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This is bfd.info, produced by Makeinfo version 3.12f from bfd.texinfo.

START-INFO-DIR-ENTRY

* Bfd: (bfd).                   The Binary File Descriptor library.

END-INFO-DIR-ENTRY

   This file documents the BFD library.

   Copyright (C) 1991 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this

manual provided the copyright notice and this permission notice are

preserved on all copies.

   Permission is granted to copy and distribute modified versions of

this manual under the conditions for verbatim copying, subject to the

terms of the GNU General Public License, which includes the provision

that the entire resulting derived work is distributed under the terms

of a permission notice identical to this one.

   Permission is granted to copy and distribute translations of this

manual into another language, under the above conditions for modified

versions.

File: bfd.info,  Node: typedef asection,  Next: section prototypes,  Prev: Section Output,  Up: Sections

typedef asection

----------------

   Here is the section structure:

      /* This structure is used for a comdat section, as in PE.  A comdat

         section is associated with a particular symbol.  When the linker

         sees a comdat section, it keeps only one of the sections with a

         given name and associated with a given symbol. */

     struct bfd_comdat_info

     {

       /* The name of the symbol associated with a comdat section.  */

       const char *name;

       /* The local symbol table index of the symbol associated with a

          comdat section.  This is only meaningful to the object file format

          specific code; it is not an index into the list returned by

          bfd_canonicalize_symtab.  */

       long symbol;

       /* If this section is being discarded, the linker uses this field

          to point to the input section which is being kept.  */

       struct sec *sec;

     };

     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;

             /* Which section is it; 0..nth.      */

        int index;

             /* The next section in the list belonging to the BFD, or NULL. */

         struct sec *next;

             /* 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   0x000

             /* Tells the OS to allocate space for this section when loading.

                This is 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 is clear for a .bss section. */

     #define SEC_LOAD       0x002

             /* The section contains data still to be relocated, so there is

                some relocation information too. */

     #define SEC_RELOC      0x004

     #if 0   /* Obsolete ? */

     #define SEC_BALIGN     0x008

     #endif

             /* 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 `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., `__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 `__CTOR_LIST__' and relocate the data

                contained within - exactly the operations it would peform on

                standard data. */

     #define SEC_CONSTRUCTOR 0x100

             /* The section is a constructor, and should be placed at the

               end of the text, data, or bss section(?). */

     #define SEC_CONSTRUCTOR_TEXT 0x1100

     #define SEC_CONSTRUCTOR_DATA 0x2100

     #define SEC_CONSTRUCTOR_BSS  0x3100

             /* The section has contents - a data section could be

                `SEC_ALLOC' | `SEC_HAS_CONTENTS'; a debug section could be

                `SEC_HAS_CONTENTS' */

     #define SEC_HAS_CONTENTS 0x200

             /* An instruction to the linker to not output the section

                even if it has information which would normally be written. */

     #define SEC_NEVER_LOAD 0x400

             /* 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 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 0x8000

             /* 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 0x10000

             /* 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 0x20000

             /* 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 0x40000

            /* The contents of this section are to be sorted by the

               based on the address specified in the associated symbol

               table.  */

     #define SEC_SORT_ENTRIES 0x80000

            /* 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 0x100000

            /* If SEC_LINK_ONCE is set, this bitfield describes how the linker

               should handle duplicate sections.  */

     #define SEC_LINK_DUPLICATES 0x600000

            /* 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 0x200000

            /* 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 0x400000

            /* 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 0x600000

            /* 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 0x800000

            /* This section should not be subject to garbage collection.  */

     #define SEC_KEEP 0x1000000

            /* This section contains "short" data, and should be placed

               "near" the GP.  */

     #define SEC_SMALL_DATA 0x2000000

            /* This section contains data which may be shared with other

               executables or shared objects.  */

     #define SEC_SHARED 0x4000000

            /* 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.  */

     #define SEC_BLOCK 0x8000000

            /* Conditionally link this section; do not link if there are no

               references found to any symbol in the section.  */

     #define SEC_CLINK 0x10000000

            /*  End of section flags.  */

            /* Some internal packed boolean fields.  */

            /* See the vma field.  */

            unsigned int user_set_vma : 1;

            /* Whether relocations have been processed.  */

            unsigned int reloc_done : 1;

            /* A mark flag used by some of the linker backends.  */

            unsigned int linker_mark : 1;

            /* A mark flag used by some linker backends for garbage collection.  */

            unsigned int gc_mark : 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 `a.out', where

                the default address for `.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 `.bss').  This will be filled in after relocation.  */

        bfd_size_type _cooked_size;

             /* The original size on disk of the section, in octets.  Normally this

                value is the same as the size, but if some relaxing has

                been done, then this value will be bigger.  */

        bfd_size_type _raw_size;

             /* 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 sec *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 */

        PTR 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;

             /* Optional information about a COMDAT entry; NULL if not COMDAT */

        struct bfd_comdat_info *comdat;

             /* 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;

        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;

             /* A symbol which points at this section only */

        struct symbol_cache_entry *symbol;

        struct symbol_cache_entry **symbol_ptr_ptr;

        struct bfd_link_order *link_order_head;

        struct bfd_link_order *link_order_tail;

     } asection ;

         /* 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.  New code should use the section_ptr macros rather

            than referring directly to the const sections.  The const sections

            may eventually vanish.  */

     #define BFD_ABS_SECTION_NAME "*ABS*"

     #define BFD_UND_SECTION_NAME "*UND*"

     #define BFD_COM_SECTION_NAME "*COM*"

     #define BFD_IND_SECTION_NAME "*IND*"

         /* the absolute section */

     extern const asection bfd_abs_section;

     #define bfd_abs_section_ptr ((asection *) &bfd_abs_section)

     #define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)

         /* Pointer to the undefined section */

     extern const asection bfd_und_section;

     #define bfd_und_section_ptr ((asection *) &bfd_und_section)

     #define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)

         /* Pointer to the common section */

     extern const asection bfd_com_section;

     #define bfd_com_section_ptr ((asection *) &bfd_com_section)

         /* Pointer to the indirect section */

     extern const asection bfd_ind_section;

     #define bfd_ind_section_ptr ((asection *) &bfd_ind_section)

     #define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)

     extern const struct symbol_cache_entry * const bfd_abs_symbol;

     extern const struct symbol_cache_entry * const bfd_com_symbol;

     extern const struct symbol_cache_entry * const bfd_und_symbol;

     extern const struct symbol_cache_entry * const bfd_ind_symbol;

     #define bfd_get_section_size_before_reloc(section) \

          ((section)->reloc_done ? (abort (), (bfd_size_type) 1) \

                                 : (section)->_raw_size)

     #define bfd_get_section_size_after_reloc(section) \

          ((section)->reloc_done ? (section)->_cooked_size \

                                 : (abort (), (bfd_size_type) 1))

File: bfd.info,  Node: section prototypes,  Prev: typedef asection,  Up: Sections

Section prototypes

------------------

   These are the functions exported by the section handling part of BFD.

`bfd_get_section_by_name'

.........................

   *Synopsis*

     asection *bfd_get_section_by_name(bfd *abfd, CONST char *name);

   *Description*

Run through ABFD and return the one of the `asection's whose name

matches NAME, otherwise `NULL'.  *Note Sections::, for more information.

   This should only be used in special cases; the normal way to process

all sections of a given name is to use `bfd_map_over_sections' and

`strcmp' on the name (or better yet, base it on the section flags or

something else) for each section.

`bfd_make_section_old_way'

..........................

   *Synopsis*

     asection *bfd_make_section_old_way(bfd *abfd, CONST char *name);

   *Description*

Create a new empty section called NAME and attach it to the end of the

chain of sections for the BFD 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:

   * `bfd_error_invalid_operation' - If output has already started for

     this BFD.

   * `bfd_error_no_memory' - If memory allocation fails.

`bfd_make_section_anyway'

.........................

   *Synopsis*

     asection *bfd_make_section_anyway(bfd *abfd, CONST char *name);

   *Description*

Create a new empty section called NAME and attach it to the end of the

chain of sections for ABFD.  Create a new section even if there is

already a section with that name.

   Return `NULL' and set `bfd_error' on error; possible errors are:

   * `bfd_error_invalid_operation' - If output has already started for

     ABFD.

   * `bfd_error_no_memory' - If memory allocation fails.

`bfd_make_section'

..................

   *Synopsis*

     asection *bfd_make_section(bfd *, CONST char *name);

   *Description*

Like `bfd_make_section_anyway', but return `NULL' (without calling

bfd_set_error ()) without changing the section chain if there is

already a section named NAME.  If there is an error, return `NULL' and

set `bfd_error'.

`bfd_set_section_flags'

.......................

   *Synopsis*

     boolean bfd_set_section_flags(bfd *abfd, asection *sec, flagword flags);

   *Description*

Set the attributes of the section SEC in the BFD ABFD to the value

FLAGS. Return `true' on success, `false' on error. Possible error

returns are:

   * `bfd_error_invalid_operation' - The section cannot have one or

     more of the attributes requested. For example, a .bss section in

     `a.out' may not have the `SEC_HAS_CONTENTS' field set.

`bfd_map_over_sections'

.......................

   *Synopsis*

     void bfd_map_over_sections(bfd *abfd,

         void (*func)(bfd *abfd,

         asection *sect,

         PTR obj),

         PTR obj);

   *Description*

Call the provided function FUNC for each section attached to the BFD

ABFD, passing OBJ as an argument. The function will be called as if by

            func(abfd, the_section, obj);

   This is the prefered method for iterating over sections; an

alternative would be to use a loop:

               section *p;

               for (p = abfd->sections; p != NULL; p = p->next)

                  func(abfd, p, ...)

`bfd_set_section_size'

......................

   *Synopsis*

     boolean bfd_set_section_size(bfd *abfd, asection *sec, bfd_size_type val);

   *Description*

Set SEC to the size VAL. If the operation is ok, then `true' is

returned, else `false'.

   Possible error returns:

   * `bfd_error_invalid_operation' - Writing has started to the BFD, so

     setting the size is invalid.

`bfd_set_section_contents'

..........................

   *Synopsis*

     boolean bfd_set_section_contents

        (bfd *abfd,

         asection *section,

         PTR data,

         file_ptr offset,

         bfd_size_type count);

   *Description*

Sets the contents of the section SECTION in BFD ABFD to the data

starting in memory at DATA. The data is written to the output section

starting at offset OFFSET for COUNT octets.

   Normally `true' is returned, else `false'. Possible error returns

are:

   * `bfd_error_no_contents' - The output section does not have the

     `SEC_HAS_CONTENTS' attribute, so nothing can be written to it.

   * and some more too

   This routine is front end to the back end function

`_bfd_set_section_contents'.

`bfd_get_section_contents'

..........................

   *Synopsis*

     boolean bfd_get_section_contents

        (bfd *abfd, asection *section, PTR location,

         file_ptr offset, bfd_size_type count);

   *Description*

Read data from SECTION in BFD ABFD into memory starting at LOCATION.

The data is read at an offset of OFFSET from the start of the input

section, and is read for COUNT bytes.

   If the contents of a constructor with the `SEC_CONSTRUCTOR' flag set

are requested or if the section does not have the `SEC_HAS_CONTENTS'

flag set, then the LOCATION is filled with zeroes. If no errors occur,

`true' is returned, else `false'.

`bfd_copy_private_section_data'

...............................

   *Synopsis*

     boolean bfd_copy_private_section_data(bfd *ibfd, asection *isec, bfd *obfd, asection *osec);

   *Description*

Copy private section information from ISEC in the BFD IBFD to the

section OSEC in the BFD OBFD.  Return `true' on success, `false' on

error.  Possible error returns are:

   * `bfd_error_no_memory' - Not enough memory exists to create private

     data for OSEC.

     #define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \

          BFD_SEND (obfd, _bfd_copy_private_section_data, \

                    (ibfd, isection, obfd, osection))

`_bfd_strip_section_from_output'

................................

   *Synopsis*

     void _bfd_strip_section_from_output

        (struct bfd_link_info *info, asection *section);

   *Description*

Remove SECTION from the output.  If the output section becomes empty,

remove it from the output bfd.  INFO may be NULL; if it is not, it is

used to decide whether the output section is empty.

File: bfd.info,  Node: Symbols,  Next: Archives,  Prev: Sections,  Up: BFD front end

Symbols

=======

   BFD tries to maintain as much symbol information as it can when it

moves information from file to file. BFD passes information to

applications though the `asymbol' structure. When the application

requests the symbol table, BFD reads the table in the native form and

translates parts of it into the internal format. To maintain more than

the information passed to applications, some targets keep some

information "behind the scenes" in a structure only the particular back

end knows about. For example, the coff back end keeps the original

symbol table structure as well as the canonical structure when a BFD is

read in. On output, the coff back end can reconstruct the output symbol

table so that no information is lost, even information unique to coff

which BFD doesn't know or understand. If a coff symbol table were read,

but were written through an a.out back end, all the coff specific

information would be lost. The symbol table of a BFD is not necessarily

read in until a canonicalize request is made. Then the BFD back end

fills in a table provided by the application with pointers to the

canonical information.  To output symbols, the application provides BFD

with a table of pointers to pointers to `asymbol's. This allows

applications like the linker to output a symbol as it was read, since

the "behind the scenes" information will be still available.

* Menu:

* Reading Symbols::

* Writing Symbols::

* Mini Symbols::

* typedef asymbol::

* symbol handling functions::

File: bfd.info,  Node: Reading Symbols,  Next: Writing Symbols,  Prev: Symbols,  Up: Symbols

Reading symbols

---------------

   There are two stages to reading a symbol table from a BFD:

allocating storage, and the actual reading process. This is an excerpt

from an application which reads the symbol table:

              long storage_needed;

              asymbol **symbol_table;

              long number_of_symbols;

              long i;

              storage_needed = bfd_get_symtab_upper_bound (abfd);

              if (storage_needed < 0)

                FAIL

              if (storage_needed == 0) {

                 return ;

              }

              symbol_table = (asymbol **) xmalloc (storage_needed);

                ...

              number_of_symbols =

                 bfd_canonicalize_symtab (abfd, symbol_table);

              if (number_of_symbols < 0)

                FAIL

              for (i = 0; i < number_of_symbols; i++) {

                 process_symbol (symbol_table[i]);

              }

   All storage for the symbols themselves is in an objalloc connected

to the BFD; it is freed when the BFD is closed.

File: bfd.info,  Node: Writing Symbols,  Next: Mini Symbols,  Prev: Reading Symbols,  Up: Symbols

Writing symbols

---------------

   Writing of a symbol table is automatic when a BFD open for writing

is closed. The application attaches a vector of pointers to pointers to

symbols to the BFD being written, and fills in the symbol count. The

close and cleanup code reads through the table provided and performs

all the necessary operations. The BFD output code must always be

provided with an "owned" symbol: one which has come from another BFD,

or one which has been created using `bfd_make_empty_symbol'.  Here is an

example showing the creation of a symbol table with only one element:

            #include "bfd.h"

            main()

            {

              bfd *abfd;

              asymbol *ptrs[2];

              asymbol *new;

              abfd = bfd_openw("foo","a.out-sunos-big");

              bfd_set_format(abfd, bfd_object);

              new = bfd_make_empty_symbol(abfd);

              new->name = "dummy_symbol";

              new->section = bfd_make_section_old_way(abfd, ".text");

              new->flags = BSF_GLOBAL;

              new->value = 0x12345;

              ptrs[0] = new;

              ptrs[1] = (asymbol *)0;

              bfd_set_symtab(abfd, ptrs, 1);

              bfd_close(abfd);

            }

            ./makesym

            nm foo

            00012345 A dummy_symbol

   Many formats cannot represent arbitary symbol information; for

instance, the `a.out' object format does not allow an arbitary number

of sections. A symbol pointing to a section which is not one  of

`.text', `.data' or `.bss' cannot be described.

File: bfd.info,  Node: Mini Symbols,  Next: typedef asymbol,  Prev: Writing Symbols,  Up: Symbols

Mini Symbols

------------

   Mini symbols provide read-only access to the symbol table.  They use

less memory space, but require more time to access.  They can be useful

for tools like nm or objdump, which may have to handle symbol tables of

extremely large executables.

   The `bfd_read_minisymbols' function will read the symbols into

memory in an internal form.  It will return a `void *' pointer to a

block of memory, a symbol count, and the size of each symbol.  The

pointer is allocated using `malloc', and should be freed by the caller

when it is no longer needed.

   The function `bfd_minisymbol_to_symbol' will take a pointer to a

minisymbol, and a pointer to a structure returned by

`bfd_make_empty_symbol', and return a `asymbol' structure.  The return

value may or may not be the same as the value from

`bfd_make_empty_symbol' which was passed in.

File: bfd.info,  Node: typedef asymbol,  Next: symbol handling functions,  Prev: Mini Symbols,  Up: Symbols

typedef asymbol

---------------

   An `asymbol' has the form:

     typedef struct symbol_cache_entry

     {

            /* A pointer to the BFD which owns the symbol. This information

               is necessary so that a back end can work out what additional

               information (invisible to the application writer) is carried

               with the symbol.

               This field is *almost* redundant, since you can use section->owner

               instead, except that some symbols point to the global sections

               bfd_{abs,com,und}_section.  This could be fixed by making

               these globals be per-bfd (or per-target-flavor).  FIXME. */

       struct _bfd *the_bfd; /* Use bfd_asymbol_bfd(sym) to access this field. */

            /* The text of the symbol. The name is left alone, and not copied; the

               application may not alter it. */

       CONST char *name;

            /* The value of the symbol.  This really should be a union of a

               numeric value with a pointer, since some flags indicate that

               a pointer to another symbol is stored here.  */

       symvalue value;

            /* Attributes of a symbol: */

     #define BSF_NO_FLAGS    0x00

            /* The symbol has local scope; `static' in `C'. The value

               is the offset into the section of the data. */

     #define BSF_LOCAL      0x01

            /* The symbol has global scope; initialized data in `C'. The

               value is the offset into the section of the data. */

     #define BSF_GLOBAL     0x02

            /* The symbol has global scope and is exported. The value is

               the offset into the section of the data. */

     #define BSF_EXPORT     BSF_GLOBAL /* no real difference */

            /* A normal C symbol would be one of:

               `BSF_LOCAL', `BSF_FORT_COMM',  `BSF_UNDEFINED' or

               `BSF_GLOBAL' */

            /* The symbol is a debugging record. The value has an arbitary

               meaning, unless BSF_DEBUGGING_RELOC is also set.  */

     #define BSF_DEBUGGING  0x08

            /* The symbol denotes a function entry point.  Used in ELF,

               perhaps others someday.  */

     #define BSF_FUNCTION    0x10

            /* Used by the linker. */

     #define BSF_KEEP        0x20

     #define BSF_KEEP_G      0x40

            /* A weak global symbol, overridable without warnings by

               a regular global symbol of the same name.  */

     #define BSF_WEAK        0x80

            /* This symbol was created to point to a section, e.g. ELF's

               STT_SECTION symbols.  */

     #define BSF_SECTION_SYM 0x100

            /* The symbol used to be a common symbol, but now it is

               allocated. */

     #define BSF_OLD_COMMON  0x200

            /* The default value for common data. */

     #define BFD_FORT_COMM_DEFAULT_VALUE 0

            /* In some files the type of a symbol sometimes alters its

               location in an output file - ie in coff a `ISFCN' symbol

               which is also `C_EXT' symbol appears where it was

               declared and not at the end of a section.  This bit is set

               by the target BFD part to convey this information. */

     #define BSF_NOT_AT_END    0x400

            /* Signal that the symbol is the label of constructor section. */

     #define BSF_CONSTRUCTOR   0x800

            /* Signal that the symbol is a warning symbol.  The name is a

               warning.  The name of the next symbol is the one to warn about;

               if a reference is made to a symbol with the same name as the next

               symbol, a warning is issued by the linker. */

     #define BSF_WARNING       0x1000

            /* Signal that the symbol is indirect.  This symbol is an indirect

               pointer to the symbol with the same name as the next symbol. */

     #define BSF_INDIRECT      0x2000

            /* BSF_FILE marks symbols that contain a file name.  This is used

               for ELF STT_FILE symbols.  */

     #define BSF_FILE          0x4000

            /* Symbol is from dynamic linking information.  */

     #define BSF_DYNAMIC       0x8000

            /* The symbol denotes a data object.  Used in ELF, and perhaps

               others someday.  */

     #define BSF_OBJECT        0x10000

            /* This symbol is a debugging symbol.  The value is the offset

               into the section of the data.  BSF_DEBUGGING should be set

               as well.  */

     #define BSF_DEBUGGING_RELOC 0x20000

       flagword flags;

            /* A pointer to the section to which this symbol is

               relative.  This will always be non NULL, there are special

               sections for undefined and absolute symbols.  */

       struct sec *section;

            /* Back end special data.  */

       union

         {

           PTR p;

           bfd_vma i;

         } udata;

     } asymbol;

File: bfd.info,  Node: symbol handling functions,  Prev: typedef asymbol,  Up: Symbols

Symbol handling functions

-------------------------

`bfd_get_symtab_upper_bound'

............................

   *Description*

Return the number of bytes required to store a vector of pointers to

`asymbols' for all the symbols in the BFD ABFD, including a terminal

NULL pointer. If there are no symbols in the BFD, then return 0.  If an

error occurs, return -1.

     #define bfd_get_symtab_upper_bound(abfd) \

          BFD_SEND (abfd, _bfd_get_symtab_upper_bound, (abfd))

`bfd_is_local_label'

....................

   *Synopsis*

     boolean bfd_is_local_label(bfd *abfd, asymbol *sym);

   *Description*

Return true if the given symbol SYM in the BFD ABFD is a compiler

generated local label, else return false.

`bfd_is_local_label_name'

.........................

   *Synopsis*

     boolean bfd_is_local_label_name(bfd *abfd, const char *name);

   *Description*

Return true if a symbol with the name NAME in the BFD ABFD is a

compiler generated local label, else return false.  This just checks

whether the name has the form of a local label.

     #define bfd_is_local_label_name(abfd, name) \

          BFD_SEND (abfd, _bfd_is_local_label_name, (abfd, name))

`bfd_canonicalize_symtab'

.........................

   *Description*

Read the symbols from the BFD ABFD, and fills in the vector LOCATION

with pointers to the symbols and a trailing NULL.  Return the actual

number of symbol pointers, not including the NULL.

     #define bfd_canonicalize_symtab(abfd, location) \

          BFD_SEND (abfd, _bfd_canonicalize_symtab,\

                       (abfd, location))

`bfd_set_symtab'

................

   *Synopsis*

     boolean bfd_set_symtab (bfd *abfd, asymbol **location, unsigned int count);

   *Description*

Arrange that when the output BFD ABFD is closed, the table LOCATION of

COUNT pointers to symbols will be written.

`bfd_print_symbol_vandf'

........................

   *Synopsis*

     void bfd_print_symbol_vandf(PTR file, asymbol *symbol);

   *Description*

Print the value and flags of the SYMBOL supplied to the stream FILE.

`bfd_make_empty_symbol'

.......................

   *Description*

Create a new `asymbol' structure for the BFD ABFD and return a pointer