diff options
Diffstat (limited to 'lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp')
| -rw-r--r-- | lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp | 160 |
1 files changed, 52 insertions, 108 deletions
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp index 232063a6f339..6166aa77bda4 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp @@ -85,35 +85,6 @@ static bool DeclKindIsCXXClass(clang::Decl::Kind decl_kind) { return false; } -struct BitfieldInfo { - uint64_t bit_size; - uint64_t bit_offset; - - BitfieldInfo() - : bit_size(LLDB_INVALID_ADDRESS), bit_offset(LLDB_INVALID_ADDRESS) {} - - void Clear() { - bit_size = LLDB_INVALID_ADDRESS; - bit_offset = LLDB_INVALID_ADDRESS; - } - - bool IsValid() const { - return (bit_size != LLDB_INVALID_ADDRESS) && - (bit_offset != LLDB_INVALID_ADDRESS); - } - - bool NextBitfieldOffsetIsValid(const uint64_t next_bit_offset) const { - if (IsValid()) { - // This bitfield info is valid, so any subsequent bitfields must not - // overlap and must be at a higher bit offset than any previous bitfield - // + size. - return (bit_size + bit_offset) <= next_bit_offset; - } else { - // If the this BitfieldInfo is not valid, then any offset isOK - return true; - } - } -}; ClangASTImporter &DWARFASTParserClang::GetClangASTImporter() { if (!m_clang_ast_importer_up) { @@ -2419,7 +2390,7 @@ void DWARFASTParserClang::ParseSingleMember( lldb::AccessType &default_accessibility, DelayedPropertyList &delayed_properties, lldb_private::ClangASTImporter::LayoutInfo &layout_info, - BitfieldInfo &last_field_info) { + FieldInfo &last_field_info) { ModuleSP module_sp = parent_die.GetDWARF()->GetObjectFile()->GetModule(); const dw_tag_t tag = die.Tag(); // Get the parent byte size so we can verify any members will fit @@ -2453,6 +2424,14 @@ void DWARFASTParserClang::ParseSingleMember( const dw_attr_t attr = attributes.AttributeAtIndex(i); DWARFFormValue form_value; if (attributes.ExtractFormValueAtIndex(i, form_value)) { + // DW_AT_data_member_location indicates the byte offset of the + // word from the base address of the structure. + // + // DW_AT_bit_offset indicates how many bits into the word + // (according to the host endianness) the low-order bit of the + // field starts. AT_bit_offset can be negative. + // + // DW_AT_bit_size indicates the size of the field in bits. switch (attr) { case DW_AT_name: name = form_value.AsCString(); @@ -2603,36 +2582,24 @@ void DWARFASTParserClang::ParseSingleMember( Type *member_type = die.ResolveTypeUID(encoding_form.Reference()); clang::FieldDecl *field_decl = nullptr; + const uint64_t character_width = 8; + const uint64_t word_width = 32; if (tag == DW_TAG_member) { if (member_type) { + CompilerType member_clang_type = member_type->GetLayoutCompilerType(); + if (accessibility == eAccessNone) accessibility = default_accessibility; member_accessibilities.push_back(accessibility); uint64_t field_bit_offset = (member_byte_offset == UINT32_MAX ? 0 : (member_byte_offset * 8)); - if (bit_size > 0) { - BitfieldInfo this_field_info; + if (bit_size > 0) { + FieldInfo this_field_info; this_field_info.bit_offset = field_bit_offset; this_field_info.bit_size = bit_size; - ///////////////////////////////////////////////////////////// - // How to locate a field given the DWARF debug information - // - // AT_byte_size indicates the size of the word in which the bit - // offset must be interpreted. - // - // AT_data_member_location indicates the byte offset of the - // word from the base address of the structure. - // - // AT_bit_offset indicates how many bits into the word - // (according to the host endianness) the low-order bit of the - // field starts. AT_bit_offset can be negative. - // - // AT_bit_size indicates the size of the field in bits. - ///////////////////////////////////////////////////////////// - if (data_bit_offset != UINT64_MAX) { this_field_info.bit_offset = data_bit_offset; } else { @@ -2649,8 +2616,9 @@ void DWARFASTParserClang::ParseSingleMember( } if ((this_field_info.bit_offset >= parent_bit_size) || - !last_field_info.NextBitfieldOffsetIsValid( - this_field_info.bit_offset)) { + (last_field_info.IsBitfield() && + !last_field_info.NextBitfieldOffsetIsValid( + this_field_info.bit_offset))) { ObjectFile *objfile = die.GetDWARF()->GetObjectFile(); objfile->GetModule()->ReportWarning( "0x%8.8" PRIx64 ": %s bitfield named \"%s\" has invalid " @@ -2659,40 +2627,12 @@ void DWARFASTParserClang::ParseSingleMember( "compiler and include the preprocessed output for %s\n", die.GetID(), DW_TAG_value_to_name(tag), name, this_field_info.bit_offset, GetUnitName(parent_die).c_str()); - this_field_info.Clear(); return; } // Update the field bit offset we will report for layout field_bit_offset = this_field_info.bit_offset; - // If the member to be emitted did not start on a character - // boundary and there is empty space between the last field and - // this one, then we need to emit an anonymous member filling - // up the space up to its start. There are three cases here: - // - // 1 If the previous member ended on a character boundary, then - // we can emit an - // anonymous member starting at the most recent character - // boundary. - // - // 2 If the previous member did not end on a character boundary - // and the distance - // from the end of the previous member to the current member - // is less than a - // word width, then we can emit an anonymous member starting - // right after the - // previous member and right before this member. - // - // 3 If the previous member did not end on a character boundary - // and the distance - // from the end of the previous member to the current member - // is greater than - // or equal a word width, then we act as in Case 1. - - const uint64_t character_width = 8; - const uint64_t word_width = 32; - // Objective-C has invalid DW_AT_bit_offset values in older // versions of clang, so we have to be careful and only insert // unnamed bitfields if we have a new enough clang. @@ -2704,53 +2644,57 @@ void DWARFASTParserClang::ParseSingleMember( die.GetCU()->Supports_unnamed_objc_bitfields(); if (detect_unnamed_bitfields) { - BitfieldInfo anon_field_info; + clang::Optional<FieldInfo> unnamed_field_info; + uint64_t last_field_end = 0; - if ((this_field_info.bit_offset % character_width) != - 0) // not char aligned - { - uint64_t last_field_end = 0; + last_field_end = + last_field_info.bit_offset + last_field_info.bit_size; - if (last_field_info.IsValid()) - last_field_end = - last_field_info.bit_offset + last_field_info.bit_size; + if (!last_field_info.IsBitfield()) { + // The last field was not a bit-field... + // but if it did take up the entire word then we need to extend + // last_field_end so the bit-field does not step into the last + // fields padding. + if (last_field_end != 0 && ((last_field_end % word_width) != 0)) + last_field_end += word_width - (last_field_end % word_width); + } - if (this_field_info.bit_offset != last_field_end) { - if (((last_field_end % character_width) == 0) || // case 1 - (this_field_info.bit_offset - last_field_end >= - word_width)) // case 3 - { - anon_field_info.bit_size = - this_field_info.bit_offset % character_width; - anon_field_info.bit_offset = - this_field_info.bit_offset - anon_field_info.bit_size; - } else // case 2 - { - anon_field_info.bit_size = - this_field_info.bit_offset - last_field_end; - anon_field_info.bit_offset = last_field_end; - } - } + // If we have a gap between the last_field_end and the current + // field we have an unnamed bit-field + if (this_field_info.bit_offset != last_field_end && + !(this_field_info.bit_offset < last_field_end)) { + unnamed_field_info = FieldInfo{}; + unnamed_field_info->bit_size = + this_field_info.bit_offset - last_field_end; + unnamed_field_info->bit_offset = last_field_end; } - if (anon_field_info.IsValid()) { + if (unnamed_field_info) { clang::FieldDecl *unnamed_bitfield_decl = ClangASTContext::AddFieldToRecordType( class_clang_type, llvm::StringRef(), m_ast.GetBuiltinTypeForEncodingAndBitSize(eEncodingSint, word_width), - accessibility, anon_field_info.bit_size); + accessibility, unnamed_field_info->bit_size); layout_info.field_offsets.insert(std::make_pair( - unnamed_bitfield_decl, anon_field_info.bit_offset)); + unnamed_bitfield_decl, unnamed_field_info->bit_offset)); } } + last_field_info = this_field_info; + last_field_info.SetIsBitfield(true); } else { - last_field_info.Clear(); + last_field_info.bit_offset = field_bit_offset; + + if (llvm::Optional<uint64_t> clang_type_size = + member_clang_type.GetByteSize(nullptr)) { + last_field_info.bit_size = *clang_type_size * character_width; + } + + last_field_info.SetIsBitfield(false); } - CompilerType member_clang_type = member_type->GetLayoutCompilerType(); if (!member_clang_type.IsCompleteType()) member_clang_type.GetCompleteType(); @@ -2885,7 +2829,7 @@ bool DWARFASTParserClang::ParseChildMembers( if (!parent_die) return false; - BitfieldInfo last_field_info; + FieldInfo last_field_info; ModuleSP module_sp = parent_die.GetDWARF()->GetObjectFile()->GetModule(); ClangASTContext *ast = |