[lldb][swift] Add helper function to find Swift concurrency's module version

Author: felipepiovezan

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntime.cpp

@@ -91,6 +91,10 @@ const char *SwiftLanguageRuntime::GetStandardLibraryBaseName() {
   return "swiftCore";
 }
 
+const char *SwiftLanguageRuntime::GetConcurrencyLibraryBaseName() {
+  return "swift_Concurrency";
+}
+
 static ConstString GetStandardLibraryName(Process &process) {
   // This result needs to be stored in the constructor.
   PlatformSP platform_sp(process.GetTarget().GetPlatform());
@@ -100,6 +104,14 @@ static ConstString GetStandardLibraryName(Process &process) {
   return {};
 }
 
+static ConstString GetConcurrencyLibraryName(Process &process) {
+  PlatformSP platform_sp = process.GetTarget().GetPlatform();
+  if (platform_sp)
+    return platform_sp->GetFullNameForDylib(
+        ConstString(SwiftLanguageRuntime::GetConcurrencyLibraryBaseName()));
+  return {};
+}
+
 ConstString SwiftLanguageRuntime::GetStandardLibraryName() {
   return ::GetStandardLibraryName(*m_process);
 }
@@ -109,6 +121,12 @@ static bool IsModuleSwiftRuntime(lldb_private::Process &process,
   return module.GetFileSpec().GetFilename() == GetStandardLibraryName(process);
 }
 
+static bool IsModuleSwiftConcurrency(lldb_private::Process &process,
+                                     lldb_private::Module &module) {
+  return module.GetFileSpec().GetFilename() ==
+         GetConcurrencyLibraryName(process);
+}
+
 AppleObjCRuntimeV2 *
 SwiftLanguageRuntime::GetObjCRuntime(lldb_private::Process &process) {
   if (auto objc_runtime = ObjCLanguageRuntime::Get(process)) {
@@ -131,6 +149,11 @@ static bool IsStaticSwiftRuntime(Module &image) {
   return image.FindFirstSymbolWithNameAndType(swift_reflection_version_sym);
 }
 
+static bool IsStaticSwiftConcurrency(Module &image) {
+  static const ConstString task_switch_symbol("_swift_task_switch");
+  return image.FindFirstSymbolWithNameAndType(task_switch_symbol);
+}
+
 /// \return the Swift or Objective-C runtime found in the loaded images.
 static ModuleSP findRuntime(Process &process, RuntimeKind runtime_kind) {
   AppleObjCRuntimeV2 *objc_runtime = nullptr;
@@ -168,6 +191,52 @@ static ModuleSP findRuntime(Process &process, RuntimeKind runtime_kind) {
   return runtime_image;
 }
 
+ModuleSP SwiftLanguageRuntime::FindConcurrencyModule(Process &process) {
+  ModuleSP concurrency_module;
+  process.GetTarget().GetImages().ForEach([&](const ModuleSP &candidate) {
+    if (candidate && IsModuleSwiftConcurrency(process, *candidate)) {
+      concurrency_module = candidate;
+      return false;
+    }
+    return true;
+  });
+  if (concurrency_module)
+    return concurrency_module;
+
+  // Do a more expensive search for a statically linked Swift runtime.
+  process.GetTarget().GetImages().ForEach([&](const ModuleSP &candidate) {
+    if (candidate && IsStaticSwiftConcurrency(*candidate)) {
+      concurrency_module = candidate;
+      return false;
+    }
+    return true;
+  });
+  return concurrency_module;
+}
+
+std::optional<uint32_t>
+SwiftLanguageRuntime::FindConcurrencyDebugVersion(Process &process) {
+  ModuleSP concurrency_module = FindConcurrencyModule(process);
+  if (!concurrency_module)
+    return {};
+
+  const Symbol *version_symbol =
+      concurrency_module->FindFirstSymbolWithNameAndType(
+          ConstString("_swift_concurrency_debug_internal_layout_version"));
+  if (!version_symbol)
+    return 0;
+
+  addr_t symbol_addr = version_symbol->GetLoadAddress(&process.GetTarget());
+  if (symbol_addr == LLDB_INVALID_ADDRESS)
+    return {};
+  Status error;
+  uint64_t version = process.ReadUnsignedIntegerFromMemory(
+      symbol_addr, /*width*/ 4, /*fail_value=*/0, error);
+  if (error.Fail())
+    return {};
+  return version;
+}
+
 static std::optional<lldb::addr_t>
 FindSymbolForSwiftObject(Process &process, RuntimeKind runtime_kind,
                          StringRef object, const SymbolType sym_type) {

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntime.h

@@ -98,6 +98,16 @@ class SwiftLanguageRuntime : public LanguageRuntime {
   static SwiftLanguageRuntime *Get(lldb::ProcessSP process_sp) {
     return SwiftLanguageRuntime::Get(process_sp.get());
   }
+
+  /// Returns the Module containing the Swift Concurrency runtime, if it exists.
+  static lldb::ModuleSP FindConcurrencyModule(Process &process);
+
+  /// Returns the version of the swift concurrency runtime debug layout.
+  /// If no Concurrency module is found, or if errors occur, nullopt is
+  /// returned.
+  /// Returns 0 for versions of the module prior to the introduction
+  /// of versioning.
+  static std::optional<uint32_t> FindConcurrencyDebugVersion(Process &process);
   /// \}
 
   /// PluginInterface protocol.
@@ -481,6 +491,8 @@ class SwiftLanguageRuntime : public LanguageRuntime {
   static const char *GetErrorBackstopName();
   ConstString GetStandardLibraryName();
   static const char *GetStandardLibraryBaseName();
+  static const char *GetConcurrencyLibraryBaseName();
+
   static bool IsSwiftClassName(const char *name);
   /// Determines wether \c variable is the "self" object.
   static bool IsSelf(Variable &variable);