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29 
30 // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
31 
32 // module.cc: Implement google_breakpad::Module.  See module.h.
33 
34 #include "common/module.h"
35 
36 #include <assert.h>
37 #include <errno.h>
38 #include <stdio.h>
39 #include <string.h>
40 
41 #include <iostream>
42 #include <utility>
43 
44 namespace google_breakpad {
45 
46 using std::dec;
47 using std::endl;
48 using std::hex;
49 
50 
Module(const string & name,const string & os,const string & architecture,const string & id)51 Module::Module(const string &name, const string &os,
52                const string &architecture, const string &id) :
53     name_(name),
54     os_(os),
55     architecture_(architecture),
56     id_(id),
57     load_address_(0) { }
58 
~Module()59 Module::~Module() {
60   for (FileByNameMap::iterator it = files_.begin(); it != files_.end(); ++it)
61     delete it->second;
62   for (FunctionSet::iterator it = functions_.begin();
63        it != functions_.end(); ++it) {
64     delete *it;
65   }
66   for (vector<StackFrameEntry *>::iterator it = stack_frame_entries_.begin();
67        it != stack_frame_entries_.end(); ++it) {
68     delete *it;
69   }
70   for (ExternSet::iterator it = externs_.begin(); it != externs_.end(); ++it)
71     delete *it;
72 }
73 
SetLoadAddress(Address address)74 void Module::SetLoadAddress(Address address) {
75   load_address_ = address;
76 }
77 
AddFunction(Function * function)78 void Module::AddFunction(Function *function) {
79   // FUNC lines must not hold an empty name, so catch the problem early if
80   // callers try to add one.
81   assert(!function->name.empty());
82 
83   // FUNCs are better than PUBLICs as they come with sizes, so remove an extern
84   // with the same address if present.
85   Extern ext(function->address);
86   ExternSet::iterator it_ext = externs_.find(&ext);
87   if (it_ext == externs_.end() &&
88       architecture_ == "arm" &&
89       (function->address & 0x1) == 0) {
90     // ARM THUMB functions have bit 0 set. ARM64 does not have THUMB.
91     Extern arm_thumb_ext(function->address | 0x1);
92     it_ext = externs_.find(&arm_thumb_ext);
93   }
94   if (it_ext != externs_.end()) {
95     delete *it_ext;
96     externs_.erase(it_ext);
97   }
98 #if _DEBUG
99   {
100     // There should be no other PUBLIC symbols that overlap with the function.
101     Extern debug_ext(function->address);
102     ExternSet::iterator it_debug = externs_.lower_bound(&ext);
103     assert(it_debug == externs_.end() ||
104            (*it_debug)->address >= function->address + function->size);
105   }
106 #endif
107 
108   std::pair<FunctionSet::iterator,bool> ret = functions_.insert(function);
109   if (!ret.second && (*ret.first != function)) {
110     // Free the duplicate that was not inserted because this Module
111     // now owns it.
112     delete function;
113   }
114 }
115 
AddFunctions(vector<Function * >::iterator begin,vector<Function * >::iterator end)116 void Module::AddFunctions(vector<Function *>::iterator begin,
117                           vector<Function *>::iterator end) {
118   for (vector<Function *>::iterator it = begin; it != end; ++it)
119     AddFunction(*it);
120 }
121 
AddStackFrameEntry(StackFrameEntry * stack_frame_entry)122 void Module::AddStackFrameEntry(StackFrameEntry *stack_frame_entry) {
123   stack_frame_entries_.push_back(stack_frame_entry);
124 }
125 
AddExtern(Extern * ext)126 void Module::AddExtern(Extern *ext) {
127   std::pair<ExternSet::iterator,bool> ret = externs_.insert(ext);
128   if (!ret.second) {
129     // Free the duplicate that was not inserted because this Module
130     // now owns it.
131     delete ext;
132   }
133 }
134 
GetFunctions(vector<Function * > * vec,vector<Function * >::iterator i)135 void Module::GetFunctions(vector<Function *> *vec,
136                           vector<Function *>::iterator i) {
137   vec->insert(i, functions_.begin(), functions_.end());
138 }
139 
GetExterns(vector<Extern * > * vec,vector<Extern * >::iterator i)140 void Module::GetExterns(vector<Extern *> *vec,
141                         vector<Extern *>::iterator i) {
142   vec->insert(i, externs_.begin(), externs_.end());
143 }
144 
FindFile(const string & name)145 Module::File *Module::FindFile(const string &name) {
146   // A tricky bit here.  The key of each map entry needs to be a
147   // pointer to the entry's File's name string.  This means that we
148   // can't do the initial lookup with any operation that would create
149   // an empty entry for us if the name isn't found (like, say,
150   // operator[] or insert do), because such a created entry's key will
151   // be a pointer the string passed as our argument.  Since the key of
152   // a map's value type is const, we can't fix it up once we've
153   // created our file.  lower_bound does the lookup without doing an
154   // insertion, and returns a good hint iterator to pass to insert.
155   // Our "destiny" is where we belong, whether we're there or not now.
156   FileByNameMap::iterator destiny = files_.lower_bound(&name);
157   if (destiny == files_.end()
158       || *destiny->first != name) {  // Repeated string comparison, boo hoo.
159     File *file = new File(name);
160     file->source_id = -1;
161     destiny = files_.insert(destiny,
162                             FileByNameMap::value_type(&file->name, file));
163   }
164   return destiny->second;
165 }
166 
FindFile(const char * name)167 Module::File *Module::FindFile(const char *name) {
168   string name_string = name;
169   return FindFile(name_string);
170 }
171 
FindExistingFile(const string & name)172 Module::File *Module::FindExistingFile(const string &name) {
173   FileByNameMap::iterator it = files_.find(&name);
174   return (it == files_.end()) ? NULL : it->second;
175 }
176 
GetFiles(vector<File * > * vec)177 void Module::GetFiles(vector<File *> *vec) {
178   vec->clear();
179   for (FileByNameMap::iterator it = files_.begin(); it != files_.end(); ++it)
180     vec->push_back(it->second);
181 }
182 
GetStackFrameEntries(vector<StackFrameEntry * > * vec) const183 void Module::GetStackFrameEntries(vector<StackFrameEntry *> *vec) const {
184   *vec = stack_frame_entries_;
185 }
186 
AssignSourceIds()187 void Module::AssignSourceIds() {
188   // First, give every source file an id of -1.
189   for (FileByNameMap::iterator file_it = files_.begin();
190        file_it != files_.end(); ++file_it) {
191     file_it->second->source_id = -1;
192   }
193 
194   // Next, mark all files actually cited by our functions' line number
195   // info, by setting each one's source id to zero.
196   for (FunctionSet::const_iterator func_it = functions_.begin();
197        func_it != functions_.end(); ++func_it) {
198     Function *func = *func_it;
199     for (vector<Line>::iterator line_it = func->lines.begin();
200          line_it != func->lines.end(); ++line_it)
201       line_it->file->source_id = 0;
202   }
203 
204   // Finally, assign source ids to those files that have been marked.
205   // We could have just assigned source id numbers while traversing
206   // the line numbers, but doing it this way numbers the files in
207   // lexicographical order by name, which is neat.
208   int next_source_id = 0;
209   for (FileByNameMap::iterator file_it = files_.begin();
210        file_it != files_.end(); ++file_it) {
211     if (!file_it->second->source_id)
212       file_it->second->source_id = next_source_id++;
213   }
214 }
215 
ReportError()216 bool Module::ReportError() {
217   fprintf(stderr, "error writing symbol file: %s\n",
218           strerror(errno));
219   return false;
220 }
221 
WriteRuleMap(const RuleMap & rule_map,std::ostream & stream)222 bool Module::WriteRuleMap(const RuleMap &rule_map, std::ostream &stream) {
223   for (RuleMap::const_iterator it = rule_map.begin();
224        it != rule_map.end(); ++it) {
225     if (it != rule_map.begin())
226       stream << ' ';
227     stream << it->first << ": " << it->second;
228   }
229   return stream.good();
230 }
231 
Write(std::ostream & stream,SymbolData symbol_data)232 bool Module::Write(std::ostream &stream, SymbolData symbol_data) {
233   stream << "MODULE " << os_ << " " << architecture_ << " "
234          << id_ << " " << name_ << endl;
235   if (!stream.good())
236     return ReportError();
237 
238   if (symbol_data != ONLY_CFI) {
239     AssignSourceIds();
240 
241     // Write out files.
242     for (FileByNameMap::iterator file_it = files_.begin();
243          file_it != files_.end(); ++file_it) {
244       File *file = file_it->second;
245       if (file->source_id >= 0) {
246         stream << "FILE " << file->source_id << " " <<  file->name << endl;
247         if (!stream.good())
248           return ReportError();
249       }
250     }
251 
252     // Write out functions and their lines.
253     for (FunctionSet::const_iterator func_it = functions_.begin();
254          func_it != functions_.end(); ++func_it) {
255       Function *func = *func_it;
256       stream << "FUNC " << hex
257              << (func->address - load_address_) << " "
258              << func->size << " "
259              << func->parameter_size << " "
260              << func->name << dec << endl;
261       if (!stream.good())
262         return ReportError();
263 
264       for (vector<Line>::iterator line_it = func->lines.begin();
265            line_it != func->lines.end(); ++line_it) {
266         stream << hex
267                << (line_it->address - load_address_) << " "
268                << line_it->size << " "
269                << dec
270                << line_it->number << " "
271                << line_it->file->source_id << endl;
272         if (!stream.good())
273           return ReportError();
274       }
275     }
276 
277     // Write out 'PUBLIC' records.
278     for (ExternSet::const_iterator extern_it = externs_.begin();
279          extern_it != externs_.end(); ++extern_it) {
280       Extern *ext = *extern_it;
281       stream << "PUBLIC " << hex
282              << (ext->address - load_address_) << " 0 "
283              << ext->name << dec << endl;
284     }
285   }
286 
287   if (symbol_data != NO_CFI) {
288     // Write out 'STACK CFI INIT' and 'STACK CFI' records.
289     vector<StackFrameEntry *>::const_iterator frame_it;
290     for (frame_it = stack_frame_entries_.begin();
291          frame_it != stack_frame_entries_.end(); ++frame_it) {
292       StackFrameEntry *entry = *frame_it;
293       stream << "STACK CFI INIT " << hex
294              << (entry->address - load_address_) << " "
295              << entry->size << " " << dec;
296       if (!stream.good()
297           || !WriteRuleMap(entry->initial_rules, stream))
298         return ReportError();
299 
300       stream << endl;
301 
302       // Write out this entry's delta rules as 'STACK CFI' records.
303       for (RuleChangeMap::const_iterator delta_it = entry->rule_changes.begin();
304            delta_it != entry->rule_changes.end(); ++delta_it) {
305         stream << "STACK CFI " << hex
306                << (delta_it->first - load_address_) << " " << dec;
307         if (!stream.good()
308             || !WriteRuleMap(delta_it->second, stream))
309           return ReportError();
310 
311         stream << endl;
312       }
313     }
314   }
315 
316   return true;
317 }
318 
319 }  // namespace google_breakpad
320