[Lldb-commits] [lldb] r144983 - in /lldb/trunk/source/Plugins: Process/gdb-remote/ProcessGDBRemote.cpp SymbolFile/DWARF/DWARFCompileUnit.cpp SymbolFile/DWARF/DWARFCompileUnit.h SymbolFile/DWARF/DWARFDebugInfoEntry.cpp SymbolFile/DWARF/DWARFDebugInfoEntry.h
Greg Clayton
gclayton at apple.com
Fri Nov 18 18:11:31 PST 2011
Author: gclayton
Date: Fri Nov 18 20:11:30 2011
New Revision: 144983
URL: http://llvm.org/viewvc/llvm-project?rev=144983&view=rev
Log:
Further performance improvements in the DWARF parser:
1 - the DIE collections no longer have the NULL tags which saves up to 25%
of the memory on typical C++ code
2 - faster parsing by not having to run the SetDIERelations() function anymore
it is done when parsing the DWARF very efficiently.
Modified:
lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp
lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.h
lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h
Modified: lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp?rev=144983&r1=144982&r2=144983&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp Fri Nov 18 20:11:30 2011
@@ -773,7 +773,7 @@
{
char packet[64];
const int packet_len = ::snprintf (packet, sizeof(packet), "vAttach;%x", attach_pid);
-
+ SetID (attach_pid);
m_async_broadcaster.BroadcastEvent (eBroadcastBitAsyncContinue, new EventDataBytes (packet, packet_len));
}
}
Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp?rev=144983&r1=144982&r2=144983&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp (original)
+++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp Fri Nov 18 20:11:30 2011
@@ -28,6 +28,7 @@
using namespace lldb_private;
using namespace std;
+
extern int g_verbose;
DWARFCompileUnit::DWARFCompileUnit(SymbolFileDWARF* dwarf2Data) :
@@ -176,7 +177,10 @@
// We are in our compile unit, parse starting at the offset
// we were told to parse
const DataExtractor& debug_info_data = m_dwarf2Data->get_debug_info_data();
-
+ std::vector<uint32_t> die_index_stack;
+ die_index_stack.reserve(32);
+ die_index_stack.push_back(0);
+ bool prev_die_had_children = false;
const uint8_t *fixed_form_sizes = DWARFFormValue::GetFixedFormSizesForAddressSize (GetAddressByteSize());
while (offset < next_cu_offset &&
die.FastExtract (debug_info_data, this, fixed_form_sizes, &offset))
@@ -188,43 +192,70 @@
// DW_TAG_value_to_name (die.Tag()),
// die.HasChildren() ? " *" : "");
+ const bool null_die = die.IsNULL();
if (depth == 0)
{
uint64_t base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_low_pc, LLDB_INVALID_ADDRESS);
if (base_addr == LLDB_INVALID_ADDRESS)
base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_entry_pc, 0);
SetBaseAddress (base_addr);
- }
-
- if (cu_die_only)
- {
- AddDIE (die);
- return 1;
- }
- else if (depth == 0 && initial_die_array_size == 1)
- {
- // Don't append the CU die as we already did that
+ if (initial_die_array_size == 0)
+ AddDIE (die);
+ if (cu_die_only)
+ return 1;
}
else
{
- AddDIE (die);
+ if (null_die)
+ {
+ if (prev_die_had_children)
+ {
+ // This will only happen if a DIE says is has children
+ // but all it contains is a NULL tag. Since we are removing
+ // the NULL DIEs from the list (saves up to 25% in C++ code),
+ // we need a way to let the DIE know that it actually doesn't
+ // have children.
+ if (!m_die_array.empty())
+ m_die_array.back().SetEmptyChildren(true);
+ }
+ }
+ else
+ {
+ die.SetParentIndex(m_die_array.size() - die_index_stack[depth-1]);
+
+ if (die_index_stack.back())
+ m_die_array[die_index_stack.back()].SetSiblingIndex(m_die_array.size()-die_index_stack.back());
+
+ // Only push the DIE if it isn't a NULL DIE
+ m_die_array.push_back(die);
+ }
}
- if (die.IsNULL())
+ if (null_die)
{
// NULL DIE.
+ if (!die_index_stack.empty())
+ die_index_stack.pop_back();
+
if (depth > 0)
--depth;
if (depth == 0)
break; // We are done with this compile unit!
+
+ prev_die_had_children = false;
}
else
{
+ die_index_stack.back() = m_die_array.size() - 1;
// Normal DIE
- if (die.HasChildren())
+ const bool die_has_children = die.HasChildren();
+ if (die_has_children)
+ {
+ die_index_stack.push_back(0);
++depth;
+ }
+ prev_die_had_children = die_has_children;
}
-
}
// Give a little bit of info if we encounter corrupt DWARF (our offset
@@ -240,8 +271,15 @@
}
fprintf (stderr, "warning: DWARF compile unit extends beyond its bounds cu 0x%8.8x at 0x%8.8x in '%s'\n", GetOffset(), offset, path);
}
+
+ LogSP log (LogChannelDWARF::GetLogIfAll (DWARF_LOG_DEBUG_INFO));
+ if (log)
+ {
+ StreamString strm;
+ DWARFDebugInfoEntry::DumpDIECollection (strm, m_die_array);
+ log->PutCString (strm.GetString().c_str());
+ }
- SetDIERelations();
return m_die_array.size();
}
@@ -406,114 +444,6 @@
}
//----------------------------------------------------------------------
-// SetDIERelations()
-//
-// We read in all of the DIE entries into our flat list of DIE entries
-// and now we need to go back through all of them and set the parent,
-// sibling and child pointers for quick DIE navigation.
-//----------------------------------------------------------------------
-void
-DWARFCompileUnit::SetDIERelations()
-{
-#if 0
- // Compute average bytes per DIE
- //
- // We can figure out what the average number of bytes per DIE is
- // to help us pre-allocate the correct number of m_die_array
- // entries so we don't end up doing a lot of memory copies as we
- // are creating our DIE array when parsing
- //
- // Enable this code by changing "#if 0" above to "#if 1" and running
- // the dsymutil or dwarfdump with a bunch of dwarf files and see what
- // the running average ends up being in the stdout log.
- static size_t g_total_cu_debug_info_size = 0;
- static size_t g_total_num_dies = 0;
- static size_t g_min_bytes_per_die = UINT32_MAX;
- static size_t g_max_bytes_per_die = 0;
- const size_t num_dies = m_die_array.size();
- const size_t cu_debug_info_size = GetDebugInfoSize();
- const size_t bytes_per_die = cu_debug_info_size / num_dies;
- if (g_min_bytes_per_die > bytes_per_die)
- g_min_bytes_per_die = bytes_per_die;
- if (g_max_bytes_per_die < bytes_per_die)
- g_max_bytes_per_die = bytes_per_die;
- if (g_total_cu_debug_info_size == 0)
- {
- cout << " min max avg" << endl
- << "n dies cu size bpd bpd bpd bpd" << endl
- << "------ -------- --- === === ===" << endl;
- }
- g_total_cu_debug_info_size += cu_debug_info_size;
- g_total_num_dies += num_dies;
- const size_t avg_bytes_per_die = g_total_cu_debug_info_size / g_total_num_dies;
- cout
- << DECIMAL_WIDTH(6) << num_dies << ' '
- << DECIMAL_WIDTH(8) << cu_debug_info_size << ' '
- << DECIMAL_WIDTH(3) << bytes_per_die << ' '
- << DECIMAL_WIDTH(3) << g_min_bytes_per_die << ' '
- << DECIMAL_WIDTH(3) << g_max_bytes_per_die << ' '
- << DECIMAL_WIDTH(3) << avg_bytes_per_die
- << endl;
-#endif
- if (m_die_array.empty())
- return;
- DWARFDebugInfoEntry* die_array_begin = &m_die_array.front();
- DWARFDebugInfoEntry* die_array_end = &m_die_array.back();
- DWARFDebugInfoEntry* curr_die;
- // We purposely are skipping the last element in the array in the loop below
- // so that we can always have a valid next item
- for (curr_die = die_array_begin; curr_die < die_array_end; ++curr_die)
- {
- // Since our loop doesn't include the last element, we can always
- // safely access the next die in the array.
- DWARFDebugInfoEntry* next_die = curr_die + 1;
-
- if (curr_die->IsNULL())
- {
- // NULL DIE that terminates a sibling chain
- DWARFDebugInfoEntry* parent = curr_die->GetParent();
- if (parent)
- parent->SetSibling(next_die);
- }
- else
- {
- // Normal DIE
- if (curr_die->HasChildren())
- next_die->SetParent(curr_die);
- else
- curr_die->SetSibling(next_die);
- }
- }
-
- // Since we skipped the last element, we need to fix it up!
- if (die_array_begin < die_array_end)
- curr_die->SetParent(die_array_begin);
-
-#if 0
- // The code below will dump the DIE relations in case any modification
- // is done to the above code. This dump can be used in a diff to make
- // sure that no functionality is lost.
- {
- DWARFDebugInfoEntry::const_iterator pos;
- DWARFDebugInfoEntry::const_iterator end = m_die_array.end();
- puts("offset parent sibling child");
- puts("-------- -------- -------- --------");
- for (pos = m_die_array.begin(); pos != end; ++pos)
- {
- const DWARFDebugInfoEntry& die_ref = *pos;
- const DWARFDebugInfoEntry* p = die_ref.GetParent();
- const DWARFDebugInfoEntry* s = die_ref.GetSibling();
- const DWARFDebugInfoEntry* c = die_ref.GetFirstChild();
- printf("%.8x: %.8x %.8x %.8x\n", die_ref.GetOffset(),
- p ? p->GetOffset() : 0,
- s ? s->GetOffset() : 0,
- c ? c->GetOffset() : 0);
- }
- }
-#endif
-
-}
-//----------------------------------------------------------------------
// Compare function DWARFDebugAranges::Range structures
//----------------------------------------------------------------------
static bool CompareDIEOffset (const DWARFDebugInfoEntry& die1, const DWARFDebugInfoEntry& die2)
Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.h?rev=144983&r1=144982&r2=144983&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.h (original)
+++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.h Fri Nov 18 20:11:30 2011
@@ -55,9 +55,6 @@
m_base_addr = base_addr;
}
- void
- SetDIERelations();
-
const DWARFDebugInfoEntry*
GetCompileUnitDIEOnly()
{
Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp?rev=144983&r1=144982&r2=144983&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp (original)
+++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp Fri Nov 18 20:11:30 2011
@@ -112,11 +112,13 @@
)
{
m_offset = *offset_ptr;
-
+ m_parent_idx = 0;
+ m_sibling_idx = 0;
+ m_empty_children = false;
uint64_t abbr_idx = debug_info_data.GetULEB128 (offset_ptr);
assert (abbr_idx < (1 << DIE_ABBR_IDX_BITSIZE));
m_abbr_idx = abbr_idx;
-
+
assert (fixed_form_sizes); // For best performance this should be specified!
if (m_abbr_idx)
@@ -1919,3 +1921,28 @@
return a.GetOffset() < b.GetOffset();
}
+void
+DWARFDebugInfoEntry::DumpDIECollection (Stream &strm, DWARFDebugInfoEntry::collection &die_collection)
+{
+ DWARFDebugInfoEntry::const_iterator pos;
+ DWARFDebugInfoEntry::const_iterator end = die_collection.end();
+ puts("offset parent sibling child");
+ puts("-------- -------- -------- --------");
+ for (pos = die_collection.begin(); pos != end; ++pos)
+ {
+ const DWARFDebugInfoEntry& die_ref = *pos;
+ const DWARFDebugInfoEntry* p = die_ref.GetParent();
+ const DWARFDebugInfoEntry* s = die_ref.GetSibling();
+ const DWARFDebugInfoEntry* c = die_ref.GetFirstChild();
+ strm.Printf("%.8x: %.8x %.8x %.8x 0x%4.4x %s%s\n",
+ die_ref.GetOffset(),
+ p ? p->GetOffset() : 0,
+ s ? s->GetOffset() : 0,
+ c ? c->GetOffset() : 0,
+ die_ref.Tag(),
+ DW_TAG_value_to_name(die_ref.Tag()),
+ die_ref.HasChildren() ? " *" : "");
+ }
+}
+
+
Modified: lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h?rev=144983&r1=144982&r2=144983&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h (original)
+++ lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h Fri Nov 18 20:11:30 2011
@@ -41,6 +41,7 @@
typedef UInt32ToDIEMMap::iterator UInt32ToDIEMMapIter;
typedef UInt32ToDIEMMap::const_iterator UInt32ToDIEMMapConstIter;
+#define DIE_SIBLING_IDX_BITSIZE 31
#define DIE_ABBR_IDX_BITSIZE 15
class DWARFDebugInfoEntry
@@ -107,11 +108,24 @@
m_offset (DW_INVALID_OFFSET),
m_parent_idx (0),
m_sibling_idx (0),
+ m_empty_children(false),
m_abbr_idx (0),
- m_has_children (false)
+ m_has_children (false),
+ m_tag (0)
{
}
+ void Clear ()
+ {
+ m_offset = DW_INVALID_OFFSET;
+ m_parent_idx = 0;
+ m_sibling_idx = 0;
+ m_empty_children = false;
+ m_abbr_idx = 0;
+ m_has_children = false;
+ m_tag = 0;
+ }
+
bool Contains (const DWARFDebugInfoEntry *die) const;
void BuildAddressRangeTable(
@@ -323,8 +337,8 @@
// We know we are kept in a vector of contiguous entries, so we know
// we don't need to store our child pointer, if we have a child it will
// be the next entry in the list...
- DWARFDebugInfoEntry* GetFirstChild() { return HasChildren() ? this + 1 : NULL; }
- const DWARFDebugInfoEntry* GetFirstChild() const { return HasChildren() ? this + 1 : NULL; }
+ DWARFDebugInfoEntry* GetFirstChild() { return (HasChildren() && !m_empty_children) ? this + 1 : NULL; }
+ const DWARFDebugInfoEntry* GetFirstChild() const { return (HasChildren() && !m_empty_children) ? this + 1 : NULL; }
void
SetParent (DWARFDebugInfoEntry* parent)
@@ -352,13 +366,42 @@
m_sibling_idx = 0;
}
+ void
+ SetSiblingIndex (uint32_t idx)
+ {
+ m_sibling_idx = idx;
+ }
+
+ void
+ SetParentIndex (uint32_t idx)
+ {
+ m_parent_idx = idx;
+ }
+
+ bool
+ GetEmptyChildren () const
+ {
+ return m_empty_children;
+ }
+
+ void
+ SetEmptyChildren (bool b)
+ {
+ m_empty_children = b;
+ }
+
+ static void
+ DumpDIECollection (lldb_private::Stream &strm,
+ DWARFDebugInfoEntry::collection &die_collection);
+
protected:
- dw_offset_t m_offset; // Offset within the .debug_info of the start of this entry
- uint32_t m_parent_idx; // How many to subtract from "this" to get the parent. If zero this die has no parent
- uint32_t m_sibling_idx; // How many to add to "this" to get the sibling.
+ dw_offset_t m_offset; // Offset within the .debug_info of the start of this entry
+ uint32_t m_parent_idx; // How many to subtract from "this" to get the parent. If zero this die has no parent
+ uint32_t m_sibling_idx:31, // How many to add to "this" to get the sibling.
+ m_empty_children:1; // If a DIE says it had children, yet it just contained a NULL tag, this will be set.
uint32_t m_abbr_idx:DIE_ABBR_IDX_BITSIZE,
- m_has_children:1,
- m_tag:16;
+ m_has_children:1, // Set to 1 if this DIE has children
+ m_tag:16; // A copy of the DW_TAG value so we don't have to go through the compile unit abbrev table
};
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