[Lldb-commits] [PATCH] D81589: [lldb/SymbolFile] Don't parse the whole line table for the support files (WIP)

[Jonas Devlieghere via Phabricator via lldb-commits]

JDevlieghere created this revision.
Herald added a reviewer: jdoerfert.
Herald added a subscriber: sstefan1.
JDevlieghere updated this revision to Diff 269893.

https://reviews.llvm.org/D81589

Files:
  lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp


Index: lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -174,6 +174,33 @@
   return *line_table;
 }
 
+static bool ParseLLVMLineTablePrologue(lldb_private::DWARFContext &context,
+                                       llvm::DWARFDebugLine::Prologue &prologue,
+                                       dw_offset_t line_offset,
+                                       dw_offset_t unit_offset) {
+  Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
+  bool success = true;
+  llvm::DWARFDataExtractor data = context.getOrLoadLineData().GetAsLLVM();
+  llvm::DWARFContext &ctx = context.GetAsLLVM();
+  uint64_t offset = line_offset;
+  llvm::Error error = prologue.parse(
+      data, &offset,
+      [&](llvm::Error e) {
+        success = false;
+        LLDB_LOG_ERROR(log, std::move(e),
+                       "SymbolFileDWARF::ParseSupportFiles failed to parse "
+                       "line table prologue");
+      },
+      ctx, nullptr);
+  if (error) {
+    LLDB_LOG_ERROR(log, std::move(error),
+                   "SymbolFileDWARF::ParseSupportFiles failed to parse line "
+                   "table prologue");
+    return false;
+  }
+  return success;
+}
+
 static llvm::Optional<std::string>
 GetFileByIndex(const llvm::DWARFDebugLine::Prologue &prologue, size_t idx,
                llvm::StringRef compile_dir, FileSpec::Style style) {
@@ -854,8 +881,29 @@
 
 bool SymbolFileDWARF::ParseSupportFiles(CompileUnit &comp_unit,
                                         FileSpecList &support_files) {
-  if (!comp_unit.GetLineTable())
-    ParseLineTable(comp_unit);
+  std::lock_guard<std::recursive_mutex> guard(GetModuleMutex());
+  DWARFUnit *dwarf_cu = GetDWARFCompileUnit(&comp_unit);
+  if (!dwarf_cu)
+    return false;
+
+  const DWARFBaseDIE dwarf_cu_die = dwarf_cu->GetUnitDIEOnly();
+  if (!dwarf_cu_die)
+    return false;
+
+  const dw_offset_t cu_line_offset = dwarf_cu_die.GetAttributeValueAsUnsigned(
+      DW_AT_stmt_list, DW_INVALID_OFFSET);
+  if (cu_line_offset == DW_INVALID_OFFSET)
+    return false;
+
+  llvm::DWARFDebugLine::Prologue prologue;
+  if (!ParseLLVMLineTablePrologue(m_context, prologue, cu_line_offset,
+                                  dwarf_cu->GetOffset()))
+    return false;
+
+  comp_unit.SetSupportFiles(ParseSupportFilesFromPrologue(
+      comp_unit.GetModule(), prologue, dwarf_cu->GetPathStyle(),
+      dwarf_cu->GetCompilationDirectory().GetCString()));
+
   return true;
 }
 
@@ -1024,10 +1072,6 @@
     comp_unit.SetLineTable(line_table_up.release());
   }
 
-  comp_unit.SetSupportFiles(ParseSupportFilesFromPrologue(
-      comp_unit.GetModule(), line_table->Prologue, dwarf_cu->GetPathStyle(),
-      dwarf_cu->GetCompilationDirectory().GetCString()));
-
   return true;
 }
 


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