angr.go.analyses.type_descriptors

Read Go runtime type descriptors (internal/abi.Type) and itabs out of a binary’s runtime.moduledata.

This is the DWARF-less counterpart of angr.go.analyses.dwarf_signatures: the descriptors are the ground truth for the layout of every type in this binary. Type strings follow the canonical syntax of angr.go.signature; named types are qualified with the full import path taken from the descriptor’s UncommonType.PkgPath.

Layouts handled (src/runtime/symtab.go and src/internal/abi/type.go):

  • go1.20 .. go1.25: moduledata.typelinks ([]int32 offsets from types) and itablinks ([]*itab).

  • go1.26+: typedesclen / itaboffset / itabsize describe contiguous runs of descriptors and itabs that are walked with Type.DescriptorSize; epclntab was inserted after gofunc.

  • go1.18 / go1.19 (no covctrs) are accepted as well since the descriptor layout is identical, except that before go1.19 a struct field’s offset word is offsetAnon (offset << 1 | embedded).

class angr.go.analyses.type_descriptors.GoTypeDescriptors

Bases: object

The runtime type descriptors of one binary.

Variables:

  • go_version – The Go release the binary was built with, when identifiable.

  • types – Every named type as a GoNamedType record (only types is filled).

  • addr_to_name – Descriptor address -> canonical Go type string.

  • name_to_addr (dict[str, int]) – The reverse map (first descriptor wins).

  • itabs – itab address -> (interface type name, concrete type name).

  • moduledata_addr – Address of runtime.firstmoduledata, or None when none was found.

  • types_addr – moduledata.types: the base that every NameOff/TypeOff (and DWARF’s DW_AT_go_runtime_type) is relative to.

The eager walk covers everything reachable from the typelinks and itabs; descriptors that only code references (anonymous interfaces of type assertions, map buckets, …) are parsed on demand by resolve().

__init__(go_version=None, goarch=None, types=None, addr_to_name=None, itabs=None, moduledata_addr=None, types_addr=None, reader=None, methods=None)
Parameters:
methods: dict[int, tuple[str, str, str]]
go_version
types
addr_to_name
name_to_addr: dict[str, int]
itabs
moduledata_addr
types_addr
resolve(addr)

The type string of the descriptor at addr, parsing it on demand when no typelink reached it.

Return type:

str | None

Parameters:

addr (int)

resolve_itab(addr)
Return type:

tuple[str, str] | None

Parameters:

addr (int)

angr.go.analyses.type_descriptors.read_go_type_descriptors(project, use_cache=True)

Parse the runtime type descriptors and itabs of the main object. Returns an empty result when the binary has no Go moduledata. Results are cached per binary within the process.

Return type:

GoTypeDescriptors

Parameters: