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StringExtras.h
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1 //===- llvm/ADT/StringExtras.h - Useful string functions --------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains some functions that are useful when dealing with strings.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ADT_STRINGEXTRAS_H
15 #define LLVM_ADT_STRINGEXTRAS_H
16 
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Twine.h"
21 #include <cassert>
22 #include <cstddef>
23 #include <cstdint>
24 #include <cstdlib>
25 #include <cstring>
26 #include <iterator>
27 #include <string>
28 #include <utility>
29 
30 namespace llvm {
31 
32 template<typename T> class SmallVectorImpl;
33 class raw_ostream;
34 
35 /// hexdigit - Return the hexadecimal character for the
36 /// given number \p X (which should be less than 16).
37 inline char hexdigit(unsigned X, bool LowerCase = false) {
38  const char HexChar = LowerCase ? 'a' : 'A';
39  return X < 10 ? '0' + X : HexChar + X - 10;
40 }
41 
42 /// Construct a string ref from a boolean.
43 inline StringRef toStringRef(bool B) { return StringRef(B ? "true" : "false"); }
44 
45 /// Construct a string ref from an array ref of unsigned chars.
47  return StringRef(reinterpret_cast<const char *>(Input.begin()), Input.size());
48 }
49 
50 /// Construct a string ref from an array ref of unsigned chars.
52  return {Input.bytes_begin(), Input.bytes_end()};
53 }
54 
55 /// Interpret the given character \p C as a hexadecimal digit and return its
56 /// value.
57 ///
58 /// If \p C is not a valid hex digit, -1U is returned.
59 inline unsigned hexDigitValue(char C) {
60  if (C >= '0' && C <= '9') return C-'0';
61  if (C >= 'a' && C <= 'f') return C-'a'+10U;
62  if (C >= 'A' && C <= 'F') return C-'A'+10U;
63  return -1U;
64 }
65 
66 /// Checks if character \p C is one of the 10 decimal digits.
67 inline bool isDigit(char C) { return C >= '0' && C <= '9'; }
68 
69 /// Checks if character \p C is a hexadecimal numeric character.
70 inline bool isHexDigit(char C) { return hexDigitValue(C) != -1U; }
71 
72 /// Checks if character \p C is a valid letter as classified by "C" locale.
73 inline bool isAlpha(char C) {
74  return ('a' <= C && C <= 'z') || ('A' <= C && C <= 'Z');
75 }
76 
77 /// Checks whether character \p C is either a decimal digit or an uppercase or
78 /// lowercase letter as classified by "C" locale.
79 inline bool isAlnum(char C) { return isAlpha(C) || isDigit(C); }
80 
81 /// Returns the corresponding lowercase character if \p x is uppercase.
82 inline char toLower(char x) {
83  if (x >= 'A' && x <= 'Z')
84  return x - 'A' + 'a';
85  return x;
86 }
87 
88 /// Returns the corresponding uppercase character if \p x is lowercase.
89 inline char toUpper(char x) {
90  if (x >= 'a' && x <= 'z')
91  return x - 'a' + 'A';
92  return x;
93 }
94 
95 inline std::string utohexstr(uint64_t X, bool LowerCase = false) {
96  char Buffer[17];
97  char *BufPtr = std::end(Buffer);
98 
99  if (X == 0) *--BufPtr = '0';
100 
101  while (X) {
102  unsigned char Mod = static_cast<unsigned char>(X) & 15;
103  *--BufPtr = hexdigit(Mod, LowerCase);
104  X >>= 4;
105  }
106 
107  return std::string(BufPtr, std::end(Buffer));
108 }
109 
110 /// Convert buffer \p Input to its hexadecimal representation.
111 /// The returned string is double the size of \p Input.
112 inline std::string toHex(StringRef Input) {
113  static const char *const LUT = "0123456789ABCDEF";
114  size_t Length = Input.size();
115 
116  std::string Output;
117  Output.reserve(2 * Length);
118  for (size_t i = 0; i < Length; ++i) {
119  const unsigned char c = Input[i];
120  Output.push_back(LUT[c >> 4]);
121  Output.push_back(LUT[c & 15]);
122  }
123  return Output;
124 }
125 
126 inline std::string toHex(ArrayRef<uint8_t> Input) {
127  return toHex(toStringRef(Input));
128 }
129 
130 inline uint8_t hexFromNibbles(char MSB, char LSB) {
131  unsigned U1 = hexDigitValue(MSB);
132  unsigned U2 = hexDigitValue(LSB);
133  assert(U1 != -1U && U2 != -1U);
134 
135  return static_cast<uint8_t>((U1 << 4) | U2);
136 }
137 
138 /// Convert hexadecimal string \p Input to its binary representation.
139 /// The return string is half the size of \p Input.
140 inline std::string fromHex(StringRef Input) {
141  if (Input.empty())
142  return std::string();
143 
144  std::string Output;
145  Output.reserve((Input.size() + 1) / 2);
146  if (Input.size() % 2 == 1) {
147  Output.push_back(hexFromNibbles('0', Input.front()));
148  Input = Input.drop_front();
149  }
150 
151  assert(Input.size() % 2 == 0);
152  while (!Input.empty()) {
153  uint8_t Hex = hexFromNibbles(Input[0], Input[1]);
154  Output.push_back(Hex);
155  Input = Input.drop_front(2);
156  }
157  return Output;
158 }
159 
160 /// \brief Convert the string \p S to an integer of the specified type using
161 /// the radix \p Base. If \p Base is 0, auto-detects the radix.
162 /// Returns true if the number was successfully converted, false otherwise.
163 template <typename N> bool to_integer(StringRef S, N &Num, unsigned Base = 0) {
164  return !S.getAsInteger(Base, Num);
165 }
166 
167 namespace detail {
168 template <typename N>
169 inline bool to_float(const Twine &T, N &Num, N (*StrTo)(const char *, char **)) {
170  SmallString<32> Storage;
171  StringRef S = T.toNullTerminatedStringRef(Storage);
172  char *End;
173  N Temp = StrTo(S.data(), &End);
174  if (*End != '\0')
175  return false;
176  Num = Temp;
177  return true;
178 }
179 }
180 
181 inline bool to_float(const Twine &T, float &Num) {
182  return detail::to_float(T, Num, strtof);
183 }
184 
185 inline bool to_float(const Twine &T, double &Num) {
186  return detail::to_float(T, Num, strtod);
187 }
188 
189 inline bool to_float(const Twine &T, long double &Num) {
190  return detail::to_float(T, Num, strtold);
191 }
192 
193 inline std::string utostr(uint64_t X, bool isNeg = false) {
194  char Buffer[21];
195  char *BufPtr = std::end(Buffer);
196 
197  if (X == 0) *--BufPtr = '0'; // Handle special case...
198 
199  while (X) {
200  *--BufPtr = '0' + char(X % 10);
201  X /= 10;
202  }
203 
204  if (isNeg) *--BufPtr = '-'; // Add negative sign...
205  return std::string(BufPtr, std::end(Buffer));
206 }
207 
208 inline std::string itostr(int64_t X) {
209  if (X < 0)
210  return utostr(static_cast<uint64_t>(-X), true);
211  else
212  return utostr(static_cast<uint64_t>(X));
213 }
214 
215 /// StrInStrNoCase - Portable version of strcasestr. Locates the first
216 /// occurrence of string 's1' in string 's2', ignoring case. Returns
217 /// the offset of s2 in s1 or npos if s2 cannot be found.
219 
220 /// getToken - This function extracts one token from source, ignoring any
221 /// leading characters that appear in the Delimiters string, and ending the
222 /// token at any of the characters that appear in the Delimiters string. If
223 /// there are no tokens in the source string, an empty string is returned.
224 /// The function returns a pair containing the extracted token and the
225 /// remaining tail string.
226 std::pair<StringRef, StringRef> getToken(StringRef Source,
227  StringRef Delimiters = " \t\n\v\f\r");
228 
229 /// SplitString - Split up the specified string according to the specified
230 /// delimiters, appending the result fragments to the output list.
231 void SplitString(StringRef Source,
232  SmallVectorImpl<StringRef> &OutFragments,
233  StringRef Delimiters = " \t\n\v\f\r");
234 
235 /// HashString - Hash function for strings.
236 ///
237 /// This is the Bernstein hash function.
238 //
239 // FIXME: Investigate whether a modified bernstein hash function performs
240 // better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx
241 // X*33+c -> X*33^c
242 inline unsigned HashString(StringRef Str, unsigned Result = 0) {
243  for (StringRef::size_type i = 0, e = Str.size(); i != e; ++i)
244  Result = Result * 33 + (unsigned char)Str[i];
245  return Result;
246 }
247 
248 /// Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
249 inline StringRef getOrdinalSuffix(unsigned Val) {
250  // It is critically important that we do this perfectly for
251  // user-written sequences with over 100 elements.
252  switch (Val % 100) {
253  case 11:
254  case 12:
255  case 13:
256  return "th";
257  default:
258  switch (Val % 10) {
259  case 1: return "st";
260  case 2: return "nd";
261  case 3: return "rd";
262  default: return "th";
263  }
264  }
265 }
266 
267 /// PrintEscapedString - Print each character of the specified string, escaping
268 /// it if it is not printable or if it is an escape char.
270 
271 /// printLowerCase - Print each character as lowercase if it is uppercase.
273 
274 namespace detail {
275 
276 template <typename IteratorT>
277 inline std::string join_impl(IteratorT Begin, IteratorT End,
278  StringRef Separator, std::input_iterator_tag) {
279  std::string S;
280  if (Begin == End)
281  return S;
282 
283  S += (*Begin);
284  while (++Begin != End) {
285  S += Separator;
286  S += (*Begin);
287  }
288  return S;
289 }
290 
291 template <typename IteratorT>
292 inline std::string join_impl(IteratorT Begin, IteratorT End,
293  StringRef Separator, std::forward_iterator_tag) {
294  std::string S;
295  if (Begin == End)
296  return S;
297 
298  size_t Len = (std::distance(Begin, End) - 1) * Separator.size();
299  for (IteratorT I = Begin; I != End; ++I)
300  Len += (*Begin).size();
301  S.reserve(Len);
302  S += (*Begin);
303  while (++Begin != End) {
304  S += Separator;
305  S += (*Begin);
306  }
307  return S;
308 }
309 
310 template <typename Sep>
311 inline void join_items_impl(std::string &Result, Sep Separator) {}
312 
313 template <typename Sep, typename Arg>
314 inline void join_items_impl(std::string &Result, Sep Separator,
315  const Arg &Item) {
316  Result += Item;
317 }
318 
319 template <typename Sep, typename Arg1, typename... Args>
320 inline void join_items_impl(std::string &Result, Sep Separator, const Arg1 &A1,
321  Args &&... Items) {
322  Result += A1;
323  Result += Separator;
324  join_items_impl(Result, Separator, std::forward<Args>(Items)...);
325 }
326 
327 inline size_t join_one_item_size(char C) { return 1; }
328 inline size_t join_one_item_size(const char *S) { return S ? ::strlen(S) : 0; }
329 
330 template <typename T> inline size_t join_one_item_size(const T &Str) {
331  return Str.size();
332 }
333 
334 inline size_t join_items_size() { return 0; }
335 
336 template <typename A1> inline size_t join_items_size(const A1 &A) {
337  return join_one_item_size(A);
338 }
339 template <typename A1, typename... Args>
340 inline size_t join_items_size(const A1 &A, Args &&... Items) {
341  return join_one_item_size(A) + join_items_size(std::forward<Args>(Items)...);
342 }
343 
344 } // end namespace detail
345 
346 /// Joins the strings in the range [Begin, End), adding Separator between
347 /// the elements.
348 template <typename IteratorT>
349 inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
350  using tag = typename std::iterator_traits<IteratorT>::iterator_category;
351  return detail::join_impl(Begin, End, Separator, tag());
352 }
353 
354 /// Joins the strings in the range [R.begin(), R.end()), adding Separator
355 /// between the elements.
356 template <typename Range>
357 inline std::string join(Range &&R, StringRef Separator) {
358  return join(R.begin(), R.end(), Separator);
359 }
360 
361 /// Joins the strings in the parameter pack \p Items, adding \p Separator
362 /// between the elements. All arguments must be implicitly convertible to
363 /// std::string, or there should be an overload of std::string::operator+=()
364 /// that accepts the argument explicitly.
365 template <typename Sep, typename... Args>
366 inline std::string join_items(Sep Separator, Args &&... Items) {
367  std::string Result;
368  if (sizeof...(Items) == 0)
369  return Result;
370 
371  size_t NS = detail::join_one_item_size(Separator);
372  size_t NI = detail::join_items_size(std::forward<Args>(Items)...);
373  Result.reserve(NI + (sizeof...(Items) - 1) * NS + 1);
374  detail::join_items_impl(Result, Separator, std::forward<Args>(Items)...);
375  return Result;
376 }
377 
378 } // end namespace llvm
379 
380 #endif // LLVM_ADT_STRINGEXTRAS_H
bool to_float(const Twine &T, N &Num, N(*StrTo)(const char *, char **))
Definition: StringExtras.h:169
uint64_t CallInst * C
const_iterator end(StringRef path)
Get end iterator over path.
Definition: Path.cpp:245
std::string join_items(Sep Separator, Args &&... Items)
Joins the strings in the parameter pack Items, adding Separator between the elements.
Definition: StringExtras.h:366
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
const unsigned char * bytes_end() const
Definition: StringRef.h:113
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:163
iterator begin() const
Definition: ArrayRef.h:137
void PrintEscapedString(StringRef Name, raw_ostream &Out)
PrintEscapedString - Print each character of the specified string, escaping it if it is not printable...
Definition: AsmWriter.cpp:386
size_t join_items_size()
Definition: StringExtras.h:334
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
size - Get the string size.
Definition: StringRef.h:138
ArrayRef< uint8_t > arrayRefFromStringRef(StringRef Input)
Construct a string ref from an array ref of unsigned chars.
Definition: StringExtras.h:51
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:128
std::string fromHex(StringRef Input)
Convert hexadecimal string Input to its binary representation.
Definition: StringExtras.h:140
bool isAlnum(char C)
Checks whether character C is either a decimal digit or an uppercase or lowercase letter as classifie...
Definition: StringExtras.h:79
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
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:349
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:208
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:133
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:37
unsigned HashString(StringRef Str, unsigned Result=0)
HashString - Hash function for strings.
Definition: StringExtras.h:242
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
void join_items_impl(std::string &Result, Sep Separator)
Definition: StringExtras.h:311
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
bool isHexDigit(char C)
Checks if character C is a hexadecimal numeric character.
Definition: StringExtras.h:70
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:73
static const unsigned End
char toLower(char x)
Returns the corresponding lowercase character if x is uppercase.
Definition: StringExtras.h:82
StringRef toStringRef(bool B)
Construct a string ref from a boolean.
Definition: StringExtras.h:43
size_t join_one_item_size(char C)
Definition: StringExtras.h:327
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:497
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE 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:645
std::string utostr(uint64_t X, bool isNeg=false)
Definition: StringExtras.h:193
std::string toHex(StringRef Input)
Convert buffer Input to its hexadecimal representation.
Definition: StringExtras.h:112
unsigned hexDigitValue(char C)
Interpret the given character C as a hexadecimal digit and return its value.
Definition: StringExtras.h:59
The access may modify the value stored in memory.
amdgpu Simplify well known AMD library false Value Value * Arg
bool isDigit(char C)
Checks if character C is one of the 10 decimal digits.
Definition: StringExtras.h:67
const unsigned char * bytes_begin() const
Definition: StringRef.h:110
#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:249
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
char toUpper(char x)
Returns the corresponding uppercase character if x is lowercase.
Definition: StringExtras.h:89
LLVM_NODISCARD char front() const
front - Get the first character in the string.
Definition: StringRef.h:142
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:44
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
uint8_t hexFromNibbles(char MSB, char LSB)
Definition: StringExtras.h:130
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:277
std::string utohexstr(uint64_t X, bool LowerCase=false)
Definition: StringExtras.h:95