1 //===-- LocateSymbolFile.cpp ----------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Symbol/LocateSymbolFile.h"
10 
11 #include "lldb/Core/ModuleList.h"
12 #include "lldb/Core/ModuleSpec.h"
13 #include "lldb/Core/Progress.h"
14 #include "lldb/Host/FileSystem.h"
15 #include "lldb/Symbol/ObjectFile.h"
16 #include "lldb/Utility/ArchSpec.h"
17 #include "lldb/Utility/DataBuffer.h"
18 #include "lldb/Utility/DataExtractor.h"
19 #include "lldb/Utility/LLDBLog.h"
20 #include "lldb/Utility/Log.h"
21 #include "lldb/Utility/Reproducer.h"
22 #include "lldb/Utility/StreamString.h"
23 #include "lldb/Utility/Timer.h"
24 #include "lldb/Utility/UUID.h"
25 
26 #include "llvm/Support/FileSystem.h"
27 
28 // From MacOSX system header "mach/machine.h"
29 typedef int cpu_type_t;
30 typedef int cpu_subtype_t;
31 
32 using namespace lldb;
33 using namespace lldb_private;
34 
35 #if defined(__APPLE__)
36 
37 // Forward declaration of method defined in source/Host/macosx/Symbols.cpp
38 int LocateMacOSXFilesUsingDebugSymbols(const ModuleSpec &module_spec,
39                                        ModuleSpec &return_module_spec);
40 
41 #else
42 
43 int LocateMacOSXFilesUsingDebugSymbols(const ModuleSpec &module_spec,
44                                        ModuleSpec &return_module_spec) {
45   // Cannot find MacOSX files using debug symbols on non MacOSX.
46   return 0;
47 }
48 
49 #endif
50 
51 static bool FileAtPathContainsArchAndUUID(const FileSpec &file_fspec,
52                                           const ArchSpec *arch,
53                                           const lldb_private::UUID *uuid) {
54   ModuleSpecList module_specs;
55   if (ObjectFile::GetModuleSpecifications(file_fspec, 0, 0, module_specs)) {
56     ModuleSpec spec;
57     for (size_t i = 0; i < module_specs.GetSize(); ++i) {
58       bool got_spec = module_specs.GetModuleSpecAtIndex(i, spec);
59       UNUSED_IF_ASSERT_DISABLED(got_spec);
60       assert(got_spec);
61       if ((uuid == nullptr || (spec.GetUUIDPtr() && spec.GetUUID() == *uuid)) &&
62           (arch == nullptr ||
63            (spec.GetArchitecturePtr() &&
64             spec.GetArchitecture().IsCompatibleMatch(*arch)))) {
65         return true;
66       }
67     }
68   }
69   return false;
70 }
71 
72 // Given a binary exec_fspec, and a ModuleSpec with an architecture/uuid,
73 // return true if there is a matching dSYM bundle next to the exec_fspec,
74 // and return that value in dsym_fspec.
75 // If there is a .dSYM.yaa compressed archive next to the exec_fspec,
76 // call through Symbols::DownloadObjectAndSymbolFile to download the
77 // expanded/uncompressed dSYM and return that filepath in dsym_fspec.
78 
79 static bool LookForDsymNextToExecutablePath(const ModuleSpec &mod_spec,
80                                             const FileSpec &exec_fspec,
81                                             FileSpec &dsym_fspec) {
82   ConstString filename = exec_fspec.GetFilename();
83   FileSpec dsym_directory = exec_fspec;
84   dsym_directory.RemoveLastPathComponent();
85 
86   std::string dsym_filename = filename.AsCString();
87   dsym_filename += ".dSYM";
88   dsym_directory.AppendPathComponent(dsym_filename);
89   dsym_directory.AppendPathComponent("Contents");
90   dsym_directory.AppendPathComponent("Resources");
91   dsym_directory.AppendPathComponent("DWARF");
92 
93   if (FileSystem::Instance().Exists(dsym_directory)) {
94 
95     // See if the binary name exists in the dSYM DWARF
96     // subdir.
97     dsym_fspec = dsym_directory;
98     dsym_fspec.AppendPathComponent(filename.AsCString());
99     if (FileSystem::Instance().Exists(dsym_fspec) &&
100         FileAtPathContainsArchAndUUID(dsym_fspec, mod_spec.GetArchitecturePtr(),
101                                       mod_spec.GetUUIDPtr())) {
102       return true;
103     }
104 
105     // See if we have "../CF.framework" - so we'll look for
106     // CF.framework.dSYM/Contents/Resources/DWARF/CF
107     // We need to drop the last suffix after '.' to match
108     // 'CF' in the DWARF subdir.
109     std::string binary_name(filename.AsCString());
110     auto last_dot = binary_name.find_last_of('.');
111     if (last_dot != std::string::npos) {
112       binary_name.erase(last_dot);
113       dsym_fspec = dsym_directory;
114       dsym_fspec.AppendPathComponent(binary_name);
115       if (FileSystem::Instance().Exists(dsym_fspec) &&
116           FileAtPathContainsArchAndUUID(dsym_fspec,
117                                         mod_spec.GetArchitecturePtr(),
118                                         mod_spec.GetUUIDPtr())) {
119         return true;
120       }
121     }
122   }
123 
124   // See if we have a .dSYM.yaa next to this executable path.
125   FileSpec dsym_yaa_fspec = exec_fspec;
126   dsym_yaa_fspec.RemoveLastPathComponent();
127   std::string dsym_yaa_filename = filename.AsCString();
128   dsym_yaa_filename += ".dSYM.yaa";
129   dsym_yaa_fspec.AppendPathComponent(dsym_yaa_filename);
130 
131   if (FileSystem::Instance().Exists(dsym_yaa_fspec)) {
132     ModuleSpec mutable_mod_spec = mod_spec;
133     if (Symbols::DownloadObjectAndSymbolFile(mutable_mod_spec, true) &&
134         FileSystem::Instance().Exists(mutable_mod_spec.GetSymbolFileSpec())) {
135       dsym_fspec = mutable_mod_spec.GetSymbolFileSpec();
136       return true;
137     }
138   }
139 
140   return false;
141 }
142 
143 // Given a ModuleSpec with a FileSpec and optionally uuid/architecture
144 // filled in, look for a .dSYM bundle next to that binary.  Returns true
145 // if a .dSYM bundle is found, and that path is returned in the dsym_fspec
146 // FileSpec.
147 //
148 // This routine looks a few directory layers above the given exec_path -
149 // exec_path might be /System/Library/Frameworks/CF.framework/CF and the
150 // dSYM might be /System/Library/Frameworks/CF.framework.dSYM.
151 //
152 // If there is a .dSYM.yaa compressed archive found next to the binary,
153 // we'll call DownloadObjectAndSymbolFile to expand it into a plain .dSYM
154 
155 static bool LocateDSYMInVincinityOfExecutable(const ModuleSpec &module_spec,
156                                               FileSpec &dsym_fspec) {
157   Log *log = GetLog(LLDBLog::Host);
158   const FileSpec &exec_fspec = module_spec.GetFileSpec();
159   if (exec_fspec) {
160     if (::LookForDsymNextToExecutablePath(module_spec, exec_fspec,
161                                           dsym_fspec)) {
162       if (log) {
163         LLDB_LOGF(log, "dSYM with matching UUID & arch found at %s",
164                   dsym_fspec.GetPath().c_str());
165       }
166       return true;
167     } else {
168       FileSpec parent_dirs = exec_fspec;
169 
170       // Remove the binary name from the FileSpec
171       parent_dirs.RemoveLastPathComponent();
172 
173       // Add a ".dSYM" name to each directory component of the path,
174       // stripping off components.  e.g. we may have a binary like
175       // /S/L/F/Foundation.framework/Versions/A/Foundation and
176       // /S/L/F/Foundation.framework.dSYM
177       //
178       // so we'll need to start with
179       // /S/L/F/Foundation.framework/Versions/A, add the .dSYM part to the
180       // "A", and if that doesn't exist, strip off the "A" and try it again
181       // with "Versions", etc., until we find a dSYM bundle or we've
182       // stripped off enough path components that there's no need to
183       // continue.
184 
185       for (int i = 0; i < 4; i++) {
186         // Does this part of the path have a "." character - could it be a
187         // bundle's top level directory?
188         const char *fn = parent_dirs.GetFilename().AsCString();
189         if (fn == nullptr)
190           break;
191         if (::strchr(fn, '.') != nullptr) {
192           if (::LookForDsymNextToExecutablePath(module_spec, parent_dirs,
193                                                 dsym_fspec)) {
194             if (log) {
195               LLDB_LOGF(log, "dSYM with matching UUID & arch found at %s",
196                         dsym_fspec.GetPath().c_str());
197             }
198             return true;
199           }
200         }
201         parent_dirs.RemoveLastPathComponent();
202       }
203     }
204   }
205   dsym_fspec.Clear();
206   return false;
207 }
208 
209 static FileSpec LocateExecutableSymbolFileDsym(const ModuleSpec &module_spec) {
210   const FileSpec *exec_fspec = module_spec.GetFileSpecPtr();
211   const ArchSpec *arch = module_spec.GetArchitecturePtr();
212   const UUID *uuid = module_spec.GetUUIDPtr();
213 
214   LLDB_SCOPED_TIMERF(
215       "LocateExecutableSymbolFileDsym (file = %s, arch = %s, uuid = %p)",
216       exec_fspec ? exec_fspec->GetFilename().AsCString("<NULL>") : "<NULL>",
217       arch ? arch->GetArchitectureName() : "<NULL>", (const void *)uuid);
218 
219   FileSpec symbol_fspec;
220   ModuleSpec dsym_module_spec;
221   // First try and find the dSYM in the same directory as the executable or in
222   // an appropriate parent directory
223   if (!LocateDSYMInVincinityOfExecutable(module_spec, symbol_fspec)) {
224     // We failed to easily find the dSYM above, so use DebugSymbols
225     LocateMacOSXFilesUsingDebugSymbols(module_spec, dsym_module_spec);
226   } else {
227     dsym_module_spec.GetSymbolFileSpec() = symbol_fspec;
228   }
229 
230   return dsym_module_spec.GetSymbolFileSpec();
231 }
232 
233 ModuleSpec Symbols::LocateExecutableObjectFile(const ModuleSpec &module_spec) {
234   ModuleSpec result;
235   const FileSpec &exec_fspec = module_spec.GetFileSpec();
236   const ArchSpec *arch = module_spec.GetArchitecturePtr();
237   const UUID *uuid = module_spec.GetUUIDPtr();
238   LLDB_SCOPED_TIMERF(
239       "LocateExecutableObjectFile (file = %s, arch = %s, uuid = %p)",
240       exec_fspec ? exec_fspec.GetFilename().AsCString("<NULL>") : "<NULL>",
241       arch ? arch->GetArchitectureName() : "<NULL>", (const void *)uuid);
242 
243   ModuleSpecList module_specs;
244   ModuleSpec matched_module_spec;
245   if (exec_fspec &&
246       ObjectFile::GetModuleSpecifications(exec_fspec, 0, 0, module_specs) &&
247       module_specs.FindMatchingModuleSpec(module_spec, matched_module_spec)) {
248     result.GetFileSpec() = exec_fspec;
249   } else {
250     LocateMacOSXFilesUsingDebugSymbols(module_spec, result);
251   }
252 
253   return result;
254 }
255 
256 // Keep "symbols.enable-external-lookup" description in sync with this function.
257 
258 FileSpec
259 Symbols::LocateExecutableSymbolFile(const ModuleSpec &module_spec,
260                                     const FileSpecList &default_search_paths) {
261   FileSpec symbol_file_spec = module_spec.GetSymbolFileSpec();
262   if (symbol_file_spec.IsAbsolute() &&
263       FileSystem::Instance().Exists(symbol_file_spec))
264     return symbol_file_spec;
265 
266   Progress progress(llvm::formatv(
267       "Locating external symbol file for {0}",
268       module_spec.GetFileSpec().GetFilename().AsCString("<Unknown>")));
269 
270   FileSpecList debug_file_search_paths = default_search_paths;
271 
272   // Add module directory.
273   FileSpec module_file_spec = module_spec.GetFileSpec();
274   // We keep the unresolved pathname if it fails.
275   FileSystem::Instance().ResolveSymbolicLink(module_file_spec,
276                                              module_file_spec);
277 
278   ConstString file_dir = module_file_spec.GetDirectory();
279   {
280     FileSpec file_spec(file_dir.AsCString("."));
281     FileSystem::Instance().Resolve(file_spec);
282     debug_file_search_paths.AppendIfUnique(file_spec);
283   }
284 
285   if (ModuleList::GetGlobalModuleListProperties().GetEnableExternalLookup()) {
286 
287     // Add current working directory.
288     {
289       FileSpec file_spec(".");
290       FileSystem::Instance().Resolve(file_spec);
291       debug_file_search_paths.AppendIfUnique(file_spec);
292     }
293 
294 #ifndef _WIN32
295 #if defined(__NetBSD__)
296     // Add /usr/libdata/debug directory.
297     {
298       FileSpec file_spec("/usr/libdata/debug");
299       FileSystem::Instance().Resolve(file_spec);
300       debug_file_search_paths.AppendIfUnique(file_spec);
301     }
302 #else
303     // Add /usr/lib/debug directory.
304     {
305       FileSpec file_spec("/usr/lib/debug");
306       FileSystem::Instance().Resolve(file_spec);
307       debug_file_search_paths.AppendIfUnique(file_spec);
308     }
309 #endif
310 #endif // _WIN32
311   }
312 
313   std::string uuid_str;
314   const UUID &module_uuid = module_spec.GetUUID();
315   if (module_uuid.IsValid()) {
316     // Some debug files are stored in the .build-id directory like this:
317     //   /usr/lib/debug/.build-id/ff/e7fe727889ad82bb153de2ad065b2189693315.debug
318     uuid_str = module_uuid.GetAsString("");
319     std::transform(uuid_str.begin(), uuid_str.end(), uuid_str.begin(),
320                    ::tolower);
321     uuid_str.insert(2, 1, '/');
322     uuid_str = uuid_str + ".debug";
323   }
324 
325   size_t num_directories = debug_file_search_paths.GetSize();
326   for (size_t idx = 0; idx < num_directories; ++idx) {
327     FileSpec dirspec = debug_file_search_paths.GetFileSpecAtIndex(idx);
328     FileSystem::Instance().Resolve(dirspec);
329     if (!FileSystem::Instance().IsDirectory(dirspec))
330       continue;
331 
332     std::vector<std::string> files;
333     std::string dirname = dirspec.GetPath();
334 
335     if (!uuid_str.empty())
336       files.push_back(dirname + "/.build-id/" + uuid_str);
337     if (symbol_file_spec.GetFilename()) {
338       files.push_back(dirname + "/" +
339                       symbol_file_spec.GetFilename().GetCString());
340       files.push_back(dirname + "/.debug/" +
341                       symbol_file_spec.GetFilename().GetCString());
342 
343       // Some debug files may stored in the module directory like this:
344       //   /usr/lib/debug/usr/lib/library.so.debug
345       if (!file_dir.IsEmpty())
346         files.push_back(dirname + file_dir.AsCString() + "/" +
347                         symbol_file_spec.GetFilename().GetCString());
348     }
349 
350     const uint32_t num_files = files.size();
351     for (size_t idx_file = 0; idx_file < num_files; ++idx_file) {
352       const std::string &filename = files[idx_file];
353       FileSpec file_spec(filename);
354       FileSystem::Instance().Resolve(file_spec);
355 
356       if (llvm::sys::fs::equivalent(file_spec.GetPath(),
357                                     module_file_spec.GetPath()))
358         continue;
359 
360       if (FileSystem::Instance().Exists(file_spec)) {
361         lldb_private::ModuleSpecList specs;
362         const size_t num_specs =
363             ObjectFile::GetModuleSpecifications(file_spec, 0, 0, specs);
364         assert(num_specs <= 1 &&
365                "Symbol Vendor supports only a single architecture");
366         if (num_specs == 1) {
367           ModuleSpec mspec;
368           if (specs.GetModuleSpecAtIndex(0, mspec)) {
369             // Skip the uuids check if module_uuid is invalid. For example,
370             // this happens for *.dwp files since at the moment llvm-dwp
371             // doesn't output build ids, nor does binutils dwp.
372             if (!module_uuid.IsValid() || module_uuid == mspec.GetUUID())
373               return file_spec;
374           }
375         }
376       }
377     }
378   }
379 
380   return LocateExecutableSymbolFileDsym(module_spec);
381 }
382 
383 #if !defined(__APPLE__)
384 
385 FileSpec Symbols::FindSymbolFileInBundle(const FileSpec &symfile_bundle,
386                                          const lldb_private::UUID *uuid,
387                                          const ArchSpec *arch) {
388   // FIXME
389   return FileSpec();
390 }
391 
392 bool Symbols::DownloadObjectAndSymbolFile(ModuleSpec &module_spec,
393                                           bool force_lookup) {
394   // Fill in the module_spec.GetFileSpec() for the object file and/or the
395   // module_spec.GetSymbolFileSpec() for the debug symbols file.
396   return false;
397 }
398 
399 #endif
400