libbfd.texi revision 1.1
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 (*(const unsigned char *) (ptr) & 0xff) 54#define bfd_get_signed_8(abfd, ptr) \ 55 (((*(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_32(abfd, val, ptr) \ 67 BFD_SEND (abfd, bfd_putx32, ((val),(ptr))) 68#define bfd_put_signed_32 \ 69 bfd_put_32 70#define bfd_get_32(abfd, ptr) \ 71 BFD_SEND (abfd, bfd_getx32, (ptr)) 72#define bfd_get_signed_32(abfd, ptr) \ 73 BFD_SEND (abfd, bfd_getx_signed_32, (ptr)) 74 75#define bfd_put_64(abfd, val, ptr) \ 76 BFD_SEND (abfd, bfd_putx64, ((val), (ptr))) 77#define bfd_put_signed_64 \ 78 bfd_put_64 79#define bfd_get_64(abfd, ptr) \ 80 BFD_SEND (abfd, bfd_getx64, (ptr)) 81#define bfd_get_signed_64(abfd, ptr) \ 82 BFD_SEND (abfd, bfd_getx_signed_64, (ptr)) 83 84#define bfd_get(bits, abfd, ptr) \ 85 ((bits) == 8 ? (bfd_vma) bfd_get_8 (abfd, ptr) \ 86 : (bits) == 16 ? bfd_get_16 (abfd, ptr) \ 87 : (bits) == 32 ? bfd_get_32 (abfd, ptr) \ 88 : (bits) == 64 ? bfd_get_64 (abfd, ptr) \ 89 : (abort (), (bfd_vma) - 1)) 90 91#define bfd_put(bits, abfd, val, ptr) \ 92 ((bits) == 8 ? bfd_put_8 (abfd, val, ptr) \ 93 : (bits) == 16 ? bfd_put_16 (abfd, val, ptr) \ 94 : (bits) == 32 ? bfd_put_32 (abfd, val, ptr) \ 95 : (bits) == 64 ? bfd_put_64 (abfd, val, ptr) \ 96 : (abort (), (void) 0)) 97 98@end example 99 100@findex bfd_h_put_size 101@subsubsection @code{bfd_h_put_size} 102@strong{Description}@* 103These macros have the same function as their @code{bfd_get_x} 104brethren, except that they are used for removing information 105for the header records of object files. Believe it or not, 106some object files keep their header records in big endian 107order and their data in little endian order. 108@example 109 110/* Byte swapping macros for file header data. */ 111 112#define bfd_h_put_8(abfd, val, ptr) \ 113 bfd_put_8 (abfd, val, ptr) 114#define bfd_h_put_signed_8(abfd, val, ptr) \ 115 bfd_put_8 (abfd, val, ptr) 116#define bfd_h_get_8(abfd, ptr) \ 117 bfd_get_8 (abfd, ptr) 118#define bfd_h_get_signed_8(abfd, ptr) \ 119 bfd_get_signed_8 (abfd, ptr) 120 121#define bfd_h_put_16(abfd, val, ptr) \ 122 BFD_SEND (abfd, bfd_h_putx16, (val, ptr)) 123#define bfd_h_put_signed_16 \ 124 bfd_h_put_16 125#define bfd_h_get_16(abfd, ptr) \ 126 BFD_SEND (abfd, bfd_h_getx16, (ptr)) 127#define bfd_h_get_signed_16(abfd, ptr) \ 128 BFD_SEND (abfd, bfd_h_getx_signed_16, (ptr)) 129 130#define bfd_h_put_32(abfd, val, ptr) \ 131 BFD_SEND (abfd, bfd_h_putx32, (val, ptr)) 132#define bfd_h_put_signed_32 \ 133 bfd_h_put_32 134#define bfd_h_get_32(abfd, ptr) \ 135 BFD_SEND (abfd, bfd_h_getx32, (ptr)) 136#define bfd_h_get_signed_32(abfd, ptr) \ 137 BFD_SEND (abfd, bfd_h_getx_signed_32, (ptr)) 138 139#define bfd_h_put_64(abfd, val, ptr) \ 140 BFD_SEND (abfd, bfd_h_putx64, (val, ptr)) 141#define bfd_h_put_signed_64 \ 142 bfd_h_put_64 143#define bfd_h_get_64(abfd, ptr) \ 144 BFD_SEND (abfd, bfd_h_getx64, (ptr)) 145#define bfd_h_get_signed_64(abfd, ptr) \ 146 BFD_SEND (abfd, bfd_h_getx_signed_64, (ptr)) 147 148/* Aliases for the above, which should eventually go away. */ 149 150#define H_PUT_64 bfd_h_put_64 151#define H_PUT_32 bfd_h_put_32 152#define H_PUT_16 bfd_h_put_16 153#define H_PUT_8 bfd_h_put_8 154#define H_PUT_S64 bfd_h_put_signed_64 155#define H_PUT_S32 bfd_h_put_signed_32 156#define H_PUT_S16 bfd_h_put_signed_16 157#define H_PUT_S8 bfd_h_put_signed_8 158#define H_GET_64 bfd_h_get_64 159#define H_GET_32 bfd_h_get_32 160#define H_GET_16 bfd_h_get_16 161#define H_GET_8 bfd_h_get_8 162#define H_GET_S64 bfd_h_get_signed_64 163#define H_GET_S32 bfd_h_get_signed_32 164#define H_GET_S16 bfd_h_get_signed_16 165#define H_GET_S8 bfd_h_get_signed_8 166 167 168@end example 169 170@findex bfd_log2 171@subsubsection @code{bfd_log2} 172@strong{Synopsis} 173@example 174unsigned int bfd_log2 (bfd_vma x); 175@end example 176@strong{Description}@* 177Return the log base 2 of the value supplied, rounded up. E.g., an 178@var{x} of 1025 returns 11. A @var{x} of 0 returns 0. 179 180