LiteralSupport.h revision 65aa6885818d4b4eea2e5a9d12085b2398148662 
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 "llvm/ADT/APFloat.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/Support/DataTypes.h"
21#include <cctype>
22
23namespace clang {
24
25class Diagnostic;
26class Preprocessor;
27class Token;
28class SourceLocation;
29class TargetInfo;
30class SourceManager;
31class LangOptions;
32
33/// NumericLiteralParser - This performs strict semantic analysis of the content
34/// of a ppnumber, classifying it as either integer, floating, or erroneous,
35/// determines the radix of the value and can convert it to a useful value.
36class NumericLiteralParser {
37  Preprocessor &PP; // needed for diagnostics
38
39  const char *const ThisTokBegin;
40  const char *const ThisTokEnd;
41  const char *DigitsBegin, *SuffixBegin; // markers
42  const char *s; // cursor
43
44  unsigned radix;
45
46  bool saw_exponent, saw_period;
47
48public:
49  NumericLiteralParser(const char *begin, const char *end,
50                       SourceLocation Loc, Preprocessor &PP);
51  bool hadError;
52  bool isUnsigned;
53  bool isLong;        // This is *not* set for long long.
54  bool isLongLong;
55  bool isFloat;       // 1.0f
56  bool isImaginary;   // 1.0i
57  bool isMicrosoftInteger;  // Microsoft suffix extension i8, i16, i32, or i64.
58
59  bool isIntegerLiteral() const {
60    return !saw_period && !saw_exponent;
61  }
62  bool isFloatingLiteral() const {
63    return saw_period || saw_exponent;
64  }
65  bool hasSuffix() const {
66    return SuffixBegin != ThisTokEnd;
67  }
68
69  unsigned getRadix() const { return radix; }
70
71  /// GetIntegerValue - Convert this numeric literal value to an APInt that
72  /// matches Val's input width.  If there is an overflow (i.e., if the unsigned
73  /// value read is larger than the APInt's bits will hold), set Val to the low
74  /// bits of the result and return true.  Otherwise, return false.
75  bool GetIntegerValue(llvm::APInt &Val);
76
77  /// GetFloatValue - Convert this numeric literal to a floating value, using
78  /// the specified APFloat fltSemantics (specifying float, double, etc).
79  /// The optional bool isExact (passed-by-reference) has its value
80  /// set to true if the returned APFloat can represent the number in the
81  /// literal exactly, and false otherwise.
82  llvm::APFloat::opStatus GetFloatValue(llvm::APFloat &Result);
83
84private:
85
86  void ParseNumberStartingWithZero(SourceLocation TokLoc);
87
88  /// SkipHexDigits - Read and skip over any hex digits, up to End.
89  /// Return a pointer to the first non-hex digit or End.
90  const char *SkipHexDigits(const char *ptr) {
91    while (ptr != ThisTokEnd && isxdigit(*ptr))
92      ptr++;
93    return ptr;
94  }
95
96  /// SkipOctalDigits - Read and skip over any octal digits, up to End.
97  /// Return a pointer to the first non-hex digit or End.
98  const char *SkipOctalDigits(const char *ptr) {
99    while (ptr != ThisTokEnd && ((*ptr >= '0') && (*ptr <= '7')))
100      ptr++;
101    return ptr;
102  }
103
104  /// SkipDigits - Read and skip over any digits, up to End.
105  /// Return a pointer to the first non-hex digit or End.
106  const char *SkipDigits(const char *ptr) {
107    while (ptr != ThisTokEnd && isdigit(*ptr))
108      ptr++;
109    return ptr;
110  }
111
112  /// SkipBinaryDigits - Read and skip over any binary digits, up to End.
113  /// Return a pointer to the first non-binary digit or End.
114  const char *SkipBinaryDigits(const char *ptr) {
115    while (ptr != ThisTokEnd && (*ptr == '0' || *ptr == '1'))
116      ptr++;
117    return ptr;
118  }
119
120};
121
122/// CharLiteralParser - Perform interpretation and semantic analysis of a
123/// character literal.
124class CharLiteralParser {
125  uint64_t Value;
126  bool IsWide;
127  bool IsMultiChar;
128  bool HadError;
129public:
130  CharLiteralParser(const char *begin, const char *end,
131                    SourceLocation Loc, Preprocessor &PP);
132
133  bool hadError() const { return HadError; }
134  bool isWide() const { return IsWide; }
135  bool isMultiChar() const { return IsMultiChar; }
136  uint64_t getValue() const { return Value; }
137};
138
139/// StringLiteralParser - This decodes string escape characters and performs
140/// wide string analysis and Translation Phase #6 (concatenation of string
141/// literals) (C99 5.1.1.2p1).
142class StringLiteralParser {
143  const SourceManager &SM;
144  const LangOptions &Features;
145  const TargetInfo &Target;
146  Diagnostic *Diags;
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, bool Complain = true);
156  StringLiteralParser(const Token *StringToks, unsigned NumStringToks,
157                      const SourceManager &sm, const LangOptions &features,
158                      const TargetInfo &target, Diagnostic *diags = 0)
159    : SM(sm), Features(features), Target(target), Diags(diags),
160      MaxTokenLength(0), SizeBound(0), wchar_tByteWidth(0),
161      ResultPtr(ResultBuf.data()), hadError(false), AnyWide(false), Pascal(false) {
162    init(StringToks, NumStringToks);
163  }
164
165
166  bool hadError;
167  bool AnyWide;
168  bool Pascal;
169
170  llvm::StringRef GetString() const {
171    return llvm::StringRef(ResultBuf.data(), GetStringLength());
172  }
173  unsigned GetStringLength() const { return ResultPtr-ResultBuf.data(); }
174
175  unsigned GetNumStringChars() const {
176    if (AnyWide)
177      return GetStringLength() / wchar_tByteWidth;
178    return GetStringLength();
179  }
180  /// getOffsetOfStringByte - This function returns the offset of the
181  /// specified byte of the string data represented by Token.  This handles
182  /// advancing over escape sequences in the string.
183  ///
184  /// If the Diagnostics pointer is non-null, then this will do semantic
185  /// checking of the string literal and emit errors and warnings.
186  unsigned getOffsetOfStringByte(const Token &TheTok, unsigned ByteNo) const;
187
188private:
189  void init(const Token *StringToks, unsigned NumStringToks);
190};
191
192}  // end namespace clang
193
194#endif
195