| //===--- LiteralSupport.cpp - Code to parse and process literals ----------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the NumericLiteralParser, CharLiteralParser, and |
| // StringLiteralParser interfaces. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/Lex/LiteralSupport.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Lex/LexDiagnostic.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/ADT/StringExtras.h" |
| using namespace clang; |
| |
| /// HexDigitValue - Return the value of the specified hex digit, or -1 if it's |
| /// not valid. |
| static int HexDigitValue(char C) { |
| if (C >= '0' && C <= '9') return C-'0'; |
| if (C >= 'a' && C <= 'f') return C-'a'+10; |
| if (C >= 'A' && C <= 'F') return C-'A'+10; |
| return -1; |
| } |
| |
| /// ProcessCharEscape - Parse a standard C escape sequence, which can occur in |
| /// either a character or a string literal. |
| static unsigned ProcessCharEscape(const char *&ThisTokBuf, |
| const char *ThisTokEnd, bool &HadError, |
| SourceLocation Loc, bool IsWide, |
| Preprocessor &PP) { |
| // Skip the '\' char. |
| ++ThisTokBuf; |
| |
| // We know that this character can't be off the end of the buffer, because |
| // that would have been \", which would not have been the end of string. |
| unsigned ResultChar = *ThisTokBuf++; |
| switch (ResultChar) { |
| // These map to themselves. |
| case '\\': case '\'': case '"': case '?': break; |
| |
| // These have fixed mappings. |
| case 'a': |
| // TODO: K&R: the meaning of '\\a' is different in traditional C |
| ResultChar = 7; |
| break; |
| case 'b': |
| ResultChar = 8; |
| break; |
| case 'e': |
| PP.Diag(Loc, diag::ext_nonstandard_escape) << "e"; |
| ResultChar = 27; |
| break; |
| case 'E': |
| PP.Diag(Loc, diag::ext_nonstandard_escape) << "E"; |
| ResultChar = 27; |
| break; |
| case 'f': |
| ResultChar = 12; |
| break; |
| case 'n': |
| ResultChar = 10; |
| break; |
| case 'r': |
| ResultChar = 13; |
| break; |
| case 't': |
| ResultChar = 9; |
| break; |
| case 'v': |
| ResultChar = 11; |
| break; |
| case 'x': { // Hex escape. |
| ResultChar = 0; |
| if (ThisTokBuf == ThisTokEnd || !isxdigit(*ThisTokBuf)) { |
| PP.Diag(Loc, diag::err_hex_escape_no_digits); |
| HadError = 1; |
| break; |
| } |
| |
| // Hex escapes are a maximal series of hex digits. |
| bool Overflow = false; |
| for (; ThisTokBuf != ThisTokEnd; ++ThisTokBuf) { |
| int CharVal = HexDigitValue(ThisTokBuf[0]); |
| if (CharVal == -1) break; |
| // About to shift out a digit? |
| Overflow |= (ResultChar & 0xF0000000) ? true : false; |
| ResultChar <<= 4; |
| ResultChar |= CharVal; |
| } |
| |
| // See if any bits will be truncated when evaluated as a character. |
| unsigned CharWidth = IsWide |
| ? PP.getTargetInfo().getWCharWidth() |
| : PP.getTargetInfo().getCharWidth(); |
| |
| if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) { |
| Overflow = true; |
| ResultChar &= ~0U >> (32-CharWidth); |
| } |
| |
| // Check for overflow. |
| if (Overflow) // Too many digits to fit in |
| PP.Diag(Loc, diag::warn_hex_escape_too_large); |
| break; |
| } |
| case '0': case '1': case '2': case '3': |
| case '4': case '5': case '6': case '7': { |
| // Octal escapes. |
| --ThisTokBuf; |
| ResultChar = 0; |
| |
| // Octal escapes are a series of octal digits with maximum length 3. |
| // "\0123" is a two digit sequence equal to "\012" "3". |
| unsigned NumDigits = 0; |
| do { |
| ResultChar <<= 3; |
| ResultChar |= *ThisTokBuf++ - '0'; |
| ++NumDigits; |
| } while (ThisTokBuf != ThisTokEnd && NumDigits < 3 && |
| ThisTokBuf[0] >= '0' && ThisTokBuf[0] <= '7'); |
| |
| // Check for overflow. Reject '\777', but not L'\777'. |
| unsigned CharWidth = IsWide |
| ? PP.getTargetInfo().getWCharWidth() |
| : PP.getTargetInfo().getCharWidth(); |
| |
| if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) { |
| PP.Diag(Loc, diag::warn_octal_escape_too_large); |
| ResultChar &= ~0U >> (32-CharWidth); |
| } |
| break; |
| } |
| |
| // Otherwise, these are not valid escapes. |
| case '(': case '{': case '[': case '%': |
| // GCC accepts these as extensions. We warn about them as such though. |
| PP.Diag(Loc, diag::ext_nonstandard_escape) |
| << std::string()+(char)ResultChar; |
| break; |
| default: |
| if (isgraph(ThisTokBuf[0])) |
| PP.Diag(Loc, diag::ext_unknown_escape) << std::string()+(char)ResultChar; |
| else |
| PP.Diag(Loc, diag::ext_unknown_escape) << "x"+llvm::utohexstr(ResultChar); |
| break; |
| } |
| |
| return ResultChar; |
| } |
| |
| /// ProcessUCNEscape - Read the Universal Character Name, check constraints and |
| /// convert the UTF32 to UTF8. This is a subroutine of StringLiteralParser. |
| /// When we decide to implement UCN's for character constants and identifiers, |
| /// we will likely rework our support for UCN's. |
| static void ProcessUCNEscape(const char *&ThisTokBuf, const char *ThisTokEnd, |
| char *&ResultBuf, bool &HadError, |
| SourceLocation Loc, bool IsWide, Preprocessor &PP) |
| { |
| // FIXME: Add a warning - UCN's are only valid in C++ & C99. |
| // FIXME: Handle wide strings. |
| |
| // Save the beginning of the string (for error diagnostics). |
| const char *ThisTokBegin = ThisTokBuf; |
| |
| // Skip the '\u' char's. |
| ThisTokBuf += 2; |
| |
| if (ThisTokBuf == ThisTokEnd || !isxdigit(*ThisTokBuf)) { |
| PP.Diag(Loc, diag::err_ucn_escape_no_digits); |
| HadError = 1; |
| return; |
| } |
| typedef uint32_t UTF32; |
| |
| UTF32 UcnVal = 0; |
| unsigned short UcnLen = (ThisTokBuf[-1] == 'u' ? 4 : 8); |
| for (; ThisTokBuf != ThisTokEnd && UcnLen; ++ThisTokBuf, UcnLen--) { |
| int CharVal = HexDigitValue(ThisTokBuf[0]); |
| if (CharVal == -1) break; |
| UcnVal <<= 4; |
| UcnVal |= CharVal; |
| } |
| // If we didn't consume the proper number of digits, there is a problem. |
| if (UcnLen) { |
| PP.Diag(PP.AdvanceToTokenCharacter(Loc, ThisTokBuf-ThisTokBegin), |
| diag::err_ucn_escape_incomplete); |
| HadError = 1; |
| return; |
| } |
| // Check UCN constraints (C99 6.4.3p2). |
| if ((UcnVal < 0xa0 && |
| (UcnVal != 0x24 && UcnVal != 0x40 && UcnVal != 0x60 )) // $, @, ` |
| || (UcnVal >= 0xD800 && UcnVal <= 0xDFFF) |
| || (UcnVal > 0x10FFFF)) /* the maximum legal UTF32 value */ { |
| PP.Diag(Loc, diag::err_ucn_escape_invalid); |
| HadError = 1; |
| return; |
| } |
| // Now that we've parsed/checked the UCN, we convert from UTF32->UTF8. |
| // The conversion below was inspired by: |
| // http://www.unicode.org/Public/PROGRAMS/CVTUTF/ConvertUTF.c |
| // First, we determine how many bytes the result will require. |
| typedef uint8_t UTF8; |
| |
| unsigned short bytesToWrite = 0; |
| if (UcnVal < (UTF32)0x80) |
| bytesToWrite = 1; |
| else if (UcnVal < (UTF32)0x800) |
| bytesToWrite = 2; |
| else if (UcnVal < (UTF32)0x10000) |
| bytesToWrite = 3; |
| else |
| bytesToWrite = 4; |
| |
| const unsigned byteMask = 0xBF; |
| const unsigned byteMark = 0x80; |
| |
| // Once the bits are split out into bytes of UTF8, this is a mask OR-ed |
| // into the first byte, depending on how many bytes follow. |
| static const UTF8 firstByteMark[5] = { |
| 0x00, 0x00, 0xC0, 0xE0, 0xF0 |
| }; |
| // Finally, we write the bytes into ResultBuf. |
| ResultBuf += bytesToWrite; |
| switch (bytesToWrite) { // note: everything falls through. |
| case 4: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6; |
| case 3: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6; |
| case 2: *--ResultBuf = (UTF8)((UcnVal | byteMark) & byteMask); UcnVal >>= 6; |
| case 1: *--ResultBuf = (UTF8) (UcnVal | firstByteMark[bytesToWrite]); |
| } |
| // Update the buffer. |
| ResultBuf += bytesToWrite; |
| } |
| |
| |
| /// integer-constant: [C99 6.4.4.1] |
| /// decimal-constant integer-suffix |
| /// octal-constant integer-suffix |
| /// hexadecimal-constant integer-suffix |
| /// decimal-constant: |
| /// nonzero-digit |
| /// decimal-constant digit |
| /// octal-constant: |
| /// 0 |
| /// octal-constant octal-digit |
| /// hexadecimal-constant: |
| /// hexadecimal-prefix hexadecimal-digit |
| /// hexadecimal-constant hexadecimal-digit |
| /// hexadecimal-prefix: one of |
| /// 0x 0X |
| /// integer-suffix: |
| /// unsigned-suffix [long-suffix] |
| /// unsigned-suffix [long-long-suffix] |
| /// long-suffix [unsigned-suffix] |
| /// long-long-suffix [unsigned-sufix] |
| /// nonzero-digit: |
| /// 1 2 3 4 5 6 7 8 9 |
| /// octal-digit: |
| /// 0 1 2 3 4 5 6 7 |
| /// hexadecimal-digit: |
| /// 0 1 2 3 4 5 6 7 8 9 |
| /// a b c d e f |
| /// A B C D E F |
| /// unsigned-suffix: one of |
| /// u U |
| /// long-suffix: one of |
| /// l L |
| /// long-long-suffix: one of |
| /// ll LL |
| /// |
| /// floating-constant: [C99 6.4.4.2] |
| /// TODO: add rules... |
| /// |
| NumericLiteralParser:: |
| NumericLiteralParser(const char *begin, const char *end, |
| SourceLocation TokLoc, Preprocessor &pp) |
| : PP(pp), ThisTokBegin(begin), ThisTokEnd(end) { |
| |
| // This routine assumes that the range begin/end matches the regex for integer |
| // and FP constants (specifically, the 'pp-number' regex), and assumes that |
| // the byte at "*end" is both valid and not part of the regex. Because of |
| // this, it doesn't have to check for 'overscan' in various places. |
| assert(!isalnum(*end) && *end != '.' && *end != '_' && |
| "Lexer didn't maximally munch?"); |
| |
| s = DigitsBegin = begin; |
| saw_exponent = false; |
| saw_period = false; |
| isLong = false; |
| isUnsigned = false; |
| isLongLong = false; |
| isFloat = false; |
| isImaginary = false; |
| hadError = false; |
| |
| if (*s == '0') { // parse radix |
| ParseNumberStartingWithZero(TokLoc); |
| if (hadError) |
| return; |
| } else { // the first digit is non-zero |
| radix = 10; |
| s = SkipDigits(s); |
| if (s == ThisTokEnd) { |
| // Done. |
| } else if (isxdigit(*s) && !(*s == 'e' || *s == 'E')) { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-begin), |
| diag::err_invalid_decimal_digit) << std::string(s, s+1); |
| hadError = true; |
| return; |
| } else if (*s == '.') { |
| s++; |
| saw_period = true; |
| s = SkipDigits(s); |
| } |
| if ((*s == 'e' || *s == 'E')) { // exponent |
| const char *Exponent = s; |
| s++; |
| saw_exponent = true; |
| if (*s == '+' || *s == '-') s++; // sign |
| const char *first_non_digit = SkipDigits(s); |
| if (first_non_digit != s) { |
| s = first_non_digit; |
| } else { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-begin), |
| diag::err_exponent_has_no_digits); |
| hadError = true; |
| return; |
| } |
| } |
| } |
| |
| SuffixBegin = s; |
| |
| // Parse the suffix. At this point we can classify whether we have an FP or |
| // integer constant. |
| bool isFPConstant = isFloatingLiteral(); |
| |
| // Loop over all of the characters of the suffix. If we see something bad, |
| // we break out of the loop. |
| for (; s != ThisTokEnd; ++s) { |
| switch (*s) { |
| case 'f': // FP Suffix for "float" |
| case 'F': |
| if (!isFPConstant) break; // Error for integer constant. |
| if (isFloat || isLong) break; // FF, LF invalid. |
| isFloat = true; |
| continue; // Success. |
| case 'u': |
| case 'U': |
| if (isFPConstant) break; // Error for floating constant. |
| if (isUnsigned) break; // Cannot be repeated. |
| isUnsigned = true; |
| continue; // Success. |
| case 'l': |
| case 'L': |
| if (isLong || isLongLong) break; // Cannot be repeated. |
| if (isFloat) break; // LF invalid. |
| |
| // Check for long long. The L's need to be adjacent and the same case. |
| if (s+1 != ThisTokEnd && s[1] == s[0]) { |
| if (isFPConstant) break; // long long invalid for floats. |
| isLongLong = true; |
| ++s; // Eat both of them. |
| } else { |
| isLong = true; |
| } |
| continue; // Success. |
| case 'i': |
| if (PP.getLangOptions().Microsoft) { |
| // Allow i8, i16, i32, i64, and i128. |
| if (++s == ThisTokEnd) break; |
| switch (*s) { |
| case '8': |
| s++; // i8 suffix |
| break; |
| case '1': |
| if (++s == ThisTokEnd) break; |
| if (*s == '6') s++; // i16 suffix |
| else if (*s == '2') { |
| if (++s == ThisTokEnd) break; |
| if (*s == '8') s++; // i128 suffix |
| } |
| break; |
| case '3': |
| if (++s == ThisTokEnd) break; |
| if (*s == '2') s++; // i32 suffix |
| break; |
| case '6': |
| if (++s == ThisTokEnd) break; |
| if (*s == '4') s++; // i64 suffix |
| break; |
| default: |
| break; |
| } |
| break; |
| } |
| // fall through. |
| case 'I': |
| case 'j': |
| case 'J': |
| if (isImaginary) break; // Cannot be repeated. |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-begin), |
| diag::ext_imaginary_constant); |
| isImaginary = true; |
| continue; // Success. |
| } |
| // If we reached here, there was an error. |
| break; |
| } |
| |
| // Report an error if there are any. |
| if (s != ThisTokEnd) { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-begin), |
| isFPConstant ? diag::err_invalid_suffix_float_constant : |
| diag::err_invalid_suffix_integer_constant) |
| << std::string(SuffixBegin, ThisTokEnd); |
| hadError = true; |
| return; |
| } |
| } |
| |
| /// ParseNumberStartingWithZero - This method is called when the first character |
| /// of the number is found to be a zero. This means it is either an octal |
| /// number (like '04') or a hex number ('0x123a') a binary number ('0b1010') or |
| /// a floating point number (01239.123e4). Eat the prefix, determining the |
| /// radix etc. |
| void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) { |
| assert(s[0] == '0' && "Invalid method call"); |
| s++; |
| |
| // Handle a hex number like 0x1234. |
| if ((*s == 'x' || *s == 'X') && (isxdigit(s[1]) || s[1] == '.')) { |
| s++; |
| radix = 16; |
| DigitsBegin = s; |
| s = SkipHexDigits(s); |
| if (s == ThisTokEnd) { |
| // Done. |
| } else if (*s == '.') { |
| s++; |
| saw_period = true; |
| s = SkipHexDigits(s); |
| } |
| // A binary exponent can appear with or with a '.'. If dotted, the |
| // binary exponent is required. |
| if (*s == 'p' || *s == 'P') { |
| const char *Exponent = s; |
| s++; |
| saw_exponent = true; |
| if (*s == '+' || *s == '-') s++; // sign |
| const char *first_non_digit = SkipDigits(s); |
| if (first_non_digit == s) { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin), |
| diag::err_exponent_has_no_digits); |
| hadError = true; |
| return; |
| } |
| s = first_non_digit; |
| |
| if (!PP.getLangOptions().HexFloats) |
| PP.Diag(TokLoc, diag::ext_hexconstant_invalid); |
| } else if (saw_period) { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin), |
| diag::err_hexconstant_requires_exponent); |
| hadError = true; |
| } |
| return; |
| } |
| |
| // Handle simple binary numbers 0b01010 |
| if (*s == 'b' || *s == 'B') { |
| // 0b101010 is a GCC extension. |
| PP.Diag(TokLoc, diag::ext_binary_literal); |
| ++s; |
| radix = 2; |
| DigitsBegin = s; |
| s = SkipBinaryDigits(s); |
| if (s == ThisTokEnd) { |
| // Done. |
| } else if (isxdigit(*s)) { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin), |
| diag::err_invalid_binary_digit) << std::string(s, s+1); |
| hadError = true; |
| } |
| // Other suffixes will be diagnosed by the caller. |
| return; |
| } |
| |
| // For now, the radix is set to 8. If we discover that we have a |
| // floating point constant, the radix will change to 10. Octal floating |
| // point constants are not permitted (only decimal and hexadecimal). |
| radix = 8; |
| DigitsBegin = s; |
| s = SkipOctalDigits(s); |
| if (s == ThisTokEnd) |
| return; // Done, simple octal number like 01234 |
| |
| // If we have some other non-octal digit that *is* a decimal digit, see if |
| // this is part of a floating point number like 094.123 or 09e1. |
| if (isdigit(*s)) { |
| const char *EndDecimal = SkipDigits(s); |
| if (EndDecimal[0] == '.' || EndDecimal[0] == 'e' || EndDecimal[0] == 'E') { |
| s = EndDecimal; |
| radix = 10; |
| } |
| } |
| |
| // If we have a hex digit other than 'e' (which denotes a FP exponent) then |
| // the code is using an incorrect base. |
| if (isxdigit(*s) && *s != 'e' && *s != 'E') { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin), |
| diag::err_invalid_octal_digit) << std::string(s, s+1); |
| hadError = true; |
| return; |
| } |
| |
| if (*s == '.') { |
| s++; |
| radix = 10; |
| saw_period = true; |
| s = SkipDigits(s); // Skip suffix. |
| } |
| if (*s == 'e' || *s == 'E') { // exponent |
| const char *Exponent = s; |
| s++; |
| radix = 10; |
| saw_exponent = true; |
| if (*s == '+' || *s == '-') s++; // sign |
| const char *first_non_digit = SkipDigits(s); |
| if (first_non_digit != s) { |
| s = first_non_digit; |
| } else { |
| PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin), |
| diag::err_exponent_has_no_digits); |
| hadError = true; |
| return; |
| } |
| } |
| } |
| |
| |
| /// GetIntegerValue - Convert this numeric literal value to an APInt that |
| /// matches Val's input width. If there is an overflow, set Val to the low bits |
| /// of the result and return true. Otherwise, return false. |
| bool NumericLiteralParser::GetIntegerValue(llvm::APInt &Val) { |
| // Fast path: Compute a conservative bound on the maximum number of |
| // bits per digit in this radix. If we can't possibly overflow a |
| // uint64 based on that bound then do the simple conversion to |
| // integer. This avoids the expensive overflow checking below, and |
| // handles the common cases that matter (small decimal integers and |
| // hex/octal values which don't overflow). |
| unsigned MaxBitsPerDigit = 1; |
| while ((1U << MaxBitsPerDigit) < radix) |
| MaxBitsPerDigit += 1; |
| if ((SuffixBegin - DigitsBegin) * MaxBitsPerDigit <= 64) { |
| uint64_t N = 0; |
| for (s = DigitsBegin; s != SuffixBegin; ++s) |
| N = N*radix + HexDigitValue(*s); |
| |
| // This will truncate the value to Val's input width. Simply check |
| // for overflow by comparing. |
| Val = N; |
| return Val.getZExtValue() != N; |
| } |
| |
| Val = 0; |
| s = DigitsBegin; |
| |
| llvm::APInt RadixVal(Val.getBitWidth(), radix); |
| llvm::APInt CharVal(Val.getBitWidth(), 0); |
| llvm::APInt OldVal = Val; |
| |
| bool OverflowOccurred = false; |
| while (s < SuffixBegin) { |
| unsigned C = HexDigitValue(*s++); |
| |
| // If this letter is out of bound for this radix, reject it. |
| assert(C < radix && "NumericLiteralParser ctor should have rejected this"); |
| |
| CharVal = C; |
| |
| // Add the digit to the value in the appropriate radix. If adding in digits |
| // made the value smaller, then this overflowed. |
| OldVal = Val; |
| |
| // Multiply by radix, did overflow occur on the multiply? |
| Val *= RadixVal; |
| OverflowOccurred |= Val.udiv(RadixVal) != OldVal; |
| |
| // Add value, did overflow occur on the value? |
| // (a + b) ult b <=> overflow |
| Val += CharVal; |
| OverflowOccurred |= Val.ult(CharVal); |
| } |
| return OverflowOccurred; |
| } |
| |
| llvm::APFloat NumericLiteralParser:: |
| GetFloatValue(const llvm::fltSemantics &Format, bool* isExact) { |
| using llvm::APFloat; |
| using llvm::StringRef; |
| |
| llvm::SmallVector<char,256> floatChars; |
| unsigned n = std::min(SuffixBegin - ThisTokBegin, ThisTokEnd - ThisTokBegin); |
| for (unsigned i = 0; i != n; ++i) |
| floatChars.push_back(ThisTokBegin[i]); |
| |
| floatChars.push_back('\0'); |
| |
| APFloat V (Format, APFloat::fcZero, false); |
| APFloat::opStatus status; |
| |
| status = V.convertFromString(StringRef(&floatChars[0], n), |
| APFloat::rmNearestTiesToEven); |
| |
| if (isExact) |
| *isExact = status == APFloat::opOK; |
| |
| return V; |
| } |
| |
| |
| CharLiteralParser::CharLiteralParser(const char *begin, const char *end, |
| SourceLocation Loc, Preprocessor &PP) { |
| // At this point we know that the character matches the regex "L?'.*'". |
| HadError = false; |
| |
| // Determine if this is a wide character. |
| IsWide = begin[0] == 'L'; |
| if (IsWide) ++begin; |
| |
| // Skip over the entry quote. |
| assert(begin[0] == '\'' && "Invalid token lexed"); |
| ++begin; |
| |
| // FIXME: The "Value" is an uint64_t so we can handle char literals of |
| // upto 64-bits. |
| // FIXME: This extensively assumes that 'char' is 8-bits. |
| assert(PP.getTargetInfo().getCharWidth() == 8 && |
| "Assumes char is 8 bits"); |
| assert(PP.getTargetInfo().getIntWidth() <= 64 && |
| (PP.getTargetInfo().getIntWidth() & 7) == 0 && |
| "Assumes sizeof(int) on target is <= 64 and a multiple of char"); |
| assert(PP.getTargetInfo().getWCharWidth() <= 64 && |
| "Assumes sizeof(wchar) on target is <= 64"); |
| |
| // This is what we will use for overflow detection |
| llvm::APInt LitVal(PP.getTargetInfo().getIntWidth(), 0); |
| |
| unsigned NumCharsSoFar = 0; |
| while (begin[0] != '\'') { |
| uint64_t ResultChar; |
| if (begin[0] != '\\') // If this is a normal character, consume it. |
| ResultChar = *begin++; |
| else // Otherwise, this is an escape character. |
| ResultChar = ProcessCharEscape(begin, end, HadError, Loc, IsWide, PP); |
| |
| // If this is a multi-character constant (e.g. 'abc'), handle it. These are |
| // implementation defined (C99 6.4.4.4p10). |
| if (NumCharsSoFar) { |
| if (IsWide) { |
| // Emulate GCC's (unintentional?) behavior: L'ab' -> L'b'. |
| LitVal = 0; |
| } else { |
| // Narrow character literals act as though their value is concatenated |
| // in this implementation, but warn on overflow. |
| if (LitVal.countLeadingZeros() < 8) |
| PP.Diag(Loc, diag::warn_char_constant_too_large); |
| LitVal <<= 8; |
| } |
| } |
| |
| LitVal = LitVal + ResultChar; |
| ++NumCharsSoFar; |
| } |
| |
| // If this is the second character being processed, do special handling. |
| if (NumCharsSoFar > 1) { |
| // Warn about discarding the top bits for multi-char wide-character |
| // constants (L'abcd'). |
| if (IsWide) |
| PP.Diag(Loc, diag::warn_extraneous_wide_char_constant); |
| else if (NumCharsSoFar != 4) |
| PP.Diag(Loc, diag::ext_multichar_character_literal); |
| else |
| PP.Diag(Loc, diag::ext_four_char_character_literal); |
| IsMultiChar = true; |
| } else |
| IsMultiChar = false; |
| |
| // Transfer the value from APInt to uint64_t |
| Value = LitVal.getZExtValue(); |
| |
| // If this is a single narrow character, sign extend it (e.g. '\xFF' is "-1") |
| // if 'char' is signed for this target (C99 6.4.4.4p10). Note that multiple |
| // character constants are not sign extended in the this implementation: |
| // '\xFF\xFF' = 65536 and '\x0\xFF' = 255, which matches GCC. |
| if (!IsWide && NumCharsSoFar == 1 && (Value & 128) && |
| PP.getLangOptions().CharIsSigned) |
| Value = (signed char)Value; |
| } |
| |
| |
| /// string-literal: [C99 6.4.5] |
| /// " [s-char-sequence] " |
| /// L" [s-char-sequence] " |
| /// s-char-sequence: |
| /// s-char |
| /// s-char-sequence s-char |
| /// s-char: |
| /// any source character except the double quote ", |
| /// backslash \, or newline character |
| /// escape-character |
| /// universal-character-name |
| /// escape-character: [C99 6.4.4.4] |
| /// \ escape-code |
| /// universal-character-name |
| /// escape-code: |
| /// character-escape-code |
| /// octal-escape-code |
| /// hex-escape-code |
| /// character-escape-code: one of |
| /// n t b r f v a |
| /// \ ' " ? |
| /// octal-escape-code: |
| /// octal-digit |
| /// octal-digit octal-digit |
| /// octal-digit octal-digit octal-digit |
| /// hex-escape-code: |
| /// x hex-digit |
| /// hex-escape-code hex-digit |
| /// universal-character-name: |
| /// \u hex-quad |
| /// \U hex-quad hex-quad |
| /// hex-quad: |
| /// hex-digit hex-digit hex-digit hex-digit |
| /// |
| StringLiteralParser:: |
| StringLiteralParser(const Token *StringToks, unsigned NumStringToks, |
| Preprocessor &pp) : PP(pp) { |
| // Scan all of the string portions, remember the max individual token length, |
| // computing a bound on the concatenated string length, and see whether any |
| // piece is a wide-string. If any of the string portions is a wide-string |
| // literal, the result is a wide-string literal [C99 6.4.5p4]. |
| MaxTokenLength = StringToks[0].getLength(); |
| SizeBound = StringToks[0].getLength()-2; // -2 for "". |
| AnyWide = StringToks[0].is(tok::wide_string_literal); |
| |
| hadError = false; |
| |
| // Implement Translation Phase #6: concatenation of string literals |
| /// (C99 5.1.1.2p1). The common case is only one string fragment. |
| for (unsigned i = 1; i != NumStringToks; ++i) { |
| // The string could be shorter than this if it needs cleaning, but this is a |
| // reasonable bound, which is all we need. |
| SizeBound += StringToks[i].getLength()-2; // -2 for "". |
| |
| // Remember maximum string piece length. |
| if (StringToks[i].getLength() > MaxTokenLength) |
| MaxTokenLength = StringToks[i].getLength(); |
| |
| // Remember if we see any wide strings. |
| AnyWide |= StringToks[i].is(tok::wide_string_literal); |
| } |
| |
| // Include space for the null terminator. |
| ++SizeBound; |
| |
| // TODO: K&R warning: "traditional C rejects string constant concatenation" |
| |
| // Get the width in bytes of wchar_t. If no wchar_t strings are used, do not |
| // query the target. As such, wchar_tByteWidth is only valid if AnyWide=true. |
| wchar_tByteWidth = ~0U; |
| if (AnyWide) { |
| wchar_tByteWidth = PP.getTargetInfo().getWCharWidth(); |
| assert((wchar_tByteWidth & 7) == 0 && "Assumes wchar_t is byte multiple!"); |
| wchar_tByteWidth /= 8; |
| } |
| |
| // The output buffer size needs to be large enough to hold wide characters. |
| // This is a worst-case assumption which basically corresponds to L"" "long". |
| if (AnyWide) |
| SizeBound *= wchar_tByteWidth; |
| |
| // Size the temporary buffer to hold the result string data. |
| ResultBuf.resize(SizeBound); |
| |
| // Likewise, but for each string piece. |
| llvm::SmallString<512> TokenBuf; |
| TokenBuf.resize(MaxTokenLength); |
| |
| // Loop over all the strings, getting their spelling, and expanding them to |
| // wide strings as appropriate. |
| ResultPtr = &ResultBuf[0]; // Next byte to fill in. |
| |
| Pascal = false; |
| |
| for (unsigned i = 0, e = NumStringToks; i != e; ++i) { |
| const char *ThisTokBuf = &TokenBuf[0]; |
| // Get the spelling of the token, which eliminates trigraphs, etc. We know |
| // that ThisTokBuf points to a buffer that is big enough for the whole token |
| // and 'spelled' tokens can only shrink. |
| unsigned ThisTokLen = PP.getSpelling(StringToks[i], ThisTokBuf); |
| const char *ThisTokEnd = ThisTokBuf+ThisTokLen-1; // Skip end quote. |
| |
| // TODO: Input character set mapping support. |
| |
| // Skip L marker for wide strings. |
| bool ThisIsWide = false; |
| if (ThisTokBuf[0] == 'L') { |
| ++ThisTokBuf; |
| ThisIsWide = true; |
| } |
| |
| assert(ThisTokBuf[0] == '"' && "Expected quote, lexer broken?"); |
| ++ThisTokBuf; |
| |
| // Check if this is a pascal string |
| if (pp.getLangOptions().PascalStrings && ThisTokBuf + 1 != ThisTokEnd && |
| ThisTokBuf[0] == '\\' && ThisTokBuf[1] == 'p') { |
| |
| // If the \p sequence is found in the first token, we have a pascal string |
| // Otherwise, if we already have a pascal string, ignore the first \p |
| if (i == 0) { |
| ++ThisTokBuf; |
| Pascal = true; |
| } else if (Pascal) |
| ThisTokBuf += 2; |
| } |
| |
| while (ThisTokBuf != ThisTokEnd) { |
| // Is this a span of non-escape characters? |
| if (ThisTokBuf[0] != '\\') { |
| const char *InStart = ThisTokBuf; |
| do { |
| ++ThisTokBuf; |
| } while (ThisTokBuf != ThisTokEnd && ThisTokBuf[0] != '\\'); |
| |
| // Copy the character span over. |
| unsigned Len = ThisTokBuf-InStart; |
| if (!AnyWide) { |
| memcpy(ResultPtr, InStart, Len); |
| ResultPtr += Len; |
| } else { |
| // Note: our internal rep of wide char tokens is always little-endian. |
| for (; Len; --Len, ++InStart) { |
| *ResultPtr++ = InStart[0]; |
| // Add zeros at the end. |
| for (unsigned i = 1, e = wchar_tByteWidth; i != e; ++i) |
| *ResultPtr++ = 0; |
| } |
| } |
| continue; |
| } |
| // Is this a Universal Character Name escape? |
| if (ThisTokBuf[1] == 'u' || ThisTokBuf[1] == 'U') { |
| ProcessUCNEscape(ThisTokBuf, ThisTokEnd, ResultPtr, |
| hadError, StringToks[i].getLocation(), ThisIsWide, PP); |
| continue; |
| } |
| // Otherwise, this is a non-UCN escape character. Process it. |
| unsigned ResultChar = ProcessCharEscape(ThisTokBuf, ThisTokEnd, hadError, |
| StringToks[i].getLocation(), |
| ThisIsWide, PP); |
| |
| // Note: our internal rep of wide char tokens is always little-endian. |
| *ResultPtr++ = ResultChar & 0xFF; |
| |
| if (AnyWide) { |
| for (unsigned i = 1, e = wchar_tByteWidth; i != e; ++i) |
| *ResultPtr++ = ResultChar >> i*8; |
| } |
| } |
| } |
| |
| if (Pascal) { |
| ResultBuf[0] = ResultPtr-&ResultBuf[0]-1; |
| |
| // Verify that pascal strings aren't too large. |
| if (GetStringLength() > 256) { |
| PP.Diag(StringToks[0].getLocation(), diag::err_pascal_string_too_long) |
| << SourceRange(StringToks[0].getLocation(), |
| StringToks[NumStringToks-1].getLocation()); |
| hadError = 1; |
| return; |
| } |
| } |
| } |
| |
| |
| /// getOffsetOfStringByte - This function returns the offset of the |
| /// specified byte of the string data represented by Token. This handles |
| /// advancing over escape sequences in the string. |
| unsigned StringLiteralParser::getOffsetOfStringByte(const Token &Tok, |
| unsigned ByteNo, |
| Preprocessor &PP) { |
| // Get the spelling of the token. |
| llvm::SmallString<16> SpellingBuffer; |
| SpellingBuffer.resize(Tok.getLength()); |
| |
| const char *SpellingPtr = &SpellingBuffer[0]; |
| unsigned TokLen = PP.getSpelling(Tok, SpellingPtr); |
| |
| assert(SpellingPtr[0] != 'L' && "Doesn't handle wide strings yet"); |
| |
| |
| const char *SpellingStart = SpellingPtr; |
| const char *SpellingEnd = SpellingPtr+TokLen; |
| |
| // Skip over the leading quote. |
| assert(SpellingPtr[0] == '"' && "Should be a string literal!"); |
| ++SpellingPtr; |
| |
| // Skip over bytes until we find the offset we're looking for. |
| while (ByteNo) { |
| assert(SpellingPtr < SpellingEnd && "Didn't find byte offset!"); |
| |
| // Step over non-escapes simply. |
| if (*SpellingPtr != '\\') { |
| ++SpellingPtr; |
| --ByteNo; |
| continue; |
| } |
| |
| // Otherwise, this is an escape character. Advance over it. |
| bool HadError = false; |
| ProcessCharEscape(SpellingPtr, SpellingEnd, HadError, |
| Tok.getLocation(), false, PP); |
| assert(!HadError && "This method isn't valid on erroneous strings"); |
| --ByteNo; |
| } |
| |
| return SpellingPtr-SpellingStart; |
| } |