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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 #include "libdwflP.h"
30 #include "../libdw/libdwP.h"
31 
32 
33 static inline const char *
dwfl_dwarf_line_file(const Dwarf_Line * line)34 dwfl_dwarf_line_file (const Dwarf_Line *line)
35 {
36   return line->files->info[line->file].name;
37 }
38 
39 static inline Dwarf_Line *
dwfl_line(const Dwfl_Line * line)40 dwfl_line (const Dwfl_Line *line)
41 {
42   return &dwfl_linecu (line)->die.cu->lines->info[line->idx];
43 }
44 
45 static inline const char *
dwfl_line_file(const Dwfl_Line * line)46 dwfl_line_file (const Dwfl_Line *line)
47 {
48   return dwfl_dwarf_line_file (dwfl_line (line));
49 }
50 
51 int
dwfl_module_getsrc_file(Dwfl_Module * mod,const char * fname,int lineno,int column,Dwfl_Line *** srcsp,size_t * nsrcs)52 dwfl_module_getsrc_file (Dwfl_Module *mod,
53 			 const char *fname, int lineno, int column,
54 			 Dwfl_Line ***srcsp, size_t *nsrcs)
55 {
56   if (mod == NULL)
57     return -1;
58 
59   if (mod->dw == NULL)
60     {
61       Dwarf_Addr bias;
62       if (INTUSE(dwfl_module_getdwarf) (mod, &bias) == NULL)
63 	return -1;
64     }
65 
66   bool is_basename = strchr (fname, '/') == NULL;
67 
68   size_t max_match = *nsrcs ?: ~0u;
69   size_t act_match = *nsrcs;
70   size_t cur_match = 0;
71   Dwfl_Line **match = *nsrcs == 0 ? NULL : *srcsp;
72 
73   struct dwfl_cu *cu = NULL;
74   Dwfl_Error error;
75   while ((error = __libdwfl_nextcu (mod, cu, &cu)) == DWFL_E_NOERROR
76 	 && cu != NULL
77 	 && (error = __libdwfl_cu_getsrclines (cu)) == DWFL_E_NOERROR)
78     {
79       /* Search through all the line number records for a matching
80 	 file and line/column number.  If any of the numbers is zero,
81 	 no match is performed.  */
82       const char *lastfile = NULL;
83       bool lastmatch = false;
84       for (size_t cnt = 0; cnt < cu->die.cu->lines->nlines; ++cnt)
85 	{
86 	  Dwarf_Line *line = &cu->die.cu->lines->info[cnt];
87 
88 	  if (unlikely (line->file >= line->files->nfiles))
89 	    {
90 	      __libdwfl_seterrno (DWFL_E (LIBDW, DWARF_E_INVALID_DWARF));
91 	      return -1;
92 	    }
93 	  else
94 	    {
95 	      const char *file = dwfl_dwarf_line_file (line);
96 	      if (file != lastfile)
97 		{
98 		  /* Match the name with the name the user provided.  */
99 		  lastfile = file;
100 		  lastmatch = !strcmp (is_basename ? basename (file) : file,
101 				       fname);
102 		}
103 	    }
104 	  if (!lastmatch)
105 	    continue;
106 
107 	  /* See whether line and possibly column match.  */
108 	  if (lineno != 0
109 	      && (lineno > line->line
110 		  || (column != 0 && column > line->column)))
111 	    /* Cannot match.  */
112 	    continue;
113 
114 	  /* Determine whether this is the best match so far.  */
115 	  size_t inner;
116 	  for (inner = 0; inner < cur_match; ++inner)
117 	    if (dwfl_line_file (match[inner])
118 		== dwfl_dwarf_line_file (line))
119 	      break;
120 	  if (inner < cur_match
121 	      && (dwfl_line (match[inner])->line != line->line
122 		  || dwfl_line (match[inner])->line != lineno
123 		  || (column != 0
124 		      && (dwfl_line (match[inner])->column != line->column
125 			  || dwfl_line (match[inner])->column != column))))
126 	    {
127 	      /* We know about this file already.  If this is a better
128 		 match for the line number, use it.  */
129 	      if (dwfl_line (match[inner])->line >= line->line
130 		  && (dwfl_line (match[inner])->line != line->line
131 		      || dwfl_line (match[inner])->column >= line->column))
132 		/* Use the new line.  Otherwise the old one.  */
133 		match[inner] = &cu->lines->idx[cnt];
134 	      continue;
135 	    }
136 
137 	  if (cur_match < max_match)
138 	    {
139 	      if (cur_match == act_match)
140 		{
141 		  /* Enlarge the array for the results.  */
142 		  act_match += 10;
143 		  Dwfl_Line **newp = realloc (match,
144 					      act_match
145 					      * sizeof (Dwfl_Line *));
146 		  if (newp == NULL)
147 		    {
148 		      free (match);
149 		      __libdwfl_seterrno (DWFL_E_NOMEM);
150 		      return -1;
151 		    }
152 		  match = newp;
153 		}
154 
155 	      match[cur_match++] = &cu->lines->idx[cnt];
156 	    }
157 	}
158     }
159 
160   if (cur_match > 0)
161     {
162       assert (*nsrcs == 0 || *srcsp == match);
163 
164       *nsrcs = cur_match;
165       *srcsp = match;
166 
167       return 0;
168     }
169 
170   __libdwfl_seterrno (DWFL_E_NO_MATCH);
171   return -1;
172 }
173