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
30namespace llvm {
31
32template<typename T> class SmallVectorImpl;
33class raw_ostream;
34
35/// hexdigit - Return the hexadecimal character for the
36/// given number \p X (which should be less than 16).
37inline 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/// Given an array of c-style strings terminated by a null pointer, construct
43/// a vector of StringRefs representing the same strings without the terminating
44/// null string.
45inline std::vector<StringRef> toStringRefArray(const char *const *Strings) {
46 std::vector<StringRef> Result;
47 while (*Strings)
48 Result.push_back(*Strings++);
49 return Result;
50}
51
52/// Construct a string ref from a boolean.
53inline StringRef toStringRef(bool B) { return StringRef(B ? "true" : "false"); }
54
55/// Construct a string ref from an array ref of unsigned chars.
56inline StringRef toStringRef(ArrayRef<uint8_t> Input) {
57 return StringRef(reinterpret_cast<const char *>(Input.begin()), Input.size());
58}
59
60/// Construct a string ref from an array ref of unsigned chars.
61inline ArrayRef<uint8_t> arrayRefFromStringRef(StringRef Input) {
62 return {Input.bytes_begin(), Input.bytes_end()};
63}
64
65/// Interpret the given character \p C as a hexadecimal digit and return its
66/// value.
67///
68/// If \p C is not a valid hex digit, -1U is returned.
69inline unsigned hexDigitValue(char C) {
70 if (C >= '0' && C <= '9') return C-'0';
71 if (C >= 'a' && C <= 'f') return C-'a'+10U;
72 if (C >= 'A' && C <= 'F') return C-'A'+10U;
73 return -1U;
74}
75
76/// Checks if character \p C is one of the 10 decimal digits.
77inline bool isDigit(char C) { return C >= '0' && C <= '9'; }
78
79/// Checks if character \p C is a hexadecimal numeric character.
80inline bool isHexDigit(char C) { return hexDigitValue(C) != -1U; }
81
82/// Checks if character \p C is a valid letter as classified by "C" locale.
83inline bool isAlpha(char C) {
84 return ('a' <= C && C <= 'z') || ('A' <= C && C <= 'Z');
85}
86
87/// Checks whether character \p C is either a decimal digit or an uppercase or
88/// lowercase letter as classified by "C" locale.
89inline bool isAlnum(char C) { return isAlpha(C) || isDigit(C); }
90
91/// Checks whether character \p C is valid ASCII (high bit is zero).
92inline bool isASCII(char C) { return static_cast<unsigned char>(C) <= 127; }
93
94/// Checks whether all characters in S are ASCII.
95inline bool isASCII(llvm::StringRef S) {
96 for (char C : S)
97 if (LLVM_UNLIKELY(!isASCII(C)))
98 return false;
99 return true;
100}
101
102/// Checks whether character \p C is printable.
103///
104/// Locale-independent version of the C standard library isprint whose results
105/// may differ on different platforms.
106inline bool isPrint(char C) {
107 unsigned char UC = static_cast<unsigned char>(C);
108 return (0x20 <= UC) && (UC <= 0x7E);
109}
110
111/// Returns the corresponding lowercase character if \p x is uppercase.
112inline char toLower(char x) {
113 if (x >= 'A' && x <= 'Z')
114 return x - 'A' + 'a';
115 return x;
116}
117
118/// Returns the corresponding uppercase character if \p x is lowercase.
119inline char toUpper(char x) {
120 if (x >= 'a' && x <= 'z')
121 return x - 'a' + 'A';
122 return x;
123}
124
125inline std::string utohexstr(uint64_t X, bool LowerCase = false) {
126 char Buffer[17];
127 char *BufPtr = std::end(Buffer);
128
129 if (X == 0) *--BufPtr = '0';
130
131 while (X) {
132 unsigned char Mod = static_cast<unsigned char>(X) & 15;
133 *--BufPtr = hexdigit(Mod, LowerCase);
134 X >>= 4;
135 }
136
137 return std::string(BufPtr, std::end(Buffer));
138}
139
140/// Convert buffer \p Input to its hexadecimal representation.
141/// The returned string is double the size of \p Input.
142inline std::string toHex(StringRef Input, bool LowerCase = false) {
143 static const char *const LUT = "0123456789ABCDEF";
144 const uint8_t Offset = LowerCase ? 32 : 0;
145 size_t Length = Input.size();
146
147 std::string Output;
148 Output.reserve(2 * Length);
149 for (size_t i = 0; i < Length; ++i) {
150 const unsigned char c = Input[i];
151 Output.push_back(LUT[c >> 4] | Offset);
152 Output.push_back(LUT[c & 15] | Offset);
153 }
154 return Output;
155}
156
157inline std::string toHex(ArrayRef<uint8_t> Input, bool LowerCase = false) {
158 return toHex(toStringRef(Input), LowerCase);
159}
160
161inline uint8_t hexFromNibbles(char MSB, char LSB) {
162 unsigned U1 = hexDigitValue(MSB);
163 unsigned U2 = hexDigitValue(LSB);
164 assert(U1 != -1U && U2 != -1U);
165
166 return static_cast<uint8_t>((U1 << 4) | U2);
167}
168
169/// Convert hexadecimal string \p Input to its binary representation.
170/// The return string is half the size of \p Input.
171inline std::string fromHex(StringRef Input) {
172 if (Input.empty())
173 return std::string();
174
175 std::string Output;
176 Output.reserve((Input.size() + 1) / 2);
177 if (Input.size() % 2 == 1) {
178 Output.push_back(hexFromNibbles('0', Input.front()));
179 Input = Input.drop_front();
180 }
181
182 assert(Input.size() % 2 == 0);
183 while (!Input.empty()) {
184 uint8_t Hex = hexFromNibbles(Input[0], Input[1]);
185 Output.push_back(Hex);
186 Input = Input.drop_front(2);
187 }
188 return Output;
189}
190
191/// Convert the string \p S to an integer of the specified type using
192/// the radix \p Base. If \p Base is 0, auto-detects the radix.
193/// Returns true if the number was successfully converted, false otherwise.
194template <typename N> bool to_integer(StringRef S, N &Num, unsigned Base = 0) {
195 return !S.getAsInteger(Base, Num);
196}
197
198namespace detail {
199template <typename N>
200inline bool to_float(const Twine &T, N &Num, N (*StrTo)(const char *, char **)) {
201 SmallString<32> Storage;
202 StringRef S = T.toNullTerminatedStringRef(Storage);
203 char *End;
204 N Temp = StrTo(S.data(), &End);
205 if (*End != '\0')
206 return false;
207 Num = Temp;
208 return true;
209}
210}
211
212inline bool to_float(const Twine &T, float &Num) {
213 return detail::to_float(T, Num, strtof);
214}
215
216inline bool to_float(const Twine &T, double &Num) {
217 return detail::to_float(T, Num, strtod);
218}
219
220inline bool to_float(const Twine &T, long double &Num) {
221 return detail::to_float(T, Num, strtold);
222}
223
224inline std::string utostr(uint64_t X, bool isNeg = false) {
225 char Buffer[21];
226 char *BufPtr = std::end(Buffer);
227
228 if (X == 0) *--BufPtr = '0'; // Handle special case...
229
230 while (X) {
231 *--BufPtr = '0' + char(X % 10);
232 X /= 10;
233 }
234
235 if (isNeg) *--BufPtr = '-'; // Add negative sign...
236 return std::string(BufPtr, std::end(Buffer));
237}
238
239inline std::string itostr(int64_t X) {
240 if (X < 0)
241 return utostr(static_cast<uint64_t>(-X), true);
242 else
243 return utostr(static_cast<uint64_t>(X));
244}
245
246/// StrInStrNoCase - Portable version of strcasestr. Locates the first
247/// occurrence of string 's1' in string 's2', ignoring case. Returns
248/// the offset of s2 in s1 or npos if s2 cannot be found.
249StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2);
250
251/// getToken - This function extracts one token from source, ignoring any
252/// leading characters that appear in the Delimiters string, and ending the
253/// token at any of the characters that appear in the Delimiters string. If
254/// there are no tokens in the source string, an empty string is returned.
255/// The function returns a pair containing the extracted token and the
256/// remaining tail string.
257std::pair<StringRef, StringRef> getToken(StringRef Source,
258 StringRef Delimiters = " \t\n\v\f\r");
259
260/// SplitString - Split up the specified string according to the specified
261/// delimiters, appending the result fragments to the output list.
262void SplitString(StringRef Source,
263 SmallVectorImpl<StringRef> &OutFragments,
264 StringRef Delimiters = " \t\n\v\f\r");
265
266/// Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
267inline StringRef getOrdinalSuffix(unsigned Val) {
268 // It is critically important that we do this perfectly for
269 // user-written sequences with over 100 elements.
270 switch (Val % 100) {
271 case 11:
272 case 12:
273 case 13:
274 return "th";
275 default:
276 switch (Val % 10) {
277 case 1: return "st";
278 case 2: return "nd";
279 case 3: return "rd";
280 default: return "th";
281 }
282 }
283}
284
285/// Print each character of the specified string, escaping it if it is not
286/// printable or if it is an escape char.
287void printEscapedString(StringRef Name, raw_ostream &Out);
288
289/// Print each character of the specified string, escaping HTML special
290/// characters.
291void printHTMLEscaped(StringRef String, raw_ostream &Out);
292
293/// printLowerCase - Print each character as lowercase if it is uppercase.
294void printLowerCase(StringRef String, raw_ostream &Out);
295
296namespace detail {
297
298template <typename IteratorT>
299inline std::string join_impl(IteratorT Begin, IteratorT End,
300 StringRef Separator, std::input_iterator_tag) {
301 std::string S;
302 if (Begin == End)
303 return S;
304
305 S += (*Begin);
306 while (++Begin != End) {
307 S += Separator;
308 S += (*Begin);
309 }
310 return S;
311}
312
313template <typename IteratorT>
314inline std::string join_impl(IteratorT Begin, IteratorT End,
315 StringRef Separator, std::forward_iterator_tag) {
316 std::string S;
317 if (Begin == End)
318 return S;
319
320 size_t Len = (std::distance(Begin, End) - 1) * Separator.size();
321 for (IteratorT I = Begin; I != End; ++I)
322 Len += (*Begin).size();
323 S.reserve(Len);
324 S += (*Begin);
325 while (++Begin != End) {
326 S += Separator;
327 S += (*Begin);
328 }
329 return S;
330}
331
332template <typename Sep>
333inline void join_items_impl(std::string &Result, Sep Separator) {}
334
335template <typename Sep, typename Arg>
336inline void join_items_impl(std::string &Result, Sep Separator,
337 const Arg &Item) {
338 Result += Item;
339}
340
341template <typename Sep, typename Arg1, typename... Args>
342inline void join_items_impl(std::string &Result, Sep Separator, const Arg1 &A1,
343 Args &&... Items) {
344 Result += A1;
345 Result += Separator;
346 join_items_impl(Result, Separator, std::forward<Args>(Items)...);
347}
348
349inline size_t join_one_item_size(char C) { return 1; }
350inline size_t join_one_item_size(const char *S) { return S ? ::strlen(S) : 0; }
351
352template <typename T> inline size_t join_one_item_size(const T &Str) {
353 return Str.size();
354}
355
356inline size_t join_items_size() { return 0; }
357
358template <typename A1> inline size_t join_items_size(const A1 &A) {
359 return join_one_item_size(A);
360}
361template <typename A1, typename... Args>
362inline size_t join_items_size(const A1 &A, Args &&... Items) {
363 return join_one_item_size(A) + join_items_size(std::forward<Args>(Items)...);
364}
365
366} // end namespace detail
367
368/// Joins the strings in the range [Begin, End), adding Separator between
369/// the elements.
370template <typename IteratorT>
371inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
372 using tag = typename std::iterator_traits<IteratorT>::iterator_category;
373 return detail::join_impl(Begin, End, Separator, tag());
374}
375
376/// Joins the strings in the range [R.begin(), R.end()), adding Separator
377/// between the elements.
378template <typename Range>
379inline std::string join(Range &&R, StringRef Separator) {
380 return join(R.begin(), R.end(), Separator);
381}
382
383/// Joins the strings in the parameter pack \p Items, adding \p Separator
384/// between the elements. All arguments must be implicitly convertible to
385/// std::string, or there should be an overload of std::string::operator+=()
386/// that accepts the argument explicitly.
387template <typename Sep, typename... Args>
388inline std::string join_items(Sep Separator, Args &&... Items) {
389 std::string Result;
390 if (sizeof...(Items) == 0)
391 return Result;
392
393 size_t NS = detail::join_one_item_size(Separator);
394 size_t NI = detail::join_items_size(std::forward<Args>(Items)...);
395 Result.reserve(NI + (sizeof...(Items) - 1) * NS + 1);
396 detail::join_items_impl(Result, Separator, std::forward<Args>(Items)...);
397 return Result;
398}
399
400} // end namespace llvm
401
402#endif // LLVM_ADT_STRINGEXTRAS_H
403