diff options
| -rw-r--r-- | contrib/gcc/ChangeLog.gcc43 | 6 | ||||
| -rw-r--r-- | contrib/gcc/doc/extend.texi | 23 | ||||
| -rw-r--r-- | contrib/gcclibs/libcpp/expr.c | 46 | ||||
| -rw-r--r-- | contrib/gcclibs/libcpp/include/cpplib.h | 1 |
4 files changed, 73 insertions, 3 deletions
diff --git a/contrib/gcc/ChangeLog.gcc43 b/contrib/gcc/ChangeLog.gcc43 index 3f893ac6bbc0..05f01073d945 100644 --- a/contrib/gcc/ChangeLog.gcc43 +++ b/contrib/gcc/ChangeLog.gcc43 @@ -1,3 +1,9 @@ +2007-06-05 Joerg Wunsch <j.gnu@uriah.heep.sax.de> (r23479) + + PR preprocessor/23479 + * doc/extend.texi: Document the 0b-prefixed binary integer + constant extension. + 2007-05-01 Dwarakanath Rajagopal <dwarak.rajagopal@amd.com> (r124341) * doc/invoke.texi: Fix typo, 'AMD Family 10h core' instead of diff --git a/contrib/gcc/doc/extend.texi b/contrib/gcc/doc/extend.texi index d7a1494eebcc..d27af1083a41 100644 --- a/contrib/gcc/doc/extend.texi +++ b/contrib/gcc/doc/extend.texi @@ -81,6 +81,7 @@ extensions, accepted by GCC in C89 mode and in C++. * Pragmas:: Pragmas accepted by GCC. * Unnamed Fields:: Unnamed struct/union fields within structs/unions. * Thread-Local:: Per-thread variables. +* Binary constants:: Binary constants using the @samp{0b} prefix. @end menu @node Statement Exprs @@ -10424,6 +10425,28 @@ Non-@code{static} members shall not be @code{__thread}. @end quotation @end itemize +@node Binary constants +@section Binary constants using the @samp{0b} prefix +@cindex Binary constants using the @samp{0b} prefix + +Integer constants can be written as binary constants, consisting of a +sequence of @samp{0} and @samp{1} digits, prefixed by @samp{0b} or +@samp{0B}. This is particularly useful in environments that operate a +lot on the bit-level (like microcontrollers). + +The following statements are identical: + +@smallexample +i = 42; +i = 0x2a; +i = 052; +i = 0b101010; +@end smallexample + +The type of these constants follows the same rules as for octal or +hexadecimal integer constants, so suffixes like @samp{L} or @samp{UL} +can be applied. + @node C++ Extensions @chapter Extensions to the C++ Language @cindex extensions, C++ language diff --git a/contrib/gcclibs/libcpp/expr.c b/contrib/gcclibs/libcpp/expr.c index bf8baaff2659..24fcb1b863e9 100644 --- a/contrib/gcclibs/libcpp/expr.c +++ b/contrib/gcclibs/libcpp/expr.c @@ -188,6 +188,11 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token) radix = 16; str++; } + else if ((*str == 'b' || *str == 'B') && (str[1] == '0' || str[1] == '1')) + { + radix = 2; + str++; + } } /* Now scan for a well-formed integer or float. */ @@ -226,10 +231,22 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token) radix = 10; if (max_digit >= radix) - SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit); + { + if (radix == 2) + SYNTAX_ERROR2 ("invalid digit \"%c\" in binary constant", '0' + max_digit); + else + SYNTAX_ERROR2 ("invalid digit \"%c\" in octal constant", '0' + max_digit); + } if (float_flag != NOT_FLOAT) { + if (radix == 2) + { + cpp_error (pfile, CPP_DL_ERROR, + "invalid prefix \"0b\" for floating constant"); + return CPP_N_INVALID; + } + if (radix == 16 && CPP_PEDANTIC (pfile) && !CPP_OPTION (pfile, c99)) cpp_error (pfile, CPP_DL_PEDWARN, "use of C99 hexadecimal floating constant"); @@ -321,11 +338,16 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token) if ((result & CPP_N_IMAGINARY) && CPP_PEDANTIC (pfile)) cpp_error (pfile, CPP_DL_PEDWARN, "imaginary constants are a GCC extension"); + if (radix == 2 && CPP_PEDANTIC (pfile)) + cpp_error (pfile, CPP_DL_PEDWARN, + "binary constants are a GCC extension"); if (radix == 10) result |= CPP_N_DECIMAL; else if (radix == 16) result |= CPP_N_HEX; + else if (radix == 2) + result |= CPP_N_BINARY; else result |= CPP_N_OCTAL; @@ -376,6 +398,11 @@ cpp_interpret_integer (cpp_reader *pfile, const cpp_token *token, base = 16; p += 2; } + else if ((type & CPP_N_RADIX) == CPP_N_BINARY) + { + base = 2; + p += 2; + } /* We can add a digit to numbers strictly less than this without needing the precision and slowness of double integers. */ @@ -431,12 +458,25 @@ static cpp_num append_digit (cpp_num num, int digit, int base, size_t precision) { cpp_num result; - unsigned int shift = 3 + (base == 16); + unsigned int shift; bool overflow; cpp_num_part add_high, add_low; - /* Multiply by 8 or 16. Catching this overflow here means we don't + /* Multiply by 2, 8 or 16. Catching this overflow here means we don't need to worry about add_high overflowing. */ + switch (base) + { + case 2: + shift = 1; + break; + + case 16: + shift = 4; + break; + + default: + shift = 3; + } overflow = !!(num.high >> (PART_PRECISION - shift)); result.high = num.high << shift; result.low = num.low << shift; diff --git a/contrib/gcclibs/libcpp/include/cpplib.h b/contrib/gcclibs/libcpp/include/cpplib.h index 851a2e3d7670..7fd73b87d8a2 100644 --- a/contrib/gcclibs/libcpp/include/cpplib.h +++ b/contrib/gcclibs/libcpp/include/cpplib.h @@ -745,6 +745,7 @@ struct cpp_num #define CPP_N_DECIMAL 0x0100 #define CPP_N_HEX 0x0200 #define CPP_N_OCTAL 0x0400 +#define CPP_N_BINARY 0x0800 #define CPP_N_UNSIGNED 0x1000 /* Properties. */ #define CPP_N_IMAGINARY 0x2000 |