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 syntax::ext::allocator::{AllocatorKind, AllocatorTy, ALLOCATOR_METHODS};
15 /// Returns whether an allocator shim was created
16 pub fn codegen(tcx: TyCtxt<'_>, module: &mut Module<impl Backend + 'static>) -> bool {
17 let any_dynamic_crate = tcx.dependency_formats(LOCAL_CRATE).iter().any(|(_, list)| {
18 use rustc::middle::dependency_format::Linkage;
19 list.iter().any(|&linkage| linkage == Linkage::Dynamic)
21 if any_dynamic_crate {
23 } else if let Some(kind) = *tcx.sess.allocator_kind.get() {
24 codegen_inner(tcx.sess, module, kind);
31 pub fn codegen_inner(sess: &Session, module: &mut Module<impl Backend + 'static>, kind: AllocatorKind) {
32 let usize_ty = module.target_config().pointer_type();
34 for method in ALLOCATOR_METHODS {
35 let mut arg_tys = Vec::with_capacity(method.inputs.len());
36 for ty in method.inputs.iter() {
38 AllocatorTy::Layout => {
39 arg_tys.push(usize_ty); // size
40 arg_tys.push(usize_ty); // align
42 AllocatorTy::Ptr => arg_tys.push(usize_ty),
43 AllocatorTy::Usize => arg_tys.push(usize_ty),
45 AllocatorTy::ResultPtr | AllocatorTy::Unit => panic!("invalid allocator arg"),
48 let output = match method.output {
49 AllocatorTy::ResultPtr => Some(usize_ty),
50 AllocatorTy::Unit => None,
52 AllocatorTy::Layout | AllocatorTy::Usize | AllocatorTy::Ptr => {
53 panic!("invalid allocator output")
58 call_conv: crate::default_call_conv(sess),
59 params: arg_tys.iter().cloned().map(AbiParam::new).collect(),
60 returns: output.into_iter().map(AbiParam::new).collect(),
63 let caller_name = format!("__rust_{}", method.name);
64 let callee_name = kind.fn_name(method.name);
65 //eprintln!("Codegen allocator shim {} -> {} ({:?} -> {:?})", caller_name, callee_name, sig.params, sig.returns);
68 .declare_function(&caller_name, Linkage::Export, &sig)
71 let callee_func_id = module
72 .declare_function(&callee_name, Linkage::Import, &sig)
75 let mut ctx = Context::new();
76 ctx.func = Function::with_name_signature(ExternalName::user(0, 0), sig.clone());
78 let mut func_ctx = FunctionBuilderContext::new();
79 let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
81 let ebb = bcx.create_ebb();
82 bcx.switch_to_block(ebb);
85 .map(|ty| bcx.append_ebb_param(ebb, ty))
86 .collect::<Vec<Value>>();
88 let callee_func_ref = module.declare_func_in_func(callee_func_id, &mut bcx.func);
90 let call_inst = bcx.ins().call(callee_func_ref, &args);
92 let results = bcx.inst_results(call_inst).to_vec(); // Clone to prevent borrow error
93 bcx.ins().return_(&results);
94 bcx.seal_all_blocks();
97 module.define_function(func_id, &mut ctx).unwrap();