always returns a
192 /// buffer, and allows you to write on it directly. This is useful if you
193 /// want efficient low-level access to apis for scribbling on one specific
194 /// FileID's buffer.
195 llvm::RewriteBuffer &getEditBuffer(FileID FID);
196
197 /// getRewriteBufferFor - Return the rewrite buffer for the specified FileID.
198 /// If no modification has been made to it, return null.
199 const llvm::RewriteBuffer *getRewriteBufferFor(FileID FID) const {
200 std::map<FileID, llvm::RewriteBuffer>::const_iterator I =
201 RewriteBuffers.find(x: FID);
202 return I == RewriteBuffers.end() ? nullptr : &I->second;
203 }
204
205 // Iterators over rewrite buffers.
206 buffer_iterator buffer_begin() { return RewriteBuffers.begin(); }
207 buffer_iterator buffer_end() { return RewriteBuffers.end(); }
208 const_buffer_iterator buffer_begin() const { return RewriteBuffers.begin(); }
209 const_buffer_iterator buffer_end() const { return RewriteBuffers.end(); }
210
211 /// overwriteChangedFiles - Save all changed files to disk.
212 ///
213 /// Returns true if any files were not saved successfully.
214 /// Outputs diagnostics via the source manager's diagnostic engine
215 /// in case of an error.
216 bool overwriteChangedFiles();
217
218private:
219 unsigned getLocationOffsetAndFileID(SourceLocation Loc, FileID &FID) const;
220};
221
222} // namespace clang
223
224#endif // LLVM_CLANG_REWRITE_CORE_REWRITER_H
225