dwarf_formref(3) [freebsd man page]

DWARF_FORMREF(3)					   BSD Library Functions Manual 					  DWARF_FORMREF(3)

NAME

     dwarf_formref, dwarf_global_formref -- retrieve offsets for REFERENCE class attributes

LIBRARY

     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

     #include <libdwarf.h>

     int
     dwarf_formref(Dwarf_Attribute attr, Dwarf_Off *retoffset, Dwarf_Error *err);

     int
     dwarf_global_formref(Dwarf_Attribute attr, Dwarf_Off *retoffset, Dwarf_Error *err);

DESCRIPTION

     These functions return the offsets associated with a DWARF attribute descriptor.

     Function dwarf_formref() returns the compilation unit relative offset of the descriptor referenced by argument attr in the location pointed
     to by argument retoffset.	Argument attr must be a reference that is local to a compilation unit.	Permitted forms for argument attr are
     DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8 and DW_FORM_ref_udata.

     Function dwarf_global_formref() returns the section-relative offset of the descriptor referenced by argument attr in the location pointed to
     by argument retoffset.  Argument attr should be a legal REFERENCE class form.  Permitted forms for argument attr are: DW_FORM_ref_addr,
     DW_FORM_ref_udata, DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8 and DW_FORM_sec_offset.	The returned offset is relative to the
     start of the ``.debug_info'' ELF section.

     If argument err is not NULL, it will be used to return an error descriptor in case of an error.

RETURN VALUES

     These functions return DW_DLV_OK on success.  In case of an error, these functions return DW_DLV_ERROR and sets argument err.

ERRORS

     These functions may fail with the following errors:

     [DW_DLE_ARGUMENT]	     Either of arguments attr or retoffset was NULL.

     [DW_DLE_ATTR_FORM_BAD]  The attribute referenced by argument attr was not of a permitted kind.

SEE ALSO

     dwarf(3), dwarf_attr(3), dwarf_formblock(3), dwarf_formflag(3), dwarf_formsdata(3), dwarf_formsig8(3), dwarf_formstring(3),
     dwarf_formudata(3), dwarf_hasattr(3)

BSD
								   June 21, 2010							       BSD

DWARF_ATTRVAL_SIGNED(3) 				   BSD Library Functions Manual 				   DWARF_ATTRVAL_SIGNED(3)

NAME

     dwarf_attrval_flag, dwarf_attrval_signed, dwarf_attrval_string, dwarf_attrval_unsigned -- retrieve the value of an attribute within a DWARF
     debugging information entry

LIBRARY

     DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

     #include <libdwarf.h>

     int
     dwarf_attrval_flag(Dwarf_Die die, Dwarf_Half attr, Dwarf_Bool *ret, Dwarf_Error *err);

     int
     dwarf_attrval_signed(Dwarf_Die die, Dwarf_Half attr, Dwarf_Signed *ret, Dwarf_Error *err);

     int
     dwarf_attrval_string(Dwarf_Die die, Dwarf_Half attr, const char **ret, Dwarf_Error *err);

     int
     dwarf_attrval_unsigned(Dwarf_Die die, Dwarf_Half attr, Dwarf_Unsigned *ret, Dwarf_Error *err);

DESCRIPTION

     These functions search the debugging information entry referenced by argument die for the attribute named by argument attr.  If the named
     attribute is found, the functions set the location pointed to by argument ret to the value of the attribute.  The argument err, if non NULL,
     will be used to return an error descriptor in case of an error.

     Function dwarf_attrval_flag() sets the location pointed to by argument ret to either 0 or 1. If the form of the attribute named by argument
     attr is DW_FORM_flag, function dwarf_attrval_flag() sets the location pointed to by argument ret to 1 if the attribute has a non-zero value,
     or to 0 otherwise.  If the form of the attribute named by argument attr is DW_FORM_flag_present, function dwarf_attrval_flag() uncondition-
     ally sets the location pointed to by argument ret to 1.  The form of the attribute must be one of DW_FORM_flag or DW_FORM_flag_present.

     Function dwarf_attrval_signed() stores the value for the attribute named by argument attr, into the location pointed to by argument ret.  The
     attribute's value is treated as a signed integral quantity and is sign-extended as needed.  The attribute named by the argument attr must
     belong to the CONSTANT class and must have one of the following forms: DW_FORM_data1, DW_FORM_data2, DW_FORM_data4, DW_FORM_data8 or
     DW_FORM_sdata.

     Function dwarf_attrval_string() sets the location pointed to by argument ret to a pointer to a NUL-terminated string that is the value of the
     attribute named by argument attr.	The form of the attribute must be one of DW_FORM_string or DW_FORM_strp.

     Function dwarf_attrval_unsigned() stores the value for the attribute named by argument attr into the location pointed to by argument ret.
     The attribute's value is treated as an unsigned integral quantity, and is zero-extended as needed.  The named attribute must belong to one of
     the CONSTANT, ADDRESS or REFERENCE classes and must have one of the following forms: DW_FORM_addr, DW_FORM_data1, DW_FORM_data2,
     DW_FORM_data4, DW_FORM_data8, DW_FORM_udata, DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8, or DW_FORM_ref_udata.

     If the attribute named by argument attr is not present in the debugging information entry referenced by argument die, and if a
     DW_AT_abstract_origin attribute is present in the debugging information entry, function dwarf_attrval_unsigned() will search for the named
     attribute in the debugging information entry referenced by the DW_AT_abstract_origin attribute.

RETURN VALUES

     On success, these functions returns DW_DLV_OK.  If the named attribute was not found in the specified debugging information entry descriptor
     these functions return DW_DLV_NO_ENTRY and set argument err.  For other errors, these functions return DW_DLV_ERROR and set argument err.

COMPATIBILITY

     These functions are extensions added by this implementation of the DWARF(3) API.

ERRORS

     These functions may fail with the following errors:

     [DW_DLE_ARGUMENT]	     Either of the arguments die or ret was NULL.

     [DW_DLE_NO_ENTRY]	     Argument die did not contain an attribute corresponding to the value in argument attr.

     [DW_DLE_ATTR_FORM_BAD]  The attribute named by argument attr was not of a permitted form.

SEE ALSO

     dwarf(3), dwarf_attr(3), dwarf_hasattr(3)

BSD
								 January 18, 2014							       BSD