1/* Find matching source locations in a module.
2   Copyright (C) 2005 Red Hat, Inc.
3   This file is part of elfutils.
4
5   This file is free software; you can redistribute it and/or modify
6   it under the terms of either
7
8     * the GNU Lesser General Public License as published by the Free
9       Software Foundation; either version 3 of the License, or (at
10       your option) any later version
11
12   or
13
14     * the GNU General Public License as published by the Free
15       Software Foundation; either version 2 of the License, or (at
16       your option) any later version
17
18   or both in parallel, as here.
19
20   elfutils is distributed in the hope that it will be useful, but
21   WITHOUT ANY WARRANTY; without even the implied warranty of
22   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23   General Public License for more details.
24
25   You should have received copies of the GNU General Public License and
26   the GNU Lesser General Public License along with this program.  If
27   not, see <http://www.gnu.org/licenses/>.  */
28
29#ifdef HAVE_CONFIG_H
30# include <config.h>
31#endif
32
33#include "libdwflP.h"
34#include "../libdw/libdwP.h"
35
36
37static inline const char *
38dwfl_dwarf_line_file (const Dwarf_Line *line)
39{
40  return line->files->info[line->file].name;
41}
42
43static inline Dwarf_Line *
44dwfl_line (const Dwfl_Line *line)
45{
46  return &dwfl_linecu (line)->die.cu->lines->info[line->idx];
47}
48
49static inline const char *
50dwfl_line_file (const Dwfl_Line *line)
51{
52  return dwfl_dwarf_line_file (dwfl_line (line));
53}
54
55int
56dwfl_module_getsrc_file (Dwfl_Module *mod,
57			 const char *fname, int lineno, int column,
58			 Dwfl_Line ***srcsp, size_t *nsrcs)
59{
60  if (mod == NULL)
61    return -1;
62
63  if (mod->dw == NULL)
64    {
65      Dwarf_Addr bias;
66      if (INTUSE(dwfl_module_getdwarf) (mod, &bias) == NULL)
67	return -1;
68    }
69
70  bool is_basename = strchr (fname, '/') == NULL;
71
72  size_t max_match = *nsrcs ?: ~0u;
73  size_t act_match = *nsrcs;
74  size_t cur_match = 0;
75  Dwfl_Line **match = *nsrcs == 0 ? NULL : *srcsp;
76
77  struct dwfl_cu *cu = NULL;
78  Dwfl_Error error;
79  while ((error = __libdwfl_nextcu (mod, cu, &cu)) == DWFL_E_NOERROR
80	 && cu != NULL
81	 && (error = __libdwfl_cu_getsrclines (cu)) == DWFL_E_NOERROR)
82    {
83      /* Search through all the line number records for a matching
84	 file and line/column number.  If any of the numbers is zero,
85	 no match is performed.  */
86      const char *lastfile = NULL;
87      bool lastmatch = false;
88      for (size_t cnt = 0; cnt < cu->die.cu->lines->nlines; ++cnt)
89	{
90	  Dwarf_Line *line = &cu->die.cu->lines->info[cnt];
91
92	  if (unlikely (line->file >= line->files->nfiles))
93	    {
94	      if (*nsrcs == 0)
95		free (match);
96	      __libdwfl_seterrno (DWFL_E (LIBDW, DWARF_E_INVALID_DWARF));
97	      return -1;
98	    }
99	  else
100	    {
101	      const char *file = dwfl_dwarf_line_file (line);
102	      if (file != lastfile)
103		{
104		  /* Match the name with the name the user provided.  */
105		  lastfile = file;
106		  lastmatch = !strcmp (is_basename ? basename (file) : file,
107				       fname);
108		}
109	    }
110	  if (!lastmatch)
111	    continue;
112
113	  /* See whether line and possibly column match.  */
114	  if (lineno != 0
115	      && (lineno > line->line
116		  || (column != 0 && column > line->column)))
117	    /* Cannot match.  */
118	    continue;
119
120	  /* Determine whether this is the best match so far.  */
121	  size_t inner;
122	  for (inner = 0; inner < cur_match; ++inner)
123	    if (dwfl_line_file (match[inner])
124		== dwfl_dwarf_line_file (line))
125	      break;
126	  if (inner < cur_match
127	      && (dwfl_line (match[inner])->line != line->line
128		  || dwfl_line (match[inner])->line != lineno
129		  || (column != 0
130		      && (dwfl_line (match[inner])->column != line->column
131			  || dwfl_line (match[inner])->column != column))))
132	    {
133	      /* We know about this file already.  If this is a better
134		 match for the line number, use it.  */
135	      if (dwfl_line (match[inner])->line >= line->line
136		  && (dwfl_line (match[inner])->line != line->line
137		      || dwfl_line (match[inner])->column >= line->column))
138		/* Use the new line.  Otherwise the old one.  */
139		match[inner] = &cu->lines->idx[cnt];
140	      continue;
141	    }
142
143	  if (cur_match < max_match)
144	    {
145	      if (cur_match == act_match)
146		{
147		  /* Enlarge the array for the results.  */
148		  act_match += 10;
149		  Dwfl_Line **newp = realloc (match,
150					      act_match
151					      * sizeof (Dwfl_Line *));
152		  if (newp == NULL)
153		    {
154		      free (match);
155		      __libdwfl_seterrno (DWFL_E_NOMEM);
156		      return -1;
157		    }
158		  match = newp;
159		}
160
161	      match[cur_match++] = &cu->lines->idx[cnt];
162	    }
163	}
164    }
165
166  if (cur_match > 0)
167    {
168      assert (*nsrcs == 0 || *srcsp == match);
169
170      *nsrcs = cur_match;
171      *srcsp = match;
172
173      return 0;
174    }
175
176  __libdwfl_seterrno (DWFL_E_NO_MATCH);
177  return -1;
178}
179