NAME
dwarf_get_section_bytes —
retrieve ELF
section byte streams
LIBRARY
DWARF Access Library (libdwarf, -ldwarf)
SYNOPSIS
#include <libdwarf.h>
Dwarf_Ptr
dwarf_get_section_bytes(
Dwarf_P_Debug
dbg,
Dwarf_Signed dwarf_section,
Dwarf_Signed *elf_section_index,
Dwarf_Unsigned *length,
Dwarf_Error
*err);
DESCRIPTION
Function
dwarf_get_section_bytes() returns the ELF section
byte streams generated by a prior call to function
dwarf_transform_to_disk_form(3).
Each call to function
dwarf_get_section_bytes() will return
the byte stream for one ELF section. The first call to this function will
always return the first ELF section, and the subsequent calls will return the
rest of sections in the order when they were generated, until the last one.
The total number of sections generated is returned by the function
dwarf_transform_to_disk_form(3).
Argument
dbg should reference a DWARF producer instance
allocated using the functions
dwarf_producer_init(3)
or
dwarf_producer_init_b(3).
Argument
dwarf_section is currently ignored.
Argument
elf_section_index should point to a location
which will be set to the section index value of the returned ELF section.
Argument
length should point to a location which will hold
the length in bytes of the returned ELF section.
If argument
err is not NULL, it will be used to store
error information in case of an error.
Memory Management
The memory areas used for the returned ELF section byte streams should be freed
using the function
dwarf_producer_finish().
RETURN VALUES
On success, function
dwarf_get_section_bytes() returns a
pointer to a ELF section byte stream. In case of an error, function
dwarf_get_section_bytes() will return NULL and set the
argument
err.
ERRORS
Function
dwarf_get_section_bytes() can fail with:
-
-
- [
DW_DLE_ARGUMENT
]
- One of the arguments dbg,
elf_section_index, or length
was NULL.
-
-
- [
DW_DLE_NO_ENTRY
]
- There were no more ELF sections to retrieve, or the
function was called before a call to
dwarf_transform_to_disk_form(3).
EXAMPLES
To generate and retrieve ELF section byte streams, use:
Dwarf_P_Debug dbg;
Dwarf_Signed count, i, sec_index;
Dwarf_Unsigned len;
Dwarf_Ptr bytes;
Dwarf_Error de;
/* ... Assume that `dbg' refers to a DWARF producer instance,
* and that application code has added DWARF debugging
* information to the producer instance. ...
*/
if ((count = dwarf_transform_to_disk_form(dbg, &de)) ==
DW_DLV_NOCOUNT) {
warnx("dwarf_transform_to_disk_form failed: %s",
dwarf_errmsg(-1));
return;
}
/* Retrieve section data. */
for (i = 0; i < count; i++) {
bytes = dwarf_get_section_bytes(dbg, i, &sec_index, &len,
&de);
if (bytes == NULL) {
warnx("dwarf_get_section_bytes failed: %s",
dwarf_errmsg(-1));
continue;
}
/* ... use the returned byte stream ... */
}
/* Release resources. */
dwarf_producer_finish(dbg, &de);
SEE ALSO
dwarf(3),
dwarf_reset_section_bytes(3),
dwarf_producer_finish(3),
dwarf_producer_init(3),
dwarf_producer_init_b(3),
dwarf_transform_to_disk_form(3)