xref: /freebsd/contrib/elftoolchain/libdwarf/dwarf_srclines.3 (revision 2e3f49888ec8851bafb22011533217487764fdb0)
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24.\" $Id: dwarf_srclines.3 3644 2018-10-15 19:55:01Z jkoshy $
25.\"
26.Dd November 9, 2011
27.Dt DWARF_SRCLINES 3
28.Os
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 EXAMPLES
97To obtain an array of
98.Vt Dwarf_Line
99descriptors and to retrieve the source file, line number, and virtual address
100associated with each descriptor:
101.Bd -literal -offset indent
102int n;
103Dwarf_Die die;
104Dwarf_Error de;
105char *filename;
106Dwarf_Line *lines;
107Dwarf_Signed nlines;
108Dwarf_Addr lineaddr;
109Dwarf_Unsigned lineno;
110
111/* variable "die" should reference a DIE for a compilation unit */
112
113if (dwarf_srclines(die, &lines, &nlines, &de) != DW_DLV_OK)
114	errx(EXIT_FAILURE, "dwarf_srclines: %s", dwarf_errmsg(de));
115
116for (n = 0; n < nlines; n++) {
117	/* Retrieve the file name for this descriptor. */
118	if (dwarf_linesrc(lines[n], &filename, &de))
119		errx(EXIT_FAILURE, "dwarf_linesrc: %s",
120		    dwarf_errmsg(de));
121
122	/* Retrieve the line number in the source file. */
123	if (dwarf_lineno(lines[n], &lineno, &de))
124		errx(EXIT_FAILURE, "dwarf_lineno: %s",
125		    dwarf_errmsg(de));
126	/* Retrieve the virtual address for this line. */
127	if (dwarf_lineaddr(lines[n], &lineaddr, &de))
128		errx(EXIT_FAILURE, "dwarf_lineaddr: %s",
129		    dwarf_errmsg(de));
130	}
131.Ed
132.Sh ERRORS
133Function
134.Fn dwarf_srclines
135can fail with:
136.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
137.It Bq Er DW_DLE_ARGUMENT
138One of the arguments
139.Ar die ,
140.Ar lines
141or
142.Ar nlines
143was NULL.
144.It Bq Er DW_DLE_NO_ENTRY
145The compilation unit referenced by argument
146.Ar die
147does not have associated line number information.
148.It Bq Er DW_DLE_MEMORY
149An out of memory condition was encountered during the execution of
150this function.
151.El
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