Limits and support

Platforms and current limitations

Check the released platform matrix, unsupported language shapes, and fail-closed ABI boundaries.Maintained byC2Go contributors

Compiler implementation coverage and published SDK coverage are different claims. Use the release asset list when selecting a supported host package.

Published SDK archives

The current coordinated release publishes and validates:

Host	Architecture	Target triple
Linux	amd64	`x86_64-unknown-linux-goabi`
Linux	arm64	`aarch64-unknown-linux-goabi`
Windows	amd64	`x86_64-pc-windows-goabi`
macOS	arm64	`aarch64-apple-darwin`

Each archive is native to its host. Generated output is also specific to (GOOS, GOARCH).

Additional code-generation paths

The compiler also contains a Darwin amd64 code-generation path. Windows arm64 is currently only an incomplete experimental path: a simple input can write a windows/arm64 manifest, but c2go_extern still reports that its calling convention is unsupported for that target. It is not a usable combination and has neither an SDK nor a complete release gate.

Boundary feature matrix

Feature	Unix	Windows
Go calls: scalar, float, pointer	supported	supported
Export C functions and records	supported	supported
Native imports: scalar, pointer, float	supported	supported
Native imports: small records by value	supported within ABI limits	supported by Win64 size rules
Callback: scalar and pointer	supported	supported
Callback: float or double	supported	fail closed
Callback: selected small records	supported	fail closed
Multi-value return	supported for valid one-slot fields	supported for valid one-slot fields

“Fail closed” means the toolchain rejects an unsupported shape instead of emitting a silently incorrect call.

Hard language limits

C only and 64-bit only; C++ is rejected.
Variable-length arrays and dynamic alloca are rejected because movable Go stacks make their bases unsound.
Packed or custom-aligned managed records are warning-only and produce target-specific generated layouts; unmanaged records containing scanned data pointers reject those layouts outright.
c2go_iface is an ABI representation only; there is currently no C-side API for dynamic interface-method calls. Bind a named Go wrapper instead.
c2go_variant cannot represent ambiguous overlapping managed pointers.
c2go_returntype fields must each occupy one supported Go ABI result slot.
Callback operands must name C2Go functions; bare C2Go function pointers cannot be passed to native callback slots.

Release-candidate status

The current binaries are unsigned. The macOS archive is not notarized and the Windows executable is not Authenticode-signed. Go 1.25.x and 1.26.x are supported; Go 1.27 and later fail closed until the centralized provider validates them. Interfaces, manifest fields, and ABI epochs may change before 1.0.

When an unsupported shape appears, reduce it to a simpler boundary—for example, pass a pointer to explicitly owned storage instead of a large record by value—and add tests for every target you intend to ship.

The troubleshooting guide maps common diagnostics to the relevant stage.