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Improve error handling in DWARF parser
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@chaoticgd
chaoticgd committed Oct 31, 2024
1 parent 92d81b5 commit 27928f0
Showing 1 changed file with 20 additions and 22 deletions.
42 changes: 20 additions & 22 deletions src/ccc/dwarf_section.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -130,6 +130,11 @@ const char* Value::string() const

// *****************************************************************************

#define DIE_CHECK(condition, message) \
CCC_CHECK(condition, message " at 0x%x inside DIE at 0x%x.", offset, m_offset);
#define DIE_CHECK_ARGS(condition, message, ...) \
CCC_CHECK(condition, message " at 0x%x inside DIE at 0x%x.", __VA_ARGS__, offset, m_offset);

Result<std::optional<DIE>> DIE::parse(std::span<const u8> debug, u32 offset, u32 importer_flags)
{
DIE die;
Expand Down Expand Up @@ -228,10 +233,8 @@ Result<void> DIE::attributes(std::span<Value*> output, const RequiredAttributes&
continue;
}

CCC_CHECK(iterator->second.valid_forms & 1 << (attribute->value.form()),
"Attribute %s has an unexpected form %s.",
form_to_string(attribute->value.form()),
attribute_to_string(attribute->attribute));
DIE_CHECK_ARGS(iterator->second.valid_forms & 1 << (attribute->value.form()),
"Attribute %x has an unexpected form %s", attribute->attribute, form_to_string(attribute->value.form()));

*output[iterator->second.index] = std::move(attribute->value);
}
Expand All @@ -254,29 +257,24 @@ Result<std::vector<AttributeTuple>> DIE::all_attributes() const
return result;
}

#define ATTRIBUTE_PARSER_CHECK(condition, message) \
CCC_CHECK(condition, message " at 0x%x inside DIE at 0x%x.", offset, m_offset);
#define ATTRIBUTE_PARSER_CHECK_ARG(condition, message, arg) \
CCC_CHECK(condition, message " at 0x%x inside DIE at 0x%x.", arg, offset, m_offset);

Result<AttributeTuple> DIE::parse_attribute(u32& offset) const
{
AttributeTuple result;

result.offset = offset;

const std::optional<u16> name = copy_unaligned<u16>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(name.has_value(), "Cannot read attribute name");
DIE_CHECK(name.has_value(), "Cannot read attribute name");
offset += sizeof(u16);

u8 form = *name & 0xf;
ATTRIBUTE_PARSER_CHECK_ARG(form_to_string(form) != nullptr, "Unknown attribute form 0x%hhx", form);
DIE_CHECK_ARGS(form_to_string(form) != nullptr, "Unknown attribute form 0x%hhx", form);

u16 attribute = *name >> 4;
bool known_attribute = attribute_to_string(attribute);
if (!known_attribute) {
const char* uknown_attribute_error_message =
"Unknown user attribute name 0x%03hx at 0x%x inside DIE at 0x%x.";
"Unknown attribute name 0x%03hx at 0x%x inside DIE at 0x%x.";
if ((m_importer_flags & STRICT_PARSING) == 0 && attribute >= AT_lo_user && attribute <= AT_hi_user) {
CCC_WARN(uknown_attribute_error_message, *name, offset, m_offset);
} else {
Expand All @@ -289,64 +287,64 @@ Result<AttributeTuple> DIE::parse_attribute(u32& offset) const
switch (form) {
case FORM_ADDR: {
std::optional<u32> address = copy_unaligned<u32>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(address.has_value(), "Cannot read address attribute");
DIE_CHECK(address.has_value(), "Cannot read address attribute");
result.value = Value::from_address(*address);
offset += sizeof(u32);
break;
}
case FORM_REF: {
std::optional<u32> reference = copy_unaligned<u32>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(reference.has_value(), "Cannot read reference attribute");
DIE_CHECK(reference.has_value(), "Cannot read reference attribute");
result.value = Value::from_reference(*reference);
offset += sizeof(u32);
break;
}
case FORM_BLOCK2: {
std::optional<u16> size = copy_unaligned<u16>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(size.has_value(), "Cannot read block attribute size");
DIE_CHECK(size.has_value(), "Cannot read block attribute size");
offset += sizeof(u16);

ATTRIBUTE_PARSER_CHECK((u64) offset + *size <= m_debug.size(), "Cannot read block attribute data");
DIE_CHECK((u64) offset + *size <= m_debug.size(), "Cannot read block attribute data");
result.value = Value::from_block_2(m_debug.subspan(offset, *size));
offset += *size;

break;
}
case FORM_BLOCK4: {
std::optional<u32> size = copy_unaligned<u32>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(size.has_value(), "Cannot read block attribute size");
DIE_CHECK(size.has_value(), "Cannot read block attribute size");
offset += sizeof(u32);

ATTRIBUTE_PARSER_CHECK((u64) offset + *size <= m_debug.size(), "Cannot read block attribute data");
DIE_CHECK((u64) offset + *size <= m_debug.size(), "Cannot read block attribute data");
result.value = Value::from_block_4(m_debug.subspan(offset, *size));
offset += *size;

break;
}
case FORM_DATA2: {
std::optional<u16> constant = copy_unaligned<u16>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(constant.has_value(), "Cannot read constant attribute");
DIE_CHECK(constant.has_value(), "Cannot read constant attribute");
result.value = Value::from_constant_2(*constant);
offset += sizeof(u16);
break;
}
case FORM_DATA4: {
std::optional<u32> constant = copy_unaligned<u32>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(constant.has_value(), "Cannot read constant attribute");
DIE_CHECK(constant.has_value(), "Cannot read constant attribute");
result.value = Value::from_constant_4(*constant);
offset += sizeof(u32);
break;
}
case FORM_DATA8: {
std::optional<u64> constant = copy_unaligned<u64>(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(constant.has_value(), "Cannot read constant attribute");
DIE_CHECK(constant.has_value(), "Cannot read constant attribute");
result.value = Value::from_constant_8(*constant);
offset += sizeof(u64);
break;
}
case FORM_STRING: {
const char* string = get_string(m_debug, offset);
ATTRIBUTE_PARSER_CHECK(string, "Cannot read string attribute");
DIE_CHECK(string, "Cannot read string attribute");
result.value = Value::from_string(string);
offset += strlen(string) + 1;
break;
Expand Down

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