[Lldb-commits] [PATCH] D71770: [lldb] Don't process symlinks deep inside DWARFUnit

[Pavel Labath via Phabricator via lldb-commits]

labath created this revision.
labath added reviewers: JDevlieghere, aprantl, clayborg.
Herald added a reviewer: jdoerfert.
Herald added a project: LLDB.

This code is handling debug info paths starting with /proc/self/cwd,
which is one of the mechanisms people use to obtain "relocatable" debug
info (the idea being that one starts the debugger with an appropriate
cwd and things "just work").

Instead of resolving the symlinks inside DWARFUnit, we can do the same
thing more elegantly by hooking into the existing Module path remapping
code. Since llvm::DWARFUnit does not support any similar functionality,
doing things this way is also a step towards unifying llvm and lldb
dwarf parsers.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71770

Files:
  lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
  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
@@ -453,6 +453,17 @@
 void SymbolFileDWARF::InitializeObject() {
   Log *log = LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_INFO);
 
+  Module &module = *GetObjectFile()->GetModule();
+
+  for (const FileSpec &symlink : GetSymlinkPaths()) {
+    FileSpec resolved;
+    Status status = FileSystem::Instance().Readlink(symlink, resolved);
+    if (status.Success())
+      module.GetSourceMappingList().Append(ConstString(symlink.GetPath()),
+                                           ConstString(resolved.GetPath()),
+                                           /*notify=*/true);
+  }
+
   if (!GetGlobalPluginProperties()->IgnoreFileIndexes()) {
     DWARFDataExtractor apple_names, apple_namespaces, apple_types, apple_objc;
     LoadSectionData(eSectionTypeDWARFAppleNames, apple_names);
Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -751,25 +751,6 @@
   return path;
 }
 
-static FileSpec resolveCompDir(const FileSpec &path) {
-  bool is_symlink = SymbolFileDWARF::GetSymlinkPaths().FindFileIndex(
-                        0, path, /*full*/ true) != UINT32_MAX;
-
-  if (!is_symlink)
-    return path;
-
-  namespace fs = llvm::sys::fs;
-  if (fs::get_file_type(path.GetPath(), false) != fs::file_type::symlink_file)
-    return path;
-
-  FileSpec resolved_symlink;
-  const auto error = FileSystem::Instance().Readlink(path, resolved_symlink);
-  if (error.Success())
-    return resolved_symlink;
-
-  return path;
-}
-
 void DWARFUnit::ComputeCompDirAndGuessPathStyle() {
   m_comp_dir = FileSpec();
   const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
@@ -781,7 +762,7 @@
   if (!comp_dir.empty()) {
     FileSpec::Style comp_dir_style =
         FileSpec::GuessPathStyle(comp_dir).getValueOr(FileSpec::Style::native);
-    m_comp_dir = resolveCompDir(FileSpec(comp_dir, comp_dir_style));
+    m_comp_dir = FileSpec(comp_dir, comp_dir_style);
   } else {
     // Try to detect the style based on the DW_AT_name attribute, but just store
     // the detected style in the m_comp_dir field.


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