Update dwarf_info (#13401)

Author: jonathanmetzman

infra/base-images/base-builder/indexer/dwarf_info.py

@@ -22,6 +22,10 @@
 from absl import logging
 from elftools.elf import elffile
 
+_IGNORED_UNIT_TYPES = ("DW_UT_type", "DW_UT_split_type")
+
+# yapf: disable
+
 
 @dataclasses.dataclass
 class CompilationUnit:
@@ -45,7 +49,8 @@ class CompilationUnit:
 
 
 def get_all_compilation_units(
-    elf_file_path: os.PathLike[str],) -> list[CompilationUnit]:
+    elf_file_path: os.PathLike[str],
+) -> list[CompilationUnit]:
   """Parses compilation units from an ELF file.
 
   Args:
@@ -62,20 +67,33 @@ def get_all_compilation_units(
       return []
     dwarf_info = elf_file.get_dwarf_info()
     for compilation_unit in dwarf_info.iter_CUs():
-      # Only compile and partial unit headers will be followed by a
-      # DW_TAG_compile_unit or DW_TAG_partial entry with the expected
-      # attributes.
-      if compilation_unit.header.unit_type not in (
+      if compilation_unit.header.version < 5:
+        # Only DWARF5 has a unit_type field in the header.
+        # For older versions, we do a best effort approach.
+        logging.warning(
+            "[!] Compilation Unit with unsupported DWARF version %d",
+            compilation_unit.header.version,
+        )
+      elif compilation_unit.header.unit_type in _IGNORED_UNIT_TYPES:
+        # Type units are not interesting for us.
+        continue
+      elif compilation_unit.header.unit_type not in (
           "DW_UT_compile",
           "DW_UT_partial",
       ):
-        continue
+        raise ValueError(
+            "Unsupported DWARF compilation unit type"
+            f" {compilation_unit.header.unit_type}"
+        )
 
       top_debug_info_entry = compilation_unit.get_top_DIE()
       if top_debug_info_entry.tag != "DW_TAG_compile_unit":
         logging.error("Top DIE is not a full compile unit")
-      producer = top_debug_info_entry.attributes["DW_AT_producer"].value.decode(
-      )
+
+      producer = top_debug_info_entry.attributes[
+          "DW_AT_producer"
+      ].value.decode()
+
       name = top_debug_info_entry.attributes["DW_AT_name"].value.decode()
       language = top_debug_info_entry.attributes["DW_AT_language"].value
       compdir = top_debug_info_entry.attributes["DW_AT_comp_dir"].value.decode()
@@ -85,12 +103,14 @@ def get_all_compilation_units(
       apple_flags = None
       if top_debug_info_entry.attributes.get("DW_AT_APPLE_flags", None):
         apple_flags = top_debug_info_entry.attributes[
-            "DW_AT_APPLE_flags"].value.decode()
+            "DW_AT_APPLE_flags"
+        ].value.decode()
 
       isysroot = None
       if top_debug_info_entry.attributes.get("DW_AT_LLVM_isysroot", None):
         isysroot = top_debug_info_entry.attributes[
-            "DW_AT_LLVM_isysroot"].value.decode()
+            "DW_AT_LLVM_isysroot"
+        ].value.decode()
 
       result.append(
           CompilationUnit(
@@ -100,7 +120,8 @@ def get_all_compilation_units(
               language=language,
               apple_flags=apple_flags,
               isysroot=isysroot,
-          ))
+          )
+      )
   return result