freebsd-dev/contrib/elftoolchain/libdwarf/dwarf_new_die.3

.\" Copyright (c) 2011 Kai Wang
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.\" $Id: dwarf_new_die.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd September 4, 2011
.Dt DWARF_NEW_DIE 3
.Os
.Sh NAME
.Nm dwarf_new_die
.Nd allocate a new debugging information entry
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft Dwarf_P_Die
.Fo dwarf_new_die
.Fa "Dwarf_P_Debug dbg"
.Fa "Dwarf_Tag tag"
.Fa "Dwarf_P_Die parent"
.Fa "Dwarf_P_Die child"
.Fa "Dwarf_P_Die left"
.Fa "Dwarf_P_Die right"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_new_die
allocates a new DWARF debugging information entry and links it
to another debugging information entry.
.Pp
Argument
.Ar dbg
should reference a DWARF producer instance allocated using
.Xr dwarf_producer_init 3
or
.Xr dwarf_producer_init_b 3 .
.Pp
Argument
.Ar tag
should specify the tag of the newly created debugging information entry.
Valid values for this argument are those for the
.Dv DW_TAG_ Ns *
symbols defined in
.In libdwarf.h .
.Pp
Argument
.Ar parent
specifies the parent link of the debugging information entry.
.Pp
Argument
.Ar child
specifies the first child link of the debugging information entry.
.Pp
Argument
.Ar left
specifies the left sibling link of the debugging information entry.
.Pp
Argument
.Ar right
specifies the right sibling link of the debugging information entry.
.Pp
Only one of arguments
.Ar parent ,
.Ar child ,
.Ar left
and
.Ar right
is allowed to be non-NULL.
Application code can subsequently call the function
.Xr dwarf_die_link 3
to change the links for the created debugging information entry.
.Pp
If argument
.Ar err
is not NULL, it will be used to store error information in case
of an error.
.Sh RETURN VALUES
On success, function
.Fn dwarf_new_die
returns the newly created debugging information entry.
In case of an error, function
.Fn dwarf_new_die
returns
.Dv DW_DLV_BADADDR
and sets the argument
.Ar err .
.Sh EXAMPLES
To create debugging information entries and add them to the producer
instance, use:
.Bd -literal -offset indent
Dwarf_P_Debug dbg;
Dwarf_P_Die die1, die2;
Dwarf_Error de;

/* ... assume dbg refers to a DWARF producer instance ... */

die1 = dwarf_new_die(dbg, DW_TAG_compilation_unit, NULL, NULL, NULL,
    NULL, &de);
if (die1 == NULL) {
	warnx("dwarf_new_die failed: %s", dwarf_errmsg(-1));
	return;
}

die2 = dwarf_new_die(dbg, DW_TAG_base_type, die1, NULL, NULL,
    NULL, &de);
if (die1 == NULL) {
	warnx("dwarf_new_die failed: %s", dwarf_errmsg(-1));
	return;
}

if (dwarf_add_die_to_debug(dbg, die1, &de) != DW_DLV_OK) {
	warnx("dwarf_add_die_to_debug failed: %s", dwarf_errmsg(-1));
	return;
}
.Ed
.Sh ERRORS
Function
.Fn dwarf_new_die
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
Argument
.Ar dbg
was NULL.
.It Bq Er DW_DLE_ARGUMENT
More than one of the arguments
.Ar parent ,
.Ar child ,
.Ar left
and
.Ar right
were non-NULL.
.It Bq Er DW_DLE_MEMORY
An out of memory condition was encountered during the execution of the
function.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_add_die_to_debug 3 ,
.Xr dwarf_die_link 3 ,
.Xr dwarf_producer_init 3 ,
.Xr dwarf_producer_init_b 3