source: rtems-tools/rtemstoolkit/elftoolchain/libdwarf/dwarf_get_pubtypes.3 @ 4bb3996

.\" Copyright (c) 2011 Kai Wang
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.\" $Id: dwarf_get_pubtypes.3 2071 2011-10-27 03:20:00Z jkoshy $
.\"
.Dd April 4, 2011
.Os
.Dt DWARF_GET_PUBTYPES 3
.Sh NAME
.Nm dwarf_get_pubtypes ,
.Nm dwarf_pubtype_cu_offset ,
.Nm dwarf_pubtype_die_offset ,
.Nm dwarf_pubtype_name_offsets ,
.Nm dwarf_pubtypename
.Nd retrieve information about user-defined types
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_get_pubtypes
.Fa "Dwarf_Debug dbg"
.Fa "Dwarf_Type **types"
.Fa "Dwarf_Signed *ntypes"
.Fa "Dwarf_Error *err"
.Fc
.Ft int
.Fo dwarf_pubtype_cu_offset
.Fa "Dwarf_Type type"
.Fa "Dwarf_Off *cu_offset"
.Fa "Dwarf_Error *err"
.Fc
.Ft int
.Fo dwarf_pubtype_die_offset
.Fa "Dwarf_Type type"
.Fa "Dwarf_Off *die_offset"
.Fa "Dwarf_Error *err"
.Fc
.Ft int
.Fo dwarf_pubtype_name_offsets
.Fa "Dwarf_Type type"
.Fa "char **name"
.Fa "Dwarf_Off *die_offset"
.Fa "Dwarf_Off *cu_die_offset"
.Fa "Dwarf_Error *err"
.Fc
.Ft int
.Fo dwarf_pubtypename
.Fa "Dwarf_Type type"
.Fa "char **name"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
These functions retrieve information about file-scope, user-defined
types recorded in lookup tables in the
.Dq ".debug_pubtypes"
DWARF section.
Information about these types is returned using opaque descriptors
of type
.Vt Dwarf_Type .
Applications need to use the functions described below to retrieve
the name and offset information contained in these descriptors.
.Pp
Function
.Fn dwarf_get_pubtypes
retrieves descriptors for all the user-defined types associated with the
DWARF debug context specified by argument
.Ar dbg .
The argument
.Ar types
should point to a location that will be set to a pointer to an array
of
.Vt Dwarf_Type
descriptors.
The argument
.Ar ntypes
should point to a location that will be set to the number of
descriptors returned.
.Pp
Function
.Fn dwarf_pubtype_cu_offset
returns the offset, relative to the
.Dq ".debug_info"
section, of the compilation unit that contains the debugging
information entry associated with the argument
.Ar type .
Argument
.Ar cu_offset
should point to a location that will hold the returned offset.
.Pp
Function
.Fn dwarf_pubtype_die_offset
retrieves the offset, relative to the
.Dq ".debug_info"
section, of the debugging information entry associated with the
argument
.Ar type ,
and stores it into the location pointed to by the argument
.Ar die_offset .
.Pp
Function
.Fn dwarf_pubtype_name_offsets
retrieves the name and offsets for the debugging information entry for
argument
.Ar type .
Argument
.Ar name
should point to a location which will be set to a pointer to a
NUL-terminated string containing the name of the associated debugging
information entry.
Argument
.Ar die_offset
should point to a location which will be set to the
offset, relative to the
.Dq ".debug_info"
section, of the associated debugging information entry.
Argument
.Ar cu_die_offset
should point to a location which will be set to the
offset, relative to the
.Dq ".debug_info"
section, of the first debugging information entry in the compilation
unit associated with argument
.Ar type .
.Pp
Function
.Fn dwarf_pubtypename
sets the location pointed to by argument
.Ar name
to a pointer to a NUL-terminated string holding the name of the
debugging information entry associated with the argument
.Ar type .
.Ss Memory Management
The memory area used for the array of
.Vt Dwarf_Type
descriptors returned in argument
.Ar types
by function
.Fn dwarf_get_pubtypes
is owned by the
.Lb libdwarf .
Application code should not attempt to directly free this pointer.
Portable code should instead use the function
.Xr dwarf_types_dealloc 3
to indicate that the memory area may be freed.
.Pp
The memory area used for the string returned in the
.Ar name
argument to functions
.Fn dwarf_pubtype_name_offsets
and
.Fn dwarf_pubtypename
is owned by the
.Lb libdwarf .
Portable code should indicate that the memory area can
be freed using the
.Xr dwarf_dealloc 3
function.
.Ss Error Returns
If argument
.Ar err
is not NULL, these functions will use it to store error information,
in case of an error.
.Sh RETURN VALUES
On success, these functions returns
.Dv DW_DLV_OK .
In case of an error, they return
.Dv DW_DLV_ERROR
and set the argument
.Ar err .
.Sh EXAMPLES
To retrieve the list of file scope user-defined types and print
their names, use:
.Bd -literal -offset indent
Dwarf_Debug dbg;
Dwarf_Signed ntypes;
Dwarf_Type *types;
Dwarf_Error err;
int n, result;
char *typename;

/* Initialize dbg etc. */;
result = dwarf_get_pubtypes(dbg, &types, &ntypes, &err);
if (result != DW_DLV_OK) /* Handle the error. */
        ;

/* Iterate over the returned array of descriptors. */
for (n = 0; n < ntypes; n++) {
        result = dwarf_pubtypename(types[n], &typename, &err);
        if (result != DW_DLV_OK) /* Handle the error. */
                ;
        printf("%s\en", typename);
}

/* Deallocate the returned array. */
dwarf_types_dealloc(dbg, types, ntypes);
.Ed
.Sh ERRORS
These functions may fail with the following errors:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
One of the arguments
.Va cu_die_offset ,
.Va cu_offset ,
.Va dbg ,
.Va die_offset ,
.Va type ,
.Va types ,
.Va name ,
or
.Va ntypes
was NULL.
.It Bq Er DW_DLE_NO_ENTRY
The DWARF debugging context referenced by argument
.Ar dbg
did not contain information about user-defined types.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_dealloc 3 ,
.Xr dwarf_get_cu_die_offset_given_cu_header_offset 3 ,
.Xr dwarf_pubtypes_dealloc 3