LiteralSupport.h revision 0c5920c3159e6a8c83a871f26f7d7ea621c29860 
1//===--- LiteralSupport.h ---------------------------------------*- 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 defines the NumericLiteralParser, CharLiteralParser, and
11// StringLiteralParser interfaces.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef CLANG_LITERALSUPPORT_H
16#define CLANG_LITERALSUPPORT_H
17
18#include <string>
19#include "llvm/ADT/SmallString.h"
20#include "llvm/Support/DataTypes.h"
21
22namespace llvm {
23  class APInt;
24  class APFloat;
25  struct fltSemantics;
26}
27
28namespace clang {
29
30class Diagnostic;
31class Preprocessor;
32class Token;
33class SourceLocation;
34class TargetInfo;
35
36/// NumericLiteralParser - This performs strict semantic analysis of the content
37/// of a ppnumber, classifying it as either integer, floating, or erroneous,
38/// determines the radix of the value and can convert it to a useful value.
39class NumericLiteralParser {
40  Preprocessor &PP; // needed for diagnostics
41
42  const char *const ThisTokBegin;
43  const char *const ThisTokEnd;
44  const char *DigitsBegin, *SuffixBegin; // markers
45  const char *s; // cursor
46
47  unsigned radix;
48
49  bool saw_exponent, saw_period;
50
51public:
52  NumericLiteralParser(const char *begin, const char *end,
53                       SourceLocation Loc, Preprocessor &PP);
54  bool hadError;
55  bool isUnsigned;
56  bool isLong;        // This is *not* set for long long.
57  bool isLongLong;
58  bool isFloat;       // 1.0f
59  bool isImaginary;   // 1.0i
60
61  bool isIntegerLiteral() const {
62    return !saw_period && !saw_exponent;
63  }
64  bool isFloatingLiteral() const {
65    return saw_period || saw_exponent;
66  }
67  bool hasSuffix() const {
68    return SuffixBegin != ThisTokEnd;
69  }
70
71  unsigned getRadix() const { return radix; }
72
73  /// GetIntegerValue - Convert this numeric literal value to an APInt that
74  /// matches Val's input width.  If there is an overflow (i.e., if the unsigned
75  /// value read is larger than the APInt's bits will hold), set Val to the low
76  /// bits of the result and return true.  Otherwise, return false.
77  bool GetIntegerValue(llvm::APInt &Val);
78
79  /// GetFloatValue - Convert this numeric literal to a floating value, using
80  /// the specified APFloat fltSemantics (specifying float, double, etc).
81  /// The optional bool isExact (passed-by-reference) has its value
82  /// set to true if the returned APFloat can represent the number in the
83  /// literal exactly, and false otherwise.
84  llvm::APFloat GetFloatValue(const llvm::fltSemantics &Format,
85                              bool* isExact = NULL);
86
87private:
88
89  void ParseNumberStartingWithZero(SourceLocation TokLoc);
90
91  /// SkipHexDigits - Read and skip over any hex digits, up to End.
92  /// Return a pointer to the first non-hex digit or End.
93  const char *SkipHexDigits(const char *ptr) {
94    while (ptr != ThisTokEnd && isxdigit(*ptr))
95      ptr++;
96    return ptr;
97  }
98
99  /// SkipOctalDigits - Read and skip over any octal digits, up to End.
100  /// Return a pointer to the first non-hex digit or End.
101  const char *SkipOctalDigits(const char *ptr) {
102    while (ptr != ThisTokEnd && ((*ptr >= '0') && (*ptr <= '7')))
103      ptr++;
104    return ptr;
105  }
106
107  /// SkipDigits - Read and skip over any digits, up to End.
108  /// Return a pointer to the first non-hex digit or End.
109  const char *SkipDigits(const char *ptr) {
110    while (ptr != ThisTokEnd && isdigit(*ptr))
111      ptr++;
112    return ptr;
113  }
114
115  /// SkipBinaryDigits - Read and skip over any binary digits, up to End.
116  /// Return a pointer to the first non-binary digit or End.
117  const char *SkipBinaryDigits(const char *ptr) {
118    while (ptr != ThisTokEnd && (*ptr == '0' || *ptr == '1'))
119      ptr++;
120    return ptr;
121  }
122
123};
124
125/// CharLiteralParser - Perform interpretation and semantic analysis of a
126/// character literal.
127class CharLiteralParser {
128  uint64_t Value;
129  bool IsWide;
130  bool IsMultiChar;
131  bool HadError;
132public:
133  CharLiteralParser(const char *begin, const char *end,
134                    SourceLocation Loc, Preprocessor &PP);
135
136  bool hadError() const { return HadError; }
137  bool isWide() const { return IsWide; }
138  bool isMultiChar() const { return IsMultiChar; }
139  uint64_t getValue() const { return Value; }
140};
141
142/// StringLiteralParser - This decodes string escape characters and performs
143/// wide string analysis and Translation Phase #6 (concatenation of string
144/// literals) (C99 5.1.1.2p1).
145class StringLiteralParser {
146  Preprocessor &PP;
147
148  unsigned MaxTokenLength;
149  unsigned SizeBound;
150  unsigned wchar_tByteWidth;
151  llvm::SmallString<512> ResultBuf;
152  char *ResultPtr; // cursor
153public:
154  StringLiteralParser(const Token *StringToks, unsigned NumStringToks,
155                      Preprocessor &PP);
156  bool hadError;
157  bool AnyWide;
158  bool Pascal;
159
160  const char *GetString() { return &ResultBuf[0]; }
161  unsigned GetStringLength() const { return ResultPtr-&ResultBuf[0]; }
162
163  unsigned GetNumStringChars() const {
164    if (AnyWide)
165      return GetStringLength() / wchar_tByteWidth;
166    return GetStringLength();
167  }
168  /// getOffsetOfStringByte - This function returns the offset of the
169  /// specified byte of the string data represented by Token.  This handles
170  /// advancing over escape sequences in the string.
171  static unsigned getOffsetOfStringByte(const Token &TheTok, unsigned ByteNo,
172                                        Preprocessor &PP);
173};
174
175}  // end namespace clang
176
177#endif
178