3 use rustc::mir::interpret::{
4 read_target_uint, AllocId, AllocKind, Allocation, ConstValue, EvalResult, GlobalId, Scalar,
6 use rustc::ty::{Const, LazyConst};
7 use rustc_mir::interpret::{
8 EvalContext, ImmTy, MPlaceTy, Machine, Memory, MemoryKind, OpTy, PlaceTy, Pointer,
12 use cranelift_module::*;
14 use crate::prelude::*;
17 pub struct ConstantCx {
18 todo: HashSet<TodoItem>,
19 done: HashSet<DataId>,
22 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
29 pub fn finalize<'a, 'tcx: 'a, B: Backend>(
31 tcx: TyCtxt<'a, 'tcx, 'tcx>,
32 module: &mut Module<B>,
34 //println!("todo {:?}", self.todo);
35 define_all_allocs(tcx, module, &mut self);
36 //println!("done {:?}", self.done);
41 pub fn codegen_static<'a, 'tcx: 'a>(ccx: &mut ConstantCx, def_id: DefId) {
42 ccx.todo.insert(TodoItem::Static(def_id));
45 pub fn codegen_static_ref<'a, 'tcx: 'a>(
46 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
47 static_: &Static<'tcx>,
49 let data_id = data_id_for_static(fx.tcx, fx.module, static_.def_id, Linkage::Import);
50 cplace_for_dataid(fx, static_.ty, data_id)
53 pub fn trans_promoted<'a, 'tcx: 'a>(
54 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
59 .const_eval(ParamEnv::reveal_all().and(GlobalId {
60 instance: fx.instance,
61 promoted: Some(promoted),
65 trans_const_place(fx, const_)
68 pub fn trans_constant<'a, 'tcx: 'a>(
69 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
70 constant: &Constant<'tcx>,
72 let const_ = fx.monomorphize(&constant.literal);
73 let const_ = force_eval_const(fx, const_);
74 trans_const_value(fx, const_)
77 pub fn force_eval_const<'a, 'tcx: 'a>(
78 fx: &FunctionCx<'a, 'tcx, impl Backend>,
79 const_: &'tcx LazyConst<'tcx>,
82 LazyConst::Unevaluated(def_id, ref substs) => {
83 let param_env = ParamEnv::reveal_all();
84 let instance = Instance::resolve(fx.tcx, param_env, def_id, substs).unwrap();
89 fx.tcx.const_eval(param_env.and(cid)).unwrap()
91 LazyConst::Evaluated(const_) => const_,
95 fn trans_const_value<'a, 'tcx: 'a>(
96 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
99 let ty = fx.monomorphize(&const_.ty);
100 let layout = fx.layout_of(ty);
103 let bits = const_.val.try_to_bits(layout.size).unwrap();
104 CValue::const_val(fx, ty, bits as u64 as i64)
107 let bits = const_.val.try_to_bits(layout.size).unwrap();
108 CValue::const_val(fx, ty, bits as u64 as i64)
111 let bits = const_.val.try_to_bits(layout.size).unwrap();
112 CValue::const_val(fx, ty, bits as i128 as i64)
114 ty::FnDef(_def_id, _substs) => CValue::ByRef(
117 .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
120 _ => trans_const_place(fx, const_).to_cvalue(fx),
124 fn trans_const_place<'a, 'tcx: 'a>(
125 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
128 // Adapted from https://github.com/rust-lang/rust/pull/53671/files#diff-e0b58bb6712edaa8595ad7237542c958L551
129 let result = || -> EvalResult<'tcx, &'tcx Allocation> {
130 let mut ecx = EvalContext::new(
132 ty::ParamEnv::reveal_all(),
133 TransPlaceInterpreter,
135 ecx.push_stack_frame(
140 StackPopCleanup::None { cleanup: false },
143 let op = ecx.eval_operand(
144 &Operand::Constant(Box::new(Constant {
148 literal: fx.tcx.mk_lazy_const(LazyConst::Evaluated(const_)),
152 let ptr = ecx.allocate(op.layout, MemoryKind::Stack);
153 ecx.copy_op(op, ptr.into())?;
154 let alloc = ecx.memory().get(ptr.to_ptr()?.alloc_id)?;
155 Ok(fx.tcx.intern_const_alloc(alloc.clone()))
157 let alloc = result().expect("unable to convert ConstValue to Allocation");
159 //println!("const value: {:?} allocation: {:?}", value, alloc);
160 let alloc_id = fx.tcx.alloc_map.lock().allocate(alloc);
161 fx.constants.todo.insert(TodoItem::Alloc(alloc_id));
162 let data_id = data_id_for_alloc_id(fx.module, alloc_id);
163 cplace_for_dataid(fx, const_.ty, data_id)
166 fn data_id_for_alloc_id<B: Backend>(module: &mut Module<B>, alloc_id: AllocId) -> DataId {
168 .declare_data(&format!("__alloc_{}", alloc_id.0), Linkage::Local, false)
172 fn data_id_for_static<'a, 'tcx: 'a, B: Backend>(
173 tcx: TyCtxt<'a, 'tcx, 'tcx>,
174 module: &mut Module<B>,
178 let symbol_name = tcx.symbol_name(Instance::mono(tcx, def_id)).as_str();
179 let is_mutable = if let ::rustc::hir::Mutability::MutMutable = tcx.is_static(def_id).unwrap() {
183 .is_freeze(tcx, ParamEnv::reveal_all(), DUMMY_SP)
186 .declare_data(&*symbol_name, linkage, is_mutable)
190 fn cplace_for_dataid<'a, 'tcx: 'a>(
191 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
195 let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
196 let global_ptr = fx.bcx.ins().global_value(fx.pointer_type, local_data_id);
197 let layout = fx.layout_of(fx.monomorphize(&ty));
198 assert!(!layout.is_unsized(), "unsized statics aren't supported");
199 CPlace::Addr(global_ptr, None, layout)
202 fn define_all_allocs<'a, 'tcx: 'a, B: Backend + 'a>(
203 tcx: TyCtxt<'a, 'tcx, 'tcx>,
204 module: &mut Module<B>,
207 let memory = Memory::<TransPlaceInterpreter>::new(tcx.at(DUMMY_SP));
209 while let Some(todo_item) = pop_set(&mut cx.todo) {
210 let (data_id, alloc) = match todo_item {
211 TodoItem::Alloc(alloc_id) => {
212 //println!("alloc_id {}", alloc_id);
213 let data_id = data_id_for_alloc_id(module, alloc_id);
214 let alloc = memory.get(alloc_id).unwrap();
217 TodoItem::Static(def_id) => {
218 //println!("static {:?}", def_id);
219 let instance = ty::Instance::mono(tcx, def_id);
224 let const_ = tcx.const_eval(ParamEnv::reveal_all().and(cid)).unwrap();
226 let alloc = match const_.val {
227 ConstValue::ByRef(ptr, alloc) if ptr.offset.bytes() == 0 => alloc,
228 _ => bug!("static const eval returned {:#?}", const_),
231 let data_id = data_id_for_static(tcx, module, def_id, Linkage::Export);
236 //("data_id {}", data_id);
237 if cx.done.contains(&data_id) {
241 let mut data_ctx = DataContext::new();
243 data_ctx.define(alloc.bytes.to_vec().into_boxed_slice());
245 for &(offset, (_tag, reloc)) in alloc.relocations.iter() {
247 let endianness = tcx.data_layout.endian;
248 let offset = offset.bytes() as usize;
249 let ptr_size = tcx.data_layout.pointer_size;
250 let bytes = &alloc.bytes[offset..offset + ptr_size.bytes() as usize];
251 read_target_uint(endianness, bytes).unwrap()
254 let data_id = match tcx.alloc_map.lock().get(reloc).unwrap() {
255 AllocKind::Function(instance) => {
256 assert_eq!(addend, 0);
257 let func_id = crate::abi::import_function(tcx, module, instance);
258 let local_func_id = module.declare_func_in_data(func_id, &mut data_ctx);
259 data_ctx.write_function_addr(offset.bytes() as u32, local_func_id);
262 AllocKind::Memory(_) => {
263 cx.todo.insert(TodoItem::Alloc(reloc));
264 data_id_for_alloc_id(module, reloc)
266 AllocKind::Static(def_id) => {
267 cx.todo.insert(TodoItem::Static(def_id));
268 data_id_for_static(tcx, module, def_id, Linkage::Import)
272 let global_value = module.declare_data_in_data(data_id, &mut data_ctx);
273 data_ctx.write_data_addr(offset.bytes() as u32, global_value, addend as i64);
276 module.define_data(data_id, &data_ctx).unwrap();
277 cx.done.insert(data_id);
280 assert!(cx.todo.is_empty(), "{:?}", cx.todo);
283 fn pop_set<T: Copy + Eq + ::std::hash::Hash>(set: &mut HashSet<T>) -> Option<T> {
284 if let Some(elem) = set.iter().next().map(|elem| *elem) {
292 struct TransPlaceInterpreter;
294 impl<'a, 'mir, 'tcx> Machine<'a, 'mir, 'tcx> for TransPlaceInterpreter {
295 type MemoryKinds = !;
296 type PointerTag = ();
297 type AllocExtra = ();
298 type MemoryExtra = ();
299 type FrameExtra = ();
300 type MemoryMap = FxHashMap<AllocId, (MemoryKind<!>, Allocation<()>)>;
301 const STATIC_KIND: Option<!> = None;
303 fn enforce_validity(_: &EvalContext<'a, 'mir, 'tcx, Self>) -> bool {
307 fn before_terminator(_: &mut EvalContext<'a, 'mir, 'tcx, Self>) -> EvalResult<'tcx> {
312 _: &mut EvalContext<'a, 'mir, 'tcx, Self>,
315 _: Option<PlaceTy<'tcx>>,
316 _: Option<BasicBlock>,
317 ) -> EvalResult<'tcx, Option<&'mir Mir<'tcx>>> {
322 _: &mut EvalContext<'a, 'mir, 'tcx, Self>,
326 ) -> EvalResult<'tcx> {
330 fn find_foreign_static(
332 _: ::rustc::ty::query::TyCtxtAt<'a, 'tcx, 'tcx>,
334 ) -> EvalResult<'tcx, Cow<'tcx, Allocation>> {
339 _: &EvalContext<'a, 'mir, 'tcx, Self>,
343 ) -> EvalResult<'tcx, (Scalar, bool)> {
347 fn box_alloc(_: &mut EvalContext<'a, 'mir, 'tcx, Self>, _: PlaceTy<'tcx>) -> EvalResult<'tcx> {
352 _: &EvalContext<'a, 'mir, 'tcx, Self>,
354 _: Option<::rustc::hir::Mutability>,
355 ) -> EvalResult<'tcx, Scalar> {
359 fn adjust_static_allocation<'alloc>(
360 alloc: &'alloc Allocation,
362 ) -> Cow<'alloc, Allocation> {
366 fn tag_new_allocation(
367 _: &mut EvalContext<'a, 'mir, 'tcx, Self>,
374 fn stack_push(_: &mut EvalContext<'a, 'mir, 'tcx, Self>) -> EvalResult<'tcx> {
378 fn stack_pop(_: &mut EvalContext<'a, 'mir, 'tcx, Self>, _: ()) -> EvalResult<'tcx> {