LLVM 17.0.0git
StringRef.h
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1//===- StringRef.h - Constant String Reference Wrapper ----------*- 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_ADT_STRINGREF_H
10#define LLVM_ADT_STRINGREF_H
11
16#include <algorithm>
17#include <cassert>
18#include <cstddef>
19#include <cstring>
20#include <limits>
21#include <string>
22#include <string_view>
23#include <type_traits>
24#include <utility>
25
26namespace llvm {
27
28 class APInt;
29 class hash_code;
30 template <typename T> class SmallVectorImpl;
31 class StringRef;
32
33 /// Helper functions for StringRef::getAsInteger.
34 bool getAsUnsignedInteger(StringRef Str, unsigned Radix,
35 unsigned long long &Result);
36
37 bool getAsSignedInteger(StringRef Str, unsigned Radix, long long &Result);
38
39 bool consumeUnsignedInteger(StringRef &Str, unsigned Radix,
40 unsigned long long &Result);
41 bool consumeSignedInteger(StringRef &Str, unsigned Radix, long long &Result);
42
43 /// StringRef - Represent a constant reference to a string, i.e. a character
44 /// array and a length, which need not be null terminated.
45 ///
46 /// This class does not own the string data, it is expected to be used in
47 /// situations where the character data resides in some other buffer, whose
48 /// lifetime extends past that of the StringRef. For this reason, it is not in
49 /// general safe to store a StringRef.
51 public:
52 static constexpr size_t npos = ~size_t(0);
53
54 using iterator = const char *;
55 using const_iterator = const char *;
56 using size_type = size_t;
57
58 private:
59 /// The start of the string, in an external buffer.
60 const char *Data = nullptr;
61
62 /// The length of the string.
63 size_t Length = 0;
64
65 // Workaround memcmp issue with null pointers (undefined behavior)
66 // by providing a specialized version
67 static int compareMemory(const char *Lhs, const char *Rhs, size_t Length) {
68 if (Length == 0) { return 0; }
69 return ::memcmp(Lhs,Rhs,Length);
70 }
71
72 public:
73 /// @name Constructors
74 /// @{
75
76 /// Construct an empty string ref.
77 /*implicit*/ StringRef() = default;
78
79 /// Disable conversion from nullptr. This prevents things like
80 /// if (S == nullptr)
81 StringRef(std::nullptr_t) = delete;
82
83 /// Construct a string ref from a cstring.
84 /*implicit*/ constexpr StringRef(const char *Str)
85 : Data(Str), Length(Str ?
86 // GCC 7 doesn't have constexpr char_traits. Fall back to __builtin_strlen.
87#if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE < 8
88 __builtin_strlen(Str)
89#else
90 std::char_traits<char>::length(Str)
91#endif
92 : 0) {
93 }
94
95 /// Construct a string ref from a pointer and length.
96 /*implicit*/ constexpr StringRef(const char *data, size_t length)
97 : Data(data), Length(length) {}
98
99 /// Construct a string ref from an std::string.
100 /*implicit*/ StringRef(const std::string &Str)
101 : Data(Str.data()), Length(Str.length()) {}
102
103 /// Construct a string ref from an std::string_view.
104 /*implicit*/ constexpr StringRef(std::string_view Str)
105 : Data(Str.data()), Length(Str.size()) {}
106
107 /// @}
108 /// @name Iterators
109 /// @{
110
111 iterator begin() const { return Data; }
112
113 iterator end() const { return Data + Length; }
114
115 const unsigned char *bytes_begin() const {
116 return reinterpret_cast<const unsigned char *>(begin());
117 }
118 const unsigned char *bytes_end() const {
119 return reinterpret_cast<const unsigned char *>(end());
120 }
122 return make_range(bytes_begin(), bytes_end());
123 }
124
125 /// @}
126 /// @name String Operations
127 /// @{
128
129 /// data - Get a pointer to the start of the string (which may not be null
130 /// terminated).
131 [[nodiscard]] const char *data() const { return Data; }
132
133 /// empty - Check if the string is empty.
134 [[nodiscard]] constexpr bool empty() const { return Length == 0; }
135
136 /// size - Get the string size.
137 [[nodiscard]] constexpr size_t size() const { return Length; }
138
139 /// front - Get the first character in the string.
140 [[nodiscard]] char front() const {
141 assert(!empty());
142 return Data[0];
143 }
144
145 /// back - Get the last character in the string.
146 [[nodiscard]] char back() const {
147 assert(!empty());
148 return Data[Length-1];
149 }
150
151 // copy - Allocate copy in Allocator and return StringRef to it.
152 template <typename Allocator>
153 [[nodiscard]] StringRef copy(Allocator &A) const {
154 // Don't request a length 0 copy from the allocator.
155 if (empty())
156 return StringRef();
157 char *S = A.template Allocate<char>(Length);
158 std::copy(begin(), end(), S);
159 return StringRef(S, Length);
160 }
161
162 /// equals - Check for string equality, this is more efficient than
163 /// compare() when the relative ordering of inequal strings isn't needed.
164 [[nodiscard]] bool equals(StringRef RHS) const {
165 return (Length == RHS.Length &&
166 compareMemory(Data, RHS.Data, RHS.Length) == 0);
167 }
168
169 /// Check for string equality, ignoring case.
170 [[nodiscard]] bool equals_insensitive(StringRef RHS) const {
171 return Length == RHS.Length && compare_insensitive(RHS) == 0;
172 }
173
174 /// compare - Compare two strings; the result is negative, zero, or positive
175 /// if this string is lexicographically less than, equal to, or greater than
176 /// the \p RHS.
177 [[nodiscard]] int compare(StringRef RHS) const {
178 // Check the prefix for a mismatch.
179 if (int Res = compareMemory(Data, RHS.Data, std::min(Length, RHS.Length)))
180 return Res < 0 ? -1 : 1;
181
182 // Otherwise the prefixes match, so we only need to check the lengths.
183 if (Length == RHS.Length)
184 return 0;
185 return Length < RHS.Length ? -1 : 1;
186 }
187
188 /// Compare two strings, ignoring case.
189 [[nodiscard]] int compare_insensitive(StringRef RHS) const;
190
191 /// compare_numeric - Compare two strings, treating sequences of digits as
192 /// numbers.
193 [[nodiscard]] int compare_numeric(StringRef RHS) const;
194
195 /// Determine the edit distance between this string and another
196 /// string.
197 ///
198 /// \param Other the string to compare this string against.
199 ///
200 /// \param AllowReplacements whether to allow character
201 /// replacements (change one character into another) as a single
202 /// operation, rather than as two operations (an insertion and a
203 /// removal).
204 ///
205 /// \param MaxEditDistance If non-zero, the maximum edit distance that
206 /// this routine is allowed to compute. If the edit distance will exceed
207 /// that maximum, returns \c MaxEditDistance+1.
208 ///
209 /// \returns the minimum number of character insertions, removals,
210 /// or (if \p AllowReplacements is \c true) replacements needed to
211 /// transform one of the given strings into the other. If zero,
212 /// the strings are identical.
213 [[nodiscard]] unsigned edit_distance(StringRef Other,
214 bool AllowReplacements = true,
215 unsigned MaxEditDistance = 0) const;
216
217 [[nodiscard]] unsigned
218 edit_distance_insensitive(StringRef Other, bool AllowReplacements = true,
219 unsigned MaxEditDistance = 0) const;
220
221 /// str - Get the contents as an std::string.
222 [[nodiscard]] std::string str() const {
223 if (!Data) return std::string();
224 return std::string(Data, Length);
225 }
226
227 /// @}
228 /// @name Operator Overloads
229 /// @{
230
231 [[nodiscard]] char operator[](size_t Index) const {
232 assert(Index < Length && "Invalid index!");
233 return Data[Index];
234 }
235
236 /// Disallow accidental assignment from a temporary std::string.
237 ///
238 /// The declaration here is extra complicated so that `stringRef = {}`
239 /// and `stringRef = "abc"` continue to select the move assignment operator.
240 template <typename T>
241 std::enable_if_t<std::is_same<T, std::string>::value, StringRef> &
242 operator=(T &&Str) = delete;
243
244 /// @}
245 /// @name Type Conversions
246 /// @{
247
248 operator std::string_view() const {
249 return std::string_view(data(), size());
250 }
251
252 /// @}
253 /// @name String Predicates
254 /// @{
255
256 /// Check if this string starts with the given \p Prefix.
257 [[nodiscard]] bool starts_with(StringRef Prefix) const {
258 return Length >= Prefix.Length &&
259 compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
260 }
261 [[nodiscard]] bool startswith(StringRef Prefix) const {
262 return starts_with(Prefix);
263 }
264
265 /// Check if this string starts with the given \p Prefix, ignoring case.
266 [[nodiscard]] bool starts_with_insensitive(StringRef Prefix) const;
267 [[nodiscard]] bool startswith_insensitive(StringRef Prefix) const {
268 return starts_with_insensitive(Prefix);
269 }
270
271 /// Check if this string ends with the given \p Suffix.
272 [[nodiscard]] bool ends_with(StringRef Suffix) const {
273 return Length >= Suffix.Length &&
274 compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) ==
275 0;
276 }
277 [[nodiscard]] bool endswith(StringRef Suffix) const {
278 return ends_with(Suffix);
279 }
280
281 /// Check if this string ends with the given \p Suffix, ignoring case.
282 [[nodiscard]] bool ends_with_insensitive(StringRef Suffix) const;
283 [[nodiscard]] bool endswith_insensitive(StringRef Suffix) const {
284 return ends_with_insensitive(Suffix);
285 }
286
287 /// @}
288 /// @name String Searching
289 /// @{
290
291 /// Search for the first character \p C in the string.
292 ///
293 /// \returns The index of the first occurrence of \p C, or npos if not
294 /// found.
295 [[nodiscard]] size_t find(char C, size_t From = 0) const {
296 return std::string_view(*this).find(C, From);
297 }
298
299 /// Search for the first character \p C in the string, ignoring case.
300 ///
301 /// \returns The index of the first occurrence of \p C, or npos if not
302 /// found.
303 [[nodiscard]] size_t find_insensitive(char C, size_t From = 0) const;
304
305 /// Search for the first character satisfying the predicate \p F
306 ///
307 /// \returns The index of the first character satisfying \p F starting from
308 /// \p From, or npos if not found.
309 [[nodiscard]] size_t find_if(function_ref<bool(char)> F,
310 size_t From = 0) const {
311 StringRef S = drop_front(From);
312 while (!S.empty()) {
313 if (F(S.front()))
314 return size() - S.size();
315 S = S.drop_front();
316 }
317 return npos;
318 }
319
320 /// Search for the first character not satisfying the predicate \p F
321 ///
322 /// \returns The index of the first character not satisfying \p F starting
323 /// from \p From, or npos if not found.
324 [[nodiscard]] size_t find_if_not(function_ref<bool(char)> F,
325 size_t From = 0) const {
326 return find_if([F](char c) { return !F(c); }, From);
327 }
328
329 /// Search for the first string \p Str in the string.
330 ///
331 /// \returns The index of the first occurrence of \p Str, or npos if not
332 /// found.
333 [[nodiscard]] size_t find(StringRef Str, size_t From = 0) const;
334
335 /// Search for the first string \p Str in the string, ignoring case.
336 ///
337 /// \returns The index of the first occurrence of \p Str, or npos if not
338 /// found.
339 [[nodiscard]] size_t find_insensitive(StringRef Str, size_t From = 0) const;
340
341 /// Search for the last character \p C in the string.
342 ///
343 /// \returns The index of the last occurrence of \p C, or npos if not
344 /// found.
345 [[nodiscard]] size_t rfind(char C, size_t From = npos) const {
346 From = std::min(From, Length);
347 size_t i = From;
348 while (i != 0) {
349 --i;
350 if (Data[i] == C)
351 return i;
352 }
353 return npos;
354 }
355
356 /// Search for the last character \p C in the string, ignoring case.
357 ///
358 /// \returns The index of the last occurrence of \p C, or npos if not
359 /// found.
360 [[nodiscard]] size_t rfind_insensitive(char C, size_t From = npos) const;
361
362 /// Search for the last string \p Str in the string.
363 ///
364 /// \returns The index of the last occurrence of \p Str, or npos if not
365 /// found.
366 [[nodiscard]] size_t rfind(StringRef Str) const;
367
368 /// Search for the last string \p Str in the string, ignoring case.
369 ///
370 /// \returns The index of the last occurrence of \p Str, or npos if not
371 /// found.
372 [[nodiscard]] size_t rfind_insensitive(StringRef Str) const;
373
374 /// Find the first character in the string that is \p C, or npos if not
375 /// found. Same as find.
376 [[nodiscard]] size_t find_first_of(char C, size_t From = 0) const {
377 return find(C, From);
378 }
379
380 /// Find the first character in the string that is in \p Chars, or npos if
381 /// not found.
382 ///
383 /// Complexity: O(size() + Chars.size())
384 [[nodiscard]] size_t find_first_of(StringRef Chars, size_t From = 0) const;
385
386 /// Find the first character in the string that is not \p C or npos if not
387 /// found.
388 [[nodiscard]] size_t find_first_not_of(char C, size_t From = 0) const;
389
390 /// Find the first character in the string that is not in the string
391 /// \p Chars, or npos if not found.
392 ///
393 /// Complexity: O(size() + Chars.size())
394 [[nodiscard]] size_t find_first_not_of(StringRef Chars,
395 size_t From = 0) const;
396
397 /// Find the last character in the string that is \p C, or npos if not
398 /// found.
399 [[nodiscard]] size_t find_last_of(char C, size_t From = npos) const {
400 return rfind(C, From);
401 }
402
403 /// Find the last character in the string that is in \p C, or npos if not
404 /// found.
405 ///
406 /// Complexity: O(size() + Chars.size())
407 [[nodiscard]] size_t find_last_of(StringRef Chars,
408 size_t From = npos) const;
409
410 /// Find the last character in the string that is not \p C, or npos if not
411 /// found.
412 [[nodiscard]] size_t find_last_not_of(char C, size_t From = npos) const;
413
414 /// Find the last character in the string that is not in \p Chars, or
415 /// npos if not found.
416 ///
417 /// Complexity: O(size() + Chars.size())
418 [[nodiscard]] size_t find_last_not_of(StringRef Chars,
419 size_t From = npos) const;
420
421 /// Return true if the given string is a substring of *this, and false
422 /// otherwise.
423 [[nodiscard]] bool contains(StringRef Other) const {
424 return find(Other) != npos;
425 }
426
427 /// Return true if the given character is contained in *this, and false
428 /// otherwise.
429 [[nodiscard]] bool contains(char C) const {
430 return find_first_of(C) != npos;
431 }
432
433 /// Return true if the given string is a substring of *this, and false
434 /// otherwise.
435 [[nodiscard]] bool contains_insensitive(StringRef Other) const {
436 return find_insensitive(Other) != npos;
437 }
438
439 /// Return true if the given character is contained in *this, and false
440 /// otherwise.
441 [[nodiscard]] bool contains_insensitive(char C) const {
442 return find_insensitive(C) != npos;
443 }
444
445 /// @}
446 /// @name Helpful Algorithms
447 /// @{
448
449 /// Return the number of occurrences of \p C in the string.
450 [[nodiscard]] size_t count(char C) const {
451 size_t Count = 0;
452 for (size_t i = 0, e = Length; i != e; ++i)
453 if (Data[i] == C)
454 ++Count;
455 return Count;
456 }
457
458 /// Return the number of non-overlapped occurrences of \p Str in
459 /// the string.
460 size_t count(StringRef Str) const;
461
462 /// Parse the current string as an integer of the specified radix. If
463 /// \p Radix is specified as zero, this does radix autosensing using
464 /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
465 ///
466 /// If the string is invalid or if only a subset of the string is valid,
467 /// this returns true to signify the error. The string is considered
468 /// erroneous if empty or if it overflows T.
469 template <typename T> bool getAsInteger(unsigned Radix, T &Result) const {
470 if constexpr (std::numeric_limits<T>::is_signed) {
471 long long LLVal;
472 if (getAsSignedInteger(*this, Radix, LLVal) ||
473 static_cast<T>(LLVal) != LLVal)
474 return true;
475 Result = LLVal;
476 } else {
477 unsigned long long ULLVal;
478 // The additional cast to unsigned long long is required to avoid the
479 // Visual C++ warning C4805: '!=' : unsafe mix of type 'bool' and type
480 // 'unsigned __int64' when instantiating getAsInteger with T = bool.
481 if (getAsUnsignedInteger(*this, Radix, ULLVal) ||
482 static_cast<unsigned long long>(static_cast<T>(ULLVal)) != ULLVal)
483 return true;
484 Result = ULLVal;
485 }
486 return false;
487 }
488
489 /// Parse the current string as an integer of the specified radix. If
490 /// \p Radix is specified as zero, this does radix autosensing using
491 /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
492 ///
493 /// If the string does not begin with a number of the specified radix,
494 /// this returns true to signify the error. The string is considered
495 /// erroneous if empty or if it overflows T.
496 /// The portion of the string representing the discovered numeric value
497 /// is removed from the beginning of the string.
498 template <typename T> bool consumeInteger(unsigned Radix, T &Result) {
499 if constexpr (std::numeric_limits<T>::is_signed) {
500 long long LLVal;
501 if (consumeSignedInteger(*this, Radix, LLVal) ||
502 static_cast<long long>(static_cast<T>(LLVal)) != LLVal)
503 return true;
504 Result = LLVal;
505 } else {
506 unsigned long long ULLVal;
507 if (consumeUnsignedInteger(*this, Radix, ULLVal) ||
508 static_cast<unsigned long long>(static_cast<T>(ULLVal)) != ULLVal)
509 return true;
510 Result = ULLVal;
511 }
512 return false;
513 }
514
515 /// Parse the current string as an integer of the specified \p Radix, or of
516 /// an autosensed radix if the \p Radix given is 0. The current value in
517 /// \p Result is discarded, and the storage is changed to be wide enough to
518 /// store the parsed integer.
519 ///
520 /// \returns true if the string does not solely consist of a valid
521 /// non-empty number in the appropriate base.
522 ///
523 /// APInt::fromString is superficially similar but assumes the
524 /// string is well-formed in the given radix.
525 bool getAsInteger(unsigned Radix, APInt &Result) const;
526
527 /// Parse the current string as an IEEE double-precision floating
528 /// point value. The string must be a well-formed double.
529 ///
530 /// If \p AllowInexact is false, the function will fail if the string
531 /// cannot be represented exactly. Otherwise, the function only fails
532 /// in case of an overflow or underflow, or an invalid floating point
533 /// representation.
534 bool getAsDouble(double &Result, bool AllowInexact = true) const;
535
536 /// @}
537 /// @name String Operations
538 /// @{
539
540 // Convert the given ASCII string to lowercase.
541 [[nodiscard]] std::string lower() const;
542
543 /// Convert the given ASCII string to uppercase.
544 [[nodiscard]] std::string upper() const;
545
546 /// @}
547 /// @name Substring Operations
548 /// @{
549
550 /// Return a reference to the substring from [Start, Start + N).
551 ///
552 /// \param Start The index of the starting character in the substring; if
553 /// the index is npos or greater than the length of the string then the
554 /// empty substring will be returned.
555 ///
556 /// \param N The number of characters to included in the substring. If N
557 /// exceeds the number of characters remaining in the string, the string
558 /// suffix (starting with \p Start) will be returned.
559 [[nodiscard]] constexpr StringRef substr(size_t Start,
560 size_t N = npos) const {
561 Start = std::min(Start, Length);
562 return StringRef(Data + Start, std::min(N, Length - Start));
563 }
564
565 /// Return a StringRef equal to 'this' but with only the first \p N
566 /// elements remaining. If \p N is greater than the length of the
567 /// string, the entire string is returned.
568 [[nodiscard]] StringRef take_front(size_t N = 1) const {
569 if (N >= size())
570 return *this;
571 return drop_back(size() - N);
572 }
573
574 /// Return a StringRef equal to 'this' but with only the last \p N
575 /// elements remaining. If \p N is greater than the length of the
576 /// string, the entire string is returned.
577 [[nodiscard]] StringRef take_back(size_t N = 1) const {
578 if (N >= size())
579 return *this;
580 return drop_front(size() - N);
581 }
582
583 /// Return the longest prefix of 'this' such that every character
584 /// in the prefix satisfies the given predicate.
585 [[nodiscard]] StringRef take_while(function_ref<bool(char)> F) const {
586 return substr(0, find_if_not(F));
587 }
588
589 /// Return the longest prefix of 'this' such that no character in
590 /// the prefix satisfies the given predicate.
591 [[nodiscard]] StringRef take_until(function_ref<bool(char)> F) const {
592 return substr(0, find_if(F));
593 }
594
595 /// Return a StringRef equal to 'this' but with the first \p N elements
596 /// dropped.
597 [[nodiscard]] StringRef drop_front(size_t N = 1) const {
598 assert(size() >= N && "Dropping more elements than exist");
599 return substr(N);
600 }
601
602 /// Return a StringRef equal to 'this' but with the last \p N elements
603 /// dropped.
604 [[nodiscard]] StringRef drop_back(size_t N = 1) const {
605 assert(size() >= N && "Dropping more elements than exist");
606 return substr(0, size()-N);
607 }
608
609 /// Return a StringRef equal to 'this', but with all characters satisfying
610 /// the given predicate dropped from the beginning of the string.
611 [[nodiscard]] StringRef drop_while(function_ref<bool(char)> F) const {
612 return substr(find_if_not(F));
613 }
614
615 /// Return a StringRef equal to 'this', but with all characters not
616 /// satisfying the given predicate dropped from the beginning of the string.
617 [[nodiscard]] StringRef drop_until(function_ref<bool(char)> F) const {
618 return substr(find_if(F));
619 }
620
621 /// Returns true if this StringRef has the given prefix and removes that
622 /// prefix.
624 if (!starts_with(Prefix))
625 return false;
626
627 *this = drop_front(Prefix.size());
628 return true;
629 }
630
631 /// Returns true if this StringRef has the given prefix, ignoring case,
632 /// and removes that prefix.
634 if (!startswith_insensitive(Prefix))
635 return false;
636
637 *this = drop_front(Prefix.size());
638 return true;
639 }
640
641 /// Returns true if this StringRef has the given suffix and removes that
642 /// suffix.
643 bool consume_back(StringRef Suffix) {
644 if (!ends_with(Suffix))
645 return false;
646
647 *this = drop_back(Suffix.size());
648 return true;
649 }
650
651 /// Returns true if this StringRef has the given suffix, ignoring case,
652 /// and removes that suffix.
654 if (!endswith_insensitive(Suffix))
655 return false;
656
657 *this = drop_back(Suffix.size());
658 return true;
659 }
660
661 /// Return a reference to the substring from [Start, End).
662 ///
663 /// \param Start The index of the starting character in the substring; if
664 /// the index is npos or greater than the length of the string then the
665 /// empty substring will be returned.
666 ///
667 /// \param End The index following the last character to include in the
668 /// substring. If this is npos or exceeds the number of characters
669 /// remaining in the string, the string suffix (starting with \p Start)
670 /// will be returned. If this is less than \p Start, an empty string will
671 /// be returned.
672 [[nodiscard]] StringRef slice(size_t Start, size_t End) const {
673 Start = std::min(Start, Length);
674 End = std::min(std::max(Start, End), Length);
675 return StringRef(Data + Start, End - Start);
676 }
677
678 /// Split into two substrings around the first occurrence of a separator
679 /// character.
680 ///
681 /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
682 /// such that (*this == LHS + Separator + RHS) is true and RHS is
683 /// maximal. If \p Separator is not in the string, then the result is a
684 /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
685 ///
686 /// \param Separator The character to split on.
687 /// \returns The split substrings.
688 [[nodiscard]] std::pair<StringRef, StringRef> split(char Separator) const {
689 return split(StringRef(&Separator, 1));
690 }
691
692 /// Split into two substrings around the first occurrence of a separator
693 /// string.
694 ///
695 /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
696 /// such that (*this == LHS + Separator + RHS) is true and RHS is
697 /// maximal. If \p Separator is not in the string, then the result is a
698 /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
699 ///
700 /// \param Separator - The string to split on.
701 /// \return - The split substrings.
702 [[nodiscard]] std::pair<StringRef, StringRef>
703 split(StringRef Separator) const {
704 size_t Idx = find(Separator);
705 if (Idx == npos)
706 return std::make_pair(*this, StringRef());
707 return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
708 }
709
710 /// Split into two substrings around the last occurrence of a separator
711 /// string.
712 ///
713 /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
714 /// such that (*this == LHS + Separator + RHS) is true and RHS is
715 /// minimal. If \p Separator is not in the string, then the result is a
716 /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
717 ///
718 /// \param Separator - The string to split on.
719 /// \return - The split substrings.
720 [[nodiscard]] std::pair<StringRef, StringRef>
721 rsplit(StringRef Separator) const {
722 size_t Idx = rfind(Separator);
723 if (Idx == npos)
724 return std::make_pair(*this, StringRef());
725 return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
726 }
727
728 /// Split into substrings around the occurrences of a separator string.
729 ///
730 /// Each substring is stored in \p A. If \p MaxSplit is >= 0, at most
731 /// \p MaxSplit splits are done and consequently <= \p MaxSplit + 1
732 /// elements are added to A.
733 /// If \p KeepEmpty is false, empty strings are not added to \p A. They
734 /// still count when considering \p MaxSplit
735 /// An useful invariant is that
736 /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
737 ///
738 /// \param A - Where to put the substrings.
739 /// \param Separator - The string to split on.
740 /// \param MaxSplit - The maximum number of times the string is split.
741 /// \param KeepEmpty - True if empty substring should be added.
743 StringRef Separator, int MaxSplit = -1,
744 bool KeepEmpty = true) const;
745
746 /// Split into substrings around the occurrences of a separator character.
747 ///
748 /// Each substring is stored in \p A. If \p MaxSplit is >= 0, at most
749 /// \p MaxSplit splits are done and consequently <= \p MaxSplit + 1
750 /// elements are added to A.
751 /// If \p KeepEmpty is false, empty strings are not added to \p A. They
752 /// still count when considering \p MaxSplit
753 /// An useful invariant is that
754 /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
755 ///
756 /// \param A - Where to put the substrings.
757 /// \param Separator - The string to split on.
758 /// \param MaxSplit - The maximum number of times the string is split.
759 /// \param KeepEmpty - True if empty substring should be added.
760 void split(SmallVectorImpl<StringRef> &A, char Separator, int MaxSplit = -1,
761 bool KeepEmpty = true) const;
762
763 /// Split into two substrings around the last occurrence of a separator
764 /// character.
765 ///
766 /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
767 /// such that (*this == LHS + Separator + RHS) is true and RHS is
768 /// minimal. If \p Separator is not in the string, then the result is a
769 /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
770 ///
771 /// \param Separator - The character to split on.
772 /// \return - The split substrings.
773 [[nodiscard]] std::pair<StringRef, StringRef> rsplit(char Separator) const {
774 return rsplit(StringRef(&Separator, 1));
775 }
776
777 /// Return string with consecutive \p Char characters starting from the
778 /// the left removed.
779 [[nodiscard]] StringRef ltrim(char Char) const {
780 return drop_front(std::min(Length, find_first_not_of(Char)));
781 }
782
783 /// Return string with consecutive characters in \p Chars starting from
784 /// the left removed.
785 [[nodiscard]] StringRef ltrim(StringRef Chars = " \t\n\v\f\r") const {
786 return drop_front(std::min(Length, find_first_not_of(Chars)));
787 }
788
789 /// Return string with consecutive \p Char characters starting from the
790 /// right removed.
791 [[nodiscard]] StringRef rtrim(char Char) const {
792 return drop_back(Length - std::min(Length, find_last_not_of(Char) + 1));
793 }
794
795 /// Return string with consecutive characters in \p Chars starting from
796 /// the right removed.
797 [[nodiscard]] StringRef rtrim(StringRef Chars = " \t\n\v\f\r") const {
798 return drop_back(Length - std::min(Length, find_last_not_of(Chars) + 1));
799 }
800
801 /// Return string with consecutive \p Char characters starting from the
802 /// left and right removed.
803 [[nodiscard]] StringRef trim(char Char) const {
804 return ltrim(Char).rtrim(Char);
805 }
806
807 /// Return string with consecutive characters in \p Chars starting from
808 /// the left and right removed.
809 [[nodiscard]] StringRef trim(StringRef Chars = " \t\n\v\f\r") const {
810 return ltrim(Chars).rtrim(Chars);
811 }
812
813 /// Detect the line ending style of the string.
814 ///
815 /// If the string contains a line ending, return the line ending character
816 /// sequence that is detected. Otherwise return '\n' for unix line endings.
817 ///
818 /// \return - The line ending character sequence.
819 [[nodiscard]] StringRef detectEOL() const {
820 size_t Pos = find('\r');
821 if (Pos == npos) {
822 // If there is no carriage return, assume unix
823 return "\n";
824 }
825 if (Pos + 1 < Length && Data[Pos + 1] == '\n')
826 return "\r\n"; // Windows
827 if (Pos > 0 && Data[Pos - 1] == '\n')
828 return "\n\r"; // You monster!
829 return "\r"; // Classic Mac
830 }
831 /// @}
832 };
833
834 /// A wrapper around a string literal that serves as a proxy for constructing
835 /// global tables of StringRefs with the length computed at compile time.
836 /// In order to avoid the invocation of a global constructor, StringLiteral
837 /// should *only* be used in a constexpr context, as such:
838 ///
839 /// constexpr StringLiteral S("test");
840 ///
841 class StringLiteral : public StringRef {
842 private:
843 constexpr StringLiteral(const char *Str, size_t N) : StringRef(Str, N) {
844 }
845
846 public:
847 template <size_t N>
848 constexpr StringLiteral(const char (&Str)[N])
849#if defined(__clang__) && __has_attribute(enable_if)
850#pragma clang diagnostic push
851#pragma clang diagnostic ignored "-Wgcc-compat"
852 __attribute((enable_if(__builtin_strlen(Str) == N - 1,
853 "invalid string literal")))
854#pragma clang diagnostic pop
855#endif
856 : StringRef(Str, N - 1) {
857 }
858
859 // Explicit construction for strings like "foo\0bar".
860 template <size_t N>
861 static constexpr StringLiteral withInnerNUL(const char (&Str)[N]) {
862 return StringLiteral(Str, N - 1);
863 }
864 };
865
866 /// @name StringRef Comparison Operators
867 /// @{
868
870 return LHS.equals(RHS);
871 }
872
873 inline bool operator!=(StringRef LHS, StringRef RHS) { return !(LHS == RHS); }
874
876 return LHS.compare(RHS) < 0;
877 }
878
880 return LHS.compare(RHS) <= 0;
881 }
882
884 return LHS.compare(RHS) > 0;
885 }
886
888 return LHS.compare(RHS) >= 0;
889 }
890
891 inline std::string &operator+=(std::string &buffer, StringRef string) {
892 return buffer.append(string.data(), string.size());
893 }
894
895 /// @}
896
897 /// Compute a hash_code for a StringRef.
898 [[nodiscard]] hash_code hash_value(StringRef S);
899
900 // Provide DenseMapInfo for StringRefs.
901 template <> struct DenseMapInfo<StringRef, void> {
902 static inline StringRef getEmptyKey() {
903 return StringRef(
904 reinterpret_cast<const char *>(~static_cast<uintptr_t>(0)), 0);
905 }
906
907 static inline StringRef getTombstoneKey() {
908 return StringRef(
909 reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)), 0);
910 }
911
912 static unsigned getHashValue(StringRef Val);
913
915 if (RHS.data() == getEmptyKey().data())
916 return LHS.data() == getEmptyKey().data();
917 if (RHS.data() == getTombstoneKey().data())
918 return LHS.data() == getTombstoneKey().data();
919 return LHS == RHS;
920 }
921 };
922
923} // end namespace llvm
924
925#endif // LLVM_ADT_STRINGREF_H
BlockVerifier::State From
static GCRegistry::Add< ErlangGC > A("erlang", "erlang-compatible garbage collector")
static GCRegistry::Add< ShadowStackGC > C("shadow-stack", "Very portable GC for uncooperative code generators")
#define LLVM_GSL_POINTER
LLVM_GSL_POINTER - Apply this to non-owning classes like StringRef to enable lifetime warnings.
Definition: Compiler.h:295
static Error split(StringRef Str, char Separator, std::pair< StringRef, StringRef > &Split)
Checked version of split, to ensure mandatory subparts.
Definition: DataLayout.cpp:219
Returns the sub type a function will return at a given Idx Should correspond to the result type of an ExtractValue instruction executed with just that one unsigned Idx
This file defines DenseMapInfo traits for DenseMap.
uint32_t Index
std::optional< std::vector< StOtherPiece > > Other
Definition: ELFYAML.cpp:1260
#define F(x, y, z)
Definition: MD5.cpp:55
return ToRemove size() > 0
if(VerifyEach)
Basic Register Allocator
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
static StringRef substr(StringRef Str, uint64_t Len)
Value * RHS
Value * LHS
Class for arbitrary precision integers.
Definition: APInt.h:75
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:577
A wrapper around a string literal that serves as a proxy for constructing global tables of StringRefs...
Definition: StringRef.h:841
constexpr StringLiteral(const char(&Str)[N])
Definition: StringRef.h:848
static constexpr StringLiteral withInnerNUL(const char(&Str)[N])
Definition: StringRef.h:861
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
bool endswith_insensitive(StringRef Suffix) const
Definition: StringRef.h:283
std::pair< StringRef, StringRef > split(char Separator) const
Split into two substrings around the first occurrence of a separator character.
Definition: StringRef.h:688
StringRef trim(StringRef Chars=" \t\n\v\f\r") const
Return string with consecutive characters in Chars starting from the left and right removed.
Definition: StringRef.h:809
bool consume_back(StringRef Suffix)
Returns true if this StringRef has the given suffix and removes that suffix.
Definition: StringRef.h:643
bool consumeInteger(unsigned Radix, T &Result)
Parse the current string as an integer of the specified radix.
Definition: StringRef.h:498
bool getAsInteger(unsigned Radix, T &Result) const
Parse the current string as an integer of the specified radix.
Definition: StringRef.h:469
iterator_range< const unsigned char * > bytes() const
Definition: StringRef.h:121
std::string str() const
str - Get the contents as an std::string.
Definition: StringRef.h:222
size_t find_if(function_ref< bool(char)> F, size_t From=0) const
Search for the first character satisfying the predicate F.
Definition: StringRef.h:309
const unsigned char * bytes_end() const
Definition: StringRef.h:118
constexpr StringRef substr(size_t Start, size_t N=npos) const
Return a reference to the substring from [Start, Start + N).
Definition: StringRef.h:559
bool starts_with(StringRef Prefix) const
Check if this string starts with the given Prefix.
Definition: StringRef.h:257
constexpr bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:134
bool contains_insensitive(StringRef Other) const
Return true if the given string is a substring of *this, and false otherwise.
Definition: StringRef.h:435
StringRef take_while(function_ref< bool(char)> F) const
Return the longest prefix of 'this' such that every character in the prefix satisfies the given predi...
Definition: StringRef.h:585
char operator[](size_t Index) const
Definition: StringRef.h:231
StringRef drop_front(size_t N=1) const
Return a StringRef equal to 'this' but with the first N elements dropped.
Definition: StringRef.h:597
bool contains_insensitive(char C) const
Return true if the given character is contained in *this, and false otherwise.
Definition: StringRef.h:441
iterator begin() const
Definition: StringRef.h:111
std::pair< StringRef, StringRef > rsplit(char Separator) const
Split into two substrings around the last occurrence of a separator character.
Definition: StringRef.h:773
StringRef drop_until(function_ref< bool(char)> F) const
Return a StringRef equal to 'this', but with all characters not satisfying the given predicate droppe...
Definition: StringRef.h:617
size_t size_type
Definition: StringRef.h:56
char back() const
back - Get the last character in the string.
Definition: StringRef.h:146
StringRef slice(size_t Start, size_t End) const
Return a reference to the substring from [Start, End).
Definition: StringRef.h:672
constexpr size_t size() const
size - Get the string size.
Definition: StringRef.h:137
char front() const
front - Get the first character in the string.
Definition: StringRef.h:140
size_t find_last_of(char C, size_t From=npos) const
Find the last character in the string that is C, or npos if not found.
Definition: StringRef.h:399
StringRef ltrim(char Char) const
Return string with consecutive Char characters starting from the the left removed.
Definition: StringRef.h:779
bool contains(StringRef Other) const
Return true if the given string is a substring of *this, and false otherwise.
Definition: StringRef.h:423
bool startswith(StringRef Prefix) const
Definition: StringRef.h:261
bool consume_front(StringRef Prefix)
Returns true if this StringRef has the given prefix and removes that prefix.
Definition: StringRef.h:623
StringRef detectEOL() const
Detect the line ending style of the string.
Definition: StringRef.h:819
size_t find_first_of(char C, size_t From=0) const
Find the first character in the string that is C, or npos if not found.
Definition: StringRef.h:376
StringRef()=default
Construct an empty string ref.
size_t rfind(char C, size_t From=npos) const
Search for the last character C in the string.
Definition: StringRef.h:345
iterator end() const
Definition: StringRef.h:113
StringRef rtrim(char Char) const
Return string with consecutive Char characters starting from the right removed.
Definition: StringRef.h:791
bool contains(char C) const
Return true if the given character is contained in *this, and false otherwise.
Definition: StringRef.h:429
StringRef(std::nullptr_t)=delete
Disable conversion from nullptr.
StringRef take_back(size_t N=1) const
Return a StringRef equal to 'this' but with only the last N elements remaining.
Definition: StringRef.h:577
StringRef take_front(size_t N=1) const
Return a StringRef equal to 'this' but with only the first N elements remaining.
Definition: StringRef.h:568
bool equals(StringRef RHS) const
equals - Check for string equality, this is more efficient than compare() when the relative ordering ...
Definition: StringRef.h:164
StringRef take_until(function_ref< bool(char)> F) const
Return the longest prefix of 'this' such that no character in the prefix satisfies the given predicat...
Definition: StringRef.h:591
bool startswith_insensitive(StringRef Prefix) const
Definition: StringRef.h:267
size_t find(char C, size_t From=0) const
Search for the first character C in the string.
Definition: StringRef.h:295
constexpr StringRef(const char *data, size_t length)
Construct a string ref from a pointer and length.
Definition: StringRef.h:96
StringRef trim(char Char) const
Return string with consecutive Char characters starting from the left and right removed.
Definition: StringRef.h:803
size_t count(char C) const
Return the number of occurrences of C in the string.
Definition: StringRef.h:450
bool consume_back_insensitive(StringRef Suffix)
Returns true if this StringRef has the given suffix, ignoring case, and removes that suffix.
Definition: StringRef.h:653
bool endswith(StringRef Suffix) const
Definition: StringRef.h:277
StringRef copy(Allocator &A) const
Definition: StringRef.h:153
bool ends_with(StringRef Suffix) const
Check if this string ends with the given Suffix.
Definition: StringRef.h:272
std::pair< StringRef, StringRef > rsplit(StringRef Separator) const
Split into two substrings around the last occurrence of a separator string.
Definition: StringRef.h:721
constexpr StringRef(const char *Str)
Construct a string ref from a cstring.
Definition: StringRef.h:84
std::pair< StringRef, StringRef > split(StringRef Separator) const
Split into two substrings around the first occurrence of a separator string.
Definition: StringRef.h:703
StringRef ltrim(StringRef Chars=" \t\n\v\f\r") const
Return string with consecutive characters in Chars starting from the left removed.
Definition: StringRef.h:785
std::enable_if_t< std::is_same< T, std::string >::value, StringRef > & operator=(T &&Str)=delete
Disallow accidental assignment from a temporary std::string.
StringRef rtrim(StringRef Chars=" \t\n\v\f\r") const
Return string with consecutive characters in Chars starting from the right removed.
Definition: StringRef.h:797
StringRef drop_while(function_ref< bool(char)> F) const
Return a StringRef equal to 'this', but with all characters satisfying the given predicate dropped fr...
Definition: StringRef.h:611
const unsigned char * bytes_begin() const
Definition: StringRef.h:115
int compare(StringRef RHS) const
compare - Compare two strings; the result is negative, zero, or positive if this string is lexicograp...
Definition: StringRef.h:177
StringRef drop_back(size_t N=1) const
Return a StringRef equal to 'this' but with the last N elements dropped.
Definition: StringRef.h:604
bool equals_insensitive(StringRef RHS) const
Check for string equality, ignoring case.
Definition: StringRef.h:170
bool consume_front_insensitive(StringRef Prefix)
Returns true if this StringRef has the given prefix, ignoring case, and removes that prefix.
Definition: StringRef.h:633
StringRef(const std::string &Str)
Construct a string ref from an std::string.
Definition: StringRef.h:100
constexpr StringRef(std::string_view Str)
Construct a string ref from an std::string_view.
Definition: StringRef.h:104
const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:131
size_t find_if_not(function_ref< bool(char)> F, size_t From=0) const
Search for the first character not satisfying the predicate F.
Definition: StringRef.h:324
An efficient, type-erasing, non-owning reference to a callable.
A range adaptor for a pair of iterators.
This provides a very simple, boring adaptor for a begin and end iterator into a range type.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Length
Definition: DWP.cpp:406
bool operator<(int64_t V1, const APSInt &V2)
Definition: APSInt.h:361
auto find(R &&Range, const T &Val)
Provide wrappers to std::find which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1755
bool getAsSignedInteger(StringRef Str, unsigned Radix, long long &Result)
Definition: StringRef.cpp:502
hash_code hash_value(const FixedPointSemantics &Val)
Definition: APFixedPoint.h:128
bool operator==(uint64_t V1, const APInt &V2)
Definition: APInt.h:2038
bool operator!=(uint64_t V1, const APInt &V2)
Definition: APInt.h:2040
bool operator>=(int64_t V1, const APSInt &V2)
Definition: APSInt.h:360
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
std::string & operator+=(std::string &buffer, StringRef string)
Definition: StringRef.h:891
bool consumeUnsignedInteger(StringRef &Str, unsigned Radix, unsigned long long &Result)
Definition: StringRef.cpp:414
bool operator>(int64_t V1, const APSInt &V2)
Definition: APSInt.h:362
auto find_if_not(R &&Range, UnaryPredicate P)
Definition: STLExtras.h:1767
bool consumeSignedInteger(StringRef &Str, unsigned Radix, long long &Result)
Definition: StringRef.cpp:462
auto count(R &&Range, const E &Element)
Wrapper function around std::count to count the number of times an element Element occurs in the give...
Definition: STLExtras.h:1896
auto find_if(R &&Range, UnaryPredicate P)
Provide wrappers to std::find_if which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1762
bool getAsUnsignedInteger(StringRef Str, unsigned Radix, unsigned long long &Result)
Helper functions for StringRef::getAsInteger.
Definition: StringRef.cpp:492
bool operator<=(int64_t V1, const APSInt &V2)
Definition: APSInt.h:359
Definition: BitVector.h:851
#define N
static bool isEqual(StringRef LHS, StringRef RHS)
Definition: StringRef.h:914
static unsigned getHashValue(StringRef Val)
static StringRef getTombstoneKey()
Definition: StringRef.h:907
An information struct used to provide DenseMap with the various necessary components for a given valu...
Definition: DenseMapInfo.h:51