Found a quick way to improve the speed with which we can read object files from memory when they are in the shared cache: always read the symbol table strings from memory and let the process' memory cache do the work.
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@157083 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index c845d09..418a93c 100644
--- a/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -1257,6 +1257,7 @@
return 0;
ProcessSP process_sp (m_process_wp.lock());
+ Process *process = process_sp.get();
const size_t addr_byte_size = m_data.GetAddressByteSize();
bool bit_width_32 = addr_byte_size == 4;
@@ -1268,9 +1269,10 @@
const addr_t nlist_data_byte_size = symtab_load_command.nsyms * nlist_byte_size;
const addr_t strtab_data_byte_size = symtab_load_command.strsize;
- if (process_sp)
+ addr_t strtab_addr = LLDB_INVALID_ADDRESS;
+ if (process)
{
- Target &target = process_sp->GetTarget();
+ Target &target = process->GetTarget();
SectionSP linkedit_section_sp(section_list->FindSectionByName(GetSegmentNameLINKEDIT()));
// Reading mach file from memory in a process or core file...
@@ -1279,7 +1281,7 @@
const addr_t linkedit_load_addr = linkedit_section_sp->GetLoadBaseAddress(&target);
const addr_t linkedit_file_offset = linkedit_section_sp->GetFileOffset();
const addr_t symoff_addr = linkedit_load_addr + symtab_load_command.symoff - linkedit_file_offset;
- const addr_t stroff_addr = linkedit_load_addr + symtab_load_command.stroff - linkedit_file_offset;
+ strtab_addr = linkedit_load_addr + symtab_load_command.stroff - linkedit_file_offset;
bool data_was_read = false;
@@ -1305,7 +1307,7 @@
{
data_was_read = true;
nlist_data.SetData((void *)symoff_addr, nlist_data_byte_size, eByteOrderLittle);
- strtab_data.SetData((void *)stroff_addr, strtab_data_byte_size, eByteOrderLittle);
+ strtab_data.SetData((void *)strtab_addr, strtab_data_byte_size, eByteOrderLittle);
if (function_starts_load_command.cmd)
{
const addr_t func_start_addr = linkedit_load_addr + function_starts_load_command.dataoff - linkedit_file_offset;
@@ -1320,9 +1322,9 @@
DataBufferSP nlist_data_sp (ReadMemory (process_sp, symoff_addr, nlist_data_byte_size));
if (nlist_data_sp)
nlist_data.SetData (nlist_data_sp, 0, nlist_data_sp->GetByteSize());
- DataBufferSP strtab_data_sp (ReadMemory (process_sp, stroff_addr, strtab_data_byte_size));
- if (strtab_data_sp)
- strtab_data.SetData (strtab_data_sp, 0, strtab_data_sp->GetByteSize());
+ //DataBufferSP strtab_data_sp (ReadMemory (process_sp, strtab_addr, strtab_data_byte_size));
+ //if (strtab_data_sp)
+ // strtab_data.SetData (strtab_data_sp, 0, strtab_data_sp->GetByteSize());
if (function_starts_load_command.cmd)
{
const addr_t func_start_addr = linkedit_load_addr + function_starts_load_command.dataoff - linkedit_file_offset;
@@ -1357,13 +1359,22 @@
}
- if (strtab_data.GetByteSize() == 0)
+ if (process)
+ {
+ if (strtab_addr == LLDB_INVALID_ADDRESS)
+ {
+ if (log)
+ module_sp->LogMessage(log.get(), "failed to locate the strtab in memory");
+ return 0;
+ }
+ }
+ else if (strtab_data.GetByteSize() == 0)
{
if (log)
module_sp->LogMessage(log.get(), "failed to read strtab data");
return 0;
}
-
+
const ConstString &g_segment_name_TEXT = GetSegmentNameTEXT();
const ConstString &g_segment_name_DATA = GetSegmentNameDATA();
const ConstString &g_segment_name_OBJC = GetSegmentNameOBJC();
@@ -1420,6 +1431,7 @@
uint32_t sym_idx = 0;
Symbol *sym = symtab->Resize (symtab_load_command.nsyms + m_dysymtab.nindirectsyms);
uint32_t num_syms = symtab->GetNumSymbols();
+ std::string memory_symbol_name;
//symtab->Reserve (symtab_load_command.nsyms + m_dysymtab.nindirectsyms);
for (nlist_idx = 0; nlist_idx < symtab_load_command.nsyms; ++nlist_idx)
@@ -1435,24 +1447,37 @@
nlist.n_value = nlist_data.GetAddress_unchecked (&nlist_data_offset);
SymbolType type = eSymbolTypeInvalid;
- const char *symbol_name = strtab_data.PeekCStr(nlist.n_strx);
- if (symbol_name == NULL)
+ const char *symbol_name = NULL;
+
+ if (process)
{
- // No symbol should be NULL, even the symbols with no
- // string values should have an offset zero which points
- // to an empty C-string
- Host::SystemLog (Host::eSystemLogError,
- "error: symbol[%u] has invalid string table offset 0x%x in %s/%s, ignoring symbol\n",
- nlist_idx,
- nlist.n_strx,
- module_sp->GetFileSpec().GetDirectory().GetCString(),
- module_sp->GetFileSpec().GetFilename().GetCString());
- continue;
+ const addr_t str_addr = strtab_addr + nlist.n_strx;
+ Error str_error;
+ if (process->ReadCStringFromMemory(str_addr, memory_symbol_name, str_error))
+ symbol_name = memory_symbol_name.c_str();
+ }
+ else
+ {
+ symbol_name = strtab_data.PeekCStr(nlist.n_strx);
+
+ if (symbol_name == NULL)
+ {
+ // No symbol should be NULL, even the symbols with no
+ // string values should have an offset zero which points
+ // to an empty C-string
+ Host::SystemLog (Host::eSystemLogError,
+ "error: symbol[%u] has invalid string table offset 0x%x in %s/%s, ignoring symbol\n",
+ nlist_idx,
+ nlist.n_strx,
+ module_sp->GetFileSpec().GetDirectory().GetCString(),
+ module_sp->GetFileSpec().GetFilename().GetCString());
+ continue;
+ }
+ if (symbol_name[0] == '\0')
+ symbol_name = NULL;
}
const char *symbol_name_non_abi_mangled = NULL;
- if (symbol_name[0] == '\0')
- symbol_name = NULL;
SectionSP symbol_section;
uint32_t symbol_byte_size = 0;
bool add_nlist = true;