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>,
60 .const_eval(ParamEnv::reveal_all().and(GlobalId {
61 instance: fx.instance,
62 promoted: Some(promoted),
66 let cplace = trans_const_place(fx, const_);
67 debug_assert_eq!(cplace.layout(), fx.layout_of(dest_ty));
70 Err(_) => crate::trap::trap_unreachable_ret_place(fx, fx.layout_of(dest_ty)),
74 pub fn trans_constant<'a, 'tcx: 'a>(
75 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
76 constant: &Constant<'tcx>,
78 let const_ = fx.monomorphize(&constant.literal);
79 let const_ = force_eval_const(fx, const_);
80 trans_const_value(fx, const_)
83 pub fn force_eval_const<'a, 'tcx: 'a>(
84 fx: &FunctionCx<'a, 'tcx, impl Backend>,
85 const_: &'tcx LazyConst<'tcx>,
88 LazyConst::Unevaluated(def_id, ref substs) => {
89 let param_env = ParamEnv::reveal_all();
90 let instance = Instance::resolve(fx.tcx, param_env, def_id, substs).unwrap();
95 fx.tcx.const_eval(param_env.and(cid)).unwrap()
97 LazyConst::Evaluated(const_) => const_,
101 fn trans_const_value<'a, 'tcx: 'a>(
102 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
105 let ty = fx.monomorphize(&const_.ty);
106 let layout = fx.layout_of(ty);
109 let bits = const_.val.try_to_bits(layout.size).unwrap();
110 CValue::const_val(fx, ty, bits as u64 as i64)
113 let bits = const_.val.try_to_bits(layout.size).unwrap();
114 CValue::const_val(fx, ty, bits as u64 as i64)
117 let bits = const_.val.try_to_bits(layout.size).unwrap();
118 CValue::const_val(fx, ty, bits as i128 as i64)
120 ty::FnDef(_def_id, _substs) => CValue::ByRef(
123 .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
126 _ => trans_const_place(fx, const_).to_cvalue(fx),
130 fn trans_const_place<'a, 'tcx: 'a>(
131 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
134 // Adapted from https://github.com/rust-lang/rust/pull/53671/files#diff-e0b58bb6712edaa8595ad7237542c958L551
135 let result = || -> EvalResult<'tcx, &'tcx Allocation> {
136 let mut ecx = EvalContext::new(
138 ty::ParamEnv::reveal_all(),
139 TransPlaceInterpreter,
141 ecx.push_stack_frame(
146 StackPopCleanup::None { cleanup: false },
149 let op = ecx.eval_operand(
150 &Operand::Constant(Box::new(Constant {
154 literal: fx.tcx.mk_lazy_const(LazyConst::Evaluated(const_)),
158 let ptr = ecx.allocate(op.layout, MemoryKind::Stack);
159 ecx.copy_op(op, ptr.into())?;
160 let alloc = ecx.memory().get(ptr.to_ptr()?.alloc_id)?;
161 Ok(fx.tcx.intern_const_alloc(alloc.clone()))
163 let alloc = result().expect("unable to convert ConstValue to Allocation");
165 //println!("const value: {:?} allocation: {:?}", value, alloc);
166 let alloc_id = fx.tcx.alloc_map.lock().allocate(alloc);
167 fx.constants.todo.insert(TodoItem::Alloc(alloc_id));
168 let data_id = data_id_for_alloc_id(fx.module, alloc_id);
169 cplace_for_dataid(fx, const_.ty, data_id)
172 fn data_id_for_alloc_id<B: Backend>(module: &mut Module<B>, alloc_id: AllocId) -> DataId {
174 .declare_data(&format!("__alloc_{}", alloc_id.0), Linkage::Local, false)
178 fn data_id_for_static<'a, 'tcx: 'a, B: Backend>(
179 tcx: TyCtxt<'a, 'tcx, 'tcx>,
180 module: &mut Module<B>,
184 let symbol_name = tcx.symbol_name(Instance::mono(tcx, def_id)).as_str();
185 let is_mutable = if let ::rustc::hir::Mutability::MutMutable = tcx.is_static(def_id).unwrap() {
189 .is_freeze(tcx, ParamEnv::reveal_all(), DUMMY_SP)
192 .declare_data(&*symbol_name, linkage, is_mutable)
196 fn cplace_for_dataid<'a, 'tcx: 'a>(
197 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
201 let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
202 let global_ptr = fx.bcx.ins().global_value(fx.pointer_type, local_data_id);
203 let layout = fx.layout_of(fx.monomorphize(&ty));
204 assert!(!layout.is_unsized(), "unsized statics aren't supported");
205 CPlace::Addr(global_ptr, None, layout)
208 fn define_all_allocs<'a, 'tcx: 'a, B: Backend + 'a>(
209 tcx: TyCtxt<'a, 'tcx, 'tcx>,
210 module: &mut Module<B>,
213 let memory = Memory::<TransPlaceInterpreter>::new(tcx.at(DUMMY_SP));
215 while let Some(todo_item) = pop_set(&mut cx.todo) {
216 let (data_id, alloc) = match todo_item {
217 TodoItem::Alloc(alloc_id) => {
218 //println!("alloc_id {}", alloc_id);
219 let data_id = data_id_for_alloc_id(module, alloc_id);
220 let alloc = memory.get(alloc_id).unwrap();
223 TodoItem::Static(def_id) => {
224 //println!("static {:?}", def_id);
225 let instance = ty::Instance::mono(tcx, def_id);
230 let const_ = tcx.const_eval(ParamEnv::reveal_all().and(cid)).unwrap();
232 let alloc = match const_.val {
233 ConstValue::ByRef(ptr, alloc) if ptr.offset.bytes() == 0 => alloc,
234 _ => bug!("static const eval returned {:#?}", const_),
237 let data_id = data_id_for_static(tcx, module, def_id, Linkage::Export);
242 //("data_id {}", data_id);
243 if cx.done.contains(&data_id) {
247 let mut data_ctx = DataContext::new();
249 data_ctx.define(alloc.bytes.to_vec().into_boxed_slice());
251 for &(offset, (_tag, reloc)) in alloc.relocations.iter() {
253 let endianness = tcx.data_layout.endian;
254 let offset = offset.bytes() as usize;
255 let ptr_size = tcx.data_layout.pointer_size;
256 let bytes = &alloc.bytes[offset..offset + ptr_size.bytes() as usize];
257 read_target_uint(endianness, bytes).unwrap()
260 let data_id = match tcx.alloc_map.lock().get(reloc).unwrap() {
261 AllocKind::Function(instance) => {
262 assert_eq!(addend, 0);
263 let func_id = crate::abi::import_function(tcx, module, instance);
264 let local_func_id = module.declare_func_in_data(func_id, &mut data_ctx);
265 data_ctx.write_function_addr(offset.bytes() as u32, local_func_id);
268 AllocKind::Memory(_) => {
269 cx.todo.insert(TodoItem::Alloc(reloc));
270 data_id_for_alloc_id(module, reloc)
272 AllocKind::Static(def_id) => {
273 cx.todo.insert(TodoItem::Static(def_id));
274 data_id_for_static(tcx, module, def_id, Linkage::Import)
278 let global_value = module.declare_data_in_data(data_id, &mut data_ctx);
279 data_ctx.write_data_addr(offset.bytes() as u32, global_value, addend as i64);
282 module.define_data(data_id, &data_ctx).unwrap();
283 cx.done.insert(data_id);
286 assert!(cx.todo.is_empty(), "{:?}", cx.todo);
289 fn pop_set<T: Copy + Eq + ::std::hash::Hash>(set: &mut HashSet<T>) -> Option<T> {
290 if let Some(elem) = set.iter().next().map(|elem| *elem) {
298 struct TransPlaceInterpreter;
300 impl<'a, 'mir, 'tcx> Machine<'a, 'mir, 'tcx> for TransPlaceInterpreter {
301 type MemoryKinds = !;
302 type PointerTag = ();
303 type AllocExtra = ();
304 type MemoryExtra = ();
305 type FrameExtra = ();
306 type MemoryMap = FxHashMap<AllocId, (MemoryKind<!>, Allocation<()>)>;
307 const STATIC_KIND: Option<!> = None;
309 fn enforce_validity(_: &EvalContext<'a, 'mir, 'tcx, Self>) -> bool {
313 fn before_terminator(_: &mut EvalContext<'a, 'mir, 'tcx, Self>) -> EvalResult<'tcx> {
318 _: &mut EvalContext<'a, 'mir, 'tcx, Self>,
321 _: Option<PlaceTy<'tcx>>,
322 _: Option<BasicBlock>,
323 ) -> EvalResult<'tcx, Option<&'mir Mir<'tcx>>> {
328 _: &mut EvalContext<'a, 'mir, 'tcx, Self>,
332 ) -> EvalResult<'tcx> {
336 fn find_foreign_static(
338 _: ::rustc::ty::query::TyCtxtAt<'a, 'tcx, 'tcx>,
340 ) -> EvalResult<'tcx, Cow<'tcx, Allocation>> {
345 _: &EvalContext<'a, 'mir, 'tcx, Self>,
349 ) -> EvalResult<'tcx, (Scalar, bool)> {
353 fn box_alloc(_: &mut EvalContext<'a, 'mir, 'tcx, Self>, _: PlaceTy<'tcx>) -> EvalResult<'tcx> {
358 _: &EvalContext<'a, 'mir, 'tcx, Self>,
360 _: Option<::rustc::hir::Mutability>,
361 ) -> EvalResult<'tcx, Scalar> {
365 fn adjust_static_allocation<'alloc>(
366 alloc: &'alloc Allocation,
368 ) -> Cow<'alloc, Allocation> {
372 fn tag_new_allocation(
373 _: &mut EvalContext<'a, 'mir, 'tcx, Self>,
380 fn stack_push(_: &mut EvalContext<'a, 'mir, 'tcx, Self>) -> EvalResult<'tcx> {
384 fn stack_pop(_: &mut EvalContext<'a, 'mir, 'tcx, Self>, _: ()) -> EvalResult<'tcx> {