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Diffstat (limited to 'bfd/doc/libbfd.texi')
| -rw-r--r-- | bfd/doc/libbfd.texi | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/bfd/doc/libbfd.texi b/bfd/doc/libbfd.texi new file mode 100644 index 0000000000..b0b03003a6 --- /dev/null +++ b/bfd/doc/libbfd.texi @@ -0,0 +1,179 @@ +@section Implementation details + + +@subsection Internal functions + + +@strong{Description}@* +These routines are used within BFD. +They are not intended for export, but are documented here for +completeness. + +@findex bfd_write_bigendian_4byte_int +@subsubsection @code{bfd_write_bigendian_4byte_int} +@strong{Synopsis} +@example +bfd_boolean bfd_write_bigendian_4byte_int (bfd *, unsigned int); +@end example +@strong{Description}@* +Write a 4 byte integer @var{i} to the output BFD @var{abfd}, in big +endian order regardless of what else is going on. This is useful in +archives. + +@findex bfd_put_size +@subsubsection @code{bfd_put_size} +@findex bfd_get_size +@subsubsection @code{bfd_get_size} +@strong{Description}@* +These macros as used for reading and writing raw data in +sections; each access (except for bytes) is vectored through +the target format of the BFD and mangled accordingly. The +mangling performs any necessary endian translations and +removes alignment restrictions. Note that types accepted and +returned by these macros are identical so they can be swapped +around in macros---for example, @file{libaout.h} defines @code{GET_WORD} +to either @code{bfd_get_32} or @code{bfd_get_64}. + +In the put routines, @var{val} must be a @code{bfd_vma}. If we are on a +system without prototypes, the caller is responsible for making +sure that is true, with a cast if necessary. We don't cast +them in the macro definitions because that would prevent @code{lint} +or @code{gcc -Wall} from detecting sins such as passing a pointer. +To detect calling these with less than a @code{bfd_vma}, use +@code{gcc -Wconversion} on a host with 64 bit @code{bfd_vma}'s. +@example + +/* Byte swapping macros for user section data. */ + +#define bfd_put_8(abfd, val, ptr) \ + ((void) (*((unsigned char *) (ptr)) = (val) & 0xff)) +#define bfd_put_signed_8 \ + bfd_put_8 +#define bfd_get_8(abfd, ptr) \ + (*(const unsigned char *) (ptr) & 0xff) +#define bfd_get_signed_8(abfd, ptr) \ + (((*(const unsigned char *) (ptr) & 0xff) ^ 0x80) - 0x80) + +#define bfd_put_16(abfd, val, ptr) \ + BFD_SEND (abfd, bfd_putx16, ((val),(ptr))) +#define bfd_put_signed_16 \ + bfd_put_16 +#define bfd_get_16(abfd, ptr) \ + BFD_SEND (abfd, bfd_getx16, (ptr)) +#define bfd_get_signed_16(abfd, ptr) \ + BFD_SEND (abfd, bfd_getx_signed_16, (ptr)) + +#define bfd_put_32(abfd, val, ptr) \ + BFD_SEND (abfd, bfd_putx32, ((val),(ptr))) +#define bfd_put_signed_32 \ + bfd_put_32 +#define bfd_get_32(abfd, ptr) \ + BFD_SEND (abfd, bfd_getx32, (ptr)) +#define bfd_get_signed_32(abfd, ptr) \ + BFD_SEND (abfd, bfd_getx_signed_32, (ptr)) + +#define bfd_put_64(abfd, val, ptr) \ + BFD_SEND (abfd, bfd_putx64, ((val), (ptr))) +#define bfd_put_signed_64 \ + bfd_put_64 +#define bfd_get_64(abfd, ptr) \ + BFD_SEND (abfd, bfd_getx64, (ptr)) +#define bfd_get_signed_64(abfd, ptr) \ + BFD_SEND (abfd, bfd_getx_signed_64, (ptr)) + +#define bfd_get(bits, abfd, ptr) \ + ((bits) == 8 ? (bfd_vma) bfd_get_8 (abfd, ptr) \ + : (bits) == 16 ? bfd_get_16 (abfd, ptr) \ + : (bits) == 32 ? bfd_get_32 (abfd, ptr) \ + : (bits) == 64 ? bfd_get_64 (abfd, ptr) \ + : (abort (), (bfd_vma) - 1)) + +#define bfd_put(bits, abfd, val, ptr) \ + ((bits) == 8 ? bfd_put_8 (abfd, val, ptr) \ + : (bits) == 16 ? bfd_put_16 (abfd, val, ptr) \ + : (bits) == 32 ? bfd_put_32 (abfd, val, ptr) \ + : (bits) == 64 ? bfd_put_64 (abfd, val, ptr) \ + : (abort (), (void) 0)) + +@end example + +@findex bfd_h_put_size +@subsubsection @code{bfd_h_put_size} +@strong{Description}@* +These macros have the same function as their @code{bfd_get_x} +brethren, except that they are used for removing information +for the header records of object files. Believe it or not, +some object files keep their header records in big endian +order and their data in little endian order. +@example + +/* Byte swapping macros for file header data. */ + +#define bfd_h_put_8(abfd, val, ptr) \ + bfd_put_8 (abfd, val, ptr) +#define bfd_h_put_signed_8(abfd, val, ptr) \ + bfd_put_8 (abfd, val, ptr) +#define bfd_h_get_8(abfd, ptr) \ + bfd_get_8 (abfd, ptr) +#define bfd_h_get_signed_8(abfd, ptr) \ + bfd_get_signed_8 (abfd, ptr) + +#define bfd_h_put_16(abfd, val, ptr) \ + BFD_SEND (abfd, bfd_h_putx16, (val, ptr)) +#define bfd_h_put_signed_16 \ + bfd_h_put_16 +#define bfd_h_get_16(abfd, ptr) \ + BFD_SEND (abfd, bfd_h_getx16, (ptr)) +#define bfd_h_get_signed_16(abfd, ptr) \ + BFD_SEND (abfd, bfd_h_getx_signed_16, (ptr)) + +#define bfd_h_put_32(abfd, val, ptr) \ + BFD_SEND (abfd, bfd_h_putx32, (val, ptr)) +#define bfd_h_put_signed_32 \ + bfd_h_put_32 +#define bfd_h_get_32(abfd, ptr) \ + BFD_SEND (abfd, bfd_h_getx32, (ptr)) +#define bfd_h_get_signed_32(abfd, ptr) \ + BFD_SEND (abfd, bfd_h_getx_signed_32, (ptr)) + +#define bfd_h_put_64(abfd, val, ptr) \ + BFD_SEND (abfd, bfd_h_putx64, (val, ptr)) +#define bfd_h_put_signed_64 \ + bfd_h_put_64 +#define bfd_h_get_64(abfd, ptr) \ + BFD_SEND (abfd, bfd_h_getx64, (ptr)) +#define bfd_h_get_signed_64(abfd, ptr) \ + BFD_SEND (abfd, bfd_h_getx_signed_64, (ptr)) + +/* Aliases for the above, which should eventually go away. */ + +#define H_PUT_64 bfd_h_put_64 +#define H_PUT_32 bfd_h_put_32 +#define H_PUT_16 bfd_h_put_16 +#define H_PUT_8 bfd_h_put_8 +#define H_PUT_S64 bfd_h_put_signed_64 +#define H_PUT_S32 bfd_h_put_signed_32 +#define H_PUT_S16 bfd_h_put_signed_16 +#define H_PUT_S8 bfd_h_put_signed_8 +#define H_GET_64 bfd_h_get_64 +#define H_GET_32 bfd_h_get_32 +#define H_GET_16 bfd_h_get_16 +#define H_GET_8 bfd_h_get_8 +#define H_GET_S64 bfd_h_get_signed_64 +#define H_GET_S32 bfd_h_get_signed_32 +#define H_GET_S16 bfd_h_get_signed_16 +#define H_GET_S8 bfd_h_get_signed_8 + + +@end example + +@findex bfd_log2 +@subsubsection @code{bfd_log2} +@strong{Synopsis} +@example +unsigned int bfd_log2 (bfd_vma x); +@end example +@strong{Description}@* +Return the log base 2 of the value supplied, rounded up. E.g., an +@var{x} of 1025 returns 11. A @var{x} of 0 returns 0. + |