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29 
30 // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
31 
32 // dump_stabs.cc --- implement the StabsToModule class.
33 
34 #include <assert.h>
35 #include <cxxabi.h>
36 #include <stdarg.h>
37 #include <stdio.h>
38 
39 #include <algorithm>
40 
41 #include "common/stabs_to_module.h"
42 #include "common/using_std_string.h"
43 
44 namespace google_breakpad {
45 
46 // Demangle using abi call.
47 // Older GCC may not support it.
Demangle(const string & mangled)48 static string Demangle(const string &mangled) {
49   int status = 0;
50   char *demangled = abi::__cxa_demangle(mangled.c_str(), NULL, NULL, &status);
51   if (status == 0 && demangled != NULL) {
52     string str(demangled);
53     free(demangled);
54     return str;
55   }
56   return string(mangled);
57 }
58 
~StabsToModule()59 StabsToModule::~StabsToModule() {
60   // Free any functions we've accumulated but not added to the module.
61   for (vector<Module::Function *>::const_iterator func_it = functions_.begin();
62        func_it != functions_.end(); func_it++)
63     delete *func_it;
64   // Free any function that we're currently within.
65   delete current_function_;
66 }
67 
StartCompilationUnit(const char * name,uint64_t address,const char * build_directory)68 bool StabsToModule::StartCompilationUnit(const char *name, uint64_t address,
69                                          const char *build_directory) {
70   assert(!in_compilation_unit_);
71   in_compilation_unit_ = true;
72   current_source_file_name_ = name;
73   current_source_file_ = module_->FindFile(name);
74   comp_unit_base_address_ = address;
75   boundaries_.push_back(static_cast<Module::Address>(address));
76   return true;
77 }
78 
EndCompilationUnit(uint64_t address)79 bool StabsToModule::EndCompilationUnit(uint64_t address) {
80   assert(in_compilation_unit_);
81   in_compilation_unit_ = false;
82   comp_unit_base_address_ = 0;
83   current_source_file_ = NULL;
84   current_source_file_name_ = NULL;
85   if (address)
86     boundaries_.push_back(static_cast<Module::Address>(address));
87   return true;
88 }
89 
StartFunction(const string & name,uint64_t address)90 bool StabsToModule::StartFunction(const string &name,
91                                   uint64_t address) {
92   assert(!current_function_);
93   Module::Function *f = new Module::Function(Demangle(name), address);
94   f->size = 0;           // We compute this in StabsToModule::Finalize().
95   f->parameter_size = 0; // We don't provide this information.
96   current_function_ = f;
97   boundaries_.push_back(static_cast<Module::Address>(address));
98   return true;
99 }
100 
EndFunction(uint64_t address)101 bool StabsToModule::EndFunction(uint64_t address) {
102   assert(current_function_);
103   // Functions in this compilation unit should have address bigger
104   // than the compilation unit's starting address.  There may be a lot
105   // of duplicated entries for functions in the STABS data. We will
106   // count on the Module to remove the duplicates.
107   if (current_function_->address >= comp_unit_base_address_)
108     functions_.push_back(current_function_);
109   else
110     delete current_function_;
111   current_function_ = NULL;
112   if (address)
113     boundaries_.push_back(static_cast<Module::Address>(address));
114   return true;
115 }
116 
Line(uint64_t address,const char * name,int number)117 bool StabsToModule::Line(uint64_t address, const char *name, int number) {
118   assert(current_function_);
119   assert(current_source_file_);
120   if (name != current_source_file_name_) {
121     current_source_file_ = module_->FindFile(name);
122     current_source_file_name_ = name;
123   }
124   Module::Line line;
125   line.address = address;
126   line.size = 0;  // We compute this in StabsToModule::Finalize().
127   line.file = current_source_file_;
128   line.number = number;
129   current_function_->lines.push_back(line);
130   return true;
131 }
132 
Extern(const string & name,uint64_t address)133 bool StabsToModule::Extern(const string &name, uint64_t address) {
134   Module::Extern *ext = new Module::Extern(address);
135   // Older libstdc++ demangle implementations can crash on unexpected
136   // input, so be careful about what gets passed in.
137   if (name.compare(0, 3, "__Z") == 0) {
138     ext->name = Demangle(name.substr(1));
139   } else if (name[0] == '_') {
140     ext->name = name.substr(1);
141   } else {
142     ext->name = name;
143   }
144   module_->AddExtern(ext);
145   return true;
146 }
147 
Warning(const char * format,...)148 void StabsToModule::Warning(const char *format, ...) {
149   va_list args;
150   va_start(args, format);
151   vfprintf(stderr, format, args);
152   va_end(args);
153 }
154 
Finalize()155 void StabsToModule::Finalize() {
156   // Sort our boundary list, so we can search it quickly.
157   sort(boundaries_.begin(), boundaries_.end());
158   // Sort all functions by address, just for neatness.
159   sort(functions_.begin(), functions_.end(),
160        Module::Function::CompareByAddress);
161 
162   for (vector<Module::Function *>::const_iterator func_it = functions_.begin();
163        func_it != functions_.end();
164        func_it++) {
165     Module::Function *f = *func_it;
166     // Compute the function f's size.
167     vector<Module::Address>::const_iterator boundary
168         = std::upper_bound(boundaries_.begin(), boundaries_.end(), f->address);
169     if (boundary != boundaries_.end())
170       f->size = *boundary - f->address;
171     else
172       // If this is the last function in the module, and the STABS
173       // reader was unable to give us its ending address, then assign
174       // it a bogus, very large value.  This will happen at most once
175       // per module: since we've added all functions' addresses to the
176       // boundary table, only one can be the last.
177       f->size = kFallbackSize;
178 
179     // Compute sizes for each of the function f's lines --- if it has any.
180     if (!f->lines.empty()) {
181       stable_sort(f->lines.begin(), f->lines.end(),
182                   Module::Line::CompareByAddress);
183       vector<Module::Line>::iterator last_line = f->lines.end() - 1;
184       for (vector<Module::Line>::iterator line_it = f->lines.begin();
185            line_it != last_line; line_it++)
186         line_it[0].size = line_it[1].address - line_it[0].address;
187       // Compute the size of the last line from f's end address.
188       last_line->size = (f->address + f->size) - last_line->address;
189     }
190   }
191   // Now that everything has a size, add our functions to the module, and
192   // dispose of our private list.
193   module_->AddFunctions(functions_.begin(), functions_.end());
194   functions_.clear();
195 }
196 
197 } // namespace google_breakpad
198