Rust IR

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Rust IR

Ref: https://rust-lang.github.io/rfcs/1211-mir.html

https://rustc-dev-guide.rust-lang.org/mir/index.html

https://doc.rust-lang.org/beta/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.layout_of

HIR

Add a high-level intermediate representation (HIR) to the compiler. This is basically a new (and additional) AST more suited for use by the compiler.

You can view the HIR representation of your code by passing the -Z unpretty=hir-tree flag to rustc:

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cargo rustc -- -Z unpretty=hir-tree

THIR

https://rustc-dev-guide.rust-lang.org/thir.html

The THIR (“Typed High-Level Intermediate Representation”), previously called HAIR for “High-Level Abstract IR”, is another IR used by rustc that is generated after type checking.

MIR

https://rustc-dev-guide.rust-lang.org/mir/index.html https://rust-lang.github.io/rfcs/1211-mir.html https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/index.html

RUST_LOG=debug RUSTFLAGS=”-Zalways-encode-mir -Zsymbol-mangling-version=v0 -C panic=abort” xargo build -v RUSTFLAGS=”–emit=mir”

Some of the key characteristics of MIR are:

  • It is based on a control-flow graph.
  • It does not have nested expressions.
  • All types in MIR are fully explicit.

Online Compiler to emit MIR, HIR, and LLVM IR:

https://play.rust-lang.org/

Rustc

A DefId identifies a particular definition, by combining a crate index and a def index.