xref: /freebsd/contrib/elftoolchain/libdwarf/dwarf_srclines.3 (revision ae500c1ff8974130f7f2692772cf288b90349e0d)

.\" Copyright (c) 2010 Joseph Koshy.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" This software is provided by Joseph Koshy ``as is'' and
.\" any express or implied warranties, including, but not limited to, the
.\" implied warranties of merchantability and fitness for a particular purpose
.\" are disclaimed.  in no event shall Joseph Koshy be liable
.\" for any direct, indirect, incidental, special, exemplary, or consequential
.\" damages (including, but not limited to, procurement of substitute goods
.\" or services; loss of use, data, or profits; or business interruption)
.\" however caused and on any theory of liability, whether in contract, strict
.\" liability, or tort (including negligence or otherwise) arising in any way
.\" out of the use of this software, even if advised of the possibility of
.\" such damage.
.\"
.\" $Id: dwarf_srclines.3 3644 2018-10-15 19:55:01Z jkoshy $
.\"
.Dd November 9, 2011
.Dt DWARF_SRCLINES 3
.Os
.Sh NAME
.Nm dwarf_srclines
.Nd retrieve line number information for a debugging information entry
.Sh LIBRARY
.Lb libdwarf
.Sh SYNOPSIS
.In libdwarf.h
.Ft int
.Fo dwarf_srclines
.Fa "Dwarf_Die die"
.Fa "Dwarf_Line **lines"
.Fa "Dwarf_Signed *nlines"
.Fa "Dwarf_Error *err"
.Fc
.Sh DESCRIPTION
Function
.Fn dwarf_srclines
returns line number information associated with a compilation unit.
Line number information is returned as an array of
.Vt Dwarf_Line
descriptors.
.Pp
Argument
.Ar die
should reference a DWARF debugging information entry descriptor
with line number information, see
.Xr dwarf 3 .
Argument
.Ar lines
should point to a location that will hold a pointer to the returned array
of
.Vt Dwarf_Line
descriptors.
Argument
.Ar nlines
should point to a location that will hold the number of descriptors
returned.
If argument
.Ar err
is not NULL, it will be used to store error information in case of an
error.
.Pp
The returned
.Vt Dwarf_Line
descriptors may be passed to the other line number functions in the
API set to retrieve specific information about each source line.
.Ss Memory Management
The memory area used for the array of
.Vt Dwarf_Line
descriptors returned in argument
.Ar lines
is owned by the
.Lb libdwarf .
The application should not attempt to free this pointer.
Portable code should instead use
.Fn dwarf_srclines_dealloc
to indicate that the memory may be freed.
.Sh RETURN VALUES
Function
.Fn dwarf_srclines
returns
.Dv DW_DLV_OK
when it succeeds.
In case of an error, it returns
.Dv DW_DLV_ERROR
and sets the argument
.Ar err .
.Sh EXAMPLES
To obtain an array of
.Vt Dwarf_Line
descriptors and to retrieve the source file, line number, and virtual address
associated with each descriptor:
.Bd -literal -offset indent
int n;
Dwarf_Die die;
Dwarf_Error de;
char *filename;
Dwarf_Line *lines;
Dwarf_Signed nlines;
Dwarf_Addr lineaddr;
Dwarf_Unsigned lineno;

/* variable "die" should reference a DIE for a compilation unit */

if (dwarf_srclines(die, &lines, &nlines, &de) != DW_DLV_OK)
	errx(EXIT_FAILURE, "dwarf_srclines: %s", dwarf_errmsg(de));

for (n = 0; n < nlines; n++) {
	/* Retrieve the file name for this descriptor. */
	if (dwarf_linesrc(lines[n], &filename, &de))
		errx(EXIT_FAILURE, "dwarf_linesrc: %s",
		    dwarf_errmsg(de));

	/* Retrieve the line number in the source file. */
	if (dwarf_lineno(lines[n], &lineno, &de))
		errx(EXIT_FAILURE, "dwarf_lineno: %s",
		    dwarf_errmsg(de));
	/* Retrieve the virtual address for this line. */
	if (dwarf_lineaddr(lines[n], &lineaddr, &de))
		errx(EXIT_FAILURE, "dwarf_lineaddr: %s",
		    dwarf_errmsg(de));
	}
.Ed
.Sh ERRORS
Function
.Fn dwarf_srclines
can fail with:
.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
.It Bq Er DW_DLE_ARGUMENT
One of the arguments
.Ar die ,
.Ar lines
or
.Ar nlines
was NULL.
.It Bq Er DW_DLE_NO_ENTRY
The compilation unit referenced by argument
.Ar die
does not have associated line number information.
.It Bq Er DW_DLE_MEMORY
An out of memory condition was encountered during the execution of
this function.
.El
.Sh SEE ALSO
.Xr dwarf 3 ,
.Xr dwarf_line_srcfileno 3 ,
.Xr dwarf_lineaddr 3 ,
.Xr dwarf_linebeginstatement 3 ,
.Xr dwarf_lineblock 3 ,
.Xr dwarf_lineendsequence 3 ,
.Xr dwarf_lineno 3 ,
.Xr dwarf_lineoff 3 ,
.Xr dwarf_linesrc 3 ,
.Xr dwarf_srcfiles 3 ,
.Xr dwarf_srclines_dealloc 3