1 //===- FormatProviders.h - Formatters for common LLVM types -----*- 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 implements format providers for many common LLVM types, for example 10 // allowing precision and width specifiers for scalar and string types. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_SUPPORT_FORMATPROVIDERS_H 15 #define LLVM_SUPPORT_FORMATPROVIDERS_H 16 17 #include "llvm/ADT/Optional.h" 18 #include "llvm/ADT/STLExtras.h" 19 #include "llvm/ADT/StringSwitch.h" 20 #include "llvm/ADT/Twine.h" 21 #include "llvm/Support/FormatVariadicDetails.h" 22 #include "llvm/Support/NativeFormatting.h" 23 24 #include <type_traits> 25 #include <vector> 26 27 namespace llvm { 28 namespace detail { 29 template <typename T> 30 struct use_integral_formatter 31 : public std::integral_constant< 32 bool, is_one_of<T, uint8_t, int16_t, uint16_t, int32_t, uint32_t, 33 int64_t, uint64_t, int, unsigned, long, unsigned long, 34 long long, unsigned long long>::value> {}; 35 36 template <typename T> 37 struct use_char_formatter 38 : public std::integral_constant<bool, std::is_same<T, char>::value> {}; 39 40 template <typename T> 41 struct is_cstring 42 : public std::integral_constant<bool, 43 is_one_of<T, char *, const char *>::value> { 44 }; 45 46 template <typename T> 47 struct use_string_formatter 48 : public std::integral_constant<bool, 49 std::is_convertible<T, llvm::StringRef>::value> {}; 50 51 template <typename T> 52 struct use_pointer_formatter 53 : public std::integral_constant<bool, std::is_pointer<T>::value && 54 !is_cstring<T>::value> {}; 55 56 template <typename T> 57 struct use_double_formatter 58 : public std::integral_constant<bool, std::is_floating_point<T>::value> {}; 59 60 class HelperFunctions { 61 protected: 62 static Optional<size_t> parseNumericPrecision(StringRef Str) { 63 size_t Prec; 64 Optional<size_t> Result; 65 if (Str.empty()) 66 Result = None; 67 else if (Str.getAsInteger(10, Prec)) { 68 assert(false && "Invalid precision specifier"); 69 Result = None; 70 } else { 71 assert(Prec < 100 && "Precision out of range"); 72 Result = std::min<size_t>(99u, Prec); 73 } 74 return Result; 75 } 76 77 static bool consumeHexStyle(StringRef &Str, HexPrintStyle &Style) { 78 if (!Str.startswith_lower("x")) 79 return false; 80 81 if (Str.consume_front("x-")) 82 Style = HexPrintStyle::Lower; 83 else if (Str.consume_front("X-")) 84 Style = HexPrintStyle::Upper; 85 else if (Str.consume_front("x+") || Str.consume_front("x")) 86 Style = HexPrintStyle::PrefixLower; 87 else if (Str.consume_front("X+") || Str.consume_front("X")) 88 Style = HexPrintStyle::PrefixUpper; 89 return true; 90 } 91 92 static size_t consumeNumHexDigits(StringRef &Str, HexPrintStyle Style, 93 size_t Default) { 94 Str.consumeInteger(10, Default); 95 if (isPrefixedHexStyle(Style)) 96 Default += 2; 97 return Default; 98 } 99 }; 100 } 101 102 /// Implementation of format_provider<T> for integral arithmetic types. 103 /// 104 /// The options string of an integral type has the grammar: 105 /// 106 /// integer_options :: [style][digits] 107 /// style :: <see table below> 108 /// digits :: <non-negative integer> 0-99 109 /// 110 /// ========================================================================== 111 /// | style | Meaning | Example | Digits Meaning | 112 /// -------------------------------------------------------------------------- 113 /// | | | Input | Output | | 114 /// ========================================================================== 115 /// | x- | Hex no prefix, lower | 42 | 2a | Minimum # digits | 116 /// | X- | Hex no prefix, upper | 42 | 2A | Minimum # digits | 117 /// | x+ / x | Hex + prefix, lower | 42 | 0x2a | Minimum # digits | 118 /// | X+ / X | Hex + prefix, upper | 42 | 0x2A | Minimum # digits | 119 /// | N / n | Digit grouped number | 123456 | 123,456 | Ignored | 120 /// | D / d | Integer | 100000 | 100000 | Ignored | 121 /// | (empty) | Same as D / d | | | | 122 /// ========================================================================== 123 /// 124 125 template <typename T> 126 struct format_provider< 127 T, typename std::enable_if<detail::use_integral_formatter<T>::value>::type> 128 : public detail::HelperFunctions { 129 private: 130 public: 131 static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) { 132 HexPrintStyle HS; 133 size_t Digits = 0; 134 if (consumeHexStyle(Style, HS)) { 135 Digits = consumeNumHexDigits(Style, HS, 0); 136 write_hex(Stream, V, HS, Digits); 137 return; 138 } 139 140 IntegerStyle IS = IntegerStyle::Integer; 141 if (Style.consume_front("N") || Style.consume_front("n")) 142 IS = IntegerStyle::Number; 143 else if (Style.consume_front("D") || Style.consume_front("d")) 144 IS = IntegerStyle::Integer; 145 146 Style.consumeInteger(10, Digits); 147 assert(Style.empty() && "Invalid integral format style!"); 148 write_integer(Stream, V, Digits, IS); 149 } 150 }; 151 152 /// Implementation of format_provider<T> for integral pointer types. 153 /// 154 /// The options string of a pointer type has the grammar: 155 /// 156 /// pointer_options :: [style][precision] 157 /// style :: <see table below> 158 /// digits :: <non-negative integer> 0-sizeof(void*) 159 /// 160 /// ========================================================================== 161 /// | S | Meaning | Example | 162 /// -------------------------------------------------------------------------- 163 /// | | | Input | Output | 164 /// ========================================================================== 165 /// | x- | Hex no prefix, lower | 0xDEADBEEF | deadbeef | 166 /// | X- | Hex no prefix, upper | 0xDEADBEEF | DEADBEEF | 167 /// | x+ / x | Hex + prefix, lower | 0xDEADBEEF | 0xdeadbeef | 168 /// | X+ / X | Hex + prefix, upper | 0xDEADBEEF | 0xDEADBEEF | 169 /// | (empty) | Same as X+ / X | | | 170 /// ========================================================================== 171 /// 172 /// The default precision is the number of nibbles in a machine word, and in all 173 /// cases indicates the minimum number of nibbles to print. 174 template <typename T> 175 struct format_provider< 176 T, typename std::enable_if<detail::use_pointer_formatter<T>::value>::type> 177 : public detail::HelperFunctions { 178 private: 179 public: 180 static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) { 181 HexPrintStyle HS = HexPrintStyle::PrefixUpper; 182 consumeHexStyle(Style, HS); 183 size_t Digits = consumeNumHexDigits(Style, HS, sizeof(void *) * 2); 184 write_hex(Stream, reinterpret_cast<std::uintptr_t>(V), HS, Digits); 185 } 186 }; 187 188 /// Implementation of format_provider<T> for c-style strings and string 189 /// objects such as std::string and llvm::StringRef. 190 /// 191 /// The options string of a string type has the grammar: 192 /// 193 /// string_options :: [length] 194 /// 195 /// where `length` is an optional integer specifying the maximum number of 196 /// characters in the string to print. If `length` is omitted, the string is 197 /// printed up to the null terminator. 198 199 template <typename T> 200 struct format_provider< 201 T, typename std::enable_if<detail::use_string_formatter<T>::value>::type> { 202 static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) { 203 size_t N = StringRef::npos; 204 if (!Style.empty() && Style.getAsInteger(10, N)) { 205 assert(false && "Style is not a valid integer"); 206 } 207 llvm::StringRef S = V; 208 Stream << S.substr(0, N); 209 } 210 }; 211 212 /// Implementation of format_provider<T> for llvm::Twine. 213 /// 214 /// This follows the same rules as the string formatter. 215 216 template <> struct format_provider<Twine> { 217 static void format(const Twine &V, llvm::raw_ostream &Stream, 218 StringRef Style) { 219 format_provider<std::string>::format(V.str(), Stream, Style); 220 } 221 }; 222 223 /// Implementation of format_provider<T> for characters. 224 /// 225 /// The options string of a character type has the grammar: 226 /// 227 /// char_options :: (empty) | [integer_options] 228 /// 229 /// If `char_options` is empty, the character is displayed as an ASCII 230 /// character. Otherwise, it is treated as an integer options string. 231 /// 232 template <typename T> 233 struct format_provider< 234 T, typename std::enable_if<detail::use_char_formatter<T>::value>::type> { 235 static void format(const char &V, llvm::raw_ostream &Stream, 236 StringRef Style) { 237 if (Style.empty()) 238 Stream << V; 239 else { 240 int X = static_cast<int>(V); 241 format_provider<int>::format(X, Stream, Style); 242 } 243 } 244 }; 245 246 /// Implementation of format_provider<T> for type `bool` 247 /// 248 /// The options string of a boolean type has the grammar: 249 /// 250 /// bool_options :: "" | "Y" | "y" | "D" | "d" | "T" | "t" 251 /// 252 /// ================================== 253 /// | C | Meaning | 254 /// ================================== 255 /// | Y | YES / NO | 256 /// | y | yes / no | 257 /// | D / d | Integer 0 or 1 | 258 /// | T | TRUE / FALSE | 259 /// | t | true / false | 260 /// | (empty) | Equivalent to 't' | 261 /// ================================== 262 template <> struct format_provider<bool> { 263 static void format(const bool &B, llvm::raw_ostream &Stream, 264 StringRef Style) { 265 Stream << StringSwitch<const char *>(Style) 266 .Case("Y", B ? "YES" : "NO") 267 .Case("y", B ? "yes" : "no") 268 .CaseLower("D", B ? "1" : "0") 269 .Case("T", B ? "TRUE" : "FALSE") 270 .Cases("t", "", B ? "true" : "false") 271 .Default(B ? "1" : "0"); 272 } 273 }; 274 275 /// Implementation of format_provider<T> for floating point types. 276 /// 277 /// The options string of a floating point type has the format: 278 /// 279 /// float_options :: [style][precision] 280 /// style :: <see table below> 281 /// precision :: <non-negative integer> 0-99 282 /// 283 /// ===================================================== 284 /// | style | Meaning | Example | 285 /// ----------------------------------------------------- 286 /// | | | Input | Output | 287 /// ===================================================== 288 /// | P / p | Percentage | 0.05 | 5.00% | 289 /// | F / f | Fixed point | 1.0 | 1.00 | 290 /// | E | Exponential with E | 100000 | 1.0E+05 | 291 /// | e | Exponential with e | 100000 | 1.0e+05 | 292 /// | (empty) | Same as F / f | | | 293 /// ===================================================== 294 /// 295 /// The default precision is 6 for exponential (E / e) and 2 for everything 296 /// else. 297 298 template <typename T> 299 struct format_provider< 300 T, typename std::enable_if<detail::use_double_formatter<T>::value>::type> 301 : public detail::HelperFunctions { 302 static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) { 303 FloatStyle S; 304 if (Style.consume_front("P") || Style.consume_front("p")) 305 S = FloatStyle::Percent; 306 else if (Style.consume_front("F") || Style.consume_front("f")) 307 S = FloatStyle::Fixed; 308 else if (Style.consume_front("E")) 309 S = FloatStyle::ExponentUpper; 310 else if (Style.consume_front("e")) 311 S = FloatStyle::Exponent; 312 else 313 S = FloatStyle::Fixed; 314 315 Optional<size_t> Precision = parseNumericPrecision(Style); 316 if (!Precision.hasValue()) 317 Precision = getDefaultPrecision(S); 318 319 write_double(Stream, static_cast<double>(V), S, Precision); 320 } 321 }; 322 323 namespace detail { 324 template <typename IterT> 325 using IterValue = typename std::iterator_traits<IterT>::value_type; 326 327 template <typename IterT> 328 struct range_item_has_provider 329 : public std::integral_constant< 330 bool, !uses_missing_provider<IterValue<IterT>>::value> {}; 331 } 332 333 /// Implementation of format_provider<T> for ranges. 334 /// 335 /// This will print an arbitrary range as a delimited sequence of items. 336 /// 337 /// The options string of a range type has the grammar: 338 /// 339 /// range_style ::= [separator] [element_style] 340 /// separator ::= "$" delimeted_expr 341 /// element_style ::= "@" delimeted_expr 342 /// delimeted_expr ::= "[" expr "]" | "(" expr ")" | "<" expr ">" 343 /// expr ::= <any string not containing delimeter> 344 /// 345 /// where the separator expression is the string to insert between consecutive 346 /// items in the range and the argument expression is the Style specification to 347 /// be used when formatting the underlying type. The default separator if 348 /// unspecified is ' ' (space). The syntax of the argument expression follows 349 /// whatever grammar is dictated by the format provider or format adapter used 350 /// to format the value type. 351 /// 352 /// Note that attempting to format an `iterator_range<T>` where no format 353 /// provider can be found for T will result in a compile error. 354 /// 355 356 template <typename IterT> class format_provider<llvm::iterator_range<IterT>> { 357 using value = typename std::iterator_traits<IterT>::value_type; 358 using reference = typename std::iterator_traits<IterT>::reference; 359 360 static StringRef consumeOneOption(StringRef &Style, char Indicator, 361 StringRef Default) { 362 if (Style.empty()) 363 return Default; 364 if (Style.front() != Indicator) 365 return Default; 366 Style = Style.drop_front(); 367 if (Style.empty()) { 368 assert(false && "Invalid range style"); 369 return Default; 370 } 371 372 for (const char *D : {"[]", "<>", "()"}) { 373 if (Style.front() != D[0]) 374 continue; 375 size_t End = Style.find_first_of(D[1]); 376 if (End == StringRef::npos) { 377 assert(false && "Missing range option end delimeter!"); 378 return Default; 379 } 380 StringRef Result = Style.slice(1, End); 381 Style = Style.drop_front(End + 1); 382 return Result; 383 } 384 assert(false && "Invalid range style!"); 385 return Default; 386 } 387 388 static std::pair<StringRef, StringRef> parseOptions(StringRef Style) { 389 StringRef Sep = consumeOneOption(Style, '$', ", "); 390 StringRef Args = consumeOneOption(Style, '@', ""); 391 assert(Style.empty() && "Unexpected text in range option string!"); 392 return std::make_pair(Sep, Args); 393 } 394 395 public: 396 static_assert(detail::range_item_has_provider<IterT>::value, 397 "Range value_type does not have a format provider!"); 398 static void format(const llvm::iterator_range<IterT> &V, 399 llvm::raw_ostream &Stream, StringRef Style) { 400 StringRef Sep; 401 StringRef ArgStyle; 402 std::tie(Sep, ArgStyle) = parseOptions(Style); 403 auto Begin = V.begin(); 404 auto End = V.end(); 405 if (Begin != End) { 406 auto Adapter = 407 detail::build_format_adapter(std::forward<reference>(*Begin)); 408 Adapter.format(Stream, ArgStyle); 409 ++Begin; 410 } 411 while (Begin != End) { 412 Stream << Sep; 413 auto Adapter = 414 detail::build_format_adapter(std::forward<reference>(*Begin)); 415 Adapter.format(Stream, ArgStyle); 416 ++Begin; 417 } 418 } 419 }; 420 } 421 422 #endif 423