LibDebug: Add support for the various DW_FORM_block types

This fixes #2885.

Libraries/LibDebug/DebugInfo.cpp

@@ -204,7 +204,7 @@ static void parse_variable_location(const Dwarf::DIE& variable_die, DebugInfo::V
         }
 
         if (location_info.value().type == Dwarf::DIE::AttributeValue::Type::DwarfExpression) {
-            auto expression_bytes = ByteBuffer::wrap(location_info.value().data.as_dwarf_expression.bytes, location_info.value().data.as_dwarf_expression.length);
+            auto expression_bytes = ByteBuffer::wrap(location_info.value().data.as_raw_bytes.bytes, location_info.value().data.as_raw_bytes.length);
             auto value = Dwarf::Expression::evaluate(expression_bytes, regs);
 
             if (value.type != Dwarf::Expression::Type::None) {

Libraries/LibDebug/Dwarf/DIE.cpp

@@ -63,6 +63,15 @@ DIE::AttributeValue DIE::get_attribute_value(AttributeDataForm form,
     BufferStream& debug_info_stream) const
 {
     AttributeValue value;
+
+    auto assign_raw_bytes_value = [&](size_t length) {
+        value.data.as_raw_bytes.length = length;
+        value.data.as_raw_bytes.bytes = reinterpret_cast<const u8*>(m_compilation_unit.dwarf_info().debug_info_data().data()
+            + debug_info_stream.offset());
+
+        debug_info_stream.advance(length);
+    };
+
     switch (form) {
     case AttributeDataForm::StringPointer: {
         u32 offset = 0;
@@ -124,11 +133,7 @@ DIE::AttributeValue DIE::get_attribute_value(AttributeDataForm form,
         size_t length = 0;
         debug_info_stream.read_LEB128_unsigned(length);
         value.type = AttributeValue::Type::DwarfExpression;
-
+        assign_raw_bytes_value(length);
-        value.data.as_dwarf_expression.length = length;
-        value.data.as_dwarf_expression.bytes = reinterpret_cast<const u8*>(m_compilation_unit.dwarf_info().debug_info_data().data() + debug_info_stream.offset());
-
-        debug_info_stream.advance(length);
         break;
     }
     case AttributeDataForm::String: {
@@ -139,6 +144,34 @@ DIE::AttributeValue DIE::get_attribute_value(AttributeDataForm form,
         value.data.as_string = reinterpret_cast<const char*>(str_offset + m_compilation_unit.dwarf_info().debug_info_data().data());
         break;
     }
+    case AttributeDataForm::Block1: {
+        value.type = AttributeValue::Type::RawBytes;
+        u8 length = 0;
+        debug_info_stream >> length;
+        assign_raw_bytes_value(length);
+        break;
+    }
+    case AttributeDataForm::Block2: {
+        value.type = AttributeValue::Type::RawBytes;
+        u16 length = 0;
+        debug_info_stream >> length;
+        assign_raw_bytes_value(length);
+        break;
+    }
+    case AttributeDataForm::Block4: {
+        value.type = AttributeValue::Type::RawBytes;
+        u32 length = 0;
+        debug_info_stream >> length;
+        assign_raw_bytes_value(length);
+        break;
+    }
+    case AttributeDataForm::Block: {
+        value.type = AttributeValue::Type::RawBytes;
+        size_t length = 0;
+        debug_info_stream.read_LEB128_unsigned(length);
+        assign_raw_bytes_value(length);
+        break;
+    }
     default:
         dbg() << "Unimplemented AttributeDataForm: " << (u32)form;
         ASSERT_NOT_REACHED();

Libraries/LibDebug/Dwarf/DIE.h

@@ -52,6 +52,7 @@ public:
             Boolean,
             DwarfExpression,
             SecOffset,
+            RawBytes,
         } type;
 
         union {
@@ -62,7 +63,7 @@ public:
             struct {
                 u32 length;
                 const u8* bytes; // points to bytes in the memory mapped elf image
-            } as_dwarf_expression;
+            } as_raw_bytes;
         } data {};
     };