1 // Utility for libstdc++ ABI analysis -*- C++ -*-
2 
3 // Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING.  If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19 // USA.
20 
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction.  Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License.  This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
29 
30 // Benjamin Kosnik  <bkoz@redhat.com>
31 // Blame subsequent hacks on Loren J. Rittle <ljrittle@acm.org>, Phil
32 // Edwards <pme@gcc.gnu.org>, and a cast of dozens at libstdc++@gcc.gnu.org.
33 
34 #include <string>
35 #include <ext/hash_map>
36 #include <deque>
37 #include <sstream>
38 #include <fstream>
39 #include <iostream>
40 #include <cxxabi.h>
41 #include <stdlib.h>    // for system(3)
42 #include <unistd.h>    // for access(2)
43 
44 struct symbol_info
45 {
46   enum category { none, function, object, error };
47   category 	type;
48   std::string 	name;
49   std::string 	demangled_name;
50   int 		size;
51   std::string 	version_name;
52 
symbol_infosymbol_info53   symbol_info() : type(none), size(0) { }
54 
symbol_infosymbol_info55   symbol_info(const symbol_info& other)
56   : type(other.type), name(other.name), demangled_name(other.demangled_name),
57    size(other.size), version_name(other.version_name) { }
58 };
59 
60 namespace __gnu_cxx
61 {
62   using namespace std;
63 
64   template<>
65     struct hash<string>
66     {
operator ()__gnu_cxx::hash67       size_t operator()(const string& s) const
68       {
69 	const collate<char>& c = use_facet<collate<char> >(locale::classic());
70 	return c.hash(s.c_str(), s.c_str() + s.size());
71       }
72     };
73 }
74 
75 typedef std::deque<std::string>				symbol_names;
76 typedef __gnu_cxx::hash_map<std::string, symbol_info> 	symbol_infos;
77 
78 
79 bool
check_version(const symbol_info & test,bool added=false)80 check_version(const symbol_info& test, bool added = false)
81 {
82   typedef std::vector<std::string> compat_list;
83   static compat_list known_versions;
84   if (known_versions.empty())
85     {
86       known_versions.push_back("GLIBCPP_3.2"); // base version
87       known_versions.push_back("GLIBCPP_3.2.1");
88       known_versions.push_back("GLIBCPP_3.2.2");
89       known_versions.push_back("GLIBCPP_3.2.3"); // gcc-3.3.0
90       known_versions.push_back("GLIBCPP_3.2.4"); // gcc-3.3.4
91       known_versions.push_back("CXXABI_1.2");
92       known_versions.push_back("CXXABI_1.2.1");
93       known_versions.push_back("CXXABI_1.2.2");
94     }
95   compat_list::iterator begin = known_versions.begin();
96   compat_list::iterator end = known_versions.end();
97 
98   // Check version names for compatibility...
99   compat_list::iterator it1 = find(begin, end, test.version_name);
100 
101   // Check for weak label.
102   compat_list::iterator it2 = find(begin, end, test.name);
103 
104   // Check that added symbols aren't added in the base version.
105   bool compat = true;
106   if (added && test.version_name == known_versions[0])
107     compat = false;
108 
109   if (it1 == end && it2 == end)
110     compat = false;
111 
112   return compat;
113 }
114 
115 bool
check_compatible(const symbol_info & lhs,const symbol_info & rhs,bool verbose=false)116 check_compatible(const symbol_info& lhs, const symbol_info& rhs,
117 		 bool verbose = false)
118 {
119   using namespace std;
120   bool ret = true;
121   const char tab = '\t';
122 
123   // Check to see if symbol_infos are compatible.
124   if (lhs.type != rhs.type)
125     {
126       ret = false;
127       if (verbose)
128 	{
129 	  cout << tab << "incompatible types" << endl;
130 	}
131     }
132 
133   if (lhs.name != rhs.name)
134     {
135       ret = false;
136       if (verbose)
137 	{
138 	  cout << tab << "incompatible names" << endl;
139 	}
140     }
141 
142   if (lhs.size != rhs.size)
143     {
144       ret = false;
145       if (verbose)
146 	{
147 	  cout << tab << "incompatible sizes" << endl;
148 	  cout << tab << lhs.size << endl;
149 	  cout << tab << rhs.size << endl;
150 	}
151     }
152 
153   if (lhs.version_name != rhs.version_name
154       && !check_version(lhs) && !check_version(rhs))
155     {
156       ret = false;
157       if (verbose)
158 	{
159 	  cout << tab << "incompatible versions" << endl;
160 	  cout << tab << lhs.version_name << endl;
161 	  cout << tab << rhs.version_name << endl;
162 	}
163     }
164 
165   if (verbose)
166     cout << endl;
167 
168   return ret;
169 }
170 
171 const char*
demangle(const std::string & mangled)172 demangle(const std::string& mangled)
173 {
174   const char* name;
175   if (mangled[0] != '_' || mangled[1] != 'Z')
176     {
177       // This is not a mangled symbol, thus has "C" linkage.
178       name = mangled.c_str();
179     }
180   else
181     {
182       // Use __cxa_demangle to demangle.
183       int status = 0;
184       name = abi::__cxa_demangle(mangled.c_str(), 0, 0, &status);
185       if (!name)
186 	{
187 	  switch (status)
188 	    {
189 	    case 0:
190 	      name = "error code = 0: success";
191 	      break;
192 	    case -1:
193 	      name = "error code = -1: memory allocation failure";
194 	      break;
195 	    case -2:
196 	      name = "error code = -2: invalid mangled name";
197 	      break;
198 	    case -3:
199 	      name = "error code = -3: invalid arguments";
200 	      break;
201 	    default:
202 	      name = "error code unknown - who knows what happened";
203 	    }
204 	}
205     }
206   return name;
207 }
208 
209 void
line_to_symbol_info(std::string & input,symbol_info & output)210 line_to_symbol_info(std::string& input, symbol_info& output)
211 {
212   using namespace std;
213   const char delim = ':';
214   const char version_delim = '@';
215   const string::size_type npos = string::npos;
216   string::size_type n = 0;
217 
218   // Set the type.
219   if (input.find("FUNC") == 0)
220     output.type = symbol_info::function;
221   else if (input.find("OBJECT") == 0)
222     output.type = symbol_info::object;
223   else
224     output.type = symbol_info::error;
225   n = input.find_first_of(delim);
226   if (n != npos)
227     input.erase(input.begin(), input.begin() + n + 1);
228 
229   // Iff object, get size info.
230   if (output.type == symbol_info::object)
231     {
232       n = input.find_first_of(delim);
233       if (n != npos)
234 	{
235 	  string size(input.begin(), input.begin() + n);
236 	  istringstream iss(size);
237 	  int x;
238 	  iss >> x;
239 	  if (!iss.fail())
240 	    output.size = x;
241 	  input.erase(input.begin(), input.begin() + n + 1);
242 	}
243     }
244 
245   // Set the name.
246   n = input.find_first_of(version_delim);
247   if (n != npos)
248     {
249       // Found version string.
250       output.name = string(input.begin(), input.begin() + n);
251       n = input.find_last_of(version_delim);
252       input.erase(input.begin(), input.begin() + n + 1);
253 
254       // Set version name.
255       output.version_name = input;
256     }
257   else
258     {
259       // No versioning info.
260       output.name = string(input.begin(), input.end());
261       input.erase(input.begin(), input.end());
262     }
263 
264   // Set the demangled name.
265   output.demangled_name = demangle(output.name);
266 }
267 
268 void
create_symbol_data(const char * file,symbol_infos & symbols,symbol_names & names)269 create_symbol_data(const char* file, symbol_infos& symbols,
270 		   symbol_names& names)
271 {
272   // Parse list of symbols in file into vectors of symbol_info.
273   // For 3.2.0 on x86/linux, this usually is
274   // 947 non-weak symbols
275   // 2084 weak symbols
276   using namespace std;
277   ifstream ifs(file);
278   if (ifs.is_open())
279     {
280       // Organize input into container of symbol_info objects.
281       const string empty;
282       string line = empty;
283       while (getline(ifs, line).good())
284 	{
285 	  symbol_info symbol;
286 	  line_to_symbol_info(line, symbol);
287 	  symbols[symbol.name] = symbol;
288 	  names.push_back(symbol.name);
289 	  line = empty;
290 	}
291     }
292 }
293 
294 void
report_symbol_info(const symbol_info & symbol,std::size_t n,bool ret=true)295 report_symbol_info(const symbol_info& symbol, std::size_t n, bool ret = true)
296 {
297   using namespace std;
298   const char tab = '\t';
299 
300   // Add any other information to display here.
301   cout << tab << symbol.demangled_name << endl;
302   cout << tab << symbol.name << endl;
303   cout << tab << symbol.version_name << endl;
304 
305   if (ret)
306     cout << endl;
307 }
308 
309 
310 int
main(int argc,char ** argv)311 main(int argc, char** argv)
312 {
313   using namespace std;
314 
315   // Get arguments.  (Heading towards getopt_long, I can feel it.)
316   bool verbose = false;
317   string argv1 = argc > 1 ? argv[1] : "";
318   if (argv1 == "--help" || argc < 4)
319     {
320       cerr << "usage: abi_check --check current baseline\n"
321               "                 --check-verbose current baseline\n"
322               "                 --help\n\n"
323               "Where CURRENT is a file containing the current results from\n"
324               "extract_symvers, and BASELINE is one from config/abi.\n"
325 	   << endl;
326       exit(1);
327     }
328   else if (argv1 == "--check-verbose")
329     verbose = true;
330 
331   // Quick sanity/setup check for arguments.
332   const char* test_file = argv[2];
333   const char* baseline_file = argv[3];
334   if (access(test_file, R_OK) != 0)
335     {
336       cerr << "Cannot read symbols file " << test_file
337            << ", did you forget to build first?" << endl;
338       exit(1);
339     }
340   if (access(baseline_file, R_OK) != 0)
341     {
342       cerr << "Cannot read baseline file " << baseline_file << endl;
343       exit(1);
344     }
345 
346   // Input both lists of symbols into container.
347   symbol_infos  baseline_symbols;
348   symbol_names  baseline_names;
349   symbol_infos  test_symbols;
350   symbol_names  test_names;
351   create_symbol_data(baseline_file, baseline_symbols, baseline_names);
352   create_symbol_data(test_file, test_symbols, test_names);
353 
354   //  Sanity check results.
355   const symbol_names::size_type baseline_size = baseline_names.size();
356   const symbol_names::size_type test_size = test_names.size();
357   if (!baseline_size || !test_size)
358     {
359       cerr << "Problems parsing the list of exported symbols." << endl;
360       exit(2);
361     }
362 
363   // Sort out names.
364   // Assuming baseline_names, test_names are both unique w/ no duplicates.
365   //
366   // The names added to missing_names are baseline_names not found in
367   // test_names
368   // -> symbols that have been deleted.
369   //
370   // The names added to added_names are test_names are names not in
371   // baseline_names
372   // -> symbols that have been added.
373   symbol_names shared_names;
374   symbol_names missing_names;
375   symbol_names added_names = test_names;
376   for (size_t i = 0; i < baseline_size; ++i)
377     {
378       string what(baseline_names[i]);
379       symbol_names::iterator end = added_names.end();
380       symbol_names::iterator it = find(added_names.begin(), end, what);
381       if (it != end)
382 	{
383 	  // Found.
384 	  shared_names.push_back(what);
385 	  added_names.erase(it);
386 	}
387       else
388 	  missing_names.push_back(what);
389     }
390 
391   // Check missing names for compatibility.
392   typedef pair<symbol_info, symbol_info> symbol_pair;
393   vector<symbol_pair> incompatible;
394   for (size_t i = 0; i < missing_names.size(); ++i)
395     {
396       symbol_info base = baseline_symbols[missing_names[i]];
397       incompatible.push_back(symbol_pair(base, base));
398     }
399 
400   // Check shared names for compatibility.
401   for (size_t i = 0; i < shared_names.size(); ++i)
402     {
403       symbol_info base = baseline_symbols[shared_names[i]];
404       symbol_info test = test_symbols[shared_names[i]];
405       if (!check_compatible(base, test))
406 	incompatible.push_back(symbol_pair(base, test));
407     }
408 
409   // Check added names for compatibility.
410   for (size_t i = 0; i < added_names.size(); ++i)
411     {
412       symbol_info test = test_symbols[added_names[i]];
413       if (!check_version(test, true))
414 	incompatible.push_back(symbol_pair(test, test));
415     }
416 
417   // Report results.
418   if (verbose && added_names.size())
419     {
420       cout << added_names.size() << " added symbols " << endl;
421       for (size_t j = 0; j < added_names.size() ; ++j)
422 	report_symbol_info(test_symbols[added_names[j]], j + 1);
423     }
424 
425   if (verbose && missing_names.size())
426     {
427       cout << missing_names.size() << " missing symbols " << endl;
428       for (size_t j = 0; j < missing_names.size() ; ++j)
429 	report_symbol_info(baseline_symbols[missing_names[j]], j + 1);
430     }
431 
432   if (verbose && incompatible.size())
433     {
434       cout << incompatible.size() << " incompatible symbols " << endl;
435       for (size_t j = 0; j < incompatible.size() ; ++j)
436 	{
437 	  // First, report name.
438 	  const symbol_info& base = incompatible[j].first;
439 	  const symbol_info& test = incompatible[j].second;
440 	  report_symbol_info(test, j + 1, false);
441 
442 	  // Second, report reason or reasons incompatible.
443 	  check_compatible(base, test, true);
444 	}
445     }
446 
447   cout << "\n\t\t=== libstdc++-v3 check-abi Summary ===" << endl;
448   cout << endl;
449   cout << "# of added symbols:\t\t " << added_names.size() << endl;
450   cout << "# of missing symbols:\t\t " << missing_names.size() << endl;
451   cout << "# of incompatible symbols:\t " << incompatible.size() << endl;
452   cout << endl;
453   cout << "using: " << baseline_file << endl;
454 
455   return 0;
456 }
457