mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-07 13:54:33 +00:00
1088 lines
40 KiB
Plaintext
1088 lines
40 KiB
Plaintext
@section Sections
|
|
The raw data contained within a BFD is maintained through the
|
|
section abstraction. A single BFD may have any number of
|
|
sections. It keeps hold of them by pointing to the first;
|
|
each one points to the next in the list.
|
|
|
|
Sections are supported in BFD in @code{section.c}.
|
|
|
|
@menu
|
|
* Section Input::
|
|
* Section Output::
|
|
* typedef asection::
|
|
* section prototypes::
|
|
@end menu
|
|
|
|
@node Section Input, Section Output, Sections, Sections
|
|
@subsection Section input
|
|
When a BFD is opened for reading, the section structures are
|
|
created and attached 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}.
|
|
|
|
Names need not be unique; for example a COFF file may have several
|
|
sections named @code{.data}.
|
|
|
|
Sometimes a BFD will contain more than the ``natural'' number of
|
|
sections. A back end may attach other sections containing
|
|
constructor data, or an application may add a section (using
|
|
@code{bfd_make_section}) to the sections attached to an already open
|
|
BFD. For example, the linker creates an extra section
|
|
@code{COMMON} for each input file's BFD to hold information about
|
|
common storage.
|
|
|
|
The raw data is not necessarily read in when
|
|
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.
|
|
|
|
@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 attached to the BFD in
|
|
the same way as input sections; data is written to the
|
|
sections using @code{bfd_set_section_contents}.
|
|
|
|
Any program that creates or combines sections (e.g., the assembler
|
|
and linker) must use the @code{asection} fields @code{output_section} and
|
|
@code{output_offset} to indicate the file sections to which each
|
|
section must be written. (If the section is being created from
|
|
scratch, @code{output_section} should probably point to the section
|
|
itself and @code{output_offset} should probably be zero.)
|
|
|
|
The data to be written comes from input sections attached
|
|
(via @code{output_section} pointers) 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.
|
|
|
|
E.g., to create a section "O", starting at 0x100, 0x123 long,
|
|
containing two subsections, "A" at offset 0x0 (i.e., at vma
|
|
0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the @code{asection}
|
|
structures would look like:
|
|
|
|
@example
|
|
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 --------|
|
|
@end example
|
|
|
|
@subsection Link orders
|
|
The data within a section is stored in a @dfn{link_order}.
|
|
These are much like the fixups in @code{gas}. The link_order
|
|
abstraction allows a section to grow and shrink within itself.
|
|
|
|
A link_order knows how big it is, and which is the next
|
|
link_order and where the raw data for it is; it also points to
|
|
a list of relocations which apply to it.
|
|
|
|
The link_order is used by the linker to perform relaxing on
|
|
final code. The compiler creates code which is as big as
|
|
necessary to make it work without relaxing, and the user can
|
|
select whether to relax. Sometimes relaxing takes a lot of
|
|
time. The linker runs around the relocations to see if any
|
|
are attached to data which can be shrunk, if so it does it on
|
|
a link_order by link_order basis.
|
|
|
|
|
|
@node typedef asection, section prototypes, Section Output, Sections
|
|
@subsection typedef asection
|
|
Here is the section structure:
|
|
|
|
|
|
@example
|
|
|
|
typedef struct bfd_section
|
|
@{
|
|
/* 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;
|
|
|
|
/* A unique sequence number. */
|
|
unsigned int id;
|
|
|
|
/* Which section in the bfd; 0..n-1 as sections are created in a bfd. */
|
|
unsigned int index;
|
|
|
|
/* The next section in the list belonging to the BFD, or NULL. */
|
|
struct bfd_section *next;
|
|
|
|
/* The previous section in the list belonging to the BFD, or NULL. */
|
|
struct bfd_section *prev;
|
|
|
|
/* The field flags contains attributes of the section. Some
|
|
flags are read in from the object file, and some are
|
|
synthesized from other information. */
|
|
flagword flags;
|
|
|
|
#define SEC_NO_FLAGS 0x0
|
|
|
|
/* Tells the OS to allocate space for this section when loading.
|
|
This is clear for a section containing debug information only. */
|
|
#define SEC_ALLOC 0x1
|
|
|
|
/* Tells the OS to load the section from the file when loading.
|
|
This is clear for a .bss section. */
|
|
#define SEC_LOAD 0x2
|
|
|
|
/* The section contains data still to be relocated, so there is
|
|
some relocation information too. */
|
|
#define SEC_RELOC 0x4
|
|
|
|
/* A signal to the OS that the section contains read only data. */
|
|
#define SEC_READONLY 0x8
|
|
|
|
/* The section contains code only. */
|
|
#define SEC_CODE 0x10
|
|
|
|
/* The section contains data only. */
|
|
#define SEC_DATA 0x20
|
|
|
|
/* The section will reside in ROM. */
|
|
#define SEC_ROM 0x40
|
|
|
|
/* 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 (e.g., @code{__CTOR_LIST__}), attaches
|
|
the symbol to it, and builds a relocation. To build the lists
|
|
of constructors, all the linker has to do is catenate all the
|
|
sections called @code{__CTOR_LIST__} and relocate the data
|
|
contained within - exactly the operations it would peform on
|
|
standard data. */
|
|
#define SEC_CONSTRUCTOR 0x80
|
|
|
|
/* The section has contents - a data section could be
|
|
@code{SEC_ALLOC} | @code{SEC_HAS_CONTENTS}; a debug section could be
|
|
@code{SEC_HAS_CONTENTS} */
|
|
#define SEC_HAS_CONTENTS 0x100
|
|
|
|
/* An instruction to the linker to not output the section
|
|
even if it has information which would normally be written. */
|
|
#define SEC_NEVER_LOAD 0x200
|
|
|
|
/* The section contains thread local data. */
|
|
#define SEC_THREAD_LOCAL 0x400
|
|
|
|
/* The section's size is fixed. Generic linker code will not
|
|
recalculate it and it is up to whoever has set this flag to
|
|
get the size right. */
|
|
#define SEC_FIXED_SIZE 0x800
|
|
|
|
/* The section contains common symbols (symbols may be defined
|
|
multiple times, the value of a symbol is the amount of
|
|
space it requires, and the largest symbol value is the one
|
|
used). Most targets have exactly one of these (which we
|
|
translate to bfd_com_section_ptr), but ECOFF has two. */
|
|
#define SEC_IS_COMMON 0x1000
|
|
|
|
/* The section contains only debugging information. For
|
|
example, this is set for ELF .debug and .stab sections.
|
|
strip tests this flag to see if a section can be
|
|
discarded. */
|
|
#define SEC_DEBUGGING 0x2000
|
|
|
|
/* The contents of this section are held in memory pointed to
|
|
by the contents field. This is checked by bfd_get_section_contents,
|
|
and the data is retrieved from memory if appropriate. */
|
|
#define SEC_IN_MEMORY 0x4000
|
|
|
|
/* The contents of this section are to be excluded by the
|
|
linker for executable and shared objects unless those
|
|
objects are to be further relocated. */
|
|
#define SEC_EXCLUDE 0x8000
|
|
|
|
/* The contents of this section are to be sorted based on the sum of
|
|
the symbol and addend values specified by the associated relocation
|
|
entries. Entries without associated relocation entries will be
|
|
appended to the end of the section in an unspecified order. */
|
|
#define SEC_SORT_ENTRIES 0x10000
|
|
|
|
/* When linking, duplicate sections of the same name should be
|
|
discarded, rather than being combined into a single section as
|
|
is usually done. This is similar to how common symbols are
|
|
handled. See SEC_LINK_DUPLICATES below. */
|
|
#define SEC_LINK_ONCE 0x20000
|
|
|
|
/* If SEC_LINK_ONCE is set, this bitfield describes how the linker
|
|
should handle duplicate sections. */
|
|
#define SEC_LINK_DUPLICATES 0xc0000
|
|
|
|
/* This value for SEC_LINK_DUPLICATES means that duplicate
|
|
sections with the same name should simply be discarded. */
|
|
#define SEC_LINK_DUPLICATES_DISCARD 0x0
|
|
|
|
/* This value for SEC_LINK_DUPLICATES means that the linker
|
|
should warn if there are any duplicate sections, although
|
|
it should still only link one copy. */
|
|
#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
|
|
|
|
/* This value for SEC_LINK_DUPLICATES means that the linker
|
|
should warn if any duplicate sections are a different size. */
|
|
#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
|
|
|
|
/* This value for SEC_LINK_DUPLICATES means that the linker
|
|
should warn if any duplicate sections contain different
|
|
contents. */
|
|
#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
|
|
(SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
|
|
|
|
/* This section was created by the linker as part of dynamic
|
|
relocation or other arcane processing. It is skipped when
|
|
going through the first-pass output, trusting that someone
|
|
else up the line will take care of it later. */
|
|
#define SEC_LINKER_CREATED 0x100000
|
|
|
|
/* This section should not be subject to garbage collection.
|
|
Also set to inform the linker that this section should not be
|
|
listed in the link map as discarded. */
|
|
#define SEC_KEEP 0x200000
|
|
|
|
/* This section contains "short" data, and should be placed
|
|
"near" the GP. */
|
|
#define SEC_SMALL_DATA 0x400000
|
|
|
|
/* Attempt to merge identical entities in the section.
|
|
Entity size is given in the entsize field. */
|
|
#define SEC_MERGE 0x800000
|
|
|
|
/* If given with SEC_MERGE, entities to merge are zero terminated
|
|
strings where entsize specifies character size instead of fixed
|
|
size entries. */
|
|
#define SEC_STRINGS 0x1000000
|
|
|
|
/* This section contains data about section groups. */
|
|
#define SEC_GROUP 0x2000000
|
|
|
|
/* The section is a COFF shared library section. This flag is
|
|
only for the linker. If this type of section appears in
|
|
the input file, the linker must copy it to the output file
|
|
without changing the vma or size. FIXME: Although this
|
|
was originally intended to be general, it really is COFF
|
|
specific (and the flag was renamed to indicate this). It
|
|
might be cleaner to have some more general mechanism to
|
|
allow the back end to control what the linker does with
|
|
sections. */
|
|
#define SEC_COFF_SHARED_LIBRARY 0x4000000
|
|
|
|
/* This input section should be copied to output in reverse order
|
|
as an array of pointers. This is for ELF linker internal use
|
|
only. */
|
|
#define SEC_ELF_REVERSE_COPY 0x4000000
|
|
|
|
/* This section contains data which may be shared with other
|
|
executables or shared objects. This is for COFF only. */
|
|
#define SEC_COFF_SHARED 0x8000000
|
|
|
|
/* This section should be compressed. This is for ELF linker
|
|
internal use only. */
|
|
#define SEC_ELF_COMPRESS 0x8000000
|
|
|
|
/* When a section with this flag is being linked, then if the size of
|
|
the input section is less than a page, it should not cross a page
|
|
boundary. If the size of the input section is one page or more,
|
|
it should be aligned on a page boundary. This is for TI
|
|
TMS320C54X only. */
|
|
#define SEC_TIC54X_BLOCK 0x10000000
|
|
|
|
/* This section should be renamed. This is for ELF linker
|
|
internal use only. */
|
|
#define SEC_ELF_RENAME 0x10000000
|
|
|
|
/* Conditionally link this section; do not link if there are no
|
|
references found to any symbol in the section. This is for TI
|
|
TMS320C54X only. */
|
|
#define SEC_TIC54X_CLINK 0x20000000
|
|
|
|
/* This section contains vliw code. This is for Toshiba MeP only. */
|
|
#define SEC_MEP_VLIW 0x20000000
|
|
|
|
/* Indicate that section has the no read flag set. This happens
|
|
when memory read flag isn't set. */
|
|
#define SEC_COFF_NOREAD 0x40000000
|
|
|
|
/* Indicate that section has the purecode flag set. */
|
|
#define SEC_ELF_PURECODE 0x80000000
|
|
|
|
/* End of section flags. */
|
|
|
|
/* Some internal packed boolean fields. */
|
|
|
|
/* See the vma field. */
|
|
unsigned int user_set_vma : 1;
|
|
|
|
/* A mark flag used by some of the linker backends. */
|
|
unsigned int linker_mark : 1;
|
|
|
|
/* Another mark flag used by some of the linker backends. Set for
|
|
output sections that have an input section. */
|
|
unsigned int linker_has_input : 1;
|
|
|
|
/* Mark flag used by some linker backends for garbage collection. */
|
|
unsigned int gc_mark : 1;
|
|
|
|
/* Section compression status. */
|
|
unsigned int compress_status : 2;
|
|
#define COMPRESS_SECTION_NONE 0
|
|
#define COMPRESS_SECTION_DONE 1
|
|
#define DECOMPRESS_SECTION_SIZED 2
|
|
|
|
/* The following flags are used by the ELF linker. */
|
|
|
|
/* Mark sections which have been allocated to segments. */
|
|
unsigned int segment_mark : 1;
|
|
|
|
/* Type of sec_info information. */
|
|
unsigned int sec_info_type:3;
|
|
#define SEC_INFO_TYPE_NONE 0
|
|
#define SEC_INFO_TYPE_STABS 1
|
|
#define SEC_INFO_TYPE_MERGE 2
|
|
#define SEC_INFO_TYPE_EH_FRAME 3
|
|
#define SEC_INFO_TYPE_JUST_SYMS 4
|
|
#define SEC_INFO_TYPE_TARGET 5
|
|
#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6
|
|
|
|
/* Nonzero if this section uses RELA relocations, rather than REL. */
|
|
unsigned int use_rela_p:1;
|
|
|
|
/* Bits used by various backends. The generic code doesn't touch
|
|
these fields. */
|
|
|
|
unsigned int sec_flg0:1;
|
|
unsigned int sec_flg1:1;
|
|
unsigned int sec_flg2:1;
|
|
unsigned int sec_flg3:1;
|
|
unsigned int sec_flg4:1;
|
|
unsigned int sec_flg5:1;
|
|
|
|
/* End of internal packed boolean fields. */
|
|
|
|
/* The virtual memory address of the section - where it will be
|
|
at run time. The symbols are relocated against this. The
|
|
user_set_vma flag is maintained by bfd; if it's not set, the
|
|
backend can assign addresses (for example, in @code{a.out}, where
|
|
the default address for @code{.data} is dependent on the specific
|
|
target and various flags). */
|
|
bfd_vma vma;
|
|
|
|
/* The load address of the section - where it would be in a
|
|
rom image; really only used for writing section header
|
|
information. */
|
|
bfd_vma lma;
|
|
|
|
/* The size of the section in *octets*, as it will be output.
|
|
Contains a value even if the section has no contents (e.g., the
|
|
size of @code{.bss}). */
|
|
bfd_size_type size;
|
|
|
|
/* For input sections, the original size on disk of the section, in
|
|
octets. This field should be set for any section whose size is
|
|
changed by linker relaxation. It is required for sections where
|
|
the linker relaxation scheme doesn't cache altered section and
|
|
reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
|
|
targets), and thus the original size needs to be kept to read the
|
|
section multiple times. For output sections, rawsize holds the
|
|
section size calculated on a previous linker relaxation pass. */
|
|
bfd_size_type rawsize;
|
|
|
|
/* The compressed size of the section in octets. */
|
|
bfd_size_type compressed_size;
|
|
|
|
/* Relaxation table. */
|
|
struct relax_table *relax;
|
|
|
|
/* Count of used relaxation table entries. */
|
|
int relax_count;
|
|
|
|
|
|
/* If this section is going to be output, then this value is the
|
|
offset in *bytes* into the output section of the first byte in the
|
|
input section (byte ==> smallest addressable unit on the
|
|
target). In most cases, if this was going to start at the
|
|
100th octet (8-bit quantity) in the output section, this value
|
|
would be 100. However, if the target byte size is 16 bits
|
|
(bfd_octets_per_byte is "2"), this value would be 50. */
|
|
bfd_vma output_offset;
|
|
|
|
/* The output section through which to map on output. */
|
|
struct bfd_section *output_section;
|
|
|
|
/* The alignment requirement of the section, as an exponent of 2 -
|
|
e.g., 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;
|
|
|
|
/* 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. */
|
|
void *userdata;
|
|
|
|
/* If the SEC_IN_MEMORY flag is set, this points to the actual
|
|
contents. */
|
|
unsigned char *contents;
|
|
|
|
/* Attached line number information. */
|
|
alent *lineno;
|
|
|
|
/* Number of line number records. */
|
|
unsigned int lineno_count;
|
|
|
|
/* Entity size for merging purposes. */
|
|
unsigned int entsize;
|
|
|
|
/* Points to the kept section if this section is a link-once section,
|
|
and is discarded. */
|
|
struct bfd_section *kept_section;
|
|
|
|
/* 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. */
|
|
int target_index;
|
|
|
|
void *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;
|
|
|
|
/* A symbol which points at this section only. */
|
|
struct bfd_symbol *symbol;
|
|
struct bfd_symbol **symbol_ptr_ptr;
|
|
|
|
/* Early in the link process, map_head and map_tail are used to build
|
|
a list of input sections attached to an output section. Later,
|
|
output sections use these fields for a list of bfd_link_order
|
|
structs. */
|
|
union @{
|
|
struct bfd_link_order *link_order;
|
|
struct bfd_section *s;
|
|
@} map_head, map_tail;
|
|
@} asection;
|
|
|
|
/* Relax table contains information about instructions which can
|
|
be removed by relaxation -- replacing a long address with a
|
|
short address. */
|
|
struct relax_table @{
|
|
/* Address where bytes may be deleted. */
|
|
bfd_vma addr;
|
|
|
|
/* Number of bytes to be deleted. */
|
|
int size;
|
|
@};
|
|
|
|
/* Note: the following are provided as inline functions rather than macros
|
|
because not all callers use the return value. A macro implementation
|
|
would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
|
|
compilers will complain about comma expressions that have no effect. */
|
|
static inline bfd_boolean
|
|
bfd_set_section_userdata (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr,
|
|
void * val)
|
|
@{
|
|
ptr->userdata = val;
|
|
return TRUE;
|
|
@}
|
|
|
|
static inline bfd_boolean
|
|
bfd_set_section_vma (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr, bfd_vma val)
|
|
@{
|
|
ptr->vma = ptr->lma = val;
|
|
ptr->user_set_vma = TRUE;
|
|
return TRUE;
|
|
@}
|
|
|
|
static inline bfd_boolean
|
|
bfd_set_section_alignment (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr,
|
|
unsigned int val)
|
|
@{
|
|
ptr->alignment_power = val;
|
|
return TRUE;
|
|
@}
|
|
|
|
/* These sections are global, and are managed by BFD. The application
|
|
and target back end are not permitted to change the values in
|
|
these sections. */
|
|
extern asection _bfd_std_section[4];
|
|
|
|
#define BFD_ABS_SECTION_NAME "*ABS*"
|
|
#define BFD_UND_SECTION_NAME "*UND*"
|
|
#define BFD_COM_SECTION_NAME "*COM*"
|
|
#define BFD_IND_SECTION_NAME "*IND*"
|
|
|
|
/* Pointer to the common section. */
|
|
#define bfd_com_section_ptr (&_bfd_std_section[0])
|
|
/* Pointer to the undefined section. */
|
|
#define bfd_und_section_ptr (&_bfd_std_section[1])
|
|
/* Pointer to the absolute section. */
|
|
#define bfd_abs_section_ptr (&_bfd_std_section[2])
|
|
/* Pointer to the indirect section. */
|
|
#define bfd_ind_section_ptr (&_bfd_std_section[3])
|
|
|
|
#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
|
|
#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
|
|
#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
|
|
|
|
#define bfd_is_const_section(SEC) \
|
|
( ((SEC) == bfd_abs_section_ptr) \
|
|
|| ((SEC) == bfd_und_section_ptr) \
|
|
|| ((SEC) == bfd_com_section_ptr) \
|
|
|| ((SEC) == bfd_ind_section_ptr))
|
|
|
|
/* Macros to handle insertion and deletion of a bfd's sections. These
|
|
only handle the list pointers, ie. do not adjust section_count,
|
|
target_index etc. */
|
|
#define bfd_section_list_remove(ABFD, S) \
|
|
do \
|
|
@{ \
|
|
asection *_s = S; \
|
|
asection *_next = _s->next; \
|
|
asection *_prev = _s->prev; \
|
|
if (_prev) \
|
|
_prev->next = _next; \
|
|
else \
|
|
(ABFD)->sections = _next; \
|
|
if (_next) \
|
|
_next->prev = _prev; \
|
|
else \
|
|
(ABFD)->section_last = _prev; \
|
|
@} \
|
|
while (0)
|
|
#define bfd_section_list_append(ABFD, S) \
|
|
do \
|
|
@{ \
|
|
asection *_s = S; \
|
|
bfd *_abfd = ABFD; \
|
|
_s->next = NULL; \
|
|
if (_abfd->section_last) \
|
|
@{ \
|
|
_s->prev = _abfd->section_last; \
|
|
_abfd->section_last->next = _s; \
|
|
@} \
|
|
else \
|
|
@{ \
|
|
_s->prev = NULL; \
|
|
_abfd->sections = _s; \
|
|
@} \
|
|
_abfd->section_last = _s; \
|
|
@} \
|
|
while (0)
|
|
#define bfd_section_list_prepend(ABFD, S) \
|
|
do \
|
|
@{ \
|
|
asection *_s = S; \
|
|
bfd *_abfd = ABFD; \
|
|
_s->prev = NULL; \
|
|
if (_abfd->sections) \
|
|
@{ \
|
|
_s->next = _abfd->sections; \
|
|
_abfd->sections->prev = _s; \
|
|
@} \
|
|
else \
|
|
@{ \
|
|
_s->next = NULL; \
|
|
_abfd->section_last = _s; \
|
|
@} \
|
|
_abfd->sections = _s; \
|
|
@} \
|
|
while (0)
|
|
#define bfd_section_list_insert_after(ABFD, A, S) \
|
|
do \
|
|
@{ \
|
|
asection *_a = A; \
|
|
asection *_s = S; \
|
|
asection *_next = _a->next; \
|
|
_s->next = _next; \
|
|
_s->prev = _a; \
|
|
_a->next = _s; \
|
|
if (_next) \
|
|
_next->prev = _s; \
|
|
else \
|
|
(ABFD)->section_last = _s; \
|
|
@} \
|
|
while (0)
|
|
#define bfd_section_list_insert_before(ABFD, B, S) \
|
|
do \
|
|
@{ \
|
|
asection *_b = B; \
|
|
asection *_s = S; \
|
|
asection *_prev = _b->prev; \
|
|
_s->prev = _prev; \
|
|
_s->next = _b; \
|
|
_b->prev = _s; \
|
|
if (_prev) \
|
|
_prev->next = _s; \
|
|
else \
|
|
(ABFD)->sections = _s; \
|
|
@} \
|
|
while (0)
|
|
#define bfd_section_removed_from_list(ABFD, S) \
|
|
((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
|
|
|
|
#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS) \
|
|
/* name, id, index, next, prev, flags, user_set_vma, */ \
|
|
@{ NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
|
|
\
|
|
/* linker_mark, linker_has_input, gc_mark, decompress_status, */ \
|
|
0, 0, 1, 0, \
|
|
\
|
|
/* segment_mark, sec_info_type, use_rela_p, */ \
|
|
0, 0, 0, \
|
|
\
|
|
/* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, */ \
|
|
0, 0, 0, 0, 0, 0, \
|
|
\
|
|
/* vma, lma, size, rawsize, compressed_size, relax, relax_count, */ \
|
|
0, 0, 0, 0, 0, 0, 0, \
|
|
\
|
|
/* output_offset, output_section, alignment_power, */ \
|
|
0, &SEC, 0, \
|
|
\
|
|
/* relocation, orelocation, reloc_count, filepos, rel_filepos, */ \
|
|
NULL, NULL, 0, 0, 0, \
|
|
\
|
|
/* line_filepos, userdata, contents, lineno, lineno_count, */ \
|
|
0, NULL, NULL, NULL, 0, \
|
|
\
|
|
/* entsize, kept_section, moving_line_filepos, */ \
|
|
0, NULL, 0, \
|
|
\
|
|
/* target_index, used_by_bfd, constructor_chain, owner, */ \
|
|
0, NULL, NULL, NULL, \
|
|
\
|
|
/* symbol, symbol_ptr_ptr, */ \
|
|
(struct bfd_symbol *) SYM, &SEC.symbol, \
|
|
\
|
|
/* map_head, map_tail */ \
|
|
@{ NULL @}, @{ NULL @} \
|
|
@}
|
|
|
|
/* We use a macro to initialize the static asymbol structures because
|
|
traditional C does not permit us to initialize a union member while
|
|
gcc warns if we don't initialize it.
|
|
the_bfd, name, value, attr, section [, udata] */
|
|
#ifdef __STDC__
|
|
#define GLOBAL_SYM_INIT(NAME, SECTION) \
|
|
@{ 0, NAME, 0, BSF_SECTION_SYM, SECTION, @{ 0 @}@}
|
|
#else
|
|
#define GLOBAL_SYM_INIT(NAME, SECTION) \
|
|
@{ 0, NAME, 0, BSF_SECTION_SYM, SECTION @}
|
|
#endif
|
|
|
|
@end example
|
|
|
|
@node section prototypes, , typedef asection, Sections
|
|
@subsection Section prototypes
|
|
These are the functions exported by the section handling part of BFD.
|
|
|
|
@findex bfd_section_list_clear
|
|
@subsubsection @code{bfd_section_list_clear}
|
|
@strong{Synopsis}
|
|
@example
|
|
void bfd_section_list_clear (bfd *);
|
|
@end example
|
|
@strong{Description}@*
|
|
Clears the section list, and also resets the section count and
|
|
hash table entries.
|
|
|
|
@findex bfd_get_section_by_name
|
|
@subsubsection @code{bfd_get_section_by_name}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_get_section_by_name (bfd *abfd, const char *name);
|
|
@end example
|
|
@strong{Description}@*
|
|
Return the most recently created section attached to @var{abfd}
|
|
named @var{name}. Return NULL if no such section exists.
|
|
|
|
@findex bfd_get_next_section_by_name
|
|
@subsubsection @code{bfd_get_next_section_by_name}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
|
|
@end example
|
|
@strong{Description}@*
|
|
Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
|
|
return the next most recently created section attached to the same
|
|
BFD with the same name, or if no such section exists in the same BFD and
|
|
IBFD is non-NULL, the next section with the same name in any input
|
|
BFD following IBFD. Return NULL on finding no section.
|
|
|
|
@findex bfd_get_linker_section
|
|
@subsubsection @code{bfd_get_linker_section}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_get_linker_section (bfd *abfd, const char *name);
|
|
@end example
|
|
@strong{Description}@*
|
|
Return the linker created section attached to @var{abfd}
|
|
named @var{name}. Return NULL if no such section exists.
|
|
|
|
@findex bfd_get_section_by_name_if
|
|
@subsubsection @code{bfd_get_section_by_name_if}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_get_section_by_name_if
|
|
(bfd *abfd,
|
|
const char *name,
|
|
bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
|
|
void *obj);
|
|
@end example
|
|
@strong{Description}@*
|
|
Call the provided function @var{func} for each section
|
|
attached to the BFD @var{abfd} whose name matches @var{name},
|
|
passing @var{obj} as an argument. The function will be called
|
|
as if by
|
|
|
|
@example
|
|
func (abfd, the_section, obj);
|
|
@end example
|
|
|
|
It returns the first section for which @var{func} returns true,
|
|
otherwise @code{NULL}.
|
|
|
|
@findex bfd_get_unique_section_name
|
|
@subsubsection @code{bfd_get_unique_section_name}
|
|
@strong{Synopsis}
|
|
@example
|
|
char *bfd_get_unique_section_name
|
|
(bfd *abfd, const char *templat, int *count);
|
|
@end example
|
|
@strong{Description}@*
|
|
Invent a section name that is unique in @var{abfd} by tacking
|
|
a dot and a digit suffix onto the original @var{templat}. If
|
|
@var{count} is non-NULL, then it specifies the first number
|
|
tried as a suffix to generate a unique name. The value
|
|
pointed to by @var{count} will be incremented in this case.
|
|
|
|
@findex bfd_make_section_old_way
|
|
@subsubsection @code{bfd_make_section_old_way}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_make_section_old_way (bfd *abfd, const char *name);
|
|
@end example
|
|
@strong{Description}@*
|
|
Create a new empty section called @var{name}
|
|
and attach it to the end of the chain of sections for the
|
|
BFD @var{abfd}. An attempt to create a section with a name which
|
|
is already in use returns its pointer without changing the
|
|
section chain.
|
|
|
|
It has the funny name since this is the way it used to be
|
|
before it was rewritten....
|
|
|
|
Possible errors are:
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_invalid_operation} -
|
|
If output has already started for this BFD.
|
|
@item
|
|
@code{bfd_error_no_memory} -
|
|
If memory allocation fails.
|
|
@end itemize
|
|
|
|
@findex bfd_make_section_anyway_with_flags
|
|
@subsubsection @code{bfd_make_section_anyway_with_flags}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_make_section_anyway_with_flags
|
|
(bfd *abfd, const char *name, flagword flags);
|
|
@end example
|
|
@strong{Description}@*
|
|
Create a new empty section called @var{name} and attach it to the end of
|
|
the chain of sections for @var{abfd}. Create a new section even if there
|
|
is already a section with that name. Also set the attributes of the
|
|
new section to the value @var{flags}.
|
|
|
|
Return @code{NULL} and set @code{bfd_error} on error; possible errors are:
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_invalid_operation} - If output has already started for @var{abfd}.
|
|
@item
|
|
@code{bfd_error_no_memory} - If memory allocation fails.
|
|
@end itemize
|
|
|
|
@findex bfd_make_section_anyway
|
|
@subsubsection @code{bfd_make_section_anyway}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_make_section_anyway (bfd *abfd, const char *name);
|
|
@end example
|
|
@strong{Description}@*
|
|
Create a new empty section called @var{name} and attach it to the end of
|
|
the chain of sections for @var{abfd}. Create a new section even if there
|
|
is already a section with that name.
|
|
|
|
Return @code{NULL} and set @code{bfd_error} on error; possible errors are:
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_invalid_operation} - If output has already started for @var{abfd}.
|
|
@item
|
|
@code{bfd_error_no_memory} - If memory allocation fails.
|
|
@end itemize
|
|
|
|
@findex bfd_make_section_with_flags
|
|
@subsubsection @code{bfd_make_section_with_flags}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_make_section_with_flags
|
|
(bfd *, const char *name, flagword flags);
|
|
@end example
|
|
@strong{Description}@*
|
|
Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling
|
|
bfd_set_error ()) without changing the section chain if there is already a
|
|
section named @var{name}. Also set the attributes of the new section to
|
|
the value @var{flags}. If there is an error, return @code{NULL} and set
|
|
@code{bfd_error}.
|
|
|
|
@findex bfd_make_section
|
|
@subsubsection @code{bfd_make_section}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_make_section (bfd *, const char *name);
|
|
@end example
|
|
@strong{Description}@*
|
|
Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling
|
|
bfd_set_error ()) without changing the section chain if there is already a
|
|
section named @var{name}. If there is an error, return @code{NULL} and set
|
|
@code{bfd_error}.
|
|
|
|
@findex bfd_set_section_flags
|
|
@subsubsection @code{bfd_set_section_flags}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_set_section_flags
|
|
(bfd *abfd, asection *sec, flagword flags);
|
|
@end example
|
|
@strong{Description}@*
|
|
Set the attributes of the section @var{sec} in the BFD
|
|
@var{abfd} to the value @var{flags}. Return @code{TRUE} on success,
|
|
@code{FALSE} on error. Possible error returns are:
|
|
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_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 itemize
|
|
|
|
@findex bfd_rename_section
|
|
@subsubsection @code{bfd_rename_section}
|
|
@strong{Synopsis}
|
|
@example
|
|
void bfd_rename_section
|
|
(bfd *abfd, asection *sec, const char *newname);
|
|
@end example
|
|
@strong{Description}@*
|
|
Rename section @var{sec} in @var{abfd} to @var{newname}.
|
|
|
|
@findex bfd_map_over_sections
|
|
@subsubsection @code{bfd_map_over_sections}
|
|
@strong{Synopsis}
|
|
@example
|
|
void bfd_map_over_sections
|
|
(bfd *abfd,
|
|
void (*func) (bfd *abfd, asection *sect, void *obj),
|
|
void *obj);
|
|
@end example
|
|
@strong{Description}@*
|
|
Call the provided function @var{func} for each section
|
|
attached 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
|
|
|
|
This is the preferred method for iterating over sections; an
|
|
alternative would be to use a loop:
|
|
|
|
@example
|
|
asection *p;
|
|
for (p = abfd->sections; p != NULL; p = p->next)
|
|
func (abfd, p, ...)
|
|
@end example
|
|
|
|
@findex bfd_sections_find_if
|
|
@subsubsection @code{bfd_sections_find_if}
|
|
@strong{Synopsis}
|
|
@example
|
|
asection *bfd_sections_find_if
|
|
(bfd *abfd,
|
|
bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
|
|
void *obj);
|
|
@end example
|
|
@strong{Description}@*
|
|
Call the provided function @var{operation} for each section
|
|
attached to the BFD @var{abfd}, passing @var{obj} as an
|
|
argument. The function will be called as if by
|
|
|
|
@example
|
|
operation (abfd, the_section, obj);
|
|
@end example
|
|
|
|
It returns the first section for which @var{operation} returns true.
|
|
|
|
@findex bfd_set_section_size
|
|
@subsubsection @code{bfd_set_section_size}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_set_section_size
|
|
(bfd *abfd, asection *sec, bfd_size_type val);
|
|
@end example
|
|
@strong{Description}@*
|
|
Set @var{sec} to the size @var{val}. If the operation is
|
|
ok, then @code{TRUE} is returned, else @code{FALSE}.
|
|
|
|
Possible error returns:
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_invalid_operation} -
|
|
Writing has started to the BFD, so setting the size is invalid.
|
|
@end itemize
|
|
|
|
@findex bfd_set_section_contents
|
|
@subsubsection @code{bfd_set_section_contents}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_set_section_contents
|
|
(bfd *abfd, asection *section, const void *data,
|
|
file_ptr offset, bfd_size_type count);
|
|
@end example
|
|
@strong{Description}@*
|
|
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} octets.
|
|
|
|
Normally @code{TRUE} is returned, else @code{FALSE}. Possible error
|
|
returns are:
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_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 itemize
|
|
This routine is front end to the back end function
|
|
@code{_bfd_set_section_contents}.
|
|
|
|
@findex bfd_get_section_contents
|
|
@subsubsection @code{bfd_get_section_contents}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_get_section_contents
|
|
(bfd *abfd, asection *section, void *location, file_ptr offset,
|
|
bfd_size_type count);
|
|
@end example
|
|
@strong{Description}@*
|
|
Read 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 constructor with the @code{SEC_CONSTRUCTOR}
|
|
flag set are requested or if the section does not have the
|
|
@code{SEC_HAS_CONTENTS} flag set, then the @var{location} is filled
|
|
with zeroes. If no errors occur, @code{TRUE} is returned, else
|
|
@code{FALSE}.
|
|
|
|
@findex bfd_malloc_and_get_section
|
|
@subsubsection @code{bfd_malloc_and_get_section}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_malloc_and_get_section
|
|
(bfd *abfd, asection *section, bfd_byte **buf);
|
|
@end example
|
|
@strong{Description}@*
|
|
Read all data from @var{section} in BFD @var{abfd}
|
|
into a buffer, *@var{buf}, malloc'd by this function.
|
|
|
|
@findex bfd_copy_private_section_data
|
|
@subsubsection @code{bfd_copy_private_section_data}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_copy_private_section_data
|
|
(bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
|
|
@end example
|
|
@strong{Description}@*
|
|
Copy private section information from @var{isec} in the BFD
|
|
@var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
|
|
Return @code{TRUE} on success, @code{FALSE} on error. Possible error
|
|
returns are:
|
|
|
|
@itemize @bullet
|
|
|
|
@item
|
|
@code{bfd_error_no_memory} -
|
|
Not enough memory exists to create private data for @var{osec}.
|
|
@end itemize
|
|
@example
|
|
#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
|
|
BFD_SEND (obfd, _bfd_copy_private_section_data, \
|
|
(ibfd, isection, obfd, osection))
|
|
@end example
|
|
|
|
@findex bfd_generic_is_group_section
|
|
@subsubsection @code{bfd_generic_is_group_section}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
|
|
@end example
|
|
@strong{Description}@*
|
|
Returns TRUE if @var{sec} is a member of a group.
|
|
|
|
@findex bfd_generic_discard_group
|
|
@subsubsection @code{bfd_generic_discard_group}
|
|
@strong{Synopsis}
|
|
@example
|
|
bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
|
|
@end example
|
|
@strong{Description}@*
|
|
Remove all members of @var{group} from the output.
|
|
|