xref: /netbsd-src/external/bsd/elftoolchain/dist/libdwarf/dwarf_srclines.3 (revision 82d56013d7b633d116a93943de88e08335357a7c)
1.\"	$NetBSD: dwarf_srclines.3,v 1.4 2020/11/26 22:51:35 jkoshy Exp $
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26.\" Id: dwarf_srclines.3 3644 2018-10-15 19:55:01Z jkoshy
27.\"
28.Dd November 9, 2011
29.Dt DWARF_SRCLINES 3
30.Os
31.Sh NAME
32.Nm dwarf_srclines
33.Nd retrieve line number information for a debugging information entry
34.Sh LIBRARY
35.Lb libdwarf
36.Sh SYNOPSIS
37.In libdwarf.h
38.Ft int
39.Fo dwarf_srclines
40.Fa "Dwarf_Die die"
41.Fa "Dwarf_Line **lines"
42.Fa "Dwarf_Signed *nlines"
43.Fa "Dwarf_Error *err"
44.Fc
45.Sh DESCRIPTION
46Function
47.Fn dwarf_srclines
48returns line number information associated with a compilation unit.
49Line number information is returned as an array of
50.Vt Dwarf_Line
51descriptors.
52.Pp
53Argument
54.Ar die
55should reference a DWARF debugging information entry descriptor
56with line number information, see
57.Xr dwarf 3 .
58Argument
59.Ar lines
60should point to a location that will hold a pointer to the returned array
61of
62.Vt Dwarf_Line
63descriptors.
64Argument
65.Ar nlines
66should point to a location that will hold the number of descriptors
67returned.
68If argument
69.Ar err
70is not NULL, it will be used to store error information in case of an
71error.
72.Pp
73The returned
74.Vt Dwarf_Line
75descriptors may be passed to the other line number functions in the
76API set to retrieve specific information about each source line.
77.Ss Memory Management
78The memory area used for the array of
79.Vt Dwarf_Line
80descriptors returned in argument
81.Ar lines
82is owned by the
83.Lb libdwarf .
84The application should not attempt to free this pointer.
85Portable code should instead use
86.Fn dwarf_srclines_dealloc
87to indicate that the memory may be freed.
88.Sh RETURN VALUES
89Function
90.Fn dwarf_srclines
91returns
92.Dv DW_DLV_OK
93when it succeeds.
94In case of an error, it returns
95.Dv DW_DLV_ERROR
96and sets the argument
97.Ar err .
98.Sh EXAMPLES
99To obtain an array of
100.Vt Dwarf_Line
101descriptors and to retrieve the source file, line number, and virtual address
102associated with each descriptor:
103.Bd -literal -offset indent
104int n;
105Dwarf_Die die;
106Dwarf_Error de;
107char *filename;
108Dwarf_Line *lines;
109Dwarf_Signed nlines;
110Dwarf_Addr lineaddr;
111Dwarf_Unsigned lineno;
112
113/* variable "die" should reference a DIE for a compilation unit */
114
115if (dwarf_srclines(die, &lines, &nlines, &de) != DW_DLV_OK)
116	errx(EXIT_FAILURE, "dwarf_srclines: %s", dwarf_errmsg(de));
117
118for (n = 0; n < nlines; n++) {
119	/* Retrieve the file name for this descriptor. */
120	if (dwarf_linesrc(lines[n], &filename, &de))
121		errx(EXIT_FAILURE, "dwarf_linesrc: %s",
122		    dwarf_errmsg(de));
123
124	/* Retrieve the line number in the source file. */
125	if (dwarf_lineno(lines[n], &lineno, &de))
126		errx(EXIT_FAILURE, "dwarf_lineno: %s",
127		    dwarf_errmsg(de));
128	/* Retrieve the virtual address for this line. */
129	if (dwarf_lineaddr(lines[n], &lineaddr, &de))
130		errx(EXIT_FAILURE, "dwarf_lineaddr: %s",
131		    dwarf_errmsg(de));
132	}
133.Ed
134.Sh ERRORS
135Function
136.Fn dwarf_srclines
137can fail with:
138.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
139.It Bq Er DW_DLE_ARGUMENT
140One of the arguments
141.Ar die ,
142.Ar lines
143or
144.Ar nlines
145was NULL.
146.It Bq Er DW_DLE_NO_ENTRY
147The compilation unit referenced by argument
148.Ar die
149does not have associated line number information.
150.It Bq Er DW_DLE_MEMORY
151An out of memory condition was encountered during the execution of
152this function.
153.El
154.Sh SEE ALSO
155.Xr dwarf 3 ,
156.Xr dwarf_line_srcfileno 3 ,
157.Xr dwarf_lineaddr 3 ,
158.Xr dwarf_linebeginstatement 3 ,
159.Xr dwarf_lineblock 3 ,
160.Xr dwarf_lineendsequence 3 ,
161.Xr dwarf_lineno 3 ,
162.Xr dwarf_lineoff 3 ,
163.Xr dwarf_linesrc 3 ,
164.Xr dwarf_srcfiles 3 ,
165.Xr dwarf_srclines_dealloc 3
166