uint32_t
Symbol::GetPrologueByteSize ()
{
if (m_type == eSymbolTypeCode || m_type == eSymbolTypeResolver)
{
if (!m_type_data_resolved)
{
m_type_data_resolved = true;
const Address &base_address = m_addr_range.GetBaseAddress();
Function *function = base_address.CalculateSymbolContextFunction();
if (function)
{
// Functions have line entries which can also potentially have end of prologue information.
// So if this symbol points to a function, use the prologue information from there.
m_type_data = function->GetPrologueByteSize();
}
else
{
ModuleSP module_sp (base_address.GetModule());
SymbolContext sc;
if (module_sp)
{
uint32_t resolved_flags = module_sp->ResolveSymbolContextForAddress (base_address,
eSymbolContextLineEntry,
sc);
if (resolved_flags & eSymbolContextLineEntry)
{
// Default to the end of the first line entry.
m_type_data = sc.line_entry.range.GetByteSize();
// Set address for next line.
Address addr (base_address);
addr.Slide (m_type_data);
// Check the first few instructions and look for one that has a line number that is
// different than the first entry. This is also done in Function::GetPrologueByteSize().
uint16_t total_offset = m_type_data;
for (int idx = 0; idx < 6; ++idx)
{
SymbolContext sc_temp;
resolved_flags = module_sp->ResolveSymbolContextForAddress (addr, eSymbolContextLineEntry, sc_temp);
// Make sure we got line number information...
if (!(resolved_flags & eSymbolContextLineEntry))
break;
// If this line number is different than our first one, use it and we're done.
if (sc_temp.line_entry.line != sc.line_entry.line)
{
m_type_data = total_offset;
break;
}
// Slide addr up to the next line address.
addr.Slide (sc_temp.line_entry.range.GetByteSize());
total_offset += sc_temp.line_entry.range.GetByteSize();
// If we've gone too far, bail out.
if (total_offset >= m_addr_range.GetByteSize())
break;
}
// Sanity check - this may be a function in the middle of code that has debug information, but
// not for this symbol. So the line entries surrounding us won't lie inside our function.
// In that case, the line entry will be bigger than we are, so we do that quick check and
// if that is true, we just return 0.
if (m_type_data >= m_addr_range.GetByteSize())
m_type_data = 0;
}
else
{
// TODO: expose something in Process to figure out the
// size of a function prologue.
m_type_data = 0;
}
}
}
}
return m_type_data;
}
return 0;
}
