Index: source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
===================================================================
--- source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
+++ source/Plugins/SymbolFile/DWARF/DWARFDebugLine.cpp
@@ -446,26 +446,48 @@
     const lldb::ModuleSP &module_sp, const DWARFDataExtractor &debug_line_data,
     const lldb_private::FileSpec &cu_comp_dir, dw_offset_t stmt_list,
     FileSpecList &support_files) {
+  lldb::offset_t data_end = debug_line_data.GetByteSize();
   lldb::offset_t offset = stmt_list;
 
-  Prologue prologue;
-  if (!ParsePrologue(debug_line_data, &offset, &prologue)) {
-    Host::SystemLog(Host::eSystemLogError, "error: parsing line table prologue "
-                                           "at 0x%8.8x (parsing ended around "
-                                           "0x%8.8" PRIx64 "\n",
-                    stmt_list, offset);
-    return false;
-  }
+  // This loop runs once for regular compile units and may run multiple times
+  // for LTO optimized ones.
+  do {
+    Prologue prologue;
+    lldb::offset_t prologue_start = offset;
+
+    if (!ParsePrologue(debug_line_data, &offset, &prologue)) {
+      Host::SystemLog(Host::eSystemLogError, "error: parsing line table prologue "
+                                             "at 0x%8.8x (parsing ended around "
+                                             "0x%8.8" PRIx64 "\n",
+                      stmt_list, offset);
+      return false;
+    }
 
-  FileSpec file_spec;
-  std::string remapped_file;
+    FileSpec file_spec;
+    std::string remapped_file;
+    bool deduplicate = (prologue_start != stmt_list);
+
+    // File index is only used for fetching information and not stored in the
+    // file spec entries. So we don't need to unify it over multiple prologues
+    // of the compile unit.
+    for (uint32_t file_idx = 1;
+         prologue.GetFile(file_idx, cu_comp_dir, file_spec); ++file_idx) {
+      if (module_sp->RemapSourceFile(file_spec.GetPath(), remapped_file))
+        file_spec.SetFile(remapped_file, false, FileSpec::Style::native);
+
+      // Avoid adding duplicate file specs from subsequent prologues.
+      if (deduplicate)
+        support_files.AppendIfUnique(file_spec);
+      else
+        support_files.Append(file_spec);
+    }
+
+    // Only parse the prologue and skip the statement table.
+    // The prologue's total_length does not include the length field itself.
+    offset = prologue_start + prologue.total_length +
+             debug_line_data.GetDWARFSizeofInitialLength();
+  } while (offset < data_end);
 
-  for (uint32_t file_idx = 1;
-       prologue.GetFile(file_idx, cu_comp_dir, file_spec); ++file_idx) {
-    if (module_sp->RemapSourceFile(file_spec.GetPath(), remapped_file))
-      file_spec.SetFile(remapped_file, false, FileSpec::Style::native);
-    support_files.Append(file_spec);
-  }
   return true;
 }
 
Index: source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
===================================================================
--- source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -992,6 +992,7 @@
   LineTable *line_table;
   std::unique_ptr<LineSequence> sequence_ap;
   lldb::addr_t addr_mask;
+  const FileSpecList &support_files;
 };
 
 //----------------------------------------------------------------------
@@ -1014,9 +1015,23 @@
       info->sequence_ap.reset(line_table->CreateLineSequenceContainer());
       assert(info->sequence_ap.get());
     }
+
+    // If this is a compile unit with multiple prologues, figure out the
+    // file's index in the aggregated list of support files.
+    uint16_t file_idx = state.file;
+    if (file_idx > 0 && file_idx <= state.prologue->file_names.size()) {
+      const char *name = state.prologue->file_names[file_idx - 1].name;
+      FileSpec file_spec(name, false);
+      uint32_t promoted_idx =
+          info->support_files.FindFileIndex(0, file_spec, false);
+
+      if (promoted_idx != UINT32_MAX && promoted_idx < UINT16_MAX)
+        file_idx = promoted_idx;
+    }
+
     line_table->AppendLineEntryToSequence(
         info->sequence_ap.get(), state.address & info->addr_mask, state.line,
-        state.column, state.file, state.is_stmt, state.basic_block,
+        state.column, file_idx, state.is_stmt, state.basic_block,
         state.prologue_end, state.epilogue_begin, state.end_sequence);
     if (state.end_sequence) {
       // First, put the current sequence into the line table.
@@ -1042,8 +1057,9 @@
       if (cu_line_offset != DW_INVALID_OFFSET) {
         std::unique_ptr<LineTable> line_table_ap(new LineTable(sc.comp_unit));
         if (line_table_ap.get()) {
-          ParseDWARFLineTableCallbackInfo info;
-          info.line_table = line_table_ap.get();
+          const FileSpecList &support_files = sc.comp_unit->GetSupportFiles();
+          ParseDWARFLineTableCallbackInfo info{line_table_ap.get(), nullptr, 0,
+                                               support_files};
 
           /*
            * MIPS:
@@ -1067,10 +1083,15 @@
             break;
           }
 
+          const DWARFDataExtractor &debug_line_data = get_debug_line_data();
+          lldb::offset_t data_end = debug_line_data.GetByteSize();
           lldb::offset_t offset = cu_line_offset;
-          DWARFDebugLine::ParseStatementTable(get_debug_line_data(), &offset,
-                                              ParseDWARFLineTableCallback,
-                                              &info);
+
+          do {
+            DWARFDebugLine::ParseStatementTable(
+                debug_line_data, &offset, ParseDWARFLineTableCallback, &info);
+          } while (offset < data_end);
+
           SymbolFileDWARFDebugMap *debug_map_symfile = GetDebugMapSymfile();
           if (debug_map_symfile) {
             // We have an object file that has a line table with addresses that