1 // Copyright 2017 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use crate::prelude::*;
13 use rustc::middle::allocator::AllocatorKind;
14 use rustc_allocator::{AllocatorTy, ALLOCATOR_METHODS};
16 pub fn codegen(module: &mut Module<impl Backend + 'static>, kind: AllocatorKind) {
17 let usize_ty = module.target_config().pointer_type();
19 for method in ALLOCATOR_METHODS {
20 let mut arg_tys = Vec::with_capacity(method.inputs.len());
21 for ty in method.inputs.iter() {
23 AllocatorTy::Layout => {
24 arg_tys.push(usize_ty); // size
25 arg_tys.push(usize_ty); // align
27 AllocatorTy::Ptr => arg_tys.push(usize_ty),
28 AllocatorTy::Usize => arg_tys.push(usize_ty),
30 AllocatorTy::ResultPtr | AllocatorTy::Unit => panic!("invalid allocator arg"),
33 let output = match method.output {
34 AllocatorTy::ResultPtr => Some(usize_ty),
35 AllocatorTy::Unit => None,
37 AllocatorTy::Layout | AllocatorTy::Usize | AllocatorTy::Ptr => {
38 panic!("invalid allocator output")
42 let mut sig = Signature {
43 call_conv: CallConv::Fast,
44 params: arg_tys.iter().cloned().map(AbiParam::new).collect(),
45 returns: output.into_iter().map(AbiParam::new).collect(),
48 let caller_name = format!("__rust_{}", method.name);
49 let callee_name = kind.fn_name(method.name);
50 //eprintln!("Codegen allocator shim {} -> {} ({:?} -> {:?})", caller_name, callee_name, sig.params, sig.returns);
52 sig.call_conv = CallConv::Fast; // "rust" abi
54 .declare_function(&caller_name, Linkage::Export, &sig)
57 sig.call_conv = CallConv::SystemV; // "C" abi
58 let callee_func_id = module
59 .declare_function(&callee_name, Linkage::Import, &sig)
62 let mut ctx = Context::new();
63 ctx.func = Function::with_name_signature(ExternalName::user(0, 0), sig.clone());
65 let mut func_ctx = FunctionBuilderContext::new();
66 let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
68 let ebb = bcx.create_ebb();
69 bcx.switch_to_block(ebb);
72 .map(|ty| bcx.append_ebb_param(ebb, ty))
73 .collect::<Vec<Value>>();
75 let callee_func_ref = module.declare_func_in_func(callee_func_id, &mut bcx.func);
77 let call_inst = bcx.ins().call(callee_func_ref, &args);
79 let results = bcx.inst_results(call_inst).to_vec(); // Clone to prevent borrow error
80 bcx.ins().return_(&results);
81 bcx.seal_all_blocks();
84 module.define_function(func_id, &mut ctx).unwrap();