Crate rucc_asm 

Instruction encoders, the integrated assembler, inline assembly and relaxation.

Design: spec/11-asm-objects-debug.md. Layer rank 10, see spec/18-package-layout.md.

Status

What is written are the two things a compiler does with a machine function: the assembly text -S produces, which is print(), and the bytes of a text section, which is assemble. Section 11.1 asks for one instruction description behind both, and there is one: the walk over a function is the same walk in both files, reading the same list out of rucc-target, and the only difference is whether an instruction is written down by name or handed to the encoder. So the listing and the object file cannot come to disagree about what an instruction is.

What assemble hands back with the bytes is what the linker has to be told: where each function starts and how long it is, and every place in the bytes that names something this file does not contain. The jumps inside a function are not among them, because by the end of a function every block has a place and they are filled in here.

The variables a file defines are here for the same reason and in the same shape. globals is the one walk over a module’s globals, and what it gives back is a list of pieces that print() writes down as directives and Globals::image writes down as bytes, so a .long in a listing and the four bytes in the object beside it cannot come to disagree either. Where a variable goes is worked out there rather than named by the front end, and what a section is called is the object format’s business.

The assembler that reads .s and .S, inline assembly and relaxation are the rest of M3 and M4 and are not here yet.

Every crate in the workspace is published, and publishing implies a promise. This one is tier 3: its Rust API is explicitly unstable and will change without a major version bump. Depend on the rucc binary’s behaviour, not on this.

Structs

Globals

Every variable a module defines, laid out.

Variable

One global variable, as the pieces of its image and what the linker is told about it.

Enums

Directives

The directives one object format wraps a function in.

Error

A function this compiler could not write out as assembly.

Piece

As much of an image as one directive says.

Constants

MILESTONE

The milestone in spec/17-milestones.md that fills this crate in.

Functions

assemble

Every function, as the bytes of a text section.

globals

Every variable a module defines, laid out.

print

Every function and every variable, as assembly text.