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		da3c4e5df5
		
	
	
	
	
		
			
			The previous solution of "lol whats a UB" was not nice and tripped over itself when it was run under UBSAN, fix this by doing explicit byte-by-byte reads where needed.
		
			
				
	
	
		
			116 lines
		
	
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			116 lines
		
	
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #include "CompilationUnit.h"
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| #include "DIE.h"
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| #include <AK/ByteReader.h>
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| 
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| namespace Debug::Dwarf {
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| 
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| CompilationUnit::CompilationUnit(DwarfInfo const& dwarf_info, u32 offset, CompilationUnitHeader const& header, NonnullOwnPtr<LineProgram>&& line_program)
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|     : m_dwarf_info(dwarf_info)
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|     , m_offset(offset)
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|     , m_header(header)
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|     , m_abbreviations(dwarf_info, header.abbrev_offset())
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|     , m_line_program(move(line_program))
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| {
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|     VERIFY(header.version() < 5 || header.unit_type() == CompilationUnitType::Full);
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| }
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| 
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| DIE CompilationUnit::root_die() const
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| {
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|     return DIE(*this, m_offset + m_header.header_size());
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| }
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| 
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| DIE CompilationUnit::get_die_at_offset(u32 die_offset) const
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| {
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|     VERIFY(die_offset >= offset() && die_offset < offset() + size());
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|     return DIE(*this, die_offset);
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| }
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| 
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| Optional<FlatPtr> CompilationUnit::base_address() const
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| {
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|     if (m_has_cached_base_address)
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|         return m_cached_base_address;
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| 
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|     auto die = root_die();
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|     auto res = die.get_attribute(Attribute::LowPc);
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|     if (res.has_value()) {
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|         m_cached_base_address = res->as_addr();
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|     }
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|     m_has_cached_base_address = true;
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|     return m_cached_base_address;
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| }
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| 
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| u64 CompilationUnit::address_table_base() const
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| {
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|     if (m_has_cached_address_table_base)
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|         return m_cached_address_table_base;
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| 
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|     auto die = root_die();
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|     auto res = die.get_attribute(Attribute::AddrBase);
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|     if (res.has_value()) {
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|         VERIFY(res->form() == AttributeDataForm::SecOffset);
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|         m_cached_address_table_base = res->as_unsigned();
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|     }
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|     m_has_cached_address_table_base = true;
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|     return m_cached_address_table_base;
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| }
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| 
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| u64 CompilationUnit::string_offsets_base() const
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| {
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|     if (m_has_cached_string_offsets_base)
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|         return m_cached_string_offsets_base;
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| 
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|     auto die = root_die();
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|     auto res = die.get_attribute(Attribute::StrOffsetsBase);
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|     if (res.has_value()) {
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|         VERIFY(res->form() == AttributeDataForm::SecOffset);
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|         m_cached_string_offsets_base = res->as_unsigned();
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|     }
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|     m_has_cached_string_offsets_base = true;
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|     return m_cached_string_offsets_base;
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| }
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| 
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| u64 CompilationUnit::range_lists_base() const
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| {
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|     if (m_has_cached_range_lists_base)
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|         return m_cached_range_lists_base;
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| 
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|     auto die = root_die();
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|     auto res = die.get_attribute(Attribute::RngListsBase);
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|     if (res.has_value()) {
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|         VERIFY(res->form() == AttributeDataForm::SecOffset);
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|         m_cached_range_lists_base = res->as_unsigned();
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|     }
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|     m_has_cached_range_lists_base = true;
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|     return m_cached_range_lists_base;
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| }
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| 
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| FlatPtr CompilationUnit::get_address(size_t index) const
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| {
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|     auto base = address_table_base();
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|     auto debug_addr_data = dwarf_info().debug_addr_data();
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|     VERIFY(base < debug_addr_data.size());
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|     auto addresses = debug_addr_data.slice(base);
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|     VERIFY(index * sizeof(FlatPtr) < addresses.size());
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|     FlatPtr value { 0 };
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|     ByteReader::load<FlatPtr>(addresses.offset_pointer(index * sizeof(FlatPtr)), value);
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|     return value;
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| }
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| 
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| char const* CompilationUnit::get_string(size_t index) const
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| {
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|     auto base = string_offsets_base();
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|     auto debug_str_offsets_data = dwarf_info().debug_str_offsets_data();
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|     VERIFY(base < debug_str_offsets_data.size());
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|     // FIXME: This assumes DWARF32
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|     auto offsets = debug_str_offsets_data.slice(base);
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|     VERIFY(index * sizeof(u32) < offsets.size());
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|     auto offset = ByteReader::load32(offsets.offset_pointer(index * sizeof(u32)));
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|     return bit_cast<char const*>(dwarf_info().debug_strings_data().offset(offset));
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| }
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| }
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