Crate rucc_target 

Target descriptions: triples, and the facts about a target that the rest of the compiler reads rather than hard-codes.

Design: spec/12-abi-and-runtime.md. Layer rank 1, see spec/18-package-layout.md.

The rule from spec/18-package-layout.md section 18.2 is that there is no target-specific code outside this crate and the per-target rule sets. Everything a pass needs to know about a target is a field it can read here. That rule is what makes the claim in spec/10-backend.md testable, namely that a new target is a rule set and a few data files, and M10 brings up a fourth target specifically to put a number on it.

TargetInfo::call is the other half of that rule and the one with teeth. How a structure travels between a caller and a callee is the target’s answer rather than C’s, so the walk to the IR flattens a C type into a Shape and asks here what form it takes. Every psABI rule is behind Call and nothing outside this crate matches on an architecture to find one.

Status

Triple parsing and the basic data model are real, which is what rucc --print-config reports, and so is the argument classification of every psABI in spec/12-abi-and-runtime.md sections 12.2 to 12.5. A register file is describable, which is RegFile, and the description of x86-64’s own comes with the target that uses it. Machine models land in M6.

This crate is tier 3 in spec/18-package-layout.md section 18.5: its Rust API is explicitly unstable and will change without a major version bump.

Structs

Call

The registers one call has left.

ClassInfo

One class of registers, and the registers in it.

ParseTripleError

Why a triple failed to parse.

PhysReg

One physical register, as its number inside its class.

Piece

One scalar inside an aggregate, at the offset the layout put it.

RegClass

Which class a register or an operand belongs to.

RegFile

Every register a target has.

Scalar

One scalar, with the two facts about it a psABI reads.

Shape

An aggregate, as much of it as an ABI cares about.

TargetInfo

The facts about a target that the compiler reads instead of hard-coding.

Triple

A target triple.

Enums

Arch

A target architecture.

Arg

One argument, or one return value, as much of it as an ABI cares about.

Env

The C runtime and ABI variant.

Kind

What a scalar is, once the ABI is the one asking.

ObjectFormat

The object file format to emit.

Os

The operating system a target runs on.

Pass

How one value travels.

Slot

One register’s worth of an aggregate that travels in registers, and which of the object’s bytes go in it.

VaList

The type a target’s __builtin_va_list is.