libbfd.texi revision 1.1.1.4
1@section Implementation details 2 3 4@subsection Internal functions 5 6 7@strong{Description}@* 8These routines are used within BFD. 9They are not intended for export, but are documented here for 10completeness. 11 12@findex bfd_write_bigendian_4byte_int 13@subsubsection @code{bfd_write_bigendian_4byte_int} 14@strong{Synopsis} 15@example 16bfd_boolean bfd_write_bigendian_4byte_int (bfd *, unsigned int); 17@end example 18@strong{Description}@* 19Write a 4 byte integer @var{i} to the output BFD @var{abfd}, in big 20endian order regardless of what else is going on. This is useful in 21archives. 22 23@findex bfd_put_size 24@subsubsection @code{bfd_put_size} 25@findex bfd_get_size 26@subsubsection @code{bfd_get_size} 27@strong{Description}@* 28These macros as used for reading and writing raw data in 29sections; each access (except for bytes) is vectored through 30the target format of the BFD and mangled accordingly. The 31mangling performs any necessary endian translations and 32removes alignment restrictions. Note that types accepted and 33returned by these macros are identical so they can be swapped 34around in macros---for example, @file{libaout.h} defines @code{GET_WORD} 35to either @code{bfd_get_32} or @code{bfd_get_64}. 36 37In the put routines, @var{val} must be a @code{bfd_vma}. If we are on a 38system without prototypes, the caller is responsible for making 39sure that is true, with a cast if necessary. We don't cast 40them in the macro definitions because that would prevent @code{lint} 41or @code{gcc -Wall} from detecting sins such as passing a pointer. 42To detect calling these with less than a @code{bfd_vma}, use 43@code{gcc -Wconversion} on a host with 64 bit @code{bfd_vma}'s. 44@example 45 46/* Byte swapping macros for user section data. */ 47 48#define bfd_put_8(abfd, val, ptr) \ 49 ((void) (*((unsigned char *) (ptr)) = (val) & 0xff)) 50#define bfd_put_signed_8 \ 51 bfd_put_8 52#define bfd_get_8(abfd, ptr) \ 53 ((bfd_vma) *(const unsigned char *) (ptr) & 0xff) 54#define bfd_get_signed_8(abfd, ptr) \ 55 ((((bfd_signed_vma) *(const unsigned char *) (ptr) & 0xff) ^ 0x80) - 0x80) 56 57#define bfd_put_16(abfd, val, ptr) \ 58 BFD_SEND (abfd, bfd_putx16, ((val),(ptr))) 59#define bfd_put_signed_16 \ 60 bfd_put_16 61#define bfd_get_16(abfd, ptr) \ 62 BFD_SEND (abfd, bfd_getx16, (ptr)) 63#define bfd_get_signed_16(abfd, ptr) \ 64 BFD_SEND (abfd, bfd_getx_signed_16, (ptr)) 65 66#define bfd_put_24(abfd, val, ptr) \ 67 do \ 68 if (bfd_big_endian (abfd)) \ 69 bfd_putb24 ((val), (ptr)); \ 70 else \ 71 bfd_putl24 ((val), (ptr)); \ 72 while (0) 73 74bfd_vma bfd_getb24 (const void *p); 75bfd_vma bfd_getl24 (const void *p); 76 77#define bfd_get_24(abfd, ptr) \ 78 (bfd_big_endian (abfd) ? bfd_getb24 (ptr) : bfd_getl24 (ptr)) 79 80#define bfd_put_32(abfd, val, ptr) \ 81 BFD_SEND (abfd, bfd_putx32, ((val),(ptr))) 82#define bfd_put_signed_32 \ 83 bfd_put_32 84#define bfd_get_32(abfd, ptr) \ 85 BFD_SEND (abfd, bfd_getx32, (ptr)) 86#define bfd_get_signed_32(abfd, ptr) \ 87 BFD_SEND (abfd, bfd_getx_signed_32, (ptr)) 88 89#define bfd_put_64(abfd, val, ptr) \ 90 BFD_SEND (abfd, bfd_putx64, ((val), (ptr))) 91#define bfd_put_signed_64 \ 92 bfd_put_64 93#define bfd_get_64(abfd, ptr) \ 94 BFD_SEND (abfd, bfd_getx64, (ptr)) 95#define bfd_get_signed_64(abfd, ptr) \ 96 BFD_SEND (abfd, bfd_getx_signed_64, (ptr)) 97 98#define bfd_get(bits, abfd, ptr) \ 99 ((bits) == 8 ? bfd_get_8 (abfd, ptr) \ 100 : (bits) == 16 ? bfd_get_16 (abfd, ptr) \ 101 : (bits) == 32 ? bfd_get_32 (abfd, ptr) \ 102 : (bits) == 64 ? bfd_get_64 (abfd, ptr) \ 103 : (abort (), (bfd_vma) - 1)) 104 105#define bfd_put(bits, abfd, val, ptr) \ 106 ((bits) == 8 ? bfd_put_8 (abfd, val, ptr) \ 107 : (bits) == 16 ? bfd_put_16 (abfd, val, ptr) \ 108 : (bits) == 32 ? bfd_put_32 (abfd, val, ptr) \ 109 : (bits) == 64 ? bfd_put_64 (abfd, val, ptr) \ 110 : (abort (), (void) 0)) 111 112@end example 113 114@findex bfd_h_put_size 115@subsubsection @code{bfd_h_put_size} 116@strong{Description}@* 117These macros have the same function as their @code{bfd_get_x} 118brethren, except that they are used for removing information 119for the header records of object files. Believe it or not, 120some object files keep their header records in big endian 121order and their data in little endian order. 122@example 123 124/* Byte swapping macros for file header data. */ 125 126#define bfd_h_put_8(abfd, val, ptr) \ 127 bfd_put_8 (abfd, val, ptr) 128#define bfd_h_put_signed_8(abfd, val, ptr) \ 129 bfd_put_8 (abfd, val, ptr) 130#define bfd_h_get_8(abfd, ptr) \ 131 bfd_get_8 (abfd, ptr) 132#define bfd_h_get_signed_8(abfd, ptr) \ 133 bfd_get_signed_8 (abfd, ptr) 134 135#define bfd_h_put_16(abfd, val, ptr) \ 136 BFD_SEND (abfd, bfd_h_putx16, (val, ptr)) 137#define bfd_h_put_signed_16 \ 138 bfd_h_put_16 139#define bfd_h_get_16(abfd, ptr) \ 140 BFD_SEND (abfd, bfd_h_getx16, (ptr)) 141#define bfd_h_get_signed_16(abfd, ptr) \ 142 BFD_SEND (abfd, bfd_h_getx_signed_16, (ptr)) 143 144#define bfd_h_put_32(abfd, val, ptr) \ 145 BFD_SEND (abfd, bfd_h_putx32, (val, ptr)) 146#define bfd_h_put_signed_32 \ 147 bfd_h_put_32 148#define bfd_h_get_32(abfd, ptr) \ 149 BFD_SEND (abfd, bfd_h_getx32, (ptr)) 150#define bfd_h_get_signed_32(abfd, ptr) \ 151 BFD_SEND (abfd, bfd_h_getx_signed_32, (ptr)) 152 153#define bfd_h_put_64(abfd, val, ptr) \ 154 BFD_SEND (abfd, bfd_h_putx64, (val, ptr)) 155#define bfd_h_put_signed_64 \ 156 bfd_h_put_64 157#define bfd_h_get_64(abfd, ptr) \ 158 BFD_SEND (abfd, bfd_h_getx64, (ptr)) 159#define bfd_h_get_signed_64(abfd, ptr) \ 160 BFD_SEND (abfd, bfd_h_getx_signed_64, (ptr)) 161 162/* Aliases for the above, which should eventually go away. */ 163 164#define H_PUT_64 bfd_h_put_64 165#define H_PUT_32 bfd_h_put_32 166#define H_PUT_16 bfd_h_put_16 167#define H_PUT_8 bfd_h_put_8 168#define H_PUT_S64 bfd_h_put_signed_64 169#define H_PUT_S32 bfd_h_put_signed_32 170#define H_PUT_S16 bfd_h_put_signed_16 171#define H_PUT_S8 bfd_h_put_signed_8 172#define H_GET_64 bfd_h_get_64 173#define H_GET_32 bfd_h_get_32 174#define H_GET_16 bfd_h_get_16 175#define H_GET_8 bfd_h_get_8 176#define H_GET_S64 bfd_h_get_signed_64 177#define H_GET_S32 bfd_h_get_signed_32 178#define H_GET_S16 bfd_h_get_signed_16 179#define H_GET_S8 bfd_h_get_signed_8 180 181 182@end example 183 184@findex bfd_log2 185@subsubsection @code{bfd_log2} 186@strong{Synopsis} 187@example 188unsigned int bfd_log2 (bfd_vma x); 189@end example 190@strong{Description}@* 191Return the log base 2 of the value supplied, rounded up. E.g., an 192@var{x} of 1025 returns 11. A @var{x} of 0 returns 0. 193 194