Revert "Revert "[lldb/DWARF] Fix a leak in line table construction""

This reverts commit 7f26c1f.

Author: fredriss

lldb/include/lldb/Symbol/LineTable.h

@@ -42,6 +42,13 @@ class LineTable {
   ///     The compile unit to which this line table belongs.
   LineTable(CompileUnit *comp_unit);
 
+  /// Construct with entries found in \a sequences.
+  ///
+  /// \param[in] sequences
+  ///     Unsorted list of line sequences.
+  LineTable(CompileUnit *comp_unit,
+            std::vector<std::unique_ptr<LineSequence>> &&sequences);
+
   /// Destructor.
   ~LineTable();
 
@@ -64,7 +71,7 @@ class LineTable {
                        bool is_epilogue_begin, bool is_terminal_entry);
 
   // Used to instantiate the LineSequence helper class
-  LineSequence *CreateLineSequenceContainer();
+  static std::unique_ptr<LineSequence> CreateLineSequenceContainer();
 
   // Append an entry to a caller-provided collection that will later be
   // inserted in this line table.
@@ -259,6 +266,8 @@ class LineTable {
     public:
       LessThanBinaryPredicate(LineTable *line_table);
       bool operator()(const LineTable::Entry &, const LineTable::Entry &) const;
+      bool operator()(const std::unique_ptr<LineSequence> &,
+                      const std::unique_ptr<LineSequence> &) const;
 
     protected:
       LineTable *m_line_table;

lldb/source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp

@@ -1818,7 +1818,7 @@ bool SymbolFilePDB::ParseCompileUnitLineTable(CompileUnit &comp_unit,
             prev_source_idx, false, false, false, false, true);
 
         line_table->InsertSequence(sequence.release());
-        sequence.reset(line_table->CreateLineSequenceContainer());
+        sequence = line_table->CreateLineSequenceContainer();
       }
 
       if (ShouldAddLine(match_line, lno, length)) {
@@ -1855,7 +1855,7 @@ bool SymbolFilePDB::ParseCompileUnitLineTable(CompileUnit &comp_unit,
           prev_source_idx, false, false, false, false, true);
     }
 
-    line_table->InsertSequence(sequence.release());
+    line_table->InsertSequence(sequence.get());
   }
 
   if (line_table->GetSize()) {

lldb/source/Symbol/LineTable.cpp

@@ -21,6 +21,18 @@ using namespace lldb_private;
 LineTable::LineTable(CompileUnit *comp_unit)
     : m_comp_unit(comp_unit), m_entries() {}
 
+LineTable::LineTable(CompileUnit *comp_unit,
+                     std::vector<std::unique_ptr<LineSequence>> &&sequences)
+    : m_comp_unit(comp_unit), m_entries() {
+  LineTable::Entry::LessThanBinaryPredicate less_than_bp(this);
+  llvm::stable_sort(sequences, less_than_bp);
+  for (const auto &sequence : sequences) {
+    LineSequenceImpl *seq = static_cast<LineSequenceImpl *>(sequence.get());
+    m_entries.insert(m_entries.end(), seq->m_entries.begin(),
+                     seq->m_entries.end());
+  }
+}
+
 // Destructor
 LineTable::~LineTable() {}
 
@@ -50,8 +62,8 @@ LineSequence::LineSequence() {}
 
 void LineTable::LineSequenceImpl::Clear() { m_entries.clear(); }
 
-LineSequence *LineTable::CreateLineSequenceContainer() {
-  return new LineTable::LineSequenceImpl();
+std::unique_ptr<LineSequence> LineTable::CreateLineSequenceContainer() {
+  return std::make_unique<LineTable::LineSequenceImpl>();
 }
 
 void LineTable::AppendLineEntryToSequence(
@@ -154,6 +166,14 @@ operator()(const LineTable::Entry &a, const LineTable::Entry &b) const {
 #undef LT_COMPARE
 }
 
+bool LineTable::Entry::LessThanBinaryPredicate::
+operator()(const std::unique_ptr<LineSequence> &sequence_a,
+           const std::unique_ptr<LineSequence> &sequence_b) const {
+  auto *seq_a = static_cast<const LineSequenceImpl *>(sequence_a.get());
+  auto *seq_b = static_cast<const LineSequenceImpl *>(sequence_b.get());
+  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) {