Compare cases¶
Cases exercising an old-vs-new comparison — abicheck compare, the default operation.
198 case(s). ← back to all examples
| Case | Title | Verdict | Category |
|---|---|---|---|
| case01_symbol_removal | Symbol Removal | 🔴 BREAKING | Breaking |
| case02_param_type_change | Parameter Type Change | 🔴 BREAKING | Breaking |
| case03_compat_addition | Compatible Addition (New Export) | 🟢 COMPATIBLE | Addition (Compatible) |
| case04_no_change | No Change | ✅ NO_CHANGE | No Change |
| case05_soname | Missing SONAME | 🟢 COMPATIBLE | Quality (Compatible) |
| case06_visibility | Symbol Visibility Leak | 🔴 BREAKING | Breaking |
| case07_struct_layout | Struct Layout Change | 🔴 BREAKING | Breaking |
| case08_enum_value_change | Enum Value Change | 🔴 BREAKING | Breaking |
| case09_cpp_vtable | C++ Vtable Change | 🔴 BREAKING | Breaking |
| case10_return_type | Return Type Change | 🔴 BREAKING | Breaking |
| case11_global_var_type | Global Variable Type Change | 🔴 BREAKING | Breaking |
| case12_function_removed | Function Removed from Shared Library | 🔴 BREAKING | Breaking |
| case13_symbol_versioning | Symbol Versioning Script | 🟢 COMPATIBLE | Quality (Compatible) |
| case14_cpp_class_size | C++ Class Size Change | 🔴 BREAKING | Breaking |
| case15_noexcept_change | noexcept Removed |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case16_inline_to_non_inline | Inline → Non-inline (ODR / Symbol Appearance) | 🟢 COMPATIBLE | Addition (Compatible) |
| case17_template_abi | Template Instantiation ABI Change | 🔴 BREAKING | Breaking |
| case18_dependency_leak | Dependency ABI Leak | 🔴 BREAKING | Breaking |
| case19_enum_member_removed | Enum Member Removed | 🔴 BREAKING | Breaking |
| case20_enum_member_value_changed | Enum Member Value Changed | 🔴 BREAKING | Breaking |
| case21_method_became_static | Method Became Static | 🔴 BREAKING | Breaking |
| case22_method_const_changed | Method Const Qualifier Changed | 🔴 BREAKING | Breaking |
| case23_pure_virtual_added | Virtual Method Became Pure Virtual | 🔴 BREAKING | Breaking |
| case24_union_field_removed | Union Field Removed | 🔴 BREAKING | Breaking |
| case25_enum_member_added | Enum Member Added | 🟢 COMPATIBLE | Addition (Compatible) |
| case26_union_field_added | Union Field Added (Size Grows) | 🔴 BREAKING | Breaking |
| case26b_union_field_added_compatible | Union Field Added (No Size Change) | 🟢 COMPATIBLE | Addition (Compatible) |
| case27_symbol_binding_weakened | Symbol Binding Weakened (GLOBAL → WEAK) | 🟢 COMPATIBLE | Quality (Compatible) |
| case28_typedef_opaque | Typedef and Opaque Type Changes | 🔴 BREAKING | Breaking |
| case29_ifunc_transition | GNU IFUNC Transition | 🟢 COMPATIBLE | Quality (Compatible) |
| case30_field_qualifiers | Field Qualifier Changes (const, volatile) | 🔴 BREAKING | Breaking |
| case31_enum_rename | Enum Member Rename | 🟠 API_BREAK | API Break |
| case32_param_defaults | Parameter Default Value Changes (C++) | 🟠 API_BREAK | API Break |
| case33_pointer_level | Pointer Level Change | 🔴 BREAKING | Breaking |
| case34_access_level | Access Level Changed | 🟠 API_BREAK | API Break |
| case35_field_rename | Field Rename | 🟠 API_BREAK | API Break |
| case36_anon_struct | Anonymous Struct/Union Change | 🔴 BREAKING | Breaking |
| case37_base_class | Base Class Changes | 🔴 BREAKING | Breaking |
| case38_virtual_methods | Virtual Method Changes | 🔴 BREAKING | Breaking |
| case39_var_const | Variable Const Change | 🔴 BREAKING | Breaking |
| case40_field_layout | Field Layout Changes | 🔴 BREAKING | Breaking |
| case41_type_changes | Type-Level Changes | 🔴 BREAKING | Breaking |
| case42_type_alignment_changed | Type Alignment Changed (standalone alignas) | 🔴 BREAKING | Breaking |
| case43_base_class_member_added | Base Class Member Added | 🔴 BREAKING | Breaking |
| case44_cyclic_type_member_added | Cyclic Type Member Added | 🔴 BREAKING | Breaking |
| case45_multi_dim_array_change | Multi-Dimensional Array Element Type Change | 🔴 BREAKING | Breaking |
| case46_pointer_chain_type_change | Pointer Chain Type Change | 🔴 BREAKING | Breaking |
| case47_inline_to_outlined | Inline Method Moved Out-of-Line | 🟢 COMPATIBLE | Addition (Compatible) |
| case48_leaf_struct_through_pointer | Leaf Struct Change Propagated Through Pointer | 🔴 BREAKING | Breaking |
| case49_executable_stack | Executable Stack (GNU_STACK RWX) | 🟢 COMPATIBLE | Quality (Compatible) |
| case50_soname_inconsistent | SONAME Inconsistent (Wrong Major Version) | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case51_protected_visibility | Protected Visibility (DEFAULT to PROTECTED) | 🟢 COMPATIBLE | Quality (Compatible) |
| case52_rpath_leak | RPATH Leak (Hardcoded Build Directory) | 🟢 COMPATIBLE | Quality (Compatible) |
| case53_namespace_pollution | Namespace Pollution (Generic Symbol Names) | 🔴 BREAKING | Breaking |
| case54_used_reserved_field | Used Reserved Field | 🟢 COMPATIBLE | Quality (Compatible) |
| case55_type_kind_changed | Type Kind Changed (struct → union) | 🔴 BREAKING | Breaking |
| case56_struct_packing_changed | Struct Packing Changed (pragma pack) | 🔴 BREAKING | Breaking |
| case57_enum_underlying_size_changed | Enum Underlying Size Changed | 🔴 BREAKING | Breaking |
| case58_var_removed | Global Variable Removed | 🔴 BREAKING | Breaking |
| case59_func_became_inline | Function Became Inline (outlined → inline) | 🔴 BREAKING | Breaking |
| case60_base_class_position_changed | Base Class Position Changed (Multiple Inheritance Reorder) | 🔴 BREAKING | Breaking |
| case61_var_added | Global Variable Added | 🟢 COMPATIBLE | Addition (Compatible) |
| case62_type_field_added_compatible | Type Field Added (Compatible — Opaque Struct) | 🟢 COMPATIBLE | Addition (Compatible) |
| case63_bitfield_changed | Bitfield Width Changed | 🔴 BREAKING | Breaking |
| case64_calling_convention_changed | Calling Convention Changed | 🔴 BREAKING | Breaking |
| case65_symbol_version_removed | Symbol Version Removed | 🔴 BREAKING | Breaking |
| case66_language_linkage_changed | Language Linkage Changed (extern "C" removed) | 🔴 BREAKING | Breaking |
| case67_tls_var_size_changed | TLS Variable Size Changed | 🔴 BREAKING | Breaking |
| case68_virtual_method_added | Virtual Method Added to Non-Virtual Class | 🔴 BREAKING | Breaking |
| case69_trivial_to_nontrivial | Trivially Copyable to Non-Trivial (Calling Convention Change) | 🔴 BREAKING | Breaking |
| case70_flexible_array_member_changed | Flexible Array Member Element Type Changed | 🔴 BREAKING | Breaking |
| case71_inline_namespace_moved | Inline Namespace Moved | 🔴 BREAKING | Breaking |
| case72_covariant_return_changed | Covariant Return Type Changed | 🔴 BREAKING | Breaking |
| case73_typedef_underlying_changed | Typedef Underlying Type Changed | 🔴 BREAKING | Breaking |
| case74_detail_base_class_changed | Internal detail:: base class layout change leaks via public API |
🔴 BREAKING | Breaking |
| case75_detail_embedded_by_value | Internal detail:: Struct Embedded by Value |
🔴 BREAKING | Breaking |
| case76_detail_pimpl_vtable_changed | Internal detail:: Polymorphic Base Vtable Change |
🔴 BREAKING | Breaking |
| case77_detail_templated_base_changed | Internal detail:: Templated Base Class Layout Change |
🔴 BREAKING | Breaking |
| case78_task_arena_attach_tag | task_arena::attach Tag Type Replaces Enum |
🔴 BREAKING | Breaking |
| case79_missing_template_instantiation | Missing Template Instantiation in Shipped Binary | 🔴 BREAKING | Breaking |
| case80_pimpl_shared_to_unique | Pimpl Alias Switched from shared_ptr to unique_ptr |
🔴 BREAKING | Breaking |
| case81_serialization_tag_reassigned | Serialization Tag ID Reassigned | 🔴 BREAKING | Breaking |
| case82_sycl_overload_set_removed | SYCL Overload Set Removed (DPC++ Build Withdrawn) | 🔴 BREAKING | Breaking |
| case83_cpu_dispatch_isa_dropped | CPU-dispatch ISA family dropped | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case84_bundle_soname_skew | Multi-Library Bundle SONAME Skew | 🔴 BREAKING | Bundle (Multi-library) |
| case85_internal_template_signature_changed | Internal Template Signature Changed | 🔴 BREAKING | Breaking |
| case86_tag_struct_renamed | Tag Struct Renamed (empty class re-mangling) | 🔴 BREAKING | Breaking |
| case87_default_template_arg_changed | Default Template Argument Changed | 🔴 BREAKING | Breaking |
| case88_cpo_kind_changed | CPO kind changed (BREAKING) | 🔴 BREAKING | Breaking |
| case89_inline_accessor_renamed_pimpl_member | Inline Accessor References Renamed Pimpl Member | 🔴 BREAKING | Breaking |
| case90_bundle_intra_dep_removed | Bundle — Intra-Bundle Removed Symbol | 🔴 BREAKING | Bundle (Multi-library) |
| case91_bundle_intra_signature_drift | Bundle — Intra-Bundle extern-C Signature Drift | 🔴 BREAKING | Bundle (Multi-library) |
| case92_bundle_provider_changed | Bundle — Symbol Provider Migration | 🟡 COMPATIBLE_WITH_RISK | Bundle (Multi-library) |
| case93_bundle_manifest_drift | Bundle — Instantiation Manifest Drift | 🔴 BREAKING | Bundle (Multi-library) |
| case94_empty_tag_gained_state | Empty Tag Gained State | 🔴 BREAKING | Breaking |
| case95_allocator_nested_typedef_removed | Allocator Nested-Typedef Removed | 🔴 BREAKING | Breaking |
| case96_hidden_friend_removed | Hidden Friend Operator Removed | 🟠 API_BREAK | API Break |
| case97_api_depends_on_consumer_env | API Depends on Consumer Environment | 🔴 BREAKING | Breaking |
| case98_cxx_standard_floor_raised | C++ Standard Floor Raised | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case99_experimental_graduated | Experimental to Stable Graduation (Compatible) | 🟢 COMPATIBLE | Addition (Compatible) |
| case100_experimental_removed_without_replacement | Experimental Declaration Removed Without Replacement | 🔴 BREAKING | Breaking |
| case101_inline_namespace_version_bumped | Inline Namespace Version Bumped | 🔴 BREAKING | Breaking |
| case102_frozen_runtime_signature_changed | Frozen Runtime Signature Changed | 🔴 BREAKING | Breaking |
| case103_toolchain_flag_drift | Toolchain Flag Drift | 🟢 COMPATIBLE | Quality (Compatible) |
| case104_glibcxx_dual_abi_flip | libstdc++ Dual-ABI Flip | 🔴 BREAKING | Breaking |
| case105_concept_tightening | Concept Tightening (C++20) | 🟠 API_BREAK | API Break |
| case106_ctor_became_explicit | Conversion Operator Became explicit |
🟠 API_BREAK | API Break |
| case107_task_scheduler_init_removed | task_scheduler_init Removed (historical ABI break) |
🔴 BREAKING | Breaking |
| case108_task_class_removed | task Class Removed (historical ABI break — vtable angle) |
🔴 BREAKING | Breaking |
| case109_flow_graph_policy_renames | flow::graph Policy Tag Renames | 🔴 BREAKING | Breaking |
| case110_concurrent_unordered_map_api_drift | concurrent_unordered_map API Drift | 🔴 BREAKING | Breaking |
| case111_enumerable_thread_specific_lambda_ambiguity | enumerable_thread_specific Lambda-Init Ambiguity | 🟠 API_BREAK | API Break |
| case112_lp64_ilp64 | LP64 → ILP64 Integer-Model Switch (oneMKL MKL_INT 32→64) | 🔴 BREAKING | Breaking |
| case113_abi_tag_changed | ABI-tag set change ([abi:cxx11] lost on a single symbol) | 🔴 BREAKING | Breaking |
| case114_char8t_migration | char8_t Migration (C++20 char-family → char8_t) | 🔴 BREAKING | Breaking |
| case115_bit_int_width_changed | _BitInt(N) Width Change (C23 64 → 128) | 🔴 BREAKING | Breaking |
| case116_atomic_qualifier_changed | _Atomic Qualifier Added (C11) | 🔴 BREAKING | Breaking |
| case117_no_unique_address | [[no_unique_address]] Layout Overlay (no dedicated ChangeKind) | 🔴 BREAKING | Breaking |
| case118_internal_struct_field_added_scoped | Internal Struct Gains a Field (Non-Public, Scoped) | ✅ NO_CHANGE | No Change |
| case119_internal_struct_field_removed_scoped | Internal Struct Loses a Field (Non-Public, Scoped) | ✅ NO_CHANGE | No Change |
| case120_internal_struct_reordered_scoped | Internal Struct Fields Reordered (Non-Public, Scoped) | ✅ NO_CHANGE | No Change |
| case121_kernel_btf_struct_field_added | Kernel BTF Struct Field Growth | 🔴 BREAKING | Breaking |
| case122_template_signature_uninstantiated | Uninstantiated Template Signature Change | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case123_default_argument_removed | Default Argument Removed | 🟠 API_BREAK | API Break |
| case124_header_constant_value_changed | Header Constant Value Changed | 🟠 API_BREAK | API Break |
| case125_class_became_final | Class Became final |
🟠 API_BREAK | API Break |
| case126_sycl_device_impl_ptr | SYCL device Impl Pointer — shared_ptr → Raw Pointer |
🔴 BREAKING | Breaking |
| case127_data_object_size_changed | Exported Data Object Size Changed | 🔴 BREAKING | Breaking |
| case128_symbol_binding_strengthened | Symbol Binding Strengthened (Weak → Global) | 🟢 COMPATIBLE | Quality (Compatible) |
| case129_struct_return_convention | Struct-Return Convention Change | 🔴 BREAKING | Breaking |
| case130_exceptions_mode_flip | Exceptions Mode Flip (-fno-exceptions) |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case131_rtti_mode_flip | RTTI Mode Flip (-fno-rtti) |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case132_threadsafe_statics_flip | Thread-Safe Statics Mode Flip | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case133_tls_model_flip | TLS Model Flip | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case134_relro_weakened | RELRO Weakened | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case135_stack_canary_removed | Stack Canary Removed | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case136_executable_stack_removed | Executable Stack Removed (the fix direction) | 🟢 COMPATIBLE | Quality (Compatible) |
| case137_runpath_changed | DT_RUNPATH Changed | 🟢 COMPATIBLE | Quality (Compatible) |
| case138_needed_added | DT_NEEDED Added | 🟢 COMPATIBLE | Quality (Compatible) |
| case139_symbol_version_node_removed | Symbol Version Node Removed | 🔴 BREAKING | Breaking |
| case140_empty_base_optimization_lost | Empty Base Optimization Lost (base subobject moved) | 🔴 BREAKING | Breaking |
| case141_versioned_symbol_scheme | Versioned-Symbol Scheme (library-wide rename) | 🔴 BREAKING | Breaking |
| case142_vtable_slot_count_binary_only | Vtable Slot Count Changed (detected from a stripped binary) | 🔴 BREAKING | Breaking |
| case152_enum_size_flag_flip | _enum_size_flag_flip — Enum-size flag flip (-fshort-enums) |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case153_struct_packing_flip | _struct_packing_flip — Struct-packing mode flip (-fpack-struct) |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case154_lto_mode_flip | _lto_mode_flip — LTO mode flip (-flto) |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case155_char_signedness_flip | _char_signedness_flip — Plain-char signedness flip (-fsigned-char ↔ -funsigned-char) |
🟡 COMPATIBLE_WITH_RISK | Risk |
| case156_public_macro_removed | _public_macro_removed — Public macro removed | 🟠 API_BREAK | API Break |
| case157_inline_function_removed | Inline Function Removed | 🟠 API_BREAK | API Break |
| case158_public_typedef_removed | Public Typedef Removed | 🟠 API_BREAK | API Break |
| case160_public_api_internal_dep_added | Public API Gains an Internal Dependency | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case161_target_dependency_added | New Inter-Target Build/Link Dependency | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case162_symbol_source_owner_changed | Exported Symbol's Declaring File Moved | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case163_python_kwarg_renamed | Python Keyword Argument Renamed (Stub-Only API Break) | 🟠 API_BREAK | API Break |
| case164_preproc_conditional_field | Preprocessor-Conditional Field (Build-Context False Positive) | ✅ NO_CHANGE | No Change |
| case165_polymorphic_nonvirtual_dtor | Polymorphic Type Without a Virtual Destructor (New Anti-Pattern) | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case166_ref_qualifier_added | Method Ref-Qualifier Added (str() → str() &) |
🔴 BREAKING | Breaking |
| case167_base_became_virtual | Base Class Became Virtual (: public Device → : public virtual Device) |
🔴 BREAKING | Breaking |
| case168_virtual_method_devirtualized | Virtual Method Devirtualized (flush() leaves the vtable) |
🔴 BREAKING | Breaking |
| case169_overload_added | Overload Added to a Previously Unique Function | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case170_env_runtime_floor_raised | Runtime Floor Raised (glibc Relink Drift) | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case171_static_tls_introduced | Static TLS Introduced | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case172_vtable_thunk_offset_changed | Vtable Thunk Offset Changed (detected from a stripped binary) | 🔴 BREAKING | Breaking |
| case173_vtt_slot_count_changed | VTT Slot Count Changed (detected from a stripped binary) | 🔴 BREAKING | Breaking |
| case174_secondary_vtable_group_changed | Secondary Vtable Group Changed | 🔴 BREAKING | Breaking |
| case175_kabi_crc_changed | kABI CRC Changed | 🔴 BREAKING | Breaking |
| case176_kabi_symbol_namespace_changed | kABI Export Namespace Changed | 🔴 BREAKING | Breaking |
| case177_long_double_abi_changed | long double ABI Changed | 🔴 BREAKING | Breaking |
| case178_unnamed_type_in_public_abi | Unnamed Type Leaks Into the Public ABI | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case179_cet_protection_weakened | CET Protection Weakened | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case180_symbol_binding_lost_unique | Symbol Binding Lost GNU_UNIQUE | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case182_accidental_export_removed_still_breaking | Accidental Export Removed — Still Breaking Under Public-Header Scoping | 🔴 BREAKING | Breaking |
| case183_internal_version_node_churn | Internal ELF symbol-version node churn | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case184_internal_enum_churn_scoped | Internal Enum Churn, Scoped Out by Private-Header Origin | ✅ NO_CHANGE | No Change |
| case185_inherited_override_reuses_slot | Inherited override reuses the base's vtable slot | 🟢 COMPATIBLE | Addition (Compatible) |
| case186_c_api_pointee_const_abi_neutral | C API Pointee const-Qualification Is ABI-Neutral | ✅ NO_CHANGE | No Change |
| case187_public_struct_private_field_type | Public Struct Field Retyped to an Internal Type | 🔴 BREAKING | Breaking |
| case188_public_class_private_base_class | Public Class Gains a Private Base Class | 🔴 BREAKING | Breaking |
| case189_public_function_private_parameter_type | Public Function Parameter Retyped to an Internal Type | 🔴 BREAKING | Breaking |
| case190_public_inline_function_references_internal_constant | Public Inline Function References Internal Constant | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case191_header_only_graph_field_type | Public Struct Gains a Field of a Private Type (Header-Only Graph) | 🔴 BREAKING | Breaking |
| case192_call_graph_break_survives_suppression | Call-Graph-Reachable Break Survives Suppression | 🔴 BREAKING | Breaking |
| case193_ordinary_exported_fn_call_not_reachable | Ordinary Exported Function's Internal Call Is Not Public-Reachable | 🔴 BREAKING | Breaking |
| case194_header_graph_rename_reconciled | Internal Dependency Target Renamed, Safely Reconciled | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case195_header_graph_ambiguous_rename_not_reconciled | Ambiguous Simultaneous Rename, Correctly Not Reconciled | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case196_header_graph_move_reconciled | Declaration Reconciled as Moved Across a Compound Edit | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case197_header_graph_identity_reconciled | Declaration Reconciled as Identity-Reconciled (Header Unchanged) | 🟡 COMPATIBLE_WITH_RISK | Risk |
| case198_public_struct_field_reorder | Public Struct Field Reorder | 🔴 BREAKING | Breaking |
| case199_public_function_parameter_added | Parameter Added to an Exported Function | 🔴 BREAKING | Breaking |
| case200_new_entry_point_instead_of_parameter_added | New Entry Point Instead of a Changed Arity | 🟢 COMPATIBLE | Addition (Compatible) |
| case201_public_function_parameters_reordered | Public Function Parameters Reordered | 🔴 BREAKING | Breaking |
| case202_public_header_declaration_order_changed | Public Header Declaration Order Changed | ✅ NO_CHANGE | No Change |
| case203_class_gained_vtable_pointer | Class Gained a Vtable Pointer | 🔴 BREAKING | Breaking |
| case204_class_gained_non_virtual_method | Class Gained a Non-Virtual Method | 🟢 COMPATIBLE | Addition (Compatible) |
| case205_public_function_marked_deprecated | Public Function Marked Deprecated | 🟢 COMPATIBLE | Quality (Compatible) |
| case206_deprecation_documented_without_attribute | Deprecation Documented Without the Attribute | ✅ NO_CHANGE | No Change |
| case207_pointer_parameter_gained_restrict | Pointer Parameter Gained restrict |
🟢 COMPATIBLE | Quality (Compatible) |
| case208_restrict_added_to_definition_only | restrict Added to the Definition Only |
✅ NO_CHANGE | No Change |