Simplify LocateDSYMInVincinityOfExecutable a bit, and call Symbols::DownloadObjectAndSymbolFile for .dSYM.yaa archives

[jasonmolenda]

Summary

Host/common/Symbols.cpp has a method LocateDSYMInVincinityOfExecutable which looks for a dSYM next to a binary ("foo" + "foo.dSYM") and it looks for a dSYM next to a bundle ("foo.framework/foo" + "foo.framework.dSYM"). It constructed these two paths differently - one with strcat's one with FileSpec component adding, which isn't great.

This patch adds a helper function LookForDsymNextToExecutablePath which only knows how to look next to a given FileSpec for a dSYM. It also knows to look for a .dSYM.yaa file -- yaa is a compressed archive format used inside Apple akin to a zip file. Instead of having lldb manage a cache directory & expanding it there, I'm calling over to Symbols::DownloadObjectAndSymbolFile() which knows how to expand the archive on the local filesystem and give lldb the path to the expanded dSYM.

There aren't any tests here because the testsuite in dSYM mode exercises this code well. I tried intentionally breaking the bundle-parent-directory-searching code and picked up more than a dozen fails, for instance.

source/Host/common/Symbols.cpp

for (size_t i = 0; i < module_specs.GetSize(); ++i) {
                             spec.GetArchitecture().IsCompatibleMatch(*arch)))) {
         return true;
       }
     }
   }
   return false;
 }
 
-static bool LocateDSYMInVincinityOfExecutable(const ModuleSpec &module_spec,
-                                              FileSpec &dsym_fspec) {
-  Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
-  const FileSpec *exec_fspec = module_spec.GetFileSpecPtr();
-  if (exec_fspec) {
-    char path[PATH_MAX];
-    if (exec_fspec->GetPath(path, sizeof(path))) {
-      // Make sure the module isn't already just a dSYM file...
-      if (strcasestr(path, ".dSYM/Contents/Resources/DWARF") == NULL) {
-        if (log) {
-          if (module_spec.GetUUIDPtr() && module_spec.GetUUIDPtr()->IsValid()) {
-            log->Printf(
-                "Searching for dSYM bundle next to executable %s, UUID %s",
-                path, module_spec.GetUUIDPtr()->GetAsString().c_str());
-          } else {
-            log->Printf("Searching for dSYM bundle next to executable %s",
-                        path);
-          }
-        }
-        ::strncat(path, ".dSYM/Contents/Resources/DWARF/",
-                  sizeof(path) - strlen(path) - 1);
-        ::strncat(path, exec_fspec->GetFilename().AsCString(),
-                  sizeof(path) - strlen(path) - 1);
+// Given a binary exec_fspec, and a ModuleSpec with an architecture/uuid,
+// return true if there is a matching dSYM bundle next to the exec_fspec,
+// and return that value in dsym_fspec.  
+// If there is a .dSYM.yaa compressed archive next to the exec_fspec, 
+// call through Symbols::DownloadObjectAndSymbolFile to download the
+// expanded/uncompressed dSYM and return that filepath in dsym_fspec.
+
+static bool LookForDsymNextToExecutablePath(const ModuleSpec &mod_spec,
+                                            const FileSpec &exec_fspec,
+  ConstString filename = exec_fspec.GetFilename();
+  FileSpec dsym_directory = exec_fspec;
+  dsym_directory.RemoveLastPathComponent();
+
+  std::string dsym_filename = filename.AsCString();
+  dsym_filename += ".dSYM";
+  dsym_directory.AppendPathComponent(dsym_filename);
+  dsym_directory.AppendPathComponent("Contents");
+  dsym_directory.AppendPathComponent("Resources");
+  dsym_directory.AppendPathComponent("DWARF");
+  
+  if (dsym_directory.Exists()) {
+
+    // See if the binary name exists in the dSYM DWARF
+    // subdir.
+    FileSpec dsym_fspec = dsym_directory;
+    dsym_fspec.AppendPathComponent(filename.AsCString());
+    if (dsym_fspec.Exists()
+        && FileAtPathContainsArchAndUUID(dsym_fspec, 
+                         mod_spec.GetArchitecturePtr(),
+                         mod_spec.GetUUIDPtr())) {
+      return true;
+    }
+
+    // See if we have "../CF.framework" - so we'll look for
+    // CF.framework.dSYM/Contents/Resources/DWARF/CF
+    // We need to drop the last suffix after '.' to match 
+    // 'CF' in the DWARF subdir.
+    std::string binary_name (filename.AsCString());
+    auto last_dot = binary_name.find_last_of('.');
+    if (last_dot != std::string::npos) {
+      binary_name.erase(last_dot);
+      dsym_fspec = dsym_directory;
+      dsym_fspec.AppendPathComponent(binary_name);
+      if (dsym_fspec.Exists()
+          && FileAtPathContainsArchAndUUID(dsym_fspec, 
+                           mod_spec.GetArchitecturePtr(),
+                           mod_spec.GetUUIDPtr())) {
+        return true;
+      }
+    }
+  } 
+  
+  // See if we have a .dSYM.yaa next to this executable path.
+  FileSpec dsym_yaa_fspec = exec_fspec;
+  dsym_yaa_fspec.RemoveLastPathComponent();
+  std::string dsym_yaa_filename = filename.AsCString();
+  dsym_yaa_filename += ".dSYM.yaa";
+  dsym_yaa_fspec.AppendPathComponent(dsym_yaa_filename);
+
+  if (dsym_yaa_fspec.Exists()) {
+    ModuleSpec mutable_mod_spec = mod_spec;
+    if (Symbols::DownloadObjectAndSymbolFile (mutable_mod_spec, true)
+        && mutable_mod_spec.GetSymbolFileSpec().Exists()) {
+      dsym_fspec = mutable_mod_spec.GetSymbolFileSpec();
+      return true;
 
-        dsym_fspec.SetFile(path, false, FileSpec::Style::native);
+  return false;
+}
 
-        ModuleSpecList module_specs;
-        ModuleSpec matched_module_spec;
-        if (dsym_fspec.Exists() &&
-            FileAtPathContainsArchAndUUID(dsym_fspec,
-                                          module_spec.GetArchitecturePtr(),
-                                          module_spec.GetUUIDPtr())) {
-          if (log) {
-            log->Printf("dSYM with matching UUID & arch found at %s", path);
-          }
-          return true;
-        } else {
-          FileSpec parent_dirs = exec_fspec;
+// Given a ModuleSpec with a FileSpec and optionally uuid/architecture
+// filled in, look for a .dSYM bundle next to that binary.  Returns true
+// if a .dSYM bundle is found, and that path is returned in the dsym_fspec
+// FileSpec.
+//
+// This routine looks a few directory layers above the given exec_path -
+// exec_path might be /System/Library/Frameworks/CF.framework/CF and the
+// dSYM might be /System/Library/Frameworks/CF.framework.dSYM.
+//
+// If there is a .dSYM.yaa compressed archive found next to the binary,
+// we'll call DownloadObjectAndSymbolFile to expand it into a plain .dSYM
+
+static bool LocateDSYMInVincinityOfExecutable(const ModuleSpec &module_spec,
+                                              FileSpec &dsym_fspec) {
+  Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
+  const FileSpec &exec_fspec = module_spec.GetFileSpec();
+  if (exec_fspec) {
+    if (::LookForDsymNextToExecutablePath (module_spec, exec_fspec, dsym_fspec)) {
+          log->Printf("dSYM with matching UUID & arch found at %s", dsym_fspec.GetPath().c_str());
 
-          // Remove the binary name from the FileSpec
-          parent_dirs.RemoveLastPathComponent();
 
-          // Add a ".dSYM" name to each directory component of the path,
-          // stripping off components.  e.g. we may have a binary like
-          // /S/L/F/Foundation.framework/Versions/A/Foundation and
-          // /S/L/F/Foundation.framework.dSYM
-          //
-          // so we'll need to start with
-          // /S/L/F/Foundation.framework/Versions/A, add the .dSYM part to the
-          // "A", and if that doesn't exist, strip off the "A" and try it again
-          // with "Versions", etc., until we find a dSYM bundle or we've
-          // stripped off enough path components that there's no need to
-          // continue.
 
-          for (int i = 0; i < 4; i++) {
-            // Does this part of the path have a "." character - could it be a
-            // bundle's top level directory?
-            const char *fn = parent_dirs.GetFilename().AsCString();
-            if (fn == nullptr)
-              break;
-            if (::strchr(fn, '.') != nullptr) {
-              dsym_fspec = parent_dirs;
-              dsym_fspec.RemoveLastPathComponent();
-
-              // If the current directory name is "Foundation.framework", see
-              // if
-              // "Foundation.framework.dSYM/Contents/Resources/DWARF/Foundation"
-              // exists & has the right uuid.
-              std::string dsym_fn = fn;
-              dsym_fn += ".dSYM";
-              dsym_fspec.AppendPathComponent(dsym_fn.c_str());
-              dsym_fspec.AppendPathComponent("Contents");
-              dsym_fspec.AppendPathComponent("Resources");
-              dsym_fspec.AppendPathComponent("DWARF");
-              dsym_fspec.AppendPathComponent(
-                  exec_fspec->GetFilename().AsCString());
-              if (dsym_fspec.Exists() &&
-                  FileAtPathContainsArchAndUUID(
-                      dsym_fspec, module_spec.GetArchitecturePtr(),
-                      module_spec.GetUUIDPtr())) {
-                if (log) {
-                  log->Printf("dSYM with matching UUID & arch found at %s",
-                              dsym_fspec.GetPath().c_str());
-                }
-                return true;
-              }
-            }
-            parent_dirs.RemoveLastPathComponent();
-          }
-        }
-      }
-    }
-  }
+          if (::LookForDsymNextToExecutablePath (module_spec, parent_dirs, dsym_fspec)) {
   dsym_fspec.Clear();
   return false;
 }
 
 FileSpec LocateExecutableSymbolFileDsym(const ModuleSpec &module_spec) {
   const FileSpec *exec_fspec = module_spec.GetFileSpecPtr();
   const ArchSpec *arch = module_spec.GetArchitecturePtr();
   const UUID *uuid = module_spec.GetUUIDPtr();