DWARF wrappers: add DWARF getter for mandatory attributes

It is a common pattern in DWARF processor to get an optional value and
check for its presence. This helper checks for the presence and directly
returns the underlying value, eliminating the need to check for presence
check by the user.

PiperOrigin-RevId: 613907941
Change-Id: Idddd9694f665935fc2b12fce161d85ab3250e324

2 files changed, 10 insertions, 0 deletions

diff --git a/dwarf_wrappers.cc b/dwarf_wrappers.cc
index d13d7b8..04e5897 100644
--- a/dwarf_wrappers.cc
+++ b/dwarf_wrappers.cc
@@ -274,6 +274,15 @@ std::optional<uint64_t> Entry::MaybeGetUnsignedConstant(uint32_t attribute) {
   return value;
 }
 
+uint64_t Entry::MustGetUnsignedConstant(uint32_t attribute) {
+  auto maybe_constant = MaybeGetUnsignedConstant(attribute);
+  if (!maybe_constant) {
+    Die() << "DWARF entry <" << Hex(GetOffset()) << "> with tag " << GetTag()
+          << " is missing attribute " << Hex(attribute);
+  }
+  return maybe_constant.value();
+}
+
 bool Entry::GetFlag(uint32_t attribute) {
   bool result = false;
   auto dwarf_attribute = (attribute == DW_AT_declaration)
diff --git a/dwarf_wrappers.h b/dwarf_wrappers.h
index d0daa5c..c584345 100644
--- a/dwarf_wrappers.h
+++ b/dwarf_wrappers.h
@@ -71,6 +71,7 @@ struct Entry {
   std::optional<std::string> MaybeGetString(uint32_t attribute);
   std::optional<std::string> MaybeGetDirectString(uint32_t attribute);
   std::optional<uint64_t> MaybeGetUnsignedConstant(uint32_t attribute);
+  uint64_t MustGetUnsignedConstant(uint32_t attribute);
   bool GetFlag(uint32_t attribute);
   std::optional<Entry> MaybeGetReference(uint32_t attribute);
   std::optional<Address> MaybeGetAddress(uint32_t attribute);