1// -*- mode: c++ -*-
2
3// Copyright (c) 2010, Google Inc.
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31
32// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
33
34// dwarf_cfi_to_module.h: Define the DwarfCFIToModule class, which
35// accepts parsed DWARF call frame info and adds it to a
36// google_breakpad::Module object, which can write that information to
37// a Breakpad symbol file.
38
39#ifndef COMMON_LINUX_DWARF_CFI_TO_MODULE_H
40#define COMMON_LINUX_DWARF_CFI_TO_MODULE_H
41
42#include <assert.h>
43#include <stdio.h>
44
45#include <set>
46#include <string>
47#include <vector>
48
49#include "common/module.h"
50#include "common/dwarf/dwarf2reader.h"
51#include "common/using_std_string.h"
52
53namespace google_breakpad {
54
55using google_breakpad::Module;
56using std::set;
57using std::vector;
58
59// A class that accepts parsed call frame information from the DWARF
60// CFI parser and populates a google_breakpad::Module object with the
61// contents.
62class DwarfCFIToModule: public CallFrameInfo::Handler {
63 public:
64
65 // DwarfCFIToModule uses an instance of this class to report errors
66 // detected while converting DWARF CFI to Breakpad STACK CFI records.
67 class Reporter {
68 public:
69 // Create a reporter that writes messages to the standard error
70 // stream. FILE is the name of the file we're processing, and
71 // SECTION is the name of the section within that file that we're
72 // looking at (.debug_frame, .eh_frame, etc.).
73 Reporter(const string& file, const string& section)
74 : file_(file), section_(section) { }
75 virtual ~Reporter() { }
76
77 // The DWARF CFI entry at OFFSET cites register REG, but REG is not
78 // covered by the vector of register names passed to the
79 // DwarfCFIToModule constructor, nor does it match the return
80 // address column number for this entry.
81 virtual void UnnamedRegister(size_t offset, int reg);
82
83 // The DWARF CFI entry at OFFSET says that REG is undefined, but the
84 // Breakpad symbol file format cannot express this.
85 virtual void UndefinedNotSupported(size_t offset, const string& reg);
86
87 // The DWARF CFI entry at OFFSET says that REG uses a DWARF
88 // expression to find its value, but DwarfCFIToModule is not
89 // capable of translating DWARF expressions to Breakpad postfix
90 // expressions.
91 virtual void ExpressionsNotSupported(size_t offset, const string& reg);
92
93 protected:
94 string file_, section_;
95 };
96
97 // Register name tables. If TABLE is a vector returned by one of these
98 // functions, then TABLE[R] is the name of the register numbered R in
99 // DWARF call frame information.
100 class RegisterNames {
101 public:
102 // Intel's "x86" or IA-32.
103 static vector<string> I386();
104
105 // AMD x86_64, AMD64, Intel EM64T, or Intel 64
106 static vector<string> X86_64();
107
108 // ARM.
109 static vector<string> ARM();
110
111 // ARM64, aka AARCH64.
112 static vector<string> ARM64();
113
114 // MIPS.
115 static vector<string> MIPS();
116
117 private:
118 // Given STRINGS, an array of C strings with SIZE elements, return an
119 // equivalent vector<string>.
120 static vector<string> MakeVector(const char* const* strings, size_t size);
121 };
122
123 // Create a handler for the CallFrameInfo parser that
124 // records the stack unwinding information it receives in MODULE.
125 //
126 // Use REGISTER_NAMES[I] as the name of register number I; *this
127 // keeps a reference to the vector, so the vector should remain
128 // alive for as long as the DwarfCFIToModule does.
129 //
130 // Use REPORTER for reporting problems encountered in the conversion
131 // process.
132 DwarfCFIToModule(Module* module, const vector<string>& register_names,
133 Reporter* reporter)
134 : module_(module), register_names_(register_names), reporter_(reporter),
135 entry_(NULL), return_address_(-1), cfa_name_(".cfa"), ra_name_(".ra") {
136 }
137 virtual ~DwarfCFIToModule() { delete entry_; }
138
139 virtual bool Entry(size_t offset, uint64_t address, uint64_t length,
140 uint8_t version, const string& augmentation,
141 unsigned return_address);
142 virtual bool UndefinedRule(uint64_t address, int reg);
143 virtual bool SameValueRule(uint64_t address, int reg);
144 virtual bool OffsetRule(uint64_t address, int reg,
145 int base_register, long offset);
146 virtual bool ValOffsetRule(uint64_t address, int reg,
147 int base_register, long offset);
148 virtual bool RegisterRule(uint64_t address, int reg, int base_register);
149 virtual bool ExpressionRule(uint64_t address, int reg,
150 const string& expression);
151 virtual bool ValExpressionRule(uint64_t address, int reg,
152 const string& expression);
153 virtual bool End();
154
155 private:
156 // Return the name to use for register REG.
157 string RegisterName(int i);
158
159 // Record RULE for register REG at ADDRESS.
160 void Record(Module::Address address, int reg, const string& rule);
161
162 // The module to which we should add entries.
163 Module* module_;
164
165 // Map from register numbers to register names.
166 const vector<string>& register_names_;
167
168 // The reporter to use to report problems.
169 Reporter* reporter_;
170
171 // The current entry we're constructing.
172 Module::StackFrameEntry* entry_;
173
174 // The section offset of the current frame description entry, for
175 // use in error messages.
176 size_t entry_offset_;
177
178 // The return address column for that entry.
179 unsigned return_address_;
180
181 // The names of the return address and canonical frame address. Putting
182 // these here instead of using string literals allows us to share their
183 // texts in reference-counted string implementations (all the
184 // popular ones). Many, many rules cite these strings.
185 string cfa_name_, ra_name_;
186
187 // A set of strings used by this CFI. Before storing a string in one of
188 // our data structures, insert it into this set, and then use the string
189 // from the set.
190 //
191 // Because string uses reference counting internally, simply using
192 // strings from this set, even if passed by value, assigned, or held
193 // directly in structures and containers (map<string, ...>, for example),
194 // causes those strings to share a single instance of each distinct piece
195 // of text.
196 set<string> common_strings_;
197};
198
199} // namespace google_breakpad
200
201#endif // COMMON_LINUX_DWARF_CFI_TO_MODULE_H
202