1//===--- LiteralSupport.h ---------------------------------------*- 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 defines the NumericLiteralParser, CharLiteralParser, and
10// StringLiteralParser interfaces.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LEX_LITERALSUPPORT_H
15#define LLVM_CLANG_LEX_LITERALSUPPORT_H
16
17#include "clang/Basic/CharInfo.h"
18#include "clang/Basic/LLVM.h"
19#include "clang/Basic/TokenKinds.h"
20#include "llvm/ADT/APFloat.h"
21#include "llvm/ADT/ArrayRef.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/StringRef.h"
24#include "llvm/Support/DataTypes.h"
25
26namespace clang {
27
28class DiagnosticsEngine;
29class Preprocessor;
30class Token;
31class SourceLocation;
32class TargetInfo;
33class SourceManager;
34class LangOptions;
35
36/// Copy characters from Input to Buf, expanding any UCNs.
37void expandUCNs(SmallVectorImpl<char> &Buf, StringRef Input);
38
39/// NumericLiteralParser - This performs strict semantic analysis of the content
40/// of a ppnumber, classifying it as either integer, floating, or erroneous,
41/// determines the radix of the value and can convert it to a useful value.
42class NumericLiteralParser {
43  const SourceManager &SM;
44  const LangOptions &LangOpts;
45  DiagnosticsEngine &Diags;
46
47  const char *const ThisTokBegin;
48  const char *const ThisTokEnd;
49  const char *DigitsBegin, *SuffixBegin; // markers
50  const char *s; // cursor
51
52  unsigned radix;
53
54  bool saw_exponent, saw_period, saw_ud_suffix, saw_fixed_point_suffix;
55
56  SmallString<32> UDSuffixBuf;
57
58public:
59  NumericLiteralParser(StringRef TokSpelling, SourceLocation TokLoc,
60                       const SourceManager &SM, const LangOptions &LangOpts,
61                       const TargetInfo &Target, DiagnosticsEngine &Diags);
62  bool hadError : 1;
63  bool isUnsigned : 1;
64  bool isLong : 1;          // This is *not* set for long long.
65  bool isLongLong : 1;
66  bool isSizeT : 1;         // 1z, 1uz (C++2b)
67  bool isHalf : 1;          // 1.0h
68  bool isFloat : 1;         // 1.0f
69  bool isImaginary : 1;     // 1.0i
70  bool isFloat16 : 1;       // 1.0f16
71  bool isFloat128 : 1;      // 1.0q
72  uint8_t MicrosoftInteger; // Microsoft suffix extension i8, i16, i32, or i64.
73
74  bool isFract : 1;         // 1.0hr/r/lr/uhr/ur/ulr
75  bool isAccum : 1;         // 1.0hk/k/lk/uhk/uk/ulk
76
77  bool isFixedPointLiteral() const {
78    return (saw_period || saw_exponent) && saw_fixed_point_suffix;
79  }
80
81  bool isIntegerLiteral() const {
82    return !saw_period && !saw_exponent && !isFixedPointLiteral();
83  }
84  bool isFloatingLiteral() const {
85    return (saw_period || saw_exponent) && !isFixedPointLiteral();
86  }
87
88  bool hasUDSuffix() const {
89    return saw_ud_suffix;
90  }
91  StringRef getUDSuffix() const {
92    assert(saw_ud_suffix);
93    return UDSuffixBuf;
94  }
95  unsigned getUDSuffixOffset() const {
96    assert(saw_ud_suffix);
97    return SuffixBegin - ThisTokBegin;
98  }
99
100  static bool isValidUDSuffix(const LangOptions &LangOpts, StringRef Suffix);
101
102  unsigned getRadix() const { return radix; }
103
104  /// GetIntegerValue - Convert this numeric literal value to an APInt that
105  /// matches Val's input width.  If there is an overflow (i.e., if the unsigned
106  /// value read is larger than the APInt's bits will hold), set Val to the low
107  /// bits of the result and return true.  Otherwise, return false.
108  bool GetIntegerValue(llvm::APInt &Val);
109
110  /// GetFloatValue - Convert this numeric literal to a floating value, using
111  /// the specified APFloat fltSemantics (specifying float, double, etc).
112  /// The optional bool isExact (passed-by-reference) has its value
113  /// set to true if the returned APFloat can represent the number in the
114  /// literal exactly, and false otherwise.
115  llvm::APFloat::opStatus GetFloatValue(llvm::APFloat &Result);
116
117  /// GetFixedPointValue - Convert this numeric literal value into a
118  /// scaled integer that represents this value. Returns true if an overflow
119  /// occurred when calculating the integral part of the scaled integer or
120  /// calculating the digit sequence of the exponent.
121  bool GetFixedPointValue(llvm::APInt &StoreVal, unsigned Scale);
122
123private:
124
125  void ParseNumberStartingWithZero(SourceLocation TokLoc);
126  void ParseDecimalOrOctalCommon(SourceLocation TokLoc);
127
128  static bool isDigitSeparator(char C) { return C == '\''; }
129
130  /// Determine whether the sequence of characters [Start, End) contains
131  /// any real digits (not digit separators).
132  bool containsDigits(const char *Start, const char *End) {
133    return Start != End && (Start + 1 != End || !isDigitSeparator(Start[0]));
134  }
135
136  enum CheckSeparatorKind { CSK_BeforeDigits, CSK_AfterDigits };
137
138  /// Ensure that we don't have a digit separator here.
139  void checkSeparator(SourceLocation TokLoc, const char *Pos,
140                      CheckSeparatorKind IsAfterDigits);
141
142  /// SkipHexDigits - Read and skip over any hex digits, up to End.
143  /// Return a pointer to the first non-hex digit or End.
144  const char *SkipHexDigits(const char *ptr) {
145    while (ptr != ThisTokEnd && (isHexDigit(*ptr) || isDigitSeparator(*ptr)))
146      ptr++;
147    return ptr;
148  }
149
150  /// SkipOctalDigits - Read and skip over any octal digits, up to End.
151  /// Return a pointer to the first non-hex digit or End.
152  const char *SkipOctalDigits(const char *ptr) {
153    while (ptr != ThisTokEnd &&
154           ((*ptr >= '0' && *ptr <= '7') || isDigitSeparator(*ptr)))
155      ptr++;
156    return ptr;
157  }
158
159  /// SkipDigits - Read and skip over any digits, up to End.
160  /// Return a pointer to the first non-hex digit or End.
161  const char *SkipDigits(const char *ptr) {
162    while (ptr != ThisTokEnd && (isDigit(*ptr) || isDigitSeparator(*ptr)))
163      ptr++;
164    return ptr;
165  }
166
167  /// SkipBinaryDigits - Read and skip over any binary digits, up to End.
168  /// Return a pointer to the first non-binary digit or End.
169  const char *SkipBinaryDigits(const char *ptr) {
170    while (ptr != ThisTokEnd &&
171           (*ptr == '0' || *ptr == '1' || isDigitSeparator(*ptr)))
172      ptr++;
173    return ptr;
174  }
175
176};
177
178/// CharLiteralParser - Perform interpretation and semantic analysis of a
179/// character literal.
180class CharLiteralParser {
181  uint64_t Value;
182  tok::TokenKind Kind;
183  bool IsMultiChar;
184  bool HadError;
185  SmallString<32> UDSuffixBuf;
186  unsigned UDSuffixOffset;
187public:
188  CharLiteralParser(const char *begin, const char *end,
189                    SourceLocation Loc, Preprocessor &PP,
190                    tok::TokenKind kind);
191
192  bool hadError() const { return HadError; }
193  bool isAscii() const { return Kind == tok::char_constant; }
194  bool isWide() const { return Kind == tok::wide_char_constant; }
195  bool isUTF8() const { return Kind == tok::utf8_char_constant; }
196  bool isUTF16() const { return Kind == tok::utf16_char_constant; }
197  bool isUTF32() const { return Kind == tok::utf32_char_constant; }
198  bool isMultiChar() const { return IsMultiChar; }
199  uint64_t getValue() const { return Value; }
200  StringRef getUDSuffix() const { return UDSuffixBuf; }
201  unsigned getUDSuffixOffset() const {
202    assert(!UDSuffixBuf.empty() && "no ud-suffix");
203    return UDSuffixOffset;
204  }
205};
206
207/// StringLiteralParser - This decodes string escape characters and performs
208/// wide string analysis and Translation Phase #6 (concatenation of string
209/// literals) (C99 5.1.1.2p1).
210class StringLiteralParser {
211  const SourceManager &SM;
212  const LangOptions &Features;
213  const TargetInfo &Target;
214  DiagnosticsEngine *Diags;
215
216  unsigned MaxTokenLength;
217  unsigned SizeBound;
218  unsigned CharByteWidth;
219  tok::TokenKind Kind;
220  SmallString<512> ResultBuf;
221  char *ResultPtr; // cursor
222  SmallString<32> UDSuffixBuf;
223  unsigned UDSuffixToken;
224  unsigned UDSuffixOffset;
225public:
226  StringLiteralParser(ArrayRef<Token> StringToks,
227                      Preprocessor &PP, bool Complain = true);
228  StringLiteralParser(ArrayRef<Token> StringToks,
229                      const SourceManager &sm, const LangOptions &features,
230                      const TargetInfo &target,
231                      DiagnosticsEngine *diags = nullptr)
232    : SM(sm), Features(features), Target(target), Diags(diags),
233      MaxTokenLength(0), SizeBound(0), CharByteWidth(0), Kind(tok::unknown),
234      ResultPtr(ResultBuf.data()), hadError(false), Pascal(false) {
235    init(StringToks);
236  }
237
238
239  bool hadError;
240  bool Pascal;
241
242  StringRef GetString() const {
243    return StringRef(ResultBuf.data(), GetStringLength());
244  }
245  unsigned GetStringLength() const { return ResultPtr-ResultBuf.data(); }
246
247  unsigned GetNumStringChars() const {
248    return GetStringLength() / CharByteWidth;
249  }
250  /// getOffsetOfStringByte - This function returns the offset of the
251  /// specified byte of the string data represented by Token.  This handles
252  /// advancing over escape sequences in the string.
253  ///
254  /// If the Diagnostics pointer is non-null, then this will do semantic
255  /// checking of the string literal and emit errors and warnings.
256  unsigned getOffsetOfStringByte(const Token &TheTok, unsigned ByteNo) const;
257
258  bool isAscii() const { return Kind == tok::string_literal; }
259  bool isWide() const { return Kind == tok::wide_string_literal; }
260  bool isUTF8() const { return Kind == tok::utf8_string_literal; }
261  bool isUTF16() const { return Kind == tok::utf16_string_literal; }
262  bool isUTF32() const { return Kind == tok::utf32_string_literal; }
263  bool isPascal() const { return Pascal; }
264
265  StringRef getUDSuffix() const { return UDSuffixBuf; }
266
267  /// Get the index of a token containing a ud-suffix.
268  unsigned getUDSuffixToken() const {
269    assert(!UDSuffixBuf.empty() && "no ud-suffix");
270    return UDSuffixToken;
271  }
272  /// Get the spelling offset of the first byte of the ud-suffix.
273  unsigned getUDSuffixOffset() const {
274    assert(!UDSuffixBuf.empty() && "no ud-suffix");
275    return UDSuffixOffset;
276  }
277
278  static bool isValidUDSuffix(const LangOptions &LangOpts, StringRef Suffix);
279
280private:
281  void init(ArrayRef<Token> StringToks);
282  bool CopyStringFragment(const Token &Tok, const char *TokBegin,
283                          StringRef Fragment);
284  void DiagnoseLexingError(SourceLocation Loc);
285};
286
287}  // end namespace clang
288
289#endif
290