[Lldb-commits] [PATCH] D72909: Make SymbolFileDWARF::ParseLineTable use std::sort instead of insertion sort

[Unnar Freyr Erlendsson via Phabricator via lldb-commits]

unnar created this revision.
unnar added a project: LLDB.
Herald added subscribers: lldb-commits, JDevlieghere, mgrang.

Motivation: When setting breakpoints in certain projects line sequences are frequently being inserted out of order.

Rather than inserting sequences one at a time into a sorted line table, store all the line sequences as we're building them up and sort and flatten afterwards.


Repository:
  rLLDB LLDB

https://reviews.llvm.org/D72909

Files:
  lldb/include/lldb/Symbol/LineTable.h
  lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
  lldb/source/Symbol/LineTable.cpp


Index: lldb/source/Symbol/LineTable.cpp
===================================================================
--- lldb/source/Symbol/LineTable.cpp
+++ lldb/source/Symbol/LineTable.cpp
@@ -130,6 +130,17 @@
   m_entries.insert(pos, seq->m_entries.begin(), seq->m_entries.end());
 }
 
+void LineTable::ReplaceLineTableWithSequences(std::vector<LineSequence*> &sequences) {
+  m_entries.clear();
+  LineTable::Entry::LessThanBinaryPredicate less_than_bp(this);
+  std::sort(sequences.begin(), sequences.end(), less_than_bp);
+  for (auto *sequence : sequences) {
+    LineSequenceImpl *seq = reinterpret_cast<LineSequenceImpl *>(sequence);
+    m_entries.insert(m_entries.end(), seq->m_entries.begin(),
+      seq->m_entries.end());
+  }
+}
+
 LineTable::Entry::LessThanBinaryPredicate::LessThanBinaryPredicate(
     LineTable *line_table)
     : m_line_table(line_table) {}
@@ -154,6 +165,13 @@
 #undef LT_COMPARE
 }
 
+bool LineTable::Entry::LessThanBinaryPredicate::
+operator()(LineSequence *sequence_a, LineSequence *sequence_b) const {
+  LineSequenceImpl *seq_a = reinterpret_cast<LineSequenceImpl *>(sequence_a);
+  LineSequenceImpl *seq_b = reinterpret_cast<LineSequenceImpl *>(sequence_b);
+  return (*this)(seq_a->m_entries.front(), seq_b->m_entries.front());
+}
+
 uint32_t LineTable::GetSize() const { return m_entries.size(); }
 
 bool LineTable::GetLineEntryAtIndex(uint32_t idx, LineEntry &line_entry) {
Index: lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -1018,17 +1018,20 @@
   std::unique_ptr<LineTable> line_table_up =
       std::make_unique<LineTable>(&comp_unit);
   LineSequence *sequence = line_table_up->CreateLineSequenceContainer();
+  std::vector<LineSequence*> sequences;
   for (auto &row : line_table->Rows) {
     line_table_up->AppendLineEntryToSequence(
         sequence, row.Address.Address, row.Line, row.Column, row.File,
         row.IsStmt, row.BasicBlock, row.PrologueEnd, row.EpilogueBegin,
         row.EndSequence);
     if (row.EndSequence) {
-      line_table_up->InsertSequence(sequence);
+      sequences.push_back(sequence);
       sequence = line_table_up->CreateLineSequenceContainer();
     }
   }
 
+  line_table_up->ReplaceLineTableWithSequences(sequences);
+
   if (SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile()) {
     // We have an object file that has a line table with addresses that are not
     // linked. We need to link the line table and convert the addresses that
Index: lldb/include/lldb/Symbol/LineTable.h
===================================================================
--- lldb/include/lldb/Symbol/LineTable.h
+++ lldb/include/lldb/Symbol/LineTable.h
@@ -78,6 +78,12 @@
   // Insert a sequence of entries into this line table.
   void InsertSequence(LineSequence *sequence);
 
+  /// Replace the current line table with entries found in \a sequences.
+  ///
+  /// \param[in] sequences
+  ///     Unsorted list of line sequences.
+  void ReplaceLineTableWithSequences(std::vector<LineSequence*> &sequences);
+
   /// Dump all line entries in this line table to the stream \a s.
   ///
   /// \param[in] s
@@ -259,6 +265,7 @@
     public:
       LessThanBinaryPredicate(LineTable *line_table);
       bool operator()(const LineTable::Entry &, const LineTable::Entry &) const;
+      bool operator()(LineSequence*, LineSequence*) const;
 
     protected:
       LineTable *m_line_table;


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