[LLDB] Enable TLS Variable Debugging Without Location Info on AArch64

lldb/include/lldb/Symbol/Variable.h

@@ -79,6 +79,8 @@ class Variable : public UserID, public std::enable_shared_from_this<Variable> {
     return m_location_list;
   }
 
+  bool IsThreadLocal() const;
+
   // When given invalid address, it dumps all locations. Otherwise it only dumps
   // the location that contains this address.
   bool DumpLocations(Stream *s, const Address &address);

lldb/source/Core/ValueObjectVariable.cpp

@@ -254,7 +254,38 @@ bool ValueObjectVariable::UpdateValue() {
       m_resolved_value.SetContext(Value::ContextType::Invalid, nullptr);
     }
   }
-
+  if (m_error.Fail() && variable->IsThreadLocal()) {
+    ExecutionContext exe_ctx(GetExecutionContextRef());
+    Thread *thread = exe_ctx.GetThreadPtr();
+    lldb::ModuleSP module_sp = GetModule();
+    if (!thread) {
+      m_error = Status::FromErrorString("no thread to evaluate TLS within");
+      return m_error.Success();
+    }
+    std::vector<uint32_t> symbol_indexes;
+    module_sp->GetSymtab()->FindAllSymbolsWithNameAndType(
+        ConstString(variable->GetName()), lldb::SymbolType::eSymbolTypeAny,
+        symbol_indexes);
+    Symbol *symbol = module_sp->GetSymtab()->SymbolAtIndex(symbol_indexes[0]);
+    lldb::addr_t tls_file_addr =
+        symbol->GetAddress().GetOffset() +
+        symbol->GetAddress().GetSection()->GetFileAddress();
+    const lldb::addr_t tls_load_addr =
+        thread->GetThreadLocalData(module_sp, tls_file_addr);
+    if (tls_load_addr == LLDB_INVALID_ADDRESS)
+      m_error = Status::FromErrorString(
+          "no TLS data currently exists for this thread");
+    else {
+      Value old_value(m_value);
+      m_value.GetScalar() = tls_load_addr;
+      m_value.SetContext(Value::ContextType::Variable, variable);
+      m_value.SetValueType(Value::ValueType::LoadAddress);
+      m_error = m_value.GetValueAsData(&exe_ctx, m_data, GetModule().get());
+      SetValueDidChange(m_value.GetValueType() != old_value.GetValueType() ||
+                        m_value.GetScalar() != old_value.GetScalar());
+      SetValueIsValid(m_error.Success());
+    }
+  }
   return m_error.Success();
 }
 

lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp

@@ -771,9 +771,12 @@ DynamicLoaderPOSIXDYLD::GetThreadLocalData(const lldb::ModuleSP module_sp,
             "GetThreadLocalData info: link_map=0x%" PRIx64
             ", thread info metadata: "
             "modid_offset=0x%" PRIx32 ", dtv_offset=0x%" PRIx32
-            ", tls_offset=0x%" PRIx32 ", dtv_slot_size=%" PRIx32 "\n",
+            ", tls_offset=0x%" PRIx32 ", dtv_slot_size=%" PRIx32
+            ", tls_file_addr=0x%" PRIx64 ", module name=%s "
+            "\n",
             link_map, metadata.modid_offset, metadata.dtv_offset,
-            metadata.tls_offset, metadata.dtv_slot_size);
+            metadata.tls_offset, metadata.dtv_slot_size, tls_file_addr,
+            module_sp->GetFileSpec().GetFilename().AsCString());
 
   // Get the thread pointer.
   addr_t tp = thread->GetThreadPointer();
@@ -790,9 +793,12 @@ DynamicLoaderPOSIXDYLD::GetThreadLocalData(const lldb::ModuleSP module_sp,
     LLDB_LOGF(log, "GetThreadLocalData error: fail to read modid");
     return LLDB_INVALID_ADDRESS;
   }
-
+  const llvm::Triple &triple_ref =
+      m_process->GetTarget().GetArchitecture().GetTriple();
   // Lookup the DTV structure for this thread.
-  addr_t dtv_ptr = tp + metadata.dtv_offset;
+  addr_t dtv_ptr = tp;
+  if (triple_ref.getArch() != llvm::Triple::aarch64)
+    dtv_ptr = dtv_ptr + metadata.dtv_offset;
   addr_t dtv = ReadPointer(dtv_ptr);
   if (dtv == LLDB_INVALID_ADDRESS) {
     LLDB_LOGF(log, "GetThreadLocalData error: fail to read dtv");

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.cpp

@@ -73,19 +73,20 @@
 #undef DECLARE_REGISTER_INFOS_ARM64_STRUCT
 
 static lldb_private::RegisterInfo g_register_infos_pauth[] = {
-    DEFINE_EXTENSION_REG(data_mask), DEFINE_EXTENSION_REG(code_mask)};
+    DEFINE_EXTENSION_REG(data_mask, KIND_ALL_INVALID),
+    DEFINE_EXTENSION_REG(code_mask, KIND_ALL_INVALID)};
 
 static lldb_private::RegisterInfo g_register_infos_mte[] = {
-    DEFINE_EXTENSION_REG(mte_ctrl)};
+    DEFINE_EXTENSION_REG(mte_ctrl, KIND_ALL_INVALID)};
 
 static lldb_private::RegisterInfo g_register_infos_tls[] = {
-    DEFINE_EXTENSION_REG(tpidr),
+    DEFINE_EXTENSION_REG(tpidr, GENERIC_KIND(LLDB_REGNUM_GENERIC_TP)),
     // Only present when SME is present
-    DEFINE_EXTENSION_REG(tpidr2)};
+    DEFINE_EXTENSION_REG(tpidr2, KIND_ALL_INVALID)};
 
 static lldb_private::RegisterInfo g_register_infos_sme[] = {
-    DEFINE_EXTENSION_REG(svcr),
-    DEFINE_EXTENSION_REG(svg),
+    DEFINE_EXTENSION_REG(svcr, KIND_ALL_INVALID),
+    DEFINE_EXTENSION_REG(svg, KIND_ALL_INVALID),
     // 16 is a default size we will change later.
     {"za", nullptr, 16, 0, lldb::eEncodingVector, lldb::eFormatVectorOfUInt8,
      KIND_ALL_INVALID, nullptr, nullptr, nullptr}};
@@ -95,7 +96,7 @@ static lldb_private::RegisterInfo g_register_infos_sme2[] = {
      KIND_ALL_INVALID, nullptr, nullptr, nullptr}};
 
 static lldb_private::RegisterInfo g_register_infos_fpmr[] = {
-    DEFINE_EXTENSION_REG(fpmr)};
+    DEFINE_EXTENSION_REG(fpmr, KIND_ALL_INVALID)};
 
 // Number of register sets provided by this context.
 enum {

lldb/source/Plugins/Process/Utility/RegisterInfos_arm64.h

@@ -470,6 +470,13 @@ static uint32_t g_d31_invalidates[] = {fpu_v31, fpu_s31, LLDB_INVALID_REGNUM};
         LLDB_INVALID_REGNUM, lldb_kind                                         \
   }
 
+// Generates register kinds array for registers with only generic kind
+#define GENERIC_KIND(generic_kind)                                             \
+  {                                                                            \
+    LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, generic_kind,                    \
+        LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM                               \
+  }
+
 // Generates register kinds array for registers with only lldb kind
 #define KIND_ALL_INVALID                                                       \
   {                                                                            \
@@ -535,10 +542,10 @@ static uint32_t g_d31_invalidates[] = {fpu_v31, fpu_s31, LLDB_INVALID_REGNUM};
   }
 
 // Defines pointer authentication mask registers
-#define DEFINE_EXTENSION_REG(reg)                                              \
+#define DEFINE_EXTENSION_REG(reg, kind)                                        \
   {                                                                            \
     #reg, nullptr, 8, 0, lldb::eEncodingUint, lldb::eFormatHex,                \
-        KIND_ALL_INVALID, nullptr, nullptr, nullptr,                           \
+        kind, nullptr, nullptr, nullptr,                                       \
   }
 
 static lldb_private::RegisterInfo g_register_infos_arm64_le[] = {

lldb/source/Plugins/SymbolFile/DWARF/ManualDWARFIndex.cpp

@@ -230,7 +230,6 @@ void ManualDWARFIndex::IndexUnitImpl(DWARFUnit &unit,
     const char *mangled_cstr = nullptr;
     bool is_declaration = false;
     bool has_address = false;
-    bool has_location_or_const_value = false;
     bool is_global_or_static_variable = false;
 
     DWARFFormValue specification_die_form;
@@ -269,9 +268,6 @@ void ManualDWARFIndex::IndexUnitImpl(DWARFUnit &unit,
 
       case DW_AT_location:
       case DW_AT_const_value:
-        has_location_or_const_value = true;
-        is_global_or_static_variable = die.IsGlobalOrStaticScopeVariable();
-
         break;
 
       case DW_AT_specification:
@@ -363,7 +359,8 @@ void ManualDWARFIndex::IndexUnitImpl(DWARFUnit &unit,
       break;
 
     case DW_TAG_variable:
-      if (name && has_location_or_const_value && is_global_or_static_variable) {
+      is_global_or_static_variable = die.IsGlobalOrStaticScopeVariable();
+      if (name && is_global_or_static_variable) {
         set.globals.Insert(ConstString(name), ref);
         // Be sure to include variables by their mangled and demangled names if
         // they have any since a variable can have a basename "i", a mangled

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

@@ -3499,6 +3499,7 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
   DWARFFormValue type_die_form;
   bool is_external = false;
   bool is_artificial = false;
+  bool is_declaration = false;
   DWARFFormValue const_value_form, location_form;
   Variable::RangeList scope_ranges;
 
@@ -3545,6 +3546,8 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
       is_artificial = form_value.Boolean();
       break;
     case DW_AT_declaration:
+      is_declaration = form_value.Boolean();
+      break;
     case DW_AT_description:
     case DW_AT_endianity:
     case DW_AT_segment:
@@ -3557,6 +3560,12 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
     }
   }
 
+  // If It's a declaration then symbol not present in this symbolfile
+  // return early to try other linked objects.
+  if (is_declaration) {
+    return nullptr;
+  }
+
   // Prefer DW_AT_location over DW_AT_const_value. Both can be emitted e.g.
   // for static constexpr member variables -- DW_AT_const_value and
   // DW_AT_location will both be present in the DIE defining the member.

lldb/source/Symbol/Variable.cpp

@@ -438,6 +438,19 @@ Status Variable::GetValuesForVariableExpressionPath(
   return error;
 }
 
+bool Variable::IsThreadLocal() const {
+  ModuleSP module_sp(m_owner_scope->CalculateSymbolContextModule());
+  // Give the symbol vendor a chance to add to the unified section list.
+  module_sp->GetSymbolFile();
+  std::vector<uint32_t> symbol_indexes;
+  module_sp->GetSymtab()->FindAllSymbolsWithNameAndType(
+      ConstString(GetName()), lldb::SymbolType::eSymbolTypeAny, symbol_indexes);
+  if (symbol_indexes.empty())
+    return false;
+  Symbol *symbol = module_sp->GetSymtab()->SymbolAtIndex(symbol_indexes[0]);
+  return symbol->GetAddress().GetSection()->IsThreadSpecific();
+}
+
 bool Variable::DumpLocations(Stream *s, const Address &address) {
   SymbolContext sc;
   CalculateSymbolContext(&sc);