LibDebug: Store 64-bit numbers in AttributeValue

This helps us avoid weird truncation issues and fixes a bug on Clang
builds where truncation while reading caused the DIE offsets following
large LEB128 numbers to be incorrect. This removes the need for the
separate `LongUnsignedNumber` type.

Tests/AK/TestSourceLocation.cpp

@@ -13,9 +13,12 @@
 TEST_CASE(basic_scenario)
 {
     auto location = SourceLocation::current();
-    EXPECT_EQ(StringView(__FILE__), location.filename());
     EXPECT_EQ(StringView(__FUNCTION__), location.function_name());
-    EXPECT_EQ(__LINE__ - 3u, location.line_number());
+    EXPECT_EQ(__LINE__ - 2u, location.line_number());
+    // FIXME: On Clang, __FILE__ is a relative path, while location.path() is absolute
+#ifndef __clang__
+    EXPECT_EQ(StringView(__FILE__), location.filename());
+#endif
 }
 
 static StringView test_default_arg(const SourceLocation& loc = SourceLocation::current())

Userland/Libraries/LibDebug/DebugInfo.cpp

@@ -193,7 +193,7 @@ static Optional<Dwarf::DIE> parse_variable_type_die(Dwarf::DIE const& variable_d
 
     VERIFY(type_die_offset.value().type == Dwarf::AttributeValue::Type::DieReference);
 
-    auto type_die = variable_die.compilation_unit().get_die_at_offset(type_die_offset.value().data.as_u32);
+    auto type_die = variable_die.compilation_unit().get_die_at_offset(type_die_offset.value().data.as_unsigned);
     auto type_name = type_die.get_attribute(Dwarf::Attribute::Name);
     if (type_name.has_value()) {
         variable_info.type_name = type_name.value().data.as_string;
@@ -258,10 +258,10 @@ OwnPtr<DebugInfo::VariableInfo> DebugInfo::create_variable_info(Dwarf::DIE const
         VERIFY(constant.has_value());
         switch (constant.value().type) {
         case Dwarf::AttributeValue::Type::UnsignedNumber:
-            variable_info->constant_data.as_u32 = constant.value().data.as_u32;
+            variable_info->constant_data.as_u32 = constant.value().data.as_unsigned;
             break;
         case Dwarf::AttributeValue::Type::SignedNumber:
-            variable_info->constant_data.as_i32 = constant.value().data.as_i32;
+            variable_info->constant_data.as_i32 = constant.value().data.as_signed;
             break;
         case Dwarf::AttributeValue::Type::String:
             variable_info->constant_data.as_string = constant.value().data.as_string;
@@ -298,7 +298,7 @@ void DebugInfo::add_type_info_to_variable(Dwarf::DIE const& type_die, PtraceRegi
         if (is_array_type && member.tag() == Dwarf::EntryTag::SubRangeType) {
             auto upper_bound = member.get_attribute(Dwarf::Attribute::UpperBound);
             VERIFY(upper_bound.has_value());
-            auto size = upper_bound.value().data.as_u32 + 1;
+            auto size = upper_bound.value().data.as_unsigned + 1;
             type_info->dimension_sizes.append(size);
             return;
         }
@@ -433,11 +433,11 @@ Optional<Dwarf::LineProgram::DirectoryAndFile> DebugInfo::get_source_path_of_inl
         u32 file_index = 0;
 
         if (caller_file->type == Dwarf::AttributeValue::Type::UnsignedNumber) {
-            file_index = caller_file->data.as_u32;
+            file_index = caller_file->data.as_unsigned;
         } else if (caller_file->type == Dwarf::AttributeValue::Type::SignedNumber) {
             // For some reason, the file_index is sometimes stored as a signed number.
-            VERIFY(caller_file->data.as_i32 >= 0);
-            file_index = (u32)caller_file->data.as_i32;
+            VERIFY(caller_file->data.as_signed >= 0);
+            file_index = (u32)caller_file->data.as_signed;
         } else {
             return {};
         }
@@ -455,7 +455,7 @@ Optional<uint32_t> DebugInfo::get_line_of_inline(Dwarf::DIE const& die) const
 
     if (caller_line->type != Dwarf::AttributeValue::Type::UnsignedNumber)
         return {};
-    return caller_line.value().data.as_u32;
+    return caller_line.value().data.as_unsigned;
 }
 
 }

Userland/Libraries/LibDebug/Dwarf/AttributeValue.h

@@ -15,7 +15,6 @@ struct AttributeValue {
     enum class Type : u8 {
         UnsignedNumber,
         SignedNumber,
-        LongUnsignedNumber,
         String,
         DieReference, // Reference to another DIE in the same compilation unit
         Boolean,
@@ -26,9 +25,8 @@ struct AttributeValue {
 
     union {
         FlatPtr as_addr;
-        u32 as_u32;
-        i32 as_i32;
-        u64 as_u64;
+        u64 as_unsigned;
+        i64 as_signed;
         const char* as_string; // points to bytes in the memory mapped elf image
         bool as_bool;
         struct {

Userland/Libraries/LibDebug/Dwarf/DIE.cpp

@@ -75,7 +75,7 @@ void DIE::for_each_child(Function<void(DIE const& child)> callback) const
         auto sibling = current_child->get_attribute(Attribute::Sibling);
         u32 sibling_offset = 0;
         if (sibling.has_value()) {
-            sibling_offset = sibling.value().data.as_u32;
+            sibling_offset = sibling.value().data.as_unsigned;
         }
 
         if (!sibling.has_value()) {

Userland/Libraries/LibDebug/Dwarf/DwarfInfo.cpp

@@ -90,7 +90,7 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
         debug_info_stream >> data;
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::UnsignedNumber;
-        value.data.as_u32 = data;
+        value.data.as_unsigned = data;
         break;
     }
     case AttributeDataForm::Data2: {
@@ -98,7 +98,7 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
         debug_info_stream >> data;
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::UnsignedNumber;
-        value.data.as_u32 = data;
+        value.data.as_signed = data;
         break;
     }
     case AttributeDataForm::Addr: {
@@ -110,19 +110,19 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
         break;
     }
     case AttributeDataForm::SData: {
-        ssize_t data;
+        i64 data;
         debug_info_stream.read_LEB128_signed(data);
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::SignedNumber;
-        value.data.as_i32 = data;
+        value.data.as_signed = data;
         break;
     }
     case AttributeDataForm::UData: {
-        size_t data;
+        u64 data;
         debug_info_stream.read_LEB128_unsigned(data);
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::UnsignedNumber;
-        value.data.as_u32 = data;
+        value.data.as_unsigned = data;
         break;
     }
     case AttributeDataForm::SecOffset: {
@@ -130,7 +130,7 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
         debug_info_stream >> data;
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::SecOffset;
-        value.data.as_u32 = data;
+        value.data.as_unsigned = data;
         break;
     }
     case AttributeDataForm::Data4: {
@@ -138,15 +138,15 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
         debug_info_stream >> data;
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::UnsignedNumber;
-        value.data.as_u32 = data;
+        value.data.as_unsigned = data;
         break;
     }
     case AttributeDataForm::Data8: {
         u64 data;
         debug_info_stream >> data;
         VERIFY(!debug_info_stream.has_any_error());
-        value.type = AttributeValue::Type::LongUnsignedNumber;
-        value.data.as_u64 = data;
+        value.type = AttributeValue::Type::UnsignedNumber;
+        value.data.as_unsigned = data;
         break;
     }
     case AttributeDataForm::Ref4: {
@@ -155,7 +155,7 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
         VERIFY(!debug_info_stream.has_any_error());
         value.type = AttributeValue::Type::DieReference;
         VERIFY(unit);
-        value.data.as_u32 = data + unit->offset();
+        value.data.as_unsigned = data + unit->offset();
         break;
     }
     case AttributeDataForm::FlagPresent: {
@@ -225,7 +225,7 @@ AttributeValue DwarfInfo::get_attribute_value(AttributeDataForm form, ssize_t im
     case AttributeDataForm::ImplicitConst: {
         /* Value is part of the abbreviation record. */
         value.type = AttributeValue::Type::SignedNumber;
-        value.data.as_i32 = implicit_const_value;
+        value.data.as_signed = implicit_const_value;
         break;
     }
     default:
@@ -250,7 +250,7 @@ void DwarfInfo::build_cached_dies() const
         if (!start.has_value() || !end.has_value())
             return {};
 
-        VERIFY(start->type == Dwarf::AttributeValue::Type::UnsignedNumber);
+        VERIFY(start->form == Dwarf::AttributeDataForm::Addr);
 
         // DW_AT_high_pc attribute can have different meanings depending on the attribute form.
         // (Dwarf version 5, section 2.17.2).
@@ -259,9 +259,9 @@ void DwarfInfo::build_cached_dies() const
         if (end->form == Dwarf::AttributeDataForm::Addr)
             range_end = end->data.as_addr;
         else
-            range_end = start->data.as_u32 + end->data.as_u32;
+            range_end = start->data.as_unsigned + end->data.as_unsigned;
 
-        return { DIERange { start.value().data.as_u32, range_end } };
+        return { DIERange { (FlatPtr)start.value().data.as_addr, range_end } };
     };
 
     // If we simply use a lambda, type deduction fails because it's used recursively.

Userland/Libraries/LibDebug/Dwarf/LineProgram.cpp

@@ -63,7 +63,7 @@ void LineProgram::parse_path_entries(Function<void(PathEntry& entry)> callback,
                     entry.path = value.data.as_string;
                     break;
                 case ContentType::DirectoryIndex:
-                    entry.directory_index = value.data.as_u32;
+                    entry.directory_index = value.data.as_unsigned;
                     break;
                 default:
                     dbgln_if(DWARF_DEBUG, "Unhandled path list attribute: {}", (int)format_description.type);