rust/tests/ui-fulldeps/regions-mock-tcx.rs

140 lines
3.5 KiB
Rust

//@ run-pass
#![allow(dead_code)]
#![allow(unused_imports)]
// Test a sample usage pattern for regions. Makes use of the
// following features:
//
// - Multiple lifetime parameters
// - Arenas
#![feature(rustc_private, libc)]
extern crate rustc_arena;
extern crate libc;
// Necessary to pull in object code as the rest of the rustc crates are shipped only as rmeta
// files.
#[allow(unused_extern_crates)]
extern crate rustc_driver;
use TypeStructure::{TypeInt, TypeFunction};
use AstKind::{ExprInt, ExprVar, ExprLambda};
use rustc_arena::TypedArena;
use std::collections::HashMap;
use std::mem;
type Type<'tcx> = &'tcx TypeStructure<'tcx>;
#[derive(Copy, Clone, Debug)]
enum TypeStructure<'tcx> {
TypeInt,
TypeFunction(Type<'tcx>, Type<'tcx>),
}
impl<'tcx> PartialEq for TypeStructure<'tcx> {
fn eq(&self, other: &TypeStructure<'tcx>) -> bool {
match (*self, *other) {
(TypeInt, TypeInt) => true,
(TypeFunction(s_a, s_b), TypeFunction(o_a, o_b)) => *s_a == *o_a && *s_b == *o_b,
_ => false
}
}
}
impl<'tcx> Eq for TypeStructure<'tcx> {}
type TyArena<'tcx> = TypedArena<TypeStructure<'tcx>>;
type AstArena<'ast> = TypedArena<AstStructure<'ast>>;
struct TypeContext<'tcx, 'ast> {
ty_arena: &'tcx TyArena<'tcx>,
types: Vec<Type<'tcx>> ,
type_table: HashMap<NodeId, Type<'tcx>>,
ast_arena: &'ast AstArena<'ast>,
ast_counter: usize,
}
impl<'tcx,'ast> TypeContext<'tcx, 'ast> {
fn new(ty_arena: &'tcx TyArena<'tcx>, ast_arena: &'ast AstArena<'ast>)
-> TypeContext<'tcx, 'ast> {
TypeContext { ty_arena: ty_arena,
types: Vec::new(),
type_table: HashMap::new(),
ast_arena: ast_arena,
ast_counter: 0 }
}
fn add_type(&mut self, s: TypeStructure<'tcx>) -> Type<'tcx> {
for &ty in &self.types {
if *ty == s {
return ty;
}
}
let ty = self.ty_arena.alloc(s);
self.types.push(ty);
ty
}
fn set_type(&mut self, id: NodeId, ty: Type<'tcx>) -> Type<'tcx> {
self.type_table.insert(id, ty);
ty
}
fn ast(&mut self, a: AstKind<'ast>) -> Ast<'ast> {
let id = self.ast_counter;
self.ast_counter += 1;
self.ast_arena.alloc(AstStructure { id: NodeId {id:id}, kind: a })
}
}
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
struct NodeId {
id: usize
}
type Ast<'ast> = &'ast AstStructure<'ast>;
#[derive(Copy, Clone)]
struct AstStructure<'ast> {
id: NodeId,
kind: AstKind<'ast>
}
#[derive(Copy, Clone)]
enum AstKind<'ast> {
ExprInt,
ExprVar(usize),
ExprLambda(Ast<'ast>),
}
fn compute_types<'tcx,'ast>(tcx: &mut TypeContext<'tcx,'ast>,
ast: Ast<'ast>) -> Type<'tcx>
{
match ast.kind {
ExprInt | ExprVar(_) => {
let ty = tcx.add_type(TypeInt);
tcx.set_type(ast.id, ty)
}
ExprLambda(ast) => {
let arg_ty = tcx.add_type(TypeInt);
let body_ty = compute_types(tcx, ast);
let lambda_ty = tcx.add_type(TypeFunction(arg_ty, body_ty));
tcx.set_type(ast.id, lambda_ty)
}
}
}
pub fn main() {
let ty_arena = TypedArena::default();
let ast_arena = TypedArena::default();
let mut tcx = TypeContext::new(&ty_arena, &ast_arena);
let ast = tcx.ast(ExprInt);
let ty = compute_types(&mut tcx, ast);
assert_eq!(*ty, TypeInt);
}