Enum rustc_codegen_llvm::abi::PassMode

pub enum PassMode {
    Ignore,
    Direct(ArgAttributes),
    Pair(ArgAttributes, ArgAttributes),
    Cast(CastTarget),
    Indirect {
        attrs: ArgAttributes,
        extra_attrs: Option<ArgAttributes>,
        on_stack: bool,
    },
}

Variants

Ignore

Ignore the argument.

The argument is either uninhabited or a ZST.

Direct(ArgAttributes)

Pass the argument directly.

The argument has a layout abi of Scalar, Vector or in rare cases Aggregate.

Pair(ArgAttributes, ArgAttributes)

Pass a pair’s elements directly in two arguments.

The argument has a layout abi of ScalarPair.

Cast(CastTarget)

Pass the argument after casting it, to either a single uniform or a pair of registers.

Indirect

Pass the argument indirectly via a hidden pointer. The extra_attrs value, if any, is for the extra data (vtable or length) which indicates that it refers to an unsized rvalue. on_stack defines that the the value should be passed at a fixed stack offset in accordance to the ABI rather than passed using a pointer. This corresponds to the byval LLVM argument attribute.

Fields of Indirect

attrs: ArgAttributesextra_attrs: Option<ArgAttributes>on_stack: bool