1// Copyright (c) 2010 Google Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8// * Redistributions of source code must retain the above copyright
9// notice, this list of conditions and the following disclaimer.
10// * Redistributions in binary form must reproduce the above
11// copyright notice, this list of conditions and the following disclaimer
12// in the documentation and/or other materials provided with the
13// distribution.
14// * Neither the name of Google Inc. nor the names of its
15// contributors may be used to endorse or promote products derived from
16// this software without specific prior written permission.
17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
31
32// dwarf_line_to_module.cc: Implementation of DwarfLineToModule class.
33// See dwarf_line_to_module.h for details.
34
35#include <stdio.h>
36
37#include <string>
38
39#include "common/dwarf_line_to_module.h"
40#include "common/using_std_string.h"
41
42// Trying to support Windows paths in a reasonable way adds a lot of
43// variations to test; it would be better to just put off dealing with
44// it until we actually have to deal with DWARF on Windows.
45
46// Return true if PATH is an absolute path, false if it is relative.
47static bool PathIsAbsolute(const string& path) {
48 return (path.size() >= 1 && path[0] == '/');
49}
50
51static bool HasTrailingSlash(const string& path) {
52 return (path.size() >= 1 && path[path.size() - 1] == '/');
53}
54
55// If PATH is an absolute path, return PATH. If PATH is a relative path,
56// treat it as relative to BASE and return the combined path.
57static string ExpandPath(const string& path,
58 const string& base) {
59 if (PathIsAbsolute(path) || base.empty())
60 return path;
61 return base + (HasTrailingSlash(base) ? "" : "/") + path;
62}
63
64namespace google_breakpad {
65
66void DwarfLineToModule::DefineDir(const string& name, uint32_t dir_num) {
67 // Directory number zero is reserved to mean the compilation
68 // directory. Silently ignore attempts to redefine it.
69 if (dir_num != 0)
70 directories_[dir_num] = ExpandPath(name, compilation_dir_);
71}
72
73void DwarfLineToModule::DefineFile(const string& name, int32_t file_num,
74 uint32_t dir_num, uint64_t mod_time,
75 uint64_t length) {
76 if (file_num == -1)
77 file_num = ++highest_file_number_;
78 else if (file_num > highest_file_number_)
79 highest_file_number_ = file_num;
80
81 string dir_name;
82 if (dir_num == 0) {
83 // Directory number zero is the compilation directory, and is stored as
84 // an attribute on the compilation unit, rather than in the program table.
85 dir_name = compilation_dir_;
86 } else {
87 DirectoryTable::const_iterator directory_it = directories_.find(dir_num);
88 if (directory_it != directories_.end()) {
89 dir_name = directory_it->second;
90 } else {
91 if (!warned_bad_directory_number_) {
92 fprintf(stderr, "warning: DWARF line number data refers to undefined"
93 " directory numbers\n");
94 warned_bad_directory_number_ = true;
95 }
96 }
97 }
98
99 string full_name = ExpandPath(name, dir_name);
100
101 // Find a Module::File object of the given name, and add it to the
102 // file table.
103 (*files_)[file_num] = module_->FindFile(full_name);
104}
105
106void DwarfLineToModule::AddLine(uint64_t address, uint64_t length,
107 uint32_t file_num, uint32_t line_num,
108 uint32_t column_num) {
109 if (length == 0)
110 return;
111
112 // Clip lines not to extend beyond the end of the address space.
113 if (address + length < address)
114 length = -address;
115
116 // Should we omit this line? (See the comments for omitted_line_end_.)
117 if (address == 0 || address == omitted_line_end_) {
118 omitted_line_end_ = address + length;
119 return;
120 } else {
121 omitted_line_end_ = 0;
122 }
123
124 // Find the source file being referred to.
125 Module::File *file = (*files_)[file_num];
126 if (!file) {
127 if (!warned_bad_file_number_) {
128 fprintf(stderr, "warning: DWARF line number data refers to "
129 "undefined file numbers\n");
130 warned_bad_file_number_ = true;
131 }
132 return;
133 }
134 Module::Line line;
135 line.address = address;
136 // We set the size when we get the next line or the EndSequence call.
137 line.size = length;
138 line.file = file;
139 line.number = line_num;
140 lines_->push_back(line);
141}
142
143} // namespace google_breakpad
144