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1//===- Replacement.h - Framework for clang refactoring tools ----*- 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// Classes supporting refactorings that span multiple translation units.
10// While single translation unit refactorings are supported via the Rewriter,
11// when refactoring multiple translation units changes must be stored in a
12// SourceManager independent form, duplicate changes need to be removed, and
13// all changes must be applied at once at the end of the refactoring so that
14// the code is always parseable.
15//
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_CLANG_TOOLING_CORE_REPLACEMENT_H
19#define LLVM_CLANG_TOOLING_CORE_REPLACEMENT_H
20
21#include "clang/Basic/LangOptions.h"
22#include "clang/Basic/SourceLocation.h"
23#include "llvm/ADT/Optional.h"
24#include "llvm/ADT/StringRef.h"
25#include "llvm/Support/Compiler.h"
26#include "llvm/Support/Error.h"
27#include "llvm/Support/raw_ostream.h"
28#include <map>
29#include <set>
30#include <string>
31#include <system_error>
32#include <utility>
33#include <vector>
34
35namespace clang {
36
37class FileManager;
38class Rewriter;
39class SourceManager;
40
41namespace tooling {
42
43/// A source range independent of the \c SourceManager.
44class Range {
45public:
46 Range() = default;
47 Range(unsigned Offset, unsigned Length) : Offset(Offset), Length(Length) {}
48
49 /// Accessors.
50 /// @{
51 unsigned getOffset() const { return Offset; }
52 unsigned getLength() const { return Length; }
53 /// @}
54
55 /// \name Range Predicates
56 /// @{
57 /// Whether this range overlaps with \p RHS or not.
58 bool overlapsWith(Range RHS) const {
59 return Offset + Length > RHS.Offset && Offset < RHS.Offset + RHS.Length;
60 }
61
62 /// Whether this range contains \p RHS or not.
63 bool contains(Range RHS) const {
64 return RHS.Offset >= Offset &&
65 (RHS.Offset + RHS.Length) <= (Offset + Length);
66 }
67
68 /// Whether this range equals to \p RHS or not.
69 bool operator==(const Range &RHS) const {
70 return Offset == RHS.getOffset() && Length == RHS.getLength();
71 }
72 /// @}
73
74private:
75 unsigned Offset = 0;
76 unsigned Length = 0;
77};
78
79/// A text replacement.
80///
81/// Represents a SourceManager independent replacement of a range of text in a
82/// specific file.
83class Replacement {
84public:
85 /// Creates an invalid (not applicable) replacement.
86 Replacement();
87
88 /// Creates a replacement of the range [Offset, Offset+Length) in
89 /// FilePath with ReplacementText.
90 ///
91 /// \param FilePath A source file accessible via a SourceManager.
92 /// \param Offset The byte offset of the start of the range in the file.
93 /// \param Length The length of the range in bytes.
94 Replacement(StringRef FilePath, unsigned Offset, unsigned Length,
95 StringRef ReplacementText);
96
97 /// Creates a Replacement of the range [Start, Start+Length) with
98 /// ReplacementText.
99 Replacement(const SourceManager &Sources, SourceLocation Start,
100 unsigned Length, StringRef ReplacementText);
101
102 /// Creates a Replacement of the given range with ReplacementText.
103 Replacement(const SourceManager &Sources, const CharSourceRange &Range,
104 StringRef ReplacementText,
105 const LangOptions &LangOpts = LangOptions());
106
107 /// Creates a Replacement of the node with ReplacementText.
108 template <typename Node>
109 Replacement(const SourceManager &Sources, const Node &NodeToReplace,
110 StringRef ReplacementText,
111 const LangOptions &LangOpts = LangOptions());
112
113 /// Returns whether this replacement can be applied to a file.
114 ///
115 /// Only replacements that are in a valid file can be applied.
116 bool isApplicable() const;
117
118 /// Accessors.
119 /// @{
120 StringRef getFilePath() const { return FilePath; }
121 unsigned getOffset() const { return ReplacementRange.getOffset(); }
122 unsigned getLength() const { return ReplacementRange.getLength(); }
123 StringRef getReplacementText() const { return ReplacementText; }
124 /// @}
125
126 /// Applies the replacement on the Rewriter.
127 bool apply(Rewriter &Rewrite) const;
128
129 /// Returns a human readable string representation.
130 std::string toString() const;
131
132private:
133 void setFromSourceLocation(const SourceManager &Sources, SourceLocation Start,
134 unsigned Length, StringRef ReplacementText);
135 void setFromSourceRange(const SourceManager &Sources,
136 const CharSourceRange &Range,
137 StringRef ReplacementText,
138 const LangOptions &LangOpts);
139
140 std::string FilePath;
141 Range ReplacementRange;
142 std::string ReplacementText;
143};
144
145enum class replacement_error {
146 fail_to_apply = 0,
147 wrong_file_path,
148 overlap_conflict,
149 insert_conflict,
150};
151
152/// Carries extra error information in replacement-related llvm::Error,
153/// e.g. fail applying replacements and replacements conflict.
154class ReplacementError : public llvm::ErrorInfo<ReplacementError> {
155public:
156 ReplacementError(replacement_error Err) : Err(Err) {}
157
158 /// Constructs an error related to an existing replacement.
159 ReplacementError(replacement_error Err, Replacement Existing)
160 : Err(Err), ExistingReplacement(std::move(Existing)) {}
161
162 /// Constructs an error related to a new replacement and an existing
163 /// replacement in a set of replacements.
164 ReplacementError(replacement_error Err, Replacement New, Replacement Existing)
165 : Err(Err), NewReplacement(std::move(New)),
166 ExistingReplacement(std::move(Existing)) {}
167
168 std::string message() const override;
169
170 void log(raw_ostream &OS) const override { OS << message(); }
171
172 replacement_error get() const { return Err; }
173
174 static char ID;
175
176 const llvm::Optional<Replacement> &getNewReplacement() const {
177 return NewReplacement;
178 }
179
180 const llvm::Optional<Replacement> &getExistingReplacement() const {
181 return ExistingReplacement;
182 }
183
184private:
185 // Users are not expected to use error_code.
186 std::error_code convertToErrorCode() const override {
187 return llvm::inconvertibleErrorCode();
188 }
189
190 replacement_error Err;
191
192 // A new replacement, which is to expected be added into a set of
193 // replacements, that is causing problem.
194 llvm::Optional<Replacement> NewReplacement;
195
196 // An existing replacement in a replacements set that is causing problem.
197 llvm::Optional<Replacement> ExistingReplacement;
198};
199
200/// Less-than operator between two Replacements.
201bool operator<(const Replacement &LHS, const Replacement &RHS);
202
203/// Equal-to operator between two Replacements.
204bool operator==(const Replacement &LHS, const Replacement &RHS);
205
206/// Maintains a set of replacements that are conflict-free.
207/// Two replacements are considered conflicts if they overlap or have the same
208/// offset (i.e. order-dependent).
209class Replacements {
210private:
211 using ReplacementsImpl = std::set<Replacement>;
212
213public:
214 using const_iterator = ReplacementsImpl::const_iterator;
215 using const_reverse_iterator = ReplacementsImpl::const_reverse_iterator;
216
217 Replacements() = default;
218
219 explicit Replacements(const Replacement &R) { Replaces.insert(R); }
220
221 /// Adds a new replacement \p R to the current set of replacements.
222 /// \p R must have the same file path as all existing replacements.
223 /// Returns `success` if the replacement is successfully inserted; otherwise,
224 /// it returns an llvm::Error, i.e. there is a conflict between R and the
225 /// existing replacements (i.e. they are order-dependent) or R's file path is
226 /// different from the filepath of existing replacements. Callers must
227 /// explicitly check the Error returned, and the returned error can be
228 /// converted to a string message with `llvm::toString()`. This prevents users
229 /// from adding order-dependent replacements. To control the order in which
230 /// order-dependent replacements are applied, use merge({R}) with R referring
231 /// to the changed code after applying all existing replacements.
232 /// Two replacements A and B are considered order-independent if applying them
233 /// in either order produces the same result. Note that the range of the
234 /// replacement that is applied later still refers to the original code.
235 /// These include (but not restricted to) replacements that:
236 /// - don't overlap (being directly adjacent is fine) and
237 /// - are overlapping deletions.
238 /// - are insertions at the same offset and applying them in either order
239 /// has the same effect, i.e. X + Y = Y + X when inserting X and Y
240 /// respectively.
241 /// - are identical replacements, i.e. applying the same replacement twice
242 /// is equivalent to applying it once.
243 /// Examples:
244 /// 1. Replacement A(0, 0, "a") and B(0, 0, "aa") are order-independent since
245 /// applying them in either order gives replacement (0, 0, "aaa").
246 /// However, A(0, 0, "a") and B(0, 0, "b") are order-dependent since
247 /// applying A first gives (0, 0, "ab") while applying B first gives (B, A,
248 /// "ba").
249 /// 2. Replacement A(0, 2, "123") and B(0, 2, "123") are order-independent
250 /// since applying them in either order gives (0, 2, "123").
251 /// 3. Replacement A(0, 3, "123") and B(2, 3, "321") are order-independent
252 /// since either order gives (0, 5, "12321").
253 /// 4. Replacement A(0, 3, "ab") and B(0, 3, "ab") are order-independent since
254 /// applying the same replacement twice is equivalent to applying it once.
255 /// Replacements with offset UINT_MAX are special - we do not detect conflicts
256 /// for such replacements since users may add them intentionally as a special
257 /// category of replacements.
258 llvm::Error add(const Replacement &R);
259
260 /// Merges \p Replaces into the current replacements. \p Replaces
261 /// refers to code after applying the current replacements.
262 [[nodiscard]] Replacements merge(const Replacements &Replaces) const;
263
264 // Returns the affected ranges in the changed code.
265 std::vector<Range> getAffectedRanges() const;
266
267 // Returns the new offset in the code after replacements being applied.
268 // Note that if there is an insertion at Offset in the current replacements,
269 // \p Offset will be shifted to Offset + Length in inserted text.
270 unsigned getShiftedCodePosition(unsigned Position) const;
271
272 unsigned size() const { return Replaces.size(); }
273
274 void clear() { Replaces.clear(); }
275
276 bool empty() const { return Replaces.empty(); }
277
278 const_iterator begin() const { return Replaces.begin(); }
279
280 const_iterator end() const { return Replaces.end(); }
281
282 const_reverse_iterator rbegin() const { return Replaces.rbegin(); }
283
284 const_reverse_iterator rend() const { return Replaces.rend(); }
285
286 bool operator==(const Replacements &RHS) const {
287 return Replaces == RHS.Replaces;
288 }
289
290private:
291 Replacements(const_iterator Begin, const_iterator End)
292 : Replaces(Begin, End) {}
293
294 // Returns `R` with new range that refers to code after `Replaces` being
295 // applied.
296 Replacement getReplacementInChangedCode(const Replacement &R) const;
297
298 // Returns a set of replacements that is equivalent to the current
299 // replacements by merging all adjacent replacements. Two sets of replacements
300 // are considered equivalent if they have the same effect when they are
301 // applied.
302 Replacements getCanonicalReplacements() const;
303
304 // If `R` and all existing replacements are order-independent, then merge it
305 // with `Replaces` and returns the merged replacements; otherwise, returns an
306 // error.
307 llvm::Expected<Replacements>
308 mergeIfOrderIndependent(const Replacement &R) const;
309
310 ReplacementsImpl Replaces;
311};
312
313/// Apply all replacements in \p Replaces to the Rewriter \p Rewrite.
314///
315/// Replacement applications happen independently of the success of
316/// other applications.
317///
318/// \returns true if all replacements apply. false otherwise.
319bool applyAllReplacements(const Replacements &Replaces, Rewriter &Rewrite);
320
321/// Applies all replacements in \p Replaces to \p Code.
322///
323/// This completely ignores the path stored in each replacement. If all
324/// replacements are applied successfully, this returns the code with
325/// replacements applied; otherwise, an llvm::Error carrying llvm::StringError
326/// is returned (the Error message can be converted to string using
327/// `llvm::toString()` and 'std::error_code` in the `Error` should be ignored).
328llvm::Expected<std::string> applyAllReplacements(StringRef Code,
329 const Replacements &Replaces);
330
331/// Collection of Replacements generated from a single translation unit.
332struct TranslationUnitReplacements {
333 /// Name of the main source for the translation unit.
334 std::string MainSourceFile;
335
336 std::vector<Replacement> Replacements;
337};
338
339/// Calculates the new ranges after \p Replaces are applied. These
340/// include both the original \p Ranges and the affected ranges of \p Replaces
341/// in the new code.
342///
343/// \pre Replacements must be for the same file.
344///
345/// \return The new ranges after \p Replaces are applied. The new ranges will be
346/// sorted and non-overlapping.
347std::vector<Range>
348calculateRangesAfterReplacements(const Replacements &Replaces,
349 const std::vector<Range> &Ranges);
350
351/// If there are multiple <File, Replacements> pairs with the same file
352/// entry, we only keep one pair and discard the rest.
353/// If a file does not exist, its corresponding replacements will be ignored.
354std::map<std::string, Replacements> groupReplacementsByFile(
355 FileManager &FileMgr,
356 const std::map<std::string, Replacements> &FileToReplaces);
357
358template <typename Node>
359Replacement::Replacement(const SourceManager &Sources,
360 const Node &NodeToReplace, StringRef ReplacementText,
361 const LangOptions &LangOpts) {
362 const CharSourceRange Range =
363 CharSourceRange::getTokenRange(NodeToReplace->getSourceRange());
364 setFromSourceRange(Sources, Range, ReplacementText, LangOpts);
365}
366
367} // namespace tooling
368
369} // namespace clang
370
371#endif // LLVM_CLANG_TOOLING_CORE_REPLACEMENT_H
372

Warning: This file is not a C or C++ file. It does not have highlighting.

source code of clang/include/clang/Tooling/Core/Replacement.h