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Enable minimized symbol tables when parsing mach-o files. This 

new change will omit unneeded symbol table entries and coalesce
function entries (N_FUN stab entries) with their linker code
symbol (N_SECT symbols) into only the function symbol to avoid
duplicate symbol table entries. It will also coalesce N_STSYM and
the data linker symbol into just one static data symbol.

llvm-svn: 113363
This commit is contained in:
Greg Clayton 2010-09-08 16:38:06 +00:00
parent 011d79aeb2
commit 928d8294c2
2 changed files with 55 additions and 5 deletions
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1
lldb/lldb.xcodeproj/project.pbxproj
View File

@ -2289,7 +2289,6 @@
isa = PBXProject;
buildConfigurationList = 1DEB91EF08733DB70010E9CD /* Build configuration list for PBXProject "lldb" */;
compatibilityVersion = "Xcode 3.1";
developmentRegion = English;
hasScannedForEncodings = 1;
knownRegions = (
en,

59
lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
View File

@ -206,7 +206,7 @@ ObjectFileMachO::GetSymtab()
if (m_symtab_ap.get() == NULL)
{
m_symtab_ap.reset(new Symtab(this));
ParseSymtab(false);
ParseSymtab (true);
}
return m_symtab_ap.get();
}
@ -646,6 +646,9 @@ ObjectFileMachO::ParseSymtab (bool minimize)
std::vector<uint32_t> N_INCL_indexes;
std::vector<uint32_t> N_BRAC_indexes;
std::vector<uint32_t> N_COMM_indexes;
typedef std::map <uint64_t, uint32_t> ValueToSymbolIndexMap;
ValueToSymbolIndexMap N_FUN_addr_to_sym_idx;
ValueToSymbolIndexMap N_STSYM_addr_to_sym_idx;
uint32_t nlist_idx = 0;
Symbol *symbol_ptr = NULL;
@ -706,6 +709,8 @@ ObjectFileMachO::ParseSymtab (bool minimize)
{
type = eSymbolTypeFunction;
symbol_section = section_info.GetSection (nlist.n_sect, nlist.n_value);
N_FUN_addr_to_sym_idx[nlist.n_value] = sym_idx;
// We use the current number of symbols in the symbol table in lieu of
// using nlist_idx in case we ever start trimming entries out
N_FUN_indexes.push_back(sym_idx);
@ -731,6 +736,7 @@ ObjectFileMachO::ParseSymtab (bool minimize)
case StabStaticSymbol:
// N_STSYM -- static symbol: name,,n_sect,type,address
N_STSYM_addr_to_sym_idx[nlist.n_value] = sym_idx;
symbol_section = section_info.GetSection (nlist.n_sect, nlist.n_value);
type = eSymbolTypeStatic;
break;
@ -1082,7 +1088,7 @@ ObjectFileMachO::ParseSymtab (bool minimize)
}
}
break;
}
}
}
}
@ -1095,13 +1101,58 @@ ObjectFileMachO::ParseSymtab (bool minimize)
symbol_name++; // Skip the leading underscore
}
uint64_t symbol_value = nlist.n_value;
if (symbol_name)
sym[sym_idx].GetMangled().SetValue(symbol_name, symbol_name_is_mangled);
if (type == eSymbolTypeCode)
{
// See if we can find a N_FUN entry for any code symbols.
// If we do find a match, and the name matches, then we
// can merge the two into just the function symbol to avoid
// duplicate entries in the symbol table
ValueToSymbolIndexMap::const_iterator pos = N_FUN_addr_to_sym_idx.find (nlist.n_value);
if (pos != N_FUN_addr_to_sym_idx.end())
{
if ((symbol_name_is_mangled == true && sym[sym_idx].GetMangled().GetMangledName() == sym[pos->second].GetMangled().GetMangledName()) ||
(symbol_name_is_mangled == false && sym[sym_idx].GetMangled().GetDemangledName() == sym[pos->second].GetMangled().GetDemangledName()))
{
// We just need the flags from the linker symbol, so put these flags
// into the N_FUN flags to avoid duplicate symbols in the symbol table
sym[pos->second].SetFlags (nlist.n_type << 16 | nlist.n_desc);
sym[sym_idx].GetMangled().Clear();
continue;
}
}
}
else if (type == eSymbolTypeData)
{
// See if we can find a N_STSYM entry for any data symbols.
// If we do find a match, and the name matches, then we
// can merge the two into just the Static symbol to avoid
// duplicate entries in the symbol table
ValueToSymbolIndexMap::const_iterator pos = N_STSYM_addr_to_sym_idx.find (nlist.n_value);
if (pos != N_STSYM_addr_to_sym_idx.end())
{
if ((symbol_name_is_mangled == true && sym[sym_idx].GetMangled().GetMangledName() == sym[pos->second].GetMangled().GetMangledName()) ||
(symbol_name_is_mangled == false && sym[sym_idx].GetMangled().GetDemangledName() == sym[pos->second].GetMangled().GetDemangledName()))
{
// We just need the flags from the linker symbol, so put these flags
// into the N_STSYM flags to avoid duplicate symbols in the symbol table
sym[pos->second].SetFlags (nlist.n_type << 16 | nlist.n_desc);
sym[sym_idx].GetMangled().Clear();
continue;
}
}
}
if (symbol_section != NULL)
symbol_value -= symbol_section->GetFileAddress();
sym[sym_idx].SetID (nlist_idx);
sym[sym_idx].SetType (type);
if (symbol_name)
sym[sym_idx].GetMangled().SetValue(symbol_name, symbol_name_is_mangled);
sym[sym_idx].GetAddressRangeRef().GetBaseAddress().SetSection (symbol_section);
sym[sym_idx].GetAddressRangeRef().GetBaseAddress().SetOffset (symbol_value);
sym[sym_idx].SetFlags (nlist.n_type << 16 | nlist.n_desc);