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24.\" $Id: dwarf_srclines.3 2122 2011-11-09 15:35:14Z jkoshy $
25.\"
26.Dd November 9, 2011
27.Os
28.Dt DWARF_SRCLINES 3
29.Sh NAME
30.Nm dwarf_srclines
31.Nd retrieve line number information for a debugging information entry
32.Sh LIBRARY
33.Lb libdwarf
34.Sh SYNOPSIS
35.In libdwarf.h
36.Ft int
37.Fo dwarf_srclines
38.Fa "Dwarf_Die die"
39.Fa "Dwarf_Line **lines"
40.Fa "Dwarf_Signed *nlines"
41.Fa "Dwarf_Error *err"
42.Fc
43.Sh DESCRIPTION
44Function
45.Fn dwarf_srclines
46returns line number information associated with a compilation unit.
47Line number information is returned as an array of
48.Vt Dwarf_Line
49descriptors.
50.Pp
51Argument
52.Ar die
53should reference a DWARF debugging information entry descriptor
54with line number information, see
55.Xr dwarf 3 .
56Argument
57.Ar lines
58should point to a location that will hold a pointer to the returned array
59of
60.Vt Dwarf_Line
61descriptors.
62Argument
63.Ar nlines
64should point to a location that will hold the number of descriptors
65returned.
66If argument
67.Ar err
68is not NULL, it will be used to store error information in case of an
69error.
70.Pp
71The returned
72.Vt Dwarf_Line
73descriptors may be passed to the other line number functions in the
74API set to retrieve specific information about each source line.
75.Ss Memory Management
76The memory area used for the array of
77.Vt Dwarf_Line
78descriptors returned in argument
79.Ar lines
80is owned by the
81.Lb libdwarf .
82The application should not attempt to free this pointer.
83Portable code should instead use
84.Fn dwarf_srclines_dealloc
85to indicate that the memory may be freed.
86.Sh RETURN VALUES
87Function
88.Fn dwarf_srclines
89returns
90.Dv DW_DLV_OK
91when it succeeds.
92In case of an error, it returns
93.Dv DW_DLV_ERROR
94and sets the argument
95.Ar err .
96.Sh ERRORS
97Function
98.Fn dwarf_srclines
99can fail with:
100.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
101.It Bq Er DW_DLE_ARGUMENT
102One of the arguments
103.Ar die ,
104.Ar lines
105or
106.Ar nlines
107was NULL.
108.It Bq Er DW_DLE_NO_ENTRY
109The compilation unit referenced by argument
110.Ar die
111does not have associated line number information.
112.It Bq Er DW_DLE_MEMORY
113An out of memory condition was encountered during the execution of
114this function.
115.El
116.Sh EXAMPLE
117To obtain an array of
118.Vt Dwarf_Line
119descriptors and to retrieve the source file, line number, and virtual address
120associated with each descriptor:
121.Bd -literal -offset indent
122int n;
123Dwarf_Die die;
124Dwarf_Error de;
125char *filename;
126Dwarf_Line *lines;
127Dwarf_Signed nlines;
128Dwarf_Addr lineaddr;
129Dwarf_Unsigned lineno;
130
131/* variable "die" should reference a DIE for a compilation unit */
132
133if (dwarf_srclines(die, &lines, &nlines, &de) != DW_DLV_OK)
134	errx(EXIT_FAILURE, "dwarf_srclines: %s", dwarf_errmsg(de));
135
136for (n = 0; n < nlines; n++) {
137	/* Retrieve the file name for this descriptor. */
138	if (dwarf_linesrc(lines[n], &filename, &de))
139		errx(EXIT_FAILURE, "dwarf_linesrc: %s",
140		    dwarf_errmsg(de));
141
142	/* Retrieve the line number in the source file. */
143	if (dwarf_lineno(lines[n], &lineno, &de))
144		errx(EXIT_FAILURE, "dwarf_lineno: %s",
145		    dwarf_errmsg(de));
146	/* Retrieve the virtual address for this line. */
147	if (dwarf_lineaddr(lines[n], &lineaddr, &de))
148		errx(EXIT_FAILURE, "dwarf_lineaddr: %s",
149		    dwarf_errmsg(de));
150	}
151.Ed
152.Sh SEE ALSO
153.Xr dwarf 3 ,
154.Xr dwarf_line_srcfileno 3 ,
155.Xr dwarf_lineaddr 3 ,
156.Xr dwarf_linebeginstatement 3 ,
157.Xr dwarf_lineblock 3 ,
158.Xr dwarf_lineendsequence 3 ,
159.Xr dwarf_lineno 3 ,
160.Xr dwarf_lineoff 3 ,
161.Xr dwarf_linesrc 3 ,
162.Xr dwarf_srcfiles 3 ,
163.Xr dwarf_srclines_dealloc 3
164