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