LiteralSupport.h revision 3f6f51e28231f65de9c2dd150a2d757b2162cfa3 
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 "clang/Basic/CharInfo.h"
19#include "clang/Basic/LLVM.h"
20#include "clang/Basic/TokenKinds.h"
21#include "llvm/ADT/APFloat.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/// 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, saw_ud_suffix;
50
51public:
52  NumericLiteralParser(StringRef TokSpelling,
53                       SourceLocation TokLoc,
54                       Preprocessor &PP);
55  bool hadError;
56  bool isUnsigned;
57  bool isLong;        // This is *not* set for long long.
58  bool isLongLong;
59  bool isFloat;       // 1.0f
60  bool isImaginary;   // 1.0i
61  bool isMicrosoftInteger;  // Microsoft suffix extension i8, i16, i32, or i64.
62
63  bool isIntegerLiteral() const {
64    return !saw_period && !saw_exponent;
65  }
66  bool isFloatingLiteral() const {
67    return saw_period || saw_exponent;
68  }
69
70  bool hasUDSuffix() const {
71    return saw_ud_suffix;
72  }
73  StringRef getUDSuffix() const {
74    assert(saw_ud_suffix);
75    return StringRef(SuffixBegin, ThisTokEnd - SuffixBegin);
76  }
77  unsigned getUDSuffixOffset() const {
78    assert(saw_ud_suffix);
79    return SuffixBegin - ThisTokBegin;
80  }
81
82  unsigned getRadix() const { return radix; }
83
84  /// GetIntegerValue - Convert this numeric literal value to an APInt that
85  /// matches Val's input width.  If there is an overflow (i.e., if the unsigned
86  /// value read is larger than the APInt's bits will hold), set Val to the low
87  /// bits of the result and return true.  Otherwise, return false.
88  bool GetIntegerValue(llvm::APInt &Val);
89
90  /// GetFloatValue - Convert this numeric literal to a floating value, using
91  /// the specified APFloat fltSemantics (specifying float, double, etc).
92  /// The optional bool isExact (passed-by-reference) has its value
93  /// set to true if the returned APFloat can represent the number in the
94  /// literal exactly, and false otherwise.
95  llvm::APFloat::opStatus GetFloatValue(llvm::APFloat &Result);
96
97private:
98
99  void ParseNumberStartingWithZero(SourceLocation TokLoc);
100
101  /// SkipHexDigits - Read and skip over any hex digits, up to End.
102  /// Return a pointer to the first non-hex digit or End.
103  const char *SkipHexDigits(const char *ptr) {
104    while (ptr != ThisTokEnd && isHexDigit(*ptr))
105      ptr++;
106    return ptr;
107  }
108
109  /// SkipOctalDigits - Read and skip over any octal digits, up to End.
110  /// Return a pointer to the first non-hex digit or End.
111  const char *SkipOctalDigits(const char *ptr) {
112    while (ptr != ThisTokEnd && ((*ptr >= '0') && (*ptr <= '7')))
113      ptr++;
114    return ptr;
115  }
116
117  /// SkipDigits - Read and skip over any digits, up to End.
118  /// Return a pointer to the first non-hex digit or End.
119  const char *SkipDigits(const char *ptr) {
120    while (ptr != ThisTokEnd && isDigit(*ptr))
121      ptr++;
122    return ptr;
123  }
124
125  /// SkipBinaryDigits - Read and skip over any binary digits, up to End.
126  /// Return a pointer to the first non-binary digit or End.
127  const char *SkipBinaryDigits(const char *ptr) {
128    while (ptr != ThisTokEnd && (*ptr == '0' || *ptr == '1'))
129      ptr++;
130    return ptr;
131  }
132
133};
134
135/// CharLiteralParser - Perform interpretation and semantic analysis of a
136/// character literal.
137class CharLiteralParser {
138  uint64_t Value;
139  tok::TokenKind Kind;
140  bool IsMultiChar;
141  bool HadError;
142  SmallString<32> UDSuffixBuf;
143  unsigned UDSuffixOffset;
144public:
145  CharLiteralParser(const char *begin, const char *end,
146                    SourceLocation Loc, Preprocessor &PP,
147                    tok::TokenKind kind);
148
149  bool hadError() const { return HadError; }
150  bool isAscii() const { return Kind == tok::char_constant; }
151  bool isWide() const { return Kind == tok::wide_char_constant; }
152  bool isUTF16() const { return Kind == tok::utf16_char_constant; }
153  bool isUTF32() const { return Kind == tok::utf32_char_constant; }
154  bool isMultiChar() const { return IsMultiChar; }
155  uint64_t getValue() const { return Value; }
156  StringRef getUDSuffix() const { return UDSuffixBuf; }
157  unsigned getUDSuffixOffset() const {
158    assert(!UDSuffixBuf.empty() && "no ud-suffix");
159    return UDSuffixOffset;
160  }
161};
162
163/// StringLiteralParser - This decodes string escape characters and performs
164/// wide string analysis and Translation Phase #6 (concatenation of string
165/// literals) (C99 5.1.1.2p1).
166class StringLiteralParser {
167  const SourceManager &SM;
168  const LangOptions &Features;
169  const TargetInfo &Target;
170  DiagnosticsEngine *Diags;
171
172  unsigned MaxTokenLength;
173  unsigned SizeBound;
174  unsigned CharByteWidth;
175  tok::TokenKind Kind;
176  SmallString<512> ResultBuf;
177  char *ResultPtr; // cursor
178  SmallString<32> UDSuffixBuf;
179  unsigned UDSuffixToken;
180  unsigned UDSuffixOffset;
181public:
182  StringLiteralParser(const Token *StringToks, unsigned NumStringToks,
183                      Preprocessor &PP, bool Complain = true);
184  StringLiteralParser(const Token *StringToks, unsigned NumStringToks,
185                      const SourceManager &sm, const LangOptions &features,
186                      const TargetInfo &target, DiagnosticsEngine *diags = 0)
187    : SM(sm), Features(features), Target(target), Diags(diags),
188      MaxTokenLength(0), SizeBound(0), CharByteWidth(0), Kind(tok::unknown),
189      ResultPtr(ResultBuf.data()), hadError(false), Pascal(false) {
190    init(StringToks, NumStringToks);
191  }
192
193
194  bool hadError;
195  bool Pascal;
196
197  StringRef GetString() const {
198    return StringRef(ResultBuf.data(), GetStringLength());
199  }
200  unsigned GetStringLength() const { return ResultPtr-ResultBuf.data(); }
201
202  unsigned GetNumStringChars() const {
203    return GetStringLength() / CharByteWidth;
204  }
205  /// getOffsetOfStringByte - This function returns the offset of the
206  /// specified byte of the string data represented by Token.  This handles
207  /// advancing over escape sequences in the string.
208  ///
209  /// If the Diagnostics pointer is non-null, then this will do semantic
210  /// checking of the string literal and emit errors and warnings.
211  unsigned getOffsetOfStringByte(const Token &TheTok, unsigned ByteNo) const;
212
213  bool isAscii() const { return Kind == tok::string_literal; }
214  bool isWide() const { return Kind == tok::wide_string_literal; }
215  bool isUTF8() const { return Kind == tok::utf8_string_literal; }
216  bool isUTF16() const { return Kind == tok::utf16_string_literal; }
217  bool isUTF32() const { return Kind == tok::utf32_string_literal; }
218  bool isPascal() const { return Pascal; }
219
220  StringRef getUDSuffix() const { return UDSuffixBuf; }
221
222  /// Get the index of a token containing a ud-suffix.
223  unsigned getUDSuffixToken() const {
224    assert(!UDSuffixBuf.empty() && "no ud-suffix");
225    return UDSuffixToken;
226  }
227  /// Get the spelling offset of the first byte of the ud-suffix.
228  unsigned getUDSuffixOffset() const {
229    assert(!UDSuffixBuf.empty() && "no ud-suffix");
230    return UDSuffixOffset;
231  }
232
233private:
234  void init(const Token *StringToks, unsigned NumStringToks);
235  bool CopyStringFragment(const Token &Tok, const char *TokBegin,
236                          StringRef Fragment);
237  void DiagnoseLexingError(SourceLocation Loc);
238};
239
240}  // end namespace clang
241
242#endif
243