Permit cross-CU references

So far dw_offset_t was global for the whole SymbolFileDWARF but with .debug_types the same dw_offset_t may mean two different things depending on its section (=CU). So references now return whole new referenced DWARFDIE instead of just dw_offset_t. This means that some functions have to now handle 16 bytes instead of 8 bytes but I do not see that anywhere performance critical. Differential Revision: https://reviews.llvm.org/D61502 llvm-svn: 360795

Author: jankratochvil

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

@@ -16,12 +16,13 @@
 DIERef::DIERef(const DWARFFormValue &form_value)
  : cu_offset(DW_INVALID_OFFSET), die_offset(DW_INVALID_OFFSET) {
  if (form_value.IsValid()) {
- if (const DWARFUnit *unit = form_value.GetUnit()) {
- if (unit->GetBaseObjOffset() != DW_INVALID_OFFSET)
- cu_offset = unit->GetBaseObjOffset();
+ DWARFDIE die = form_value.Reference();
+ die_offset = die.GetOffset();
+ if (die) {
+ if (die.GetCU()->GetBaseObjOffset() != DW_INVALID_OFFSET)
+ cu_offset = die.GetCU()->GetBaseObjOffset();
  else
- cu_offset = unit->GetOffset();
+ cu_offset = die.GetCU()->GetOffset();
  }
- die_offset = form_value.Reference();
  }
 }

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

@@ -348,7 +348,7 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  // will have a hard time tracking down an unnammed structure type in
  // the module DWO file, so we make sure we don't get into this
  // situation by always resolving typedefs from the DWO file.
- const DWARFDIE encoding_die = dwarf->GetDIE(DIERef(encoding_uid));
+ const DWARFDIE encoding_die = encoding_uid.Reference();
 
  // First make sure that the die that this is typedef'ed to _is_ just
  // a declaration (DW_AT_declaration == 1), not a full definition
@@ -499,7 +499,7 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  // Clang sometimes erroneously emits id as objc_object*. In that
  // case we fix up the type to "id".
 
- const DWARFDIE encoding_die = dwarf->GetDIE(DIERef(encoding_uid));
+ const DWARFDIE encoding_die = encoding_uid.Reference();
 
  if (encoding_die && encoding_die.Tag() == DW_TAG_structure_type) {
  if (const char *struct_name = encoding_die.GetName()) {
@@ -1150,7 +1150,7 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  bool has_template_params = false;
  DWARFFormValue specification_die_form;
  DWARFFormValue abstract_origin_die_form;
- dw_offset_t object_pointer_die_offset = DW_INVALID_OFFSET;
+ DWARFDIE object_pointer_die;
 
  unsigned type_quals = 0;
  clang::StorageClass storage =
@@ -1221,7 +1221,7 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  break;
 
  case DW_AT_object_pointer:
- object_pointer_die_offset = form_value.Reference();
+ object_pointer_die = form_value.Reference();
  break;
 
  case DW_AT_allocated:
@@ -1254,13 +1254,10 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  }
 
  std::string object_pointer_name;
- if (object_pointer_die_offset != DW_INVALID_OFFSET) {
- DWARFDIE object_pointer_die = die.GetDIE(object_pointer_die_offset);
- if (object_pointer_die) {
- const char *object_pointer_name_cstr = object_pointer_die.GetName();
- if (object_pointer_name_cstr)
- object_pointer_name = object_pointer_name_cstr;
- }
+ if (object_pointer_die) {
+ const char *object_pointer_name_cstr = object_pointer_die.GetName();
+ if (object_pointer_name_cstr)
+ object_pointer_name = object_pointer_name_cstr;
  }
 
  DEBUG_PRINTF("0x%8.8" PRIx64 ": %s (\"%s\")\n", die.GetID(),
@@ -1422,9 +1419,10 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  LinkDeclContextToDIE(spec_clang_decl_ctx, die);
  } else {
  dwarf->GetObjectFile()->GetModule()->ReportWarning(
- "0x%8.8" PRIx64 ": DW_AT_specification(0x%8.8" PRIx64
+ "0x%8.8" PRIx64 ": DW_AT_specification(0x%8.8x"
  ") has no decl\n",
- die.GetID(), specification_die_form.Reference());
+ die.GetID(),
+ specification_die_form.Reference().GetOffset());
  }
  type_handled = true;
  } else if (abstract_origin_die_form.IsValid()) {
@@ -1442,9 +1440,10 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  LinkDeclContextToDIE(abs_clang_decl_ctx, die);
  } else {
  dwarf->GetObjectFile()->GetModule()->ReportWarning(
- "0x%8.8" PRIx64 ": DW_AT_abstract_origin(0x%8.8" PRIx64
+ "0x%8.8" PRIx64 ": DW_AT_abstract_origin(0x%8.8x"
  ") has no decl\n",
- die.GetID(), abstract_origin_die_form.Reference());
+ die.GetID(),
+ abstract_origin_die_form.Reference().GetOffset());
  }
  type_handled = true;
  } else {
@@ -1587,8 +1586,7 @@ TypeSP DWARFASTParserClang::ParseTypeFromDWARF(const SymbolContext &sc,
  clang::FunctionDecl *template_function_decl = nullptr;
 
  if (abstract_origin_die_form.IsValid()) {
- DWARFDIE abs_die =
- dwarf->DebugInfo()->GetDIE(DIERef(abstract_origin_die_form));
+ DWARFDIE abs_die = abstract_origin_die_form.Reference();
 
  SymbolContext sc;
 
@@ -3070,9 +3068,10 @@ bool DWARFASTParserClang::ParseChildMembers(
  member_byte_offset > parent_byte_size)) {
  module_sp->ReportError(
  "0x%8.8" PRIx64
- ": DW_TAG_member '%s' refers to type 0x%8.8" PRIx64
+ ": DW_TAG_member '%s' refers to type 0x%8.8x"
  " which extends beyond the bounds of 0x%8.8" PRIx64,
- die.GetID(), name, encoding_form.Reference(),
+ die.GetID(), name,
+ encoding_form.Reference().GetOffset(),
  parent_die.GetID());
  }
 
@@ -3135,15 +3134,14 @@ bool DWARFASTParserClang::ParseChildMembers(
  if (name)
  module_sp->ReportError(
  "0x%8.8" PRIx64
- ": DW_TAG_member '%s' refers to type 0x%8.8" PRIx64
+ ": DW_TAG_member '%s' refers to type 0x%8.8x"
  " which was unable to be parsed",
- die.GetID(), name, encoding_form.Reference());
+ die.GetID(), name, encoding_form.Reference().GetOffset());
  else
  module_sp->ReportError(
- "0x%8.8" PRIx64
- ": DW_TAG_member refers to type 0x%8.8" PRIx64
+ "0x%8.8" PRIx64 ": DW_TAG_member refers to type 0x%8.8x"
  " which was unable to be parsed",
- die.GetID(), encoding_form.Reference());
+ die.GetID(), encoding_form.Reference().GetOffset());
  }
  }
 
@@ -3253,11 +3251,12 @@ bool DWARFASTParserClang::ParseChildMembers(
  Type *base_class_type = die.ResolveTypeUID(DIERef(encoding_form));
  if (base_class_type == NULL) {
  module_sp->ReportError("0x%8.8x: DW_TAG_inheritance failed to "
- "resolve the base class at 0x%8.8" PRIx64
+ "resolve the base class at 0x%8.8x"
  " from enclosing type 0x%8.8x. \nPlease file "
  "a bug and attach the file at the start of "
  "this error message",
- die.GetOffset(), encoding_form.Reference(),
+ die.GetOffset(),
+ encoding_form.Reference().GetOffset(),
  parent_die.GetOffset());
  break;
  }
@@ -3550,7 +3549,7 @@ Type *DWARFASTParserClang::GetTypeForDIE(const DWARFDIE &die) {
 
  if (attr == DW_AT_type &&
  attributes.ExtractFormValueAtIndex(i, form_value))
- return dwarf->ResolveTypeUID(dwarf->GetDIE(DIERef(form_value)), true);
+ return dwarf->ResolveTypeUID(form_value.Reference(), true);
  }
  }
  }

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

@@ -41,19 +41,18 @@ bool DWARFAttributes::ExtractFormValueAtIndex(
  return form_value.ExtractValue(cu->GetData(), &offset);
 }
 
-uint64_t DWARFAttributes::FormValueAsUnsigned(dw_attr_t attr,
- uint64_t fail_value) const {
+DWARFDIE
+DWARFAttributes::FormValueAsReference(dw_attr_t attr) const {
  const uint32_t attr_idx = FindAttributeIndex(attr);
  if (attr_idx != UINT32_MAX)
- return FormValueAsUnsignedAtIndex(attr_idx, fail_value);
- return fail_value;
+ return FormValueAsReferenceAtIndex(attr_idx);
+ return {};
 }
 
-uint64_t
-DWARFAttributes::FormValueAsUnsignedAtIndex(uint32_t i,
- uint64_t fail_value) const {
+DWARFDIE
+DWARFAttributes::FormValueAsReferenceAtIndex(uint32_t i) const {
  DWARFFormValue form_value;
  if (ExtractFormValueAtIndex(i, form_value))
  return form_value.Reference();
- return fail_value;
+ return {};
 }

lldb/source/Plugins/SymbolFile/DWARF/DWARFAttribute.h

@@ -65,8 +65,8 @@ class DWARFAttributes {
  }
  dw_attr_t FormAtIndex(uint32_t i) const { return m_infos[i].attr.get_form(); }
  bool ExtractFormValueAtIndex(uint32_t i, DWARFFormValue &form_value) const;
- uint64_t FormValueAsUnsignedAtIndex(uint32_t i, uint64_t fail_value) const;
- uint64_t FormValueAsUnsigned(dw_attr_t attr, uint64_t fail_value) const;
+ DWARFDIE FormValueAsReferenceAtIndex(uint32_t i) const;
+ DWARFDIE FormValueAsReference(dw_attr_t attr) const;
  uint32_t FindAttributeIndex(dw_attr_t attr) const;
  void Clear() { m_infos.clear(); }
  size_t Size() const { return m_infos.size(); }

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

@@ -56,15 +56,6 @@ uint64_t DWARFBaseDIE::GetAttributeValueAsUnsigned(const dw_attr_t attr,
  return fail_value;
 }
 
-uint64_t DWARFBaseDIE::GetAttributeValueAsReference(const dw_attr_t attr,
- uint64_t fail_value) const {
- if (IsValid())
- return m_die->GetAttributeValueAsReference(GetDWARF(), GetCU(), attr,
- fail_value);
- else
- return fail_value;
-}
-
 uint64_t DWARFBaseDIE::GetAttributeValueAsAddress(const dw_attr_t attr,
  uint64_t fail_value) const {
  if (IsValid())

lldb/source/Plugins/SymbolFile/DWARF/DWARFBaseDIE.h

@@ -19,6 +19,7 @@ class DWARFUnit;
 class DWARFDebugInfoEntry;
 class DWARFDeclContext;
 class SymbolFileDWARF;
+class DWARFDIE;
 
 class DWARFBaseDIE {
 public:
@@ -113,9 +114,6 @@ class DWARFBaseDIE {
  uint64_t GetAttributeValueAsUnsigned(const dw_attr_t attr,
  uint64_t fail_value) const;
 
- uint64_t GetAttributeValueAsReference(const dw_attr_t attr,
- uint64_t fail_value) const;
-
  uint64_t GetAttributeValueAsAddress(const dw_attr_t attr,
  uint64_t fail_value) const;
 

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

@@ -112,12 +112,10 @@ DWARFDIE::GetSibling() const {
 
 DWARFDIE
 DWARFDIE::GetReferencedDIE(const dw_attr_t attr) const {
- const dw_offset_t die_offset =
- GetAttributeValueAsReference(attr, DW_INVALID_OFFSET);
- if (die_offset != DW_INVALID_OFFSET)
- return GetDIE(die_offset);
+ if (IsValid())
+ return m_die->GetAttributeValueAsReference(GetDWARF(), GetCU(), attr);
  else
- return DWARFDIE();
+ return {};
 }
 
 DWARFDIE
@@ -137,7 +135,7 @@ DWARFDIE::GetAttributeValueAsReferenceDIE(const dw_attr_t attr) const {
  DWARFFormValue form_value;
  if (m_die->GetAttributeValue(dwarf, cu, attr, form_value, nullptr,
  check_specification_or_abstract_origin))
- return dwarf->GetDIE(DIERef(form_value));
+ return form_value.Reference();
  }
  return DWARFDIE();
 }

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

@@ -693,16 +693,16 @@ void DWARFDebugInfoEntry::DumpAttribute(
 
  case DW_AT_abstract_origin:
  case DW_AT_specification: {
- uint64_t abstract_die_offset = form_value.Reference();
+ DWARFDIE abstract_die = form_value.Reference();
  form_value.Dump(s);
- // *ostrm_ptr << HEX32 << abstract_die_offset << " ( ";
- GetName(dwarf2Data, cu, abstract_die_offset, s);
+ // *ostrm_ptr << HEX32 << abstract_die.GetOffset() << " ( ";
+ GetName(dwarf2Data, abstract_die.GetCU(), abstract_die.GetOffset(), s);
  } break;
 
  case DW_AT_type: {
- uint64_t type_die_offset = form_value.Reference();
+ DWARFDIE type_die = form_value.Reference();
  s.PutCString(" ( ");
- AppendTypeName(dwarf2Data, cu, type_die_offset, s);
+ AppendTypeName(dwarf2Data, type_die.GetCU(), type_die.GetOffset(), s);
  s.PutCString(" )");
  } break;
 
@@ -734,13 +734,6 @@ size_t DWARFDebugInfoEntry::GetAttributes(
  const DWARFAbbreviationDeclaration *abbrevDecl = nullptr;
  lldb::offset_t offset = 0;
  if (cu) {
- if (m_tag != DW_TAG_compile_unit && m_tag != DW_TAG_partial_unit) {
- SymbolFileDWARFDwo *dwo_symbol_file = cu->GetDwoSymbolFile();
- if (dwo_symbol_file)
- return GetAttributes(dwo_symbol_file->GetCompileUnit(),
- fixed_form_sizes, attributes, curr_depth);
- }
-
  dwarf2Data = cu->GetSymbolFileDWARF();
  abbrevDecl = GetAbbreviationDeclarationPtr(dwarf2Data, cu, offset);
  }
@@ -779,9 +772,7 @@ size_t DWARFDebugInfoEntry::GetAttributes(
 
  if ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin)) {
  if (form_value.ExtractValue(debug_info_data, &offset)) {
- dw_offset_t die_offset = form_value.Reference();
- DWARFDIE spec_die =
- const_cast<DWARFUnit *>(cu)->GetDIE(die_offset);
+ DWARFDIE spec_die = form_value.Reference();
  if (spec_die)
  spec_die.GetAttributes(attributes, curr_depth + 1);
  }
@@ -845,8 +836,7 @@ dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
 
  if (check_specification_or_abstract_origin) {
  if (GetAttributeValue(dwarf2Data, cu, DW_AT_specification, form_value)) {
- DWARFDIE die =
- const_cast<DWARFUnit *>(cu)->GetDIE(form_value.Reference());
+ DWARFDIE die = form_value.Reference();
  if (die) {
  dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
  die.GetDWARF(), die.GetCU(), attr, form_value, end_attr_offset_ptr,
@@ -857,8 +847,7 @@ dw_offset_t DWARFDebugInfoEntry::GetAttributeValue(
  }
 
  if (GetAttributeValue(dwarf2Data, cu, DW_AT_abstract_origin, form_value)) {
- DWARFDIE die =
- const_cast<DWARFUnit *>(cu)->GetDIE(form_value.Reference());
+ DWARFDIE die = form_value.Reference();
  if (die) {
  dw_offset_t die_offset = die.GetDIE()->GetAttributeValue(
  die.GetDWARF(), die.GetCU(), attr, form_value, end_attr_offset_ptr,
@@ -920,15 +909,14 @@ uint64_t DWARFDebugInfoEntry::GetAttributeValueAsUnsigned(
 //
 // Get the value of an attribute as reference and fix up and compile unit
 // relative offsets as needed.
-uint64_t DWARFDebugInfoEntry::GetAttributeValueAsReference(
- SymbolFileDWARF *dwarf2Data, const DWARFUnit *cu,
- const dw_attr_t attr, uint64_t fail_value,
+DWARFDIE DWARFDebugInfoEntry::GetAttributeValueAsReference(
+ SymbolFileDWARF *dwarf2Data, const DWARFUnit *cu, const dw_attr_t attr,
  bool check_specification_or_abstract_origin) const {
  DWARFFormValue form_value;
  if (GetAttributeValue(dwarf2Data, cu, attr, form_value, nullptr,
  check_specification_or_abstract_origin))
  return form_value.Reference();
- return fail_value;
+ return {};
 }
 
 uint64_t DWARFDebugInfoEntry::GetAttributeValueAsAddress(
@@ -1207,8 +1195,9 @@ bool DWARFDebugInfoEntry::AppendTypeName(SymbolFileDWARF *dwarf2Data,
  // Follow the DW_AT_type if possible
  DWARFFormValue form_value;
  if (die.GetAttributeValue(dwarf2Data, cu, DW_AT_type, form_value)) {
- uint64_t next_die_offset = form_value.Reference();
- result = AppendTypeName(dwarf2Data, cu, next_die_offset, s);
+ DWARFDIE next_die = form_value.Reference();
+ result = AppendTypeName(dwarf2Data, next_die.GetCU(),
+ next_die.GetOffset(), s);
  }
 
  switch (abbrevDecl->Tag()) {
@@ -1353,28 +1342,18 @@ DWARFDebugInfoEntry::GetParentDeclContextDIE(
  }
  }
 
- dw_offset_t die_offset;
-
- die_offset =
- attributes.FormValueAsUnsigned(DW_AT_specification, DW_INVALID_OFFSET);
- if (die_offset != DW_INVALID_OFFSET) {
- DWARFDIE spec_die = cu->GetDIE(die_offset);
- if (spec_die) {
- DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
- if (decl_ctx_die)
- return decl_ctx_die;
- }
+ DWARFDIE spec_die = attributes.FormValueAsReference(DW_AT_specification);
+ if (spec_die) {
+ DWARFDIE decl_ctx_die = spec_die.GetParentDeclContextDIE();
+ if (decl_ctx_die)
+ return decl_ctx_die;
  }
 
- die_offset = attributes.FormValueAsUnsigned(DW_AT_abstract_origin,
- DW_INVALID_OFFSET);
- if (die_offset != DW_INVALID_OFFSET) {
- DWARFDIE abs_die = cu->GetDIE(die_offset);
- if (abs_die) {
- DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
- if (decl_ctx_die)
- return decl_ctx_die;
- }
+ DWARFDIE abs_die = attributes.FormValueAsReference(DW_AT_abstract_origin);
+ if (abs_die) {
+ DWARFDIE decl_ctx_die = abs_die.GetParentDeclContextDIE();
+ if (decl_ctx_die)
+ return decl_ctx_die;
  }
 
  die = die.GetParent();