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StringExtras.h
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1 //===- llvm/ADT/StringExtras.h - Useful string functions --------*- 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 contains some functions that are useful when dealing with strings.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_ADT_STRINGEXTRAS_H
14 #define LLVM_ADT_STRINGEXTRAS_H
15 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/SmallString.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Twine.h"
20 #include <cassert>
21 #include <cstddef>
22 #include <cstdint>
23 #include <cstdlib>
24 #include <cstring>
25 #include <iterator>
26 #include <string>
27 #include <utility>
28 
29 namespace llvm {
30 
31 template<typename T> class SmallVectorImpl;
32 class raw_ostream;
33 
34 /// hexdigit - Return the hexadecimal character for the
35 /// given number \p X (which should be less than 16).
36 inline char hexdigit(unsigned X, bool LowerCase = false) {
37  const char HexChar = LowerCase ? 'a' : 'A';
38  return X < 10 ? '0' + X : HexChar + X - 10;
39 }
40 
41 /// Given an array of c-style strings terminated by a null pointer, construct
42 /// a vector of StringRefs representing the same strings without the terminating
43 /// null string.
44 inline std::vector<StringRef> toStringRefArray(const char *const *Strings) {
45  std::vector<StringRef> Result;
46  while (*Strings)
47  Result.push_back(*Strings++);
48  return Result;
49 }
50 
51 /// Construct a string ref from a boolean.
52 inline StringRef toStringRef(bool B) { return StringRef(B ? "true" : "false"); }
53 
54 /// Construct a string ref from an array ref of unsigned chars.
56  return StringRef(reinterpret_cast<const char *>(Input.begin()), Input.size());
57 }
58 
59 /// Construct a string ref from an array ref of unsigned chars.
61  return {Input.bytes_begin(), Input.bytes_end()};
62 }
63 
64 /// Interpret the given character \p C as a hexadecimal digit and return its
65 /// value.
66 ///
67 /// If \p C is not a valid hex digit, -1U is returned.
68 inline unsigned hexDigitValue(char C) {
69  if (C >= '0' && C <= '9') return C-'0';
70  if (C >= 'a' && C <= 'f') return C-'a'+10U;
71  if (C >= 'A' && C <= 'F') return C-'A'+10U;
72  return -1U;
73 }
74 
75 /// Checks if character \p C is one of the 10 decimal digits.
76 inline bool isDigit(char C) { return C >= '0' && C <= '9'; }
77 
78 /// Checks if character \p C is a hexadecimal numeric character.
79 inline bool isHexDigit(char C) { return hexDigitValue(C) != -1U; }
80 
81 /// Checks if character \p C is a valid letter as classified by "C" locale.
82 inline bool isAlpha(char C) {
83  return ('a' <= C && C <= 'z') || ('A' <= C && C <= 'Z');
84 }
85 
86 /// Checks whether character \p C is either a decimal digit or an uppercase or
87 /// lowercase letter as classified by "C" locale.
88 inline bool isAlnum(char C) { return isAlpha(C) || isDigit(C); }
89 
90 /// Checks whether character \p C is valid ASCII (high bit is zero).
91 inline bool isASCII(char C) { return static_cast<unsigned char>(C) <= 127; }
92 
93 /// Checks whether all characters in S are ASCII.
94 inline bool isASCII(llvm::StringRef S) {
95  for (char C : S)
96  if (LLVM_UNLIKELY(!isASCII(C)))
97  return false;
98  return true;
99 }
100 
101 /// Checks whether character \p C is printable.
102 ///
103 /// Locale-independent version of the C standard library isprint whose results
104 /// may differ on different platforms.
105 inline bool isPrint(char C) {
106  unsigned char UC = static_cast<unsigned char>(C);
107  return (0x20 <= UC) && (UC <= 0x7E);
108 }
109 
110 /// Returns the corresponding lowercase character if \p x is uppercase.
111 inline char toLower(char x) {
112  if (x >= 'A' && x <= 'Z')
113  return x - 'A' + 'a';
114  return x;
115 }
116 
117 /// Returns the corresponding uppercase character if \p x is lowercase.
118 inline char toUpper(char x) {
119  if (x >= 'a' && x <= 'z')
120  return x - 'a' + 'A';
121  return x;
122 }
123 
124 inline std::string utohexstr(uint64_t X, bool LowerCase = false) {
125  char Buffer[17];
126  char *BufPtr = std::end(Buffer);
127 
128  if (X == 0) *--BufPtr = '0';
129 
130  while (X) {
131  unsigned char Mod = static_cast<unsigned char>(X) & 15;
132  *--BufPtr = hexdigit(Mod, LowerCase);
133  X >>= 4;
134  }
135 
136  return std::string(BufPtr, std::end(Buffer));
137 }
138 
139 /// Convert buffer \p Input to its hexadecimal representation.
140 /// The returned string is double the size of \p Input.
141 inline std::string toHex(StringRef Input, bool LowerCase = false) {
142  static const char *const LUT = "0123456789ABCDEF";
143  const uint8_t Offset = LowerCase ? 32 : 0;
144  size_t Length = Input.size();
145 
146  std::string Output;
147  Output.reserve(2 * Length);
148  for (size_t i = 0; i < Length; ++i) {
149  const unsigned char c = Input[i];
150  Output.push_back(LUT[c >> 4] | Offset);
151  Output.push_back(LUT[c & 15] | Offset);
152  }
153  return Output;
154 }
155 
156 inline std::string toHex(ArrayRef<uint8_t> Input, bool LowerCase = false) {
157  return toHex(toStringRef(Input), LowerCase);
158 }
159 
160 inline uint8_t hexFromNibbles(char MSB, char LSB) {
161  unsigned U1 = hexDigitValue(MSB);
162  unsigned U2 = hexDigitValue(LSB);
163  assert(U1 != -1U && U2 != -1U);
164 
165  return static_cast<uint8_t>((U1 << 4) | U2);
166 }
167 
168 /// Convert hexadecimal string \p Input to its binary representation.
169 /// The return string is half the size of \p Input.
170 inline std::string fromHex(StringRef Input) {
171  if (Input.empty())
172  return std::string();
173 
174  std::string Output;
175  Output.reserve((Input.size() + 1) / 2);
176  if (Input.size() % 2 == 1) {
177  Output.push_back(hexFromNibbles('0', Input.front()));
178  Input = Input.drop_front();
179  }
180 
181  assert(Input.size() % 2 == 0);
182  while (!Input.empty()) {
183  uint8_t Hex = hexFromNibbles(Input[0], Input[1]);
184  Output.push_back(Hex);
185  Input = Input.drop_front(2);
186  }
187  return Output;
188 }
189 
190 /// Convert the string \p S to an integer of the specified type using
191 /// the radix \p Base. If \p Base is 0, auto-detects the radix.
192 /// Returns true if the number was successfully converted, false otherwise.
193 template <typename N> bool to_integer(StringRef S, N &Num, unsigned Base = 0) {
194  return !S.getAsInteger(Base, Num);
195 }
196 
197 namespace detail {
198 template <typename N>
199 inline bool to_float(const Twine &T, N &Num, N (*StrTo)(const char *, char **)) {
200  SmallString<32> Storage;
201  StringRef S = T.toNullTerminatedStringRef(Storage);
202  char *End;
203  N Temp = StrTo(S.data(), &End);
204  if (*End != '\0')
205  return false;
206  Num = Temp;
207  return true;
208 }
209 }
210 
211 inline bool to_float(const Twine &T, float &Num) {
212  return detail::to_float(T, Num, strtof);
213 }
214 
215 inline bool to_float(const Twine &T, double &Num) {
216  return detail::to_float(T, Num, strtod);
217 }
218 
219 inline bool to_float(const Twine &T, long double &Num) {
220  return detail::to_float(T, Num, strtold);
221 }
222 
223 inline std::string utostr(uint64_t X, bool isNeg = false) {
224  char Buffer[21];
225  char *BufPtr = std::end(Buffer);
226 
227  if (X == 0) *--BufPtr = '0'; // Handle special case...
228 
229  while (X) {
230  *--BufPtr = '0' + char(X % 10);
231  X /= 10;
232  }
233 
234  if (isNeg) *--BufPtr = '-'; // Add negative sign...
235  return std::string(BufPtr, std::end(Buffer));
236 }
237 
238 inline std::string itostr(int64_t X) {
239  if (X < 0)
240  return utostr(static_cast<uint64_t>(-X), true);
241  else
242  return utostr(static_cast<uint64_t>(X));
243 }
244 
245 /// StrInStrNoCase - Portable version of strcasestr. Locates the first
246 /// occurrence of string 's1' in string 's2', ignoring case. Returns
247 /// the offset of s2 in s1 or npos if s2 cannot be found.
249 
250 /// getToken - This function extracts one token from source, ignoring any
251 /// leading characters that appear in the Delimiters string, and ending the
252 /// token at any of the characters that appear in the Delimiters string. If
253 /// there are no tokens in the source string, an empty string is returned.
254 /// The function returns a pair containing the extracted token and the
255 /// remaining tail string.
256 std::pair<StringRef, StringRef> getToken(StringRef Source,
257  StringRef Delimiters = " \t\n\v\f\r");
258 
259 /// SplitString - Split up the specified string according to the specified
260 /// delimiters, appending the result fragments to the output list.
261 void SplitString(StringRef Source,
262  SmallVectorImpl<StringRef> &OutFragments,
263  StringRef Delimiters = " \t\n\v\f\r");
264 
265 /// Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
266 inline StringRef getOrdinalSuffix(unsigned Val) {
267  // It is critically important that we do this perfectly for
268  // user-written sequences with over 100 elements.
269  switch (Val % 100) {
270  case 11:
271  case 12:
272  case 13:
273  return "th";
274  default:
275  switch (Val % 10) {
276  case 1: return "st";
277  case 2: return "nd";
278  case 3: return "rd";
279  default: return "th";
280  }
281  }
282 }
283 
284 /// Print each character of the specified string, escaping it if it is not
285 /// printable or if it is an escape char.
287 
288 /// Print each character of the specified string, escaping HTML special
289 /// characters.
290 void printHTMLEscaped(StringRef String, raw_ostream &Out);
291 
292 /// printLowerCase - Print each character as lowercase if it is uppercase.
293 void printLowerCase(StringRef String, raw_ostream &Out);
294 
295 namespace detail {
296 
297 template <typename IteratorT>
298 inline std::string join_impl(IteratorT Begin, IteratorT End,
299  StringRef Separator, std::input_iterator_tag) {
300  std::string S;
301  if (Begin == End)
302  return S;
303 
304  S += (*Begin);
305  while (++Begin != End) {
306  S += Separator;
307  S += (*Begin);
308  }
309  return S;
310 }
311 
312 template <typename IteratorT>
313 inline std::string join_impl(IteratorT Begin, IteratorT End,
314  StringRef Separator, std::forward_iterator_tag) {
315  std::string S;
316  if (Begin == End)
317  return S;
318 
319  size_t Len = (std::distance(Begin, End) - 1) * Separator.size();
320  for (IteratorT I = Begin; I != End; ++I)
321  Len += (*Begin).size();
322  S.reserve(Len);
323  S += (*Begin);
324  while (++Begin != End) {
325  S += Separator;
326  S += (*Begin);
327  }
328  return S;
329 }
330 
331 template <typename Sep>
332 inline void join_items_impl(std::string &Result, Sep Separator) {}
333 
334 template <typename Sep, typename Arg>
335 inline void join_items_impl(std::string &Result, Sep Separator,
336  const Arg &Item) {
337  Result += Item;
338 }
339 
340 template <typename Sep, typename Arg1, typename... Args>
341 inline void join_items_impl(std::string &Result, Sep Separator, const Arg1 &A1,
342  Args &&... Items) {
343  Result += A1;
344  Result += Separator;
345  join_items_impl(Result, Separator, std::forward<Args>(Items)...);
346 }
347 
348 inline size_t join_one_item_size(char C) { return 1; }
349 inline size_t join_one_item_size(const char *S) { return S ? ::strlen(S) : 0; }
350 
351 template <typename T> inline size_t join_one_item_size(const T &Str) {
352  return Str.size();
353 }
354 
355 inline size_t join_items_size() { return 0; }
356 
357 template <typename A1> inline size_t join_items_size(const A1 &A) {
358  return join_one_item_size(A);
359 }
360 template <typename A1, typename... Args>
361 inline size_t join_items_size(const A1 &A, Args &&... Items) {
362  return join_one_item_size(A) + join_items_size(std::forward<Args>(Items)...);
363 }
364 
365 } // end namespace detail
366 
367 /// Joins the strings in the range [Begin, End), adding Separator between
368 /// the elements.
369 template <typename IteratorT>
370 inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
371  using tag = typename std::iterator_traits<IteratorT>::iterator_category;
372  return detail::join_impl(Begin, End, Separator, tag());
373 }
374 
375 /// Joins the strings in the range [R.begin(), R.end()), adding Separator
376 /// between the elements.
377 template <typename Range>
378 inline std::string join(Range &&R, StringRef Separator) {
379  return join(R.begin(), R.end(), Separator);
380 }
381 
382 /// Joins the strings in the parameter pack \p Items, adding \p Separator
383 /// between the elements. All arguments must be implicitly convertible to
384 /// std::string, or there should be an overload of std::string::operator+=()
385 /// that accepts the argument explicitly.
386 template <typename Sep, typename... Args>
387 inline std::string join_items(Sep Separator, Args &&... Items) {
388  std::string Result;
389  if (sizeof...(Items) == 0)
390  return Result;
391 
392  size_t NS = detail::join_one_item_size(Separator);
393  size_t NI = detail::join_items_size(std::forward<Args>(Items)...);
394  Result.reserve(NI + (sizeof...(Items) - 1) * NS + 1);
395  detail::join_items_impl(Result, Separator, std::forward<Args>(Items)...);
396  return Result;
397 }
398 
399 } // end namespace llvm
400 
401 #endif // LLVM_ADT_STRINGEXTRAS_H
bool to_float(const Twine &T, N &Num, N(*StrTo)(const char *, char **))
Definition: StringExtras.h:199
uint64_t CallInst * C
const_iterator end(StringRef path)
Get end iterator over path.
Definition: Path.cpp:233
std::string join_items(Sep Separator, Args &&... Items)
Joins the strings in the parameter pack Items, adding Separator between the elements.
Definition: StringExtras.h:387
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
bool isPrint(char C)
Checks whether character C is printable.
Definition: StringExtras.h:105
This class represents lattice values for constants.
Definition: AllocatorList.h:23
const unsigned char * bytes_end() const
Definition: StringRef.h:108
bool to_integer(StringRef S, N &Num, unsigned Base=0)
Convert the string S to an integer of the specified type using the radix Base.
Definition: StringExtras.h:193
#define LLVM_UNLIKELY(EXPR)
Definition: Compiler.h:199
iterator begin() const
Definition: ArrayRef.h:136
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
size_t join_items_size()
Definition: StringExtras.h:355
bool isASCII(char C)
Checks whether character C is valid ASCII (high bit is zero).
Definition: StringExtras.h:91
void printEscapedString(StringRef Name, raw_ostream &Out)
Print each character of the specified string, escaping it if it is not printable or if it is an escap...
ArrayRef< uint8_t > arrayRefFromStringRef(StringRef Input)
Construct a string ref from an array ref of unsigned chars.
Definition: StringExtras.h:60
std::string fromHex(StringRef Input)
Convert hexadecimal string Input to its binary representation.
Definition: StringExtras.h:170
bool isAlnum(char C)
Checks whether character C is either a decimal digit or an uppercase or lowercase letter as classifie...
Definition: StringExtras.h:88
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:80
LLVM_NODISCARD StringRef drop_front(size_t N=1) const
Return a StringRef equal to &#39;this&#39; but with the first N elements dropped.
Definition: StringRef.h:620
std::string join(IteratorT Begin, IteratorT End, StringRef Separator)
Joins the strings in the range [Begin, End), adding Separator between the elements.
Definition: StringExtras.h:370
LLVM_NODISCARD bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:126
void SplitString(StringRef Source, SmallVectorImpl< StringRef > &OutFragments, StringRef Delimiters=" \\\)
SplitString - Split up the specified string according to the specified delimiters, appending the result fragments to the output list.
std::pair< StringRef, StringRef > getToken(StringRef Source, StringRef Delimiters=" \\\)
getToken - This function extracts one token from source, ignoring any leading characters that appear ...
std::string itostr(int64_t X)
Definition: StringExtras.h:238
LLVM_NODISCARD size_t size() const
size - Get the string size.
Definition: StringRef.h:130
char hexdigit(unsigned X, bool LowerCase=false)
hexdigit - Return the hexadecimal character for the given number X (which should be less than 16)...
Definition: StringExtras.h:36
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
void join_items_impl(std::string &Result, Sep Separator)
Definition: StringExtras.h:332
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:148
bool isHexDigit(char C)
Checks if character C is a hexadecimal numeric character.
Definition: StringExtras.h:79
StringRef toNullTerminatedStringRef(SmallVectorImpl< char > &Out) const
This returns the twine as a single null terminated StringRef if it can be represented as such...
Definition: Twine.cpp:37
bool isAlpha(char C)
Checks if character C is a valid letter as classified by "C" locale.
Definition: StringExtras.h:82
amdgpu Simplify well known AMD library false FunctionCallee Value * Arg
char toLower(char x)
Returns the corresponding lowercase character if x is uppercase.
Definition: StringExtras.h:111
StringRef toStringRef(bool B)
Construct a string ref from a boolean.
Definition: StringExtras.h:52
size_t join_one_item_size(char C)
Definition: StringExtras.h:348
std::enable_if< std::numeric_limits< T >::is_signed, bool >::type getAsInteger(unsigned Radix, T &Result) const
Parse the current string as an integer of the specified radix.
Definition: StringRef.h:478
std::string utostr(uint64_t X, bool isNeg=false)
Definition: StringExtras.h:223
The access may modify the value stored in memory.
unsigned hexDigitValue(char C)
Interpret the given character C as a hexadecimal digit and return its value.
Definition: StringExtras.h:68
bool isDigit(char C)
Checks if character C is one of the 10 decimal digits.
Definition: StringExtras.h:76
const unsigned char * bytes_begin() const
Definition: StringRef.h:105
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2)
StrInStrNoCase - Portable version of strcasestr.
StringRef getOrdinalSuffix(unsigned Val)
Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
Definition: StringExtras.h:266
LLVM_NODISCARD const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:122
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
char toUpper(char x)
Returns the corresponding uppercase character if x is lowercase.
Definition: StringExtras.h:118
LLVM_NODISCARD char front() const
front - Get the first character in the string.
Definition: StringRef.h:134
void printLowerCase(StringRef String, raw_ostream &Out)
printLowerCase - Print each character as lowercase if it is uppercase.
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
uint8_t hexFromNibbles(char MSB, char LSB)
Definition: StringExtras.h:160
std::string toHex(StringRef Input, bool LowerCase=false)
Convert buffer Input to its hexadecimal representation.
Definition: StringExtras.h:141
void printHTMLEscaped(StringRef String, raw_ostream &Out)
Print each character of the specified string, escaping HTML special characters.
constexpr char Args[]
Key for Kernel::Metadata::mArgs.
std::string join_impl(IteratorT Begin, IteratorT End, StringRef Separator, std::input_iterator_tag)
Definition: StringExtras.h:298
std::vector< StringRef > toStringRefArray(const char *const *Strings)
Given an array of c-style strings terminated by a null pointer, construct a vector of StringRefs repr...
Definition: StringExtras.h:44
std::string utohexstr(uint64_t X, bool LowerCase=false)
Definition: StringExtras.h:124