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dwarf_hasform(3) [freebsd man page]

DWARF_HASFORM(3)					   BSD Library Functions Manual 					  DWARF_HASFORM(3)

NAME
dwarf_hasform, dwarf_whatform, dwarf_whatform_direct -- query attribute forms LIBRARY
DWARF Access Library (libdwarf, -ldwarf) SYNOPSIS
#include <libdwarf.h> int dwarf_hasform(Dwarf_Attribute attr, Dwarf_Half form, Dwarf_Bool *ret, Dwarf_Error *err); int dwarf_whatform(Dwarf_Attribute attr, Dwarf_Half *retform, Dwarf_Error *err); int dwarf_whatform_direct(Dwarf_Attribute attr, Dwarf_Half *retform, Dwarf_Error *err); DESCRIPTION
Function dwarf_hasform() indicates whether the DWARF attribute denoted by argument attr has the attribute form specified by argument form. If the attribute has the specified form, then argument ret is set to a non-zero value, otherwise it is set to zero. If argument err is non- NULL, it will be used to return an error descriptor in case of an error. Function dwarf_whatform() sets the location specified by argument retform to the attribute form code for the DWARF attribute referenced by argument attr. If the attribute referenced by argument attr has an indirect form attribute, this function will return the final form for the attribute. If argument err is non-NULL, it will be used to return an error descriptor in case of an error. Function dwarf_whatform_direct() sets the location specified by argument retform to the attribute form code for the DWARF attribute refer- enced by argument attr. If the form is an indirect form, the function sets the location specified by argument retform to DW_FORM_indirect. If argument err is non-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_ERR and set argument err. ERRORS
These functions may fail with the following errors: [DW_DLE_ARGUMENT] Any of the arguments attr, ret, or retform was NULL. SEE ALSO
dwarf(3), dwarf_attr(3), dwarf_hasattr(3) BSD
May 22, 2010 BSD

Check Out this Related Man Page

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

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