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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,263 +1,18 @@ | ||
| # Chatper 4. Preliminary: Understand Compiler Internals | ||
|
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| ## Toy Example | ||
|
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| **Source Rust code** | ||
| ```rust | ||
| fn main() { | ||
| let bob = Box::new(1); | ||
| } | ||
| ``` | ||
|
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||
| **HIR** | ||
| Obtain the HIR of the source code | ||
| ``` | ||
| cargo rustc -- -Z unpretty=hir-tree | ||
| ``` | ||
| ``` | ||
| Crate { | ||
| owners: [ | ||
| ... | ||
| Owner( | ||
| OwnerInfo { | ||
| nodes: OwnerNodes { | ||
| node: Some( | ||
| ParentedNode { | ||
| parent: 4294967040, | ||
| node: Item( | ||
| Item { | ||
| ident: main#0, | ||
| owner_id: DefId(0:3 ~ toy[5100]::main), | ||
| kind: Fn( | ||
| FnSig { | ||
| header: FnHeader { | ||
| unsafety: Normal, | ||
| constness: NotConst, | ||
| asyncness: NotAsync, | ||
| abi: Rust, | ||
| }, | ||
| decl: FnDecl { | ||
| inputs: [], | ||
| output: DefaultReturn( | ||
| src/main.rs:1:10: 1:10 (#0), | ||
| ), | ||
| c_variadic: false, | ||
| implicit_self: None, | ||
| lifetime_elision_allowed: false, | ||
| }, | ||
| span: src/main.rs:1:1: 1:10 (#0), | ||
| }, | ||
| Generics { | ||
| params: [], | ||
| predicates: [], | ||
| has_where_clause_predicates: false, | ||
| where_clause_span: src/main.rs:1:10: 1:10 (#0), | ||
| span: src/main.rs:1:8: 1:8 (#0), | ||
| }, | ||
| BodyId { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).11), | ||
| }, | ||
| ), | ||
| span: src/main.rs:1:1: 3:2 (#0), | ||
| vis_span: no-location (#0), | ||
| }, | ||
| ), | ||
| }, | ||
| ), | ||
| ... | ||
| bodies: { | ||
| 11: Body { | ||
| params: [], | ||
| value: Expr { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).11), | ||
| kind: Block( | ||
| Block { | ||
| stmts: [ | ||
| Stmt { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).1), | ||
| kind: Local( | ||
| Local { | ||
| pat: Pat { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).9), | ||
| kind: Binding( | ||
| BindingAnnotation( | ||
| No, | ||
| Not, | ||
| ), | ||
| HirId(DefId(0:3 ~ toy[5100]::main).9), | ||
| bob#0, | ||
| None, | ||
| ), | ||
| span: src/main.rs:2:9: 2:12 (#0), | ||
| default_binding_modes: true, | ||
| }, | ||
| ty: None, | ||
| init: Some( | ||
| Expr { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).2), | ||
| kind: Call( | ||
| Expr { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).3), | ||
| kind: Path( | ||
| TypeRelative( | ||
| Ty { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).5), | ||
| kind: Path( | ||
| Resolved( | ||
| None, | ||
| Path { | ||
| span: src/main.rs:2:15: 2:18 (#0), | ||
| res: Def( | ||
| Struct, | ||
| DefId(5:276 ~ alloc[1281]::boxed::Box), | ||
| ), | ||
| segments: [ | ||
| PathSegment { | ||
| ident: Box#0, | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).4), | ||
| res: Def( | ||
| Struct, | ||
| DefId(5:276 ~ alloc[1281]::boxed::Box), | ||
| ), | ||
| args: None, | ||
| infer_args: true, | ||
| }, | ||
| ], | ||
| }, | ||
| ), | ||
| ), | ||
| span: src/main.rs:2:15: 2:18 (#0), | ||
| }, | ||
| PathSegment { | ||
| ident: new#0, | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).6), | ||
| res: Err, | ||
| args: None, | ||
| infer_args: true, | ||
| }, | ||
| ), | ||
| ), | ||
| span: src/main.rs:2:15: 2:23 (#0), | ||
| }, | ||
| [ | ||
| Expr { | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).7), | ||
| kind: Lit( | ||
| Spanned { | ||
| node: Int( | ||
| 1, | ||
| Unsuffixed, | ||
| ), | ||
| span: src/main.rs:2:24: 2:25 (#0), | ||
| }, | ||
| ), | ||
| span: src/main.rs:2:24: 2:25 (#0), | ||
| }, | ||
| ], | ||
| ), | ||
| span: src/main.rs:2:15: 2:26 (#0), | ||
| }, | ||
| ), | ||
| els: None, | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).8), | ||
| span: src/main.rs:2:5: 2:27 (#0), | ||
| source: Normal, | ||
| }, | ||
| ), | ||
| span: src/main.rs:2:5: 2:27 (#0), | ||
| }, | ||
| ], | ||
| expr: None, | ||
| hir_id: HirId(DefId(0:3 ~ toy[5100]::main).10), | ||
| rules: DefaultBlock, | ||
| span: src/main.rs:1:11: 3:2 (#0), | ||
| targeted_by_break: false, | ||
| }, | ||
| None, | ||
| ), | ||
| span: src/main.rs:1:11: 3:2 (#0), | ||
| }, | ||
| generator_kind: None, | ||
| }, | ||
| }, | ||
| opt_hash_including_bodies: Some( | ||
| Fingerprint( | ||
| 17038548455900965345, | ||
| 6128119105717993704, | ||
| ), | ||
| ), | ||
| }, | ||
| parenting: {}, | ||
| attrs: AttributeMap { | ||
| map: {}, | ||
| opt_hash: Some( | ||
| Fingerprint( | ||
| 17025902295854411478, | ||
| 11375155654212205663, | ||
| ), | ||
| ), | ||
| }, | ||
| trait_map: { | ||
| 3: [], | ||
| }, | ||
| }, | ||
| ), | ||
| ], | ||
| opt_hir_hash: Some( | ||
| Fingerprint( | ||
| 13212131797653419263, | ||
| 9623007000143043823, | ||
| ), | ||
| ), | ||
| } | ||
| ``` | ||
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| **MIR** | ||
| Obtain the MIR of the source code | ||
| ``` | ||
| cargo rustc -- -Zunpretty=mir | ||
| ``` | ||
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| ``` | ||
| fn main() -> () { | ||
| let mut _0: (); | ||
| let _1: std::boxed::Box<i32>; | ||
| scope 1 { | ||
| debug bob => _1; | ||
| } | ||
| bb0: { | ||
| _1 = Box::<i32>::new(const 1_i32) -> [return: bb1, unwind continue]; | ||
| } | ||
| bb1: { | ||
| drop(_1) -> [return: bb2, unwind continue]; | ||
| } | ||
| bb2: { | ||
| return; | ||
| } | ||
| } | ||
| ``` | ||
| # Chatper 4. Preliminary: Compiler Internals | ||
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| ## Compiler Internal | ||
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| We list the essential official documents to read for better understanding the internal data structures of Rust compiler. | ||
| - [**HIR**](https://rustc-dev-guide.rust-lang.org/hir.html) | ||
| - [**MIR**](https://rustc-dev-guide.rust-lang.org/mir/index.html) | ||
| - [**TyCtxt**](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html) is the central data structure of Rust compilers. We can obtain the hir or mir of a function based on the object. | ||
| ```rust | ||
| let hir = tcx.hir(); | ||
| let mir = optimized_mir(def_id); // def_id is of type DefId | ||
| ``` | ||
|
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| ### HIR | ||
| [HIR](https://rustc-dev-guide.rust-lang.org/hir.html) | ||
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| - [**DefId**](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/def_id/struct.DefId.html): | ||
| - [**Local**](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/struct.Local.html): | ||
| - [**LocalDecl**](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/struct.LocalDecl.html): | ||
|
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| ### MIR | ||
| [MIR](https://rustc-dev-guide.rust-lang.org/mir/index.html) | ||
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| ## Command to Display HIR/MIR | ||
| Execute the following command to obtain the HIR/MIR of the source code. | ||
| ``` | ||
| cargo rustc -- -Z unpretty=hir-tree | ||
| cargo rustc -- -Zunpretty=mir | ||
| ``` |