| @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. 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 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. */ |
| int id; |
| |
| /* Which section in the bfd; 0..n-1 as sections are created in a bfd. */ |
| 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 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 |
| |
| /* A signal to the OS that the section contains read only data. */ |
| #define SEC_READONLY 0x008 |
| |
| /* The section contains code only. */ |
| #define SEC_CODE 0x010 |
| |
| /* The section contains data only. */ |
| #define SEC_DATA 0x020 |
| |
| /* The section will reside in ROM. */ |
| #define SEC_ROM 0x040 |
| |
| /* 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 0x080 |
| |
| /* 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 has GOT references. This flag is only for the |
| linker, and is currently only used by the elf32-hppa back end. |
| It will be set if global offset table references were detected |
| in this section, which indicate to the linker that the section |
| contains PIC code, and must be handled specially when doing a |
| static link. */ |
| #define SEC_HAS_GOT_REF 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 |
| |
| /* 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 |
| |
| /* 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 |
| |
| /* Indicate that section has the no read flag set. This happens |
| when memory read flag isn't set. */ |
| #define SEC_COFF_NOREAD 0x40000000 |
| |
| /* 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 ELF_INFO_TYPE_NONE 0 |
| #define ELF_INFO_TYPE_STABS 1 |
| #define ELF_INFO_TYPE_MERGE 2 |
| #define ELF_INFO_TYPE_EH_FRAME 3 |
| #define ELF_INFO_TYPE_JUST_SYMS 4 |
| |
| /* 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; |
| |
| /* INPUT_SECTION_FLAGS if specified in the linker script. */ |
| struct flag_info *section_flag_info; |
| |
| /* 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; |
| @}; |
| |
| /* 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 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 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 asection bfd_com_section; |
| #define bfd_com_section_ptr ((asection *) &bfd_com_section) |
| /* Pointer to the indirect section. */ |
| extern asection bfd_ind_section; |
| #define bfd_ind_section_ptr ((asection *) &bfd_ind_section) |
| #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, FLAGS, SYM, NAME, IDX) \ |
| /* 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, (struct bfd_section *) &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, \ |
| \ |
| /* flag_info, */ \ |
| NULL, \ |
| \ |
| /* symbol, symbol_ptr_ptr, */ \ |
| (struct bfd_symbol *) SYM, &SEC.symbol, \ |
| \ |
| /* map_head, map_tail */ \ |
| @{ NULL @}, @{ NULL @} \ |
| @} |
| |
| @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}@* |
| Run through @var{abfd} and return the one of the |
| @code{asection}s whose name matches @var{name}, otherwise @code{NULL}. |
| @xref{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 @code{bfd_map_over_sections} and |
| @code{strcmp} on the name (or better yet, base it on the section flags |
| or something else) for each section. |
| |
| @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 |
| section *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. |
| |