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This commit is contained in:
Steve Chamberlain 1991-07-04 16:52:19 +00:00
parent bdf3621b9e
commit 985fca1293
3 changed files with 1230 additions and 0 deletions
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65
bfd/core.c Normal file
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/*doc*
@section Core files
Buff output this facinating topic
*/
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
/** Some core file info commands */
/*proto*i bfd_core_file_failing_command
Returns a read-only string explaining what program was running when
it failed and produced the core file being read
*; PROTO(CONST char *, bfd_core_file_failing_command, (bfd *));
*/
CONST char *
DEFUN(bfd_core_file_failing_command,(abfd),
bfd *abfd)
{
if (abfd->format != bfd_core) {
bfd_error = invalid_operation;
return NULL;
}
return BFD_SEND (abfd, _core_file_failing_command, (abfd));
}
/*proto* bfd_core_file_failing_signal
Returns the signal number which caused the core dump which generated
the file the bfd is attatched to.
*; PROTO(int, bfd_core_file_failing_signal, (bfd *));
*/
int
bfd_core_file_failing_signal (abfd)
bfd *abfd;
{
if (abfd->format != bfd_core) {
bfd_error = invalid_operation;
return 0;
}
return BFD_SEND (abfd, _core_file_failing_signal, (abfd));
}
/*proto* core_file_matches_executable_p
Returns @code{true} if the core file attatched to @var{core_bfd} was
generated by a run of the executable file attatched to @var{exec_bfd},
or else @code{false}.
*; PROTO(boolean, core_file_matches_executable_p,
(bfd *core_bfd, bfd *exec_bfd));
*/
boolean
core_file_matches_executable_p (core_bfd, exec_bfd)
bfd *core_bfd, *exec_bfd;
{
if ((core_bfd->format != bfd_core) || (exec_bfd->format != bfd_object)) {
bfd_error = wrong_format;
return false;
}
return BFD_SEND (core_bfd, _core_file_matches_executable_p, (core_bfd, exec_bfd));
}

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/*doc*
@section Relocations
Bfd maintains relocations in much the same was as it maintains
symbols; they are left alone until required, then read in en-mass and
traslated into an internal form. There is a common routine
@code{bfd_perform_relocation} which acts upon the canonical form to to
the actual fixup.
Note that relocations are maintained on a per section basis, whilst
symbols are maintained on a per bfd basis.
All a back end has to do to fit the bfd interface is to create as many
@code{struct reloc_cache_entry} as there are relocations in a
particuar section, and fill in the right bits:
@menu
* typedef arelent::
* reloc handling functions::
@end menu
*/
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
/*doc
*node typedef arelent, Relocations, reloc handling functions, Relocations
@section typedef arelent
*/
/*proto* bfd_perform_relocation
The relocation routine returns as a status an enumerated type:
*+++
$typedef enum bfd_reloc_status {
No errors detected
$ bfd_reloc_ok,
The relocation was performed, but there was an overflow.
$ bfd_reloc_overflow,
The address to relocate was not within the section supplied
$ bfd_reloc_outofrange,
Used by special functions
$ bfd_reloc_continue,
Unused
$ bfd_reloc_notsupported,
Unsupported relocation size requested.
$ bfd_reloc_other,
The symbol to relocate against was undefined.
$ bfd_reloc_undefined,
The relocaction was performed, but may not be ok - presently generated
only when linking i960 coff files with i960 b.out symbols.
$ bfd_reloc_dangerous
$ }
$ bfd_reloc_status_enum_type;
*---
*/
/*proto*
*+++
$typedef struct reloc_cache_entry
${
A pointer into the canonical table of pointers
$ struct symbol_cache_entry **sym_ptr_ptr;
offset in section
$ rawdata_offset address;
addend for relocation value
$ bfd_vma addend;
if sym is null this is the section
$ struct sec *section;
Pointer to how to perform the required relocation
$ struct reloc_howto_struct *howto;
$} arelent;
*---
*/
/*doc*
@table @code
@item sym_ptr_ptr
The symbol table pointer points to a pointer to the symbol ascociated with the
relocation request. This would naturaly be the pointer into the table
returned by the back end's get_symtab action. @xref{Symbols}. The
symbol is referenced through a pointer to a pointer so that tools like
the linker can fixup all the symbols of the same name by modifying
only one pointer. The relocation routine looks in the symbol and uses
the base of the section the symbol is attatched to and the value of
the symbol as the initial relocation offset. If the symbol pointer is
zero, then the section provided is looked up.
@item address
The address field gives the offset in bytes from the base of the
section data which owns the relocation record to the first byte of
relocatable information. The actual data relocated will be relative to
this point - for example, a relocation type which modifies the bottom
two bytes of a four byte word would not touch the first byte pointed
to in a big endian world.
@item addend
The addend is a value provided by the back end to be added (!) to the
relocation offset. It's interpretation is dependent upon the howto.
For example, on the 68k the code:
*+
char foo[];
main()
{
return foo[0x12345678];
}
*-
Could be compiled into:
*+
linkw fp,#-4
moveb @@#12345678,d0
extbl d0
unlk fp
rts
*-
This could create a reloc pointing to foo, but leave the offset in the data
(something like)
*+
RELOCATION RECORDS FOR [.text]:
OFFSET TYPE VALUE
00000006 32 _foo
00000000 4e56 fffc ; linkw fp,#-4
00000004 1039 1234 5678 ; moveb @@#12345678,d0
0000000a 49c0 ; extbl d0
0000000c 4e5e ; unlk fp
0000000e 4e75 ; rts
*-
Using coff and an 88k, some instructions don't have enough space in them to
represent the full address range, and pointers have to be loaded in
two parts. So you'd get something like:
*+
or.u r13,r0,hi16(_foo+0x12345678)
ld.b r2,r13,lo16(_foo+0x12345678)
jmp r1
*-
This whould create two relocs, both pointing to _foo, and with 0x12340000
in their addend field. The data would consist of:
*+
RELOCATION RECORDS FOR [.text]:
OFFSET TYPE VALUE
00000002 HVRT16 _foo+0x12340000
00000006 LVRT16 _foo+0x12340000
00000000 5da05678 ; or.u r13,r0,0x5678
00000004 1c4d5678 ; ld.b r2,r13,0x5678
00000008 f400c001 ; jmp r1
*-
The relocation routine digs out the value from the data, adds it to
the addend to get the original offset and then adds the value of _foo.
Note that all 32 bits have to be kept around somewhere, to cope with
carry from bit 15 to bit 16.
On further example is the sparc and the a.out format. The sparc has a
similar problem to the 88k, in that some instructions don't have
room for an entire offset, but on the sparc the parts are created odd
sized lumps. The designers of the a.out format chose not to use the
data within the section for storing part of the offset; all the offset
is kept within the reloc. Any thing in the data should be ignored.
*+
save %sp,-112,%sp
sethi %hi(_foo+0x12345678),%g2
ldsb [%g2+%lo(_foo+0x12345678)],%i0
ret
restore
*-
Both relocs contains a pointer to foo, and the offsets would contain junk.
*+
RELOCATION RECORDS FOR [.text]:
OFFSET TYPE VALUE
00000004 HI22 _foo+0x12345678
00000008 LO10 _foo+0x12345678
00000000 9de3bf90 ; save %sp,-112,%sp
00000004 05000000 ; sethi %hi(_foo+0),%g2
00000008 f048a000 ; ldsb [%g2+%lo(_foo+0)],%i0
0000000c 81c7e008 ; ret
00000010 81e80000 ; restore
*-
@item section
The section field is only used when the symbol pointer field is null.
It supplies the section into which the data should be relocated. The
field's main use comes from assemblers which do most of the symbol fixups
themselves; an assembler may take an internal reference to a label,
but since it knows where the label is, it can turn the relocation
request from a symbol lookup into a section relative relocation - the
relocation emitted has no symbol, just a section to relocate against.
I'm not sure what it means when both a symbol pointer an a section
pointer are present. Some formats use this sort of mechanism to
describe PIC relocations, but bfd can't to that sort of thing yet.
@item howto
The howto field can be imagined as a relocation instruction. It is a
pointer to a struct which contains information on what to do with all
the other information in the reloc record and data section. A back end
would normally have a relocation instruction set and turn relocations
into pointers to the correct structure on input - but it would be
possible to create each howto field on demand.
@end table
*/
/*proto* reloc_howto_type
The @code{reloc_howto_type} is a structure which contains all the
information that bfd needs to know to tie up a back end's data.
*+++
$typedef CONST struct reloc_howto_struct
${
The type field has mainly a documetary use - the back end can to what
it wants with it, though the normally the back end's external idea of
what a reloc number would be would be stored in this field. For
example, the a PC relative word relocation in a coff environment would
have the type 023 - because that's what the outside world calls a
R_PCRWORD reloc.
$ unsigned int type;
The value the final relocation is shifted right by. This drops
unwanted data from the relocation.
$ unsigned int rightshift;
The size of the item to be relocated - 0, is one byte, 1 is 2 bytes, 3
is four bytes.
$ unsigned int size;
Now obsolete
$ unsigned int bitsize;
Notes that the relocation is relative to the location in the data
section of the addend. The relocation function will subtract from the
relocation value the address of the location being relocated.
$ boolean pc_relative;
Now obsolete
$ unsigned int bitpos;
Now obsolete
$ boolean absolute;
Causes the relocation routine to return an error if overflow is
detected when relocating.
$ boolean complain_on_overflow;
If this field is non null, then the supplied function is called rather
than the normal function. This allows really strange relocation
methods to be accomodated (eg, i960 callj instructions).
$ bfd_reloc_status_enum_type (*special_function)();
The textual name of the relocation type.
$ char *name;
When performing a partial link, some formats must modify the
relocations rather than the data - this flag signals this.
$ boolean partial_inplace;
The src_mask is used to select what parts of the read in data are to
be used in the relocation sum. Eg, if this was an 8 bit bit of data
which we read and relocated, this would be 0x000000ff. When we have
relocs which have an addend, such as sun4 extended relocs, the value
in the offset part of a relocating field is garbage so we never use
it. In this case the mask would be 0x00000000.
$ bfd_word src_mask;
The dst_mask is what parts of the instruction are replaced into the
instruction. In most cases src_mask == dst_mask, except in the above
special case, where dst_mask would be 0x000000ff, and src_mask would
be 0x00000000.
$ bfd_word dst_mask;
When some formats create PC relative instructions, they leave the
value of the pc of the place being relocated in the offset slot of the
instruction, so that a PC relative relocation can be made just by
adding in an ordinary offset (eg sun3 a.out). Some formats leave the
displacement part of an instruction empty (eg m88k bcs), this flag
signals the fact.
$ boolean pcrel_offset;
$} reloc_howto_type;
*---
*/
/*proto* HOWTO
The HOWTO define is horrible and will go away.
*+
#define HOWTO(C, R,S,B, P, BI, ABS, O, SF, NAME, INPLACE, MASKSRC, MASKDST, PC) \
{(unsigned)C,R,S,B, P, BI, ABS,O,SF,NAME,INPLACE,MASKSRC,MASKDST,PC}
*-
*/
/*proto* reloc_chain
*+
typedef unsigned char bfd_byte;
typedef struct relent_chain {
arelent relent;
struct relent_chain *next;
} arelent_chain;
*-
*/
/*proto*
If an output_bfd is supplied to this function the generated image
will be relocatable, the relocations are copied to the output file
after they have been changed to reflect the new state of the world.
There are two ways of reflecting the results of partial linkage in an
output file; by modifying the output data in place, and by modifying
the relocation record. Some native formats (eg basic a.out and basic
coff) have no way of specifying an addend in the relocation type, so
the addend has to go in the output data. This is no big deal since in
these formats the output data slot will always be big enough for the
addend. Complex reloc types with addends were invented to solve just
this problem.
*; PROTO(bfd_reloc_status_enum_type,
bfd_perform_relocation,
(bfd * abfd,
arelent *reloc_entry,
PTR data,
asection *input_section,
bfd *output_bfd));
*/
bfd_reloc_status_enum_type
DEFUN(bfd_perform_relocation,(abfd,
reloc_entry,
data,
input_section,
output_bfd),
bfd *abfd AND
arelent *reloc_entry AND
PTR data AND
asection *input_section AND
bfd *output_bfd)
{
bfd_vma relocation;
bfd_reloc_status_enum_type flag = bfd_reloc_ok;
bfd_vma addr = reloc_entry->address ;
bfd_vma output_base = 0;
reloc_howto_type *howto = reloc_entry->howto;
asection *reloc_target_output_section;
asection *reloc_target_input_section;
asymbol *symbol;
if (reloc_entry->sym_ptr_ptr) {
symbol = *( reloc_entry->sym_ptr_ptr);
if ((symbol->flags & BSF_UNDEFINED) && output_bfd == (bfd *)NULL) {
flag = bfd_reloc_undefined;
}
}
else {
symbol = (asymbol*)NULL;
}
if (howto->special_function){
bfd_reloc_status_enum_type cont;
cont = howto->special_function(abfd,
reloc_entry,
symbol,
data,
input_section);
if (cont != bfd_reloc_continue) return cont;
}
/*
Work out which section the relocation is targetted at and the
initial relocation command value.
*/
if (symbol != (asymbol *)NULL){
if (symbol->flags & BSF_FORT_COMM) {
relocation = 0;
}
else {
relocation = symbol->value;
}
if (symbol->section != (asection *)NULL)
{
reloc_target_input_section = symbol->section;
}
else {
reloc_target_input_section = (asection *)NULL;
}
}
else if (reloc_entry->section != (asection *)NULL)
{
relocation = 0;
reloc_target_input_section = reloc_entry->section;
}
else {
relocation = 0;
reloc_target_input_section = (asection *)NULL;
}
if (reloc_target_input_section != (asection *)NULL) {
reloc_target_output_section =
reloc_target_input_section->output_section;
if (output_bfd && howto->partial_inplace==false) {
output_base = 0;
}
else {
output_base = reloc_target_output_section->vma;
}
relocation += output_base + reloc_target_input_section->output_offset;
}
relocation += reloc_entry->addend ;
if(reloc_entry->address > (bfd_vma)(input_section->size))
{
return bfd_reloc_outofrange;
}
if (howto->pc_relative == true)
{
/*
Anything which started out as pc relative should end up that
way too.
There are two ways we can see a pcrel instruction. Sometimes
the pcrel displacement has been partially calculated, it
includes the distance from the start of the section to the
instruction in it (eg sun3), and sometimes the field is
totally blank - eg m88kbcs.
*/
relocation -=
output_base + input_section->output_offset;
if (howto->pcrel_offset == true) {
relocation -= reloc_entry->address;
}
}
if (output_bfd!= (bfd *)NULL) {
if ( howto->partial_inplace == false) {
/*
This is a partial relocation, and we want to apply the relocation
to the reloc entry rather than the raw data. Modify the reloc
inplace to reflect what we now know.
*/
reloc_entry->addend = relocation ;
reloc_entry->section = reloc_target_input_section;
if (reloc_target_input_section != (asection *)NULL) {
/* If we know the output section we can forget the symbol */
reloc_entry->sym_ptr_ptr = (asymbol**)NULL;
}
reloc_entry->address +=
input_section->output_offset;
return flag;
}
else
{
/* This is a partial relocation, but inplace, so modify the
reloc record a bit
*/
}
}
reloc_entry->addend = 0;
/*
Either we are relocating all the way, or we don't want to apply
the relocation to the reloc entry (probably because there isn't
any room in the output format to describe addends to relocs)
*/
relocation >>= howto->rightshift;
/* Shift everything up to where it's going to be used */
relocation <<= howto->bitpos;
/* Wait for the day when all have the mask in them */
/* What we do:
i instruction to be left alone
o offset within instruction
r relocation offset to apply
S src mask
D dst mask
N ~dst mask
A part 1
B part 2
R result
Do this:
i i i i i o o o o o from bfd_get<size>
and S S S S S to get the size offset we want
+ r r r r r r r r r r to get the final value to place
and D D D D D to chop to right size
-----------------------
A A A A A
And this:
... i i i i i o o o o o from bfd_get<size>
and N N N N N get instruction
-----------------------
... B B B B B
And then:
B B B B B
or A A A A A
-----------------------
R R R R R R R R R R put into bfd_put<size>
*/
#define DOIT(x) \
x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
switch (howto->size)
{
case 0:
{
char x = bfd_get_8(abfd, (char *)data + addr);
DOIT(x);
bfd_put_8(abfd,x, (unsigned char *) data + addr);
}
break;
case 1:
{
short x = bfd_get_16(abfd, (bfd_byte *)data + addr);
DOIT(x);
bfd_put_16(abfd, x, (unsigned char *)data + addr);
}
break;
case 2:
{
long x = bfd_get_32(abfd, (bfd_byte *) data + addr);
DOIT(x);
bfd_put_32(abfd,x, (bfd_byte *)data + addr);
}
break;
case 3:
/* Do nothing */
break;
default:
return bfd_reloc_other;
}
return flag;
}

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/*doc*
@section Sections
Sections are supported in bfd in @code{section.c}.
The raw data contained within a bfd is maintained through the section
abstraction. A single bfd may have any number of sections, and keeps
hold of them by pointing to the first, each one points to the next in
the list.
@menu
* Section Input::
* Section Output::
* typedef asection::
* section prototypes::
@end menu
@node Section Input, Section Output,,Sections
@comment node-name, next, previous, up
@subsection Section Input
When a bfd is opened for reading, the section structures are created
and attatched to the bfd.
Each section has a name which describes the section in the outside
world - for example, @code{a.out} would contain at least three
sections, called @code{.text}, @code{.data} and @code{.bss}.
Sometimes a bfd will contain more than the 'natural' number of
sections. A back end may attatch other sections containing constructor
data, or an application may add a section (using bfd_make_section) to
the sections attatched to an already open bfd. For example, the linker
creates a supernumary section @code{COMMON} for each input file's bfd
to hold information about common storage.
The raw data is not necessarily read in at the same time as the
section descriptor is created. Some targets may leave the data in
place until a @code{bfd_get_section_contents} call is made. Other back
ends may read in all the data at once - For example; an S-record file
has to be read once to determine the size of the data. An IEEE-695
file doesn't contain raw data in sections, but data and relocation
expressions intermixed, so the data area has to be parsed to get out
the data and relocations.
@node Section Output,typedef asection,Section Input,Sections
@subsection Section Output
To write a new object style bfd, the various sections to be written
have to be created. They are attatched to the bfd in the same way as
input sections, data is written to the sections using
@code{bfd_set_section_contents}.
The linker uses the fields @code{output_section} and
@code{output_offset} to create an output file.
The data to be written comes from input sections attatched to the
output sections. The output section structure can be considered a
filter for the input section, the output section determines the vma of
the output data and the name, but the input section determines the
offset into the output section of the data to be written.
Eg to create a section "O", starting at 0x100, 0x123 long, containing two
subsections, "A" at offset 0x0 (ie at vma 0x100) and "B" at offset
0x20 (ie at vma 0x120) the structures would look like:
*+
section name "A"
output_offset 0x00
size 0x20
output_section -----------> section name "O"
| vma 0x100
section name "B" | size 0x123
output_offset 0x20 |
size 0x103 |
output_section --------|
*-
*/
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
/*doc*
@node typedef asection,section prototypes,Section Output,Sections
@subsection typedef asection
*/
/*proto*
The shape of a section struct:
*+++
$typedef struct sec {
The name of the section, the name isn't a copy, the pointer is
the same as that passed to bfd_make_section.
$ CONST char *name;
The next section in the list belonging to the bfd, or NULL.
$ struct sec *next;
The field flags contains attributes of the section. Some of these
flags are read in from the object file, and some are synthesized from
other information.
$flagword flags;
$#define SEC_NO_FLAGS 0x000
Tells the OS to allocate space for this section when loaded.
This would clear for a section containing debug information only.
$#define SEC_ALLOC 0x001
Tells the OS to load the section from the file when loading.
This would be clear for a .bss section
$#define SEC_LOAD 0x002
The section contains data still to be relocated, so there will be some
relocation information too.
$#define SEC_RELOC 0x004
Obsolete ?
$#define SEC_BALIGN 0x008
A signal to the OS that the section contains read only data.
$#define SEC_READONLY 0x010
The section contains code only.
$#define SEC_CODE 0x020
The section contains data only.
$#define SEC_DATA 0x040
The section will reside in ROM.
$#define SEC_ROM 0x080
The section contains constructor information. This section type is
used by the linker to create lists of constructors and destructors
used by @code{g++}. When a back end sees a symbol which should be used
in a constructor list, it creates a new section for the type of name
(eg @code{__CTOR_LIST__}), attatches the symbol to it and builds a
relocation. To build the lists of constructors, all the linker has to
to is catenate all the sections called @code{__CTOR_LIST__} and
relocte the data contained within - exactly the operations it would
peform on standard data.
$#define SEC_CONSTRUCTOR 0x100
The section has contents - a bss section could be
@code{SEC_ALLOC} | @code{SEC_HAS_CONTENTS}, a debug section could be
@code{SEC_HAS_CONTENTS}
$#define SEC_HAS_CONTENTS 0x200
An instruction to the linker not to output sections containing
this flag even if they have information which would normally be written.
$#define SEC_NEVER_LOAD 0x400
The base address of the section in the address space of the target.
$ bfd_vma vma;
The size of the section in bytes of the loaded section. This contains
a value even if the section has no contents (eg, the size of @code{.bss}).
$ bfd_size_type size;
If this section is going to be output, then this value is the
offset into the output section of the first byte in the input
section. Eg, if this was going to start at the 100th byte in the
output section, this value would be 100.
$ bfd_vma output_offset;
The output section through which to map on output.
$ struct sec *output_section;
The alignment requirement of the section, as an exponent - eg 3
aligns to 2^3 (or 8)
$ unsigned int alignment_power;
If an input section, a pointer to a vector of relocation records for
the data in this section.
$ struct reloc_cache_entry *relocation;
If an output section, a pointer to a vector of pointers to
relocation records for the data in this section.
$ struct reloc_cache_entry **orelocation;
The number of relocation records in one of the above
$ unsigned reloc_count;
Which section is it 0..nth
$ int index;
Information below is back end specific - and not always used or
updated
File position of section data
$ file_ptr filepos;
File position of relocation info
$ file_ptr rel_filepos;
File position of line data
$ file_ptr line_filepos;
Pointer to data for applications
$ PTR userdata;
$ struct lang_output_section *otheruserdata;
Attached line number information
$ alent *lineno;
Number of line number records
$ unsigned int lineno_count;
When a section is being output, this value changes as more
linenumbers are written out
$ file_ptr moving_line_filepos;
what the section number is in the target world
$ unsigned int target_index;
$ PTR used_by_bfd;
If this is a constructor section then here is a list of the
relocations created to relocate items within it.
$ struct relent_chain *constructor_chain;
The bfd which owns the section.
$ bfd *owner;
$} asection ;
*---
*/
/*doc*
@node section prototypes,Section,typedef section,Sections
@subsection section prototypes
*/
/*proto* bfd_get_section_by_name
Runs through the provided @var{abfd} and returns the @code{asection}
who's name matches that provided, otherwise NULL. @xref{Sections}, for more information.
*; PROTO(asection *, bfd_get_section_by_name,
(bfd *abfd, CONST char *name));
*/
asection *
DEFUN(bfd_get_section_by_name,(abfd, name),
bfd *abfd AND
CONST char *name)
{
asection *sect;
for (sect = abfd->sections; sect != NULL; sect = sect->next)
if (!strcmp (sect->name, name)) return sect;
return NULL;
}
/*proto* bfd_make_section
This function creates a new empty section called @var{name} and attatches it
to the end of the chain of sections for @var{bfd}. An attempt to
create a section with a name which is already in use, returns the old
section by that name instead.
Possible errors are:
@table @code
@item invalid_operation
If output has already started for this bfd.
@item no_memory
If obstack alloc fails.
@end table
*; PROTO(asection *, bfd_make_section, (bfd *, CONST char *name));
*/
sec_ptr
DEFUN(bfd_make_section,(abfd, name),
bfd *abfd AND
CONST char * name)
{
asection *newsect;
asection ** prev = &abfd->sections;
asection * sect = abfd->sections;
if (abfd->output_has_begun) {
bfd_error = invalid_operation;
return NULL;
}
while (sect) {
if (!strcmp(sect->name, name)) return sect;
prev = &sect->next;
sect = sect->next;
}
newsect = (asection *) bfd_zalloc(abfd, sizeof (asection));
if (newsect == NULL) {
bfd_error = no_memory;
return NULL;
}
newsect->name = name;
newsect->index = abfd->section_count++;
newsect->flags = SEC_NO_FLAGS;
newsect->userdata = 0;
newsect->next = (asection *)NULL;
newsect->relocation = (arelent *)NULL;
newsect->reloc_count = 0;
newsect->line_filepos =0;
newsect->owner = abfd;
if (BFD_SEND (abfd, _new_section_hook, (abfd, newsect)) != true) {
free (newsect);
return NULL;
}
*prev = newsect;
return newsect;
}
/*proto* bfd_set_section_flags
Attempts to set the attributes of the section named in the bfd
supplied to the value. Returns true on success, false on error.
Possible error returns are:
@table @code
@item invalid operation
The section cannot have one or more of the attributes requested. For
example, a .bss section in @code{a.out} may not have the
@code{SEC_HAS_CONTENTS} field set.
@end table
*; PROTO(boolean, bfd_set_section_flags,
(bfd *, asection *, flagword));
*/
boolean
DEFUN(bfd_set_section_flags,(abfd, section, flags),
bfd *abfd AND
sec_ptr section AND
flagword flags)
{
if ((flags & bfd_applicable_section_flags (abfd)) != flags) {
bfd_error = invalid_operation;
return false;
}
section->flags = flags;
return true;
}
/*proto* bfd_map_over_sections
Calls the provided function @var{func} for each section attatched to
the bfd @var{abfd}, passing @var{obj} as an argument. The function
will be called as if by
@example
func(abfd, the_section, obj);
@end example
*; PROTO(void, bfd_map_over_sections,
(bfd *abfd, void (*func)(), PTR obj));
This is the prefered method for iterating over sections, an
alternative would be to use a loop:
@example
section *p;
for (p = abfd->sections; p != NULL; p = p->next)
func(abfd, p, ...)
@end example
*/
/*VARARGS2*/
void
DEFUN(bfd_map_over_sections,(abfd, operation, user_storage),
bfd *abfd AND
void (*operation)() AND
PTR user_storage)
{
asection *sect;
int i = 0;
for (sect = abfd->sections; sect != NULL; i++, sect = sect->next)
(*operation) (abfd, sect, user_storage);
if (i != abfd->section_count) /* Debugging */
abort();
}
/*proto* bfd_set_section_size
Sets @var{section} to the size @var{val}. If the operation is ok, then
@code{true} is returned, else @code{false}.
Possible error returns:
@table @code
@item invalid_operation
Writing has started to the bfd, so setting the size is invalid
@end table
*; PROTO(boolean, bfd_set_section_size,
(bfd *, asection *, bfd_size_type val));
*/
boolean
DEFUN(bfd_set_section_size,(abfd, ptr, val),
bfd *abfd AND
sec_ptr ptr AND
unsigned long val)
{
/* Once you've started writing to any section you cannot create or change
the size of any others. */
if (abfd->output_has_begun) {
bfd_error = invalid_operation;
return false;
}
ptr->size = val;
return true;
}
/*proto* bfd_set_section_contents
Sets the contents of the section @var{section} in bfd @var{abfd} to
the data starting in memory at @var{data}. The data is written to the
output section starting at offset @var{offset} for @var{count} bytes.
Normally @code{true} is returned, else @code{false}. Possible error
returns are:
@table @code
@item no_contents
The output section does not have the @code{SEC_HAS_CONTENTS}
attribute, so nothing can be written to it.
@item and some more too
@end table
This routine is front end to the back end function @code{_bfd_set_section_contents}.
*; PROTO(boolean, bfd_set_section_contents,
(bfd *abfd,
asection *section,
PTR data,
file_ptr offset,
bfd_size_type count));
*/
boolean
DEFUN(bfd_set_section_contents,(abfd, section, location, offset, count),
bfd *abfd AND
sec_ptr section AND
PTR location AND
file_ptr offset AND
bfd_size_type count)
{
if (!(bfd_get_section_flags(abfd, section) & SEC_HAS_CONTENTS))
{
bfd_error = no_contents;
return(false);
}
if (BFD_SEND (abfd, _bfd_set_section_contents,
(abfd, section, location, offset, count)))
{
abfd->output_has_begun = true;
return true;
}
return false;
}
/*proto* bfd_get_section_contents
This function reads data from @var{section} in bfd @var{abfd} into
memory starting at @var{location}. The data is read at an offset of
@var{offset} from the start of the input section, and is read for
@var{count} bytes.
If the contents of a constuctor with the @code{SEC_CONSTUCTOR} flag
set are requested, then the @var{location} is filled with zeroes.
If no errors occur, @code{true} is returned, else @code{false}.
Possible errors are:
@table @code
@item unknown yet
@end table
*; PROTO(boolean, bfd_get_section_contents,
(bfd *abfd, asection *section, PTR location,
file_ptr offset, bfd_size_type count));
*/
boolean
DEFUN(bfd_get_section_contents,(abfd, section, location, offset, count),
bfd *abfd AND
sec_ptr section AND
PTR location AND
file_ptr offset AND
bfd_size_type count)
{
if (section->flags & SEC_CONSTRUCTOR)
{
memset(location, 0, (unsigned)count);
return true;
}
else
{
return (BFD_SEND (abfd, _bfd_get_section_contents,
(abfd, section, location, offset, count)));
}
}