3 use rustc::mir::interpret::{
4 read_target_uint, AllocId, AllocKind, Allocation, ConstValue, EvalResult, GlobalId, Scalar,
7 use rustc_mir::interpret::{
8 InterpretCx, 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>,
50 let linkage = crate::linkage::get_static_ref_linkage(fx.tcx, def_id);
51 let data_id = data_id_for_static(fx.tcx, fx.module, def_id, linkage);
52 cplace_for_dataid(fx, ty, data_id)
55 pub fn trans_promoted<'a, 'tcx: 'a>(
56 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
62 .const_eval(ParamEnv::reveal_all().and(GlobalId {
63 instance: fx.instance,
64 promoted: Some(promoted),
68 let cplace = trans_const_place(fx, const_);
69 debug_assert_eq!(cplace.layout(), fx.layout_of(dest_ty));
73 crate::trap::trap_unreachable_ret_place(
75 fx.layout_of(dest_ty),
76 "[panic] Tried to get value of promoted value with errored during const eval.",
82 pub fn trans_constant<'a, 'tcx: 'a>(
83 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
84 constant: &Constant<'tcx>,
86 let const_ = force_eval_const(fx, &constant.literal);
87 trans_const_value(fx, const_)
90 pub fn force_eval_const<'a, 'tcx: 'a>(
91 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
95 ConstValue::Unevaluated(def_id, ref substs) => {
96 let param_env = ParamEnv::reveal_all();
97 let substs = fx.monomorphize(substs);
98 let instance = Instance::resolve(fx.tcx, param_env, def_id, substs).unwrap();
103 fx.tcx.const_eval(param_env.and(cid)).unwrap()
105 _ => *fx.monomorphize(&const_),
109 fn trans_const_value<'a, 'tcx: 'a>(
110 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
113 let ty = fx.monomorphize(&const_.ty);
114 let layout = fx.layout_of(ty);
117 let bits = const_.val.try_to_bits(layout.size).unwrap();
118 CValue::const_val(fx, ty, bits as u64 as i64)
121 let bits = const_.val.try_to_bits(layout.size).unwrap();
122 CValue::const_val(fx, ty, bits as u64 as i64)
125 let bits = const_.val.try_to_bits(layout.size).unwrap();
126 CValue::const_val(fx, ty, rustc::mir::interpret::sign_extend(bits, layout.size) as i128 as i64)
128 ty::FnDef(_def_id, _substs) => CValue::ByRef(
131 .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
134 _ => trans_const_place(fx, const_).to_cvalue(fx),
138 fn trans_const_place<'a, 'tcx: 'a>(
139 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
142 // Adapted from https://github.com/rust-lang/rust/pull/53671/files#diff-e0b58bb6712edaa8595ad7237542c958L551
143 let result = || -> EvalResult<'tcx, &'tcx Allocation> {
144 let mut ecx = InterpretCx::new(
146 ty::ParamEnv::reveal_all(),
147 TransPlaceInterpreter,
149 ecx.push_stack_frame(
154 StackPopCleanup::None { cleanup: false },
157 let op = ecx.eval_operand(
158 &Operand::Constant(Box::new(Constant {
162 literal: fx.tcx.mk_const(const_),
166 let ptr = ecx.allocate(op.layout, MemoryKind::Stack);
167 ecx.copy_op(op, ptr.into())?;
168 let alloc = ecx.memory().get(ptr.to_ptr()?.alloc_id)?;
169 Ok(fx.tcx.intern_const_alloc(alloc.clone()))
171 let alloc = result().expect("unable to convert ConstValue to Allocation");
173 //println!("const value: {:?} allocation: {:?}", value, alloc);
174 let alloc_id = fx.tcx.alloc_map.lock().allocate(alloc);
175 fx.constants.todo.insert(TodoItem::Alloc(alloc_id));
176 let data_id = data_id_for_alloc_id(fx.module, alloc_id);
177 cplace_for_dataid(fx, const_.ty, data_id)
180 fn data_id_for_alloc_id<B: Backend>(module: &mut Module<B>, alloc_id: AllocId) -> DataId {
182 .declare_data(&format!("__alloc_{}", alloc_id.0), Linkage::Local, false)
186 fn data_id_for_static<'a, 'tcx: 'a, B: Backend>(
187 tcx: TyCtxt<'a, 'tcx, 'tcx>,
188 module: &mut Module<B>,
192 let symbol_name = tcx.symbol_name(Instance::mono(tcx, def_id)).as_str();
193 let is_mutable = if let ::rustc::hir::Mutability::MutMutable = tcx.is_static(def_id).unwrap() {
197 .is_freeze(tcx, ParamEnv::reveal_all(), DUMMY_SP)
201 .declare_data(&*symbol_name, linkage, is_mutable)
204 if linkage == Linkage::Preemptible {
205 if let ty::RawPtr(_) = tcx.type_of(def_id).sty {
207 tcx.sess.span_fatal(tcx.def_span(def_id), "must have type `*const T` or `*mut T`")
210 let mut data_ctx = DataContext::new();
211 let zero_bytes = std::iter::repeat(0)
212 .take(pointer_ty(tcx).bytes() as usize)
213 .collect::<Vec<u8>>()
215 data_ctx.define(zero_bytes);
216 match module.define_data(data_id, &data_ctx) {
217 // Everytime a weak static is referenced, there will be a zero pointer definition,
218 // so duplicate definitions are expected and allowed.
219 Err(ModuleError::DuplicateDefinition(_)) => {}
227 fn cplace_for_dataid<'a, 'tcx: 'a>(
228 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
232 let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
233 let global_ptr = fx.bcx.ins().global_value(fx.pointer_type, local_data_id);
234 let layout = fx.layout_of(fx.monomorphize(&ty));
235 assert!(!layout.is_unsized(), "unsized statics aren't supported");
236 CPlace::Addr(global_ptr, None, layout)
239 fn define_all_allocs<'a, 'tcx: 'a, B: Backend + 'a>(
240 tcx: TyCtxt<'a, 'tcx, 'tcx>,
241 module: &mut Module<B>,
244 let memory = Memory::<TransPlaceInterpreter>::new(tcx.at(DUMMY_SP));
246 while let Some(todo_item) = pop_set(&mut cx.todo) {
247 let (data_id, alloc) = match todo_item {
248 TodoItem::Alloc(alloc_id) => {
249 //println!("alloc_id {}", alloc_id);
250 let data_id = data_id_for_alloc_id(module, alloc_id);
251 let alloc = memory.get(alloc_id).unwrap();
254 TodoItem::Static(def_id) => {
255 //println!("static {:?}", def_id);
257 if tcx.is_foreign_item(def_id) {
261 let instance = ty::Instance::mono(tcx, def_id);
266 let const_ = tcx.const_eval(ParamEnv::reveal_all().and(cid)).unwrap();
268 let alloc = match const_.val {
269 ConstValue::ByRef(ptr, alloc) if ptr.offset.bytes() == 0 => alloc,
270 _ => bug!("static const eval returned {:#?}", const_),
273 // FIXME set correct linkage
274 let data_id = data_id_for_static(tcx, module, def_id, Linkage::Export);
279 //("data_id {}", data_id);
280 if cx.done.contains(&data_id) {
284 let mut data_ctx = DataContext::new();
286 data_ctx.define(alloc.bytes.to_vec().into_boxed_slice());
288 for &(offset, (_tag, reloc)) in alloc.relocations.iter() {
290 let endianness = tcx.data_layout.endian;
291 let offset = offset.bytes() as usize;
292 let ptr_size = tcx.data_layout.pointer_size;
293 let bytes = &alloc.bytes[offset..offset + ptr_size.bytes() as usize];
294 read_target_uint(endianness, bytes).unwrap()
297 let data_id = match tcx.alloc_map.lock().get(reloc).unwrap() {
298 AllocKind::Function(instance) => {
299 assert_eq!(addend, 0);
300 let func_id = crate::abi::import_function(tcx, module, instance);
301 let local_func_id = module.declare_func_in_data(func_id, &mut data_ctx);
302 data_ctx.write_function_addr(offset.bytes() as u32, local_func_id);
305 AllocKind::Memory(_) => {
306 cx.todo.insert(TodoItem::Alloc(reloc));
307 data_id_for_alloc_id(module, reloc)
309 AllocKind::Static(def_id) => {
310 cx.todo.insert(TodoItem::Static(def_id));
311 let linkage = crate::linkage::get_static_ref_linkage(tcx, def_id);
312 data_id_for_static(tcx, module, def_id, linkage)
316 let global_value = module.declare_data_in_data(data_id, &mut data_ctx);
317 data_ctx.write_data_addr(offset.bytes() as u32, global_value, addend as i64);
320 module.define_data(data_id, &data_ctx).unwrap();
321 cx.done.insert(data_id);
324 assert!(cx.todo.is_empty(), "{:?}", cx.todo);
327 fn pop_set<T: Copy + Eq + ::std::hash::Hash>(set: &mut HashSet<T>) -> Option<T> {
328 if let Some(elem) = set.iter().next().map(|elem| *elem) {
336 struct TransPlaceInterpreter;
338 impl<'a, 'mir, 'tcx> Machine<'a, 'mir, 'tcx> for TransPlaceInterpreter {
339 type MemoryKinds = !;
340 type PointerTag = ();
341 type AllocExtra = ();
342 type MemoryExtra = ();
343 type FrameExtra = ();
344 type MemoryMap = FxHashMap<AllocId, (MemoryKind<!>, Allocation<()>)>;
345 const STATIC_KIND: Option<!> = None;
347 fn enforce_validity(_: &InterpretCx<'a, 'mir, 'tcx, Self>) -> bool {
351 fn before_terminator(_: &mut InterpretCx<'a, 'mir, 'tcx, Self>) -> EvalResult<'tcx> {
356 _: &mut InterpretCx<'a, 'mir, 'tcx, Self>,
359 _: Option<PlaceTy<'tcx>>,
360 _: Option<BasicBlock>,
361 ) -> EvalResult<'tcx, Option<&'mir Mir<'tcx>>> {
366 _: &mut InterpretCx<'a, 'mir, 'tcx, Self>,
370 ) -> EvalResult<'tcx> {
374 fn find_foreign_static(
376 _: ::rustc::ty::query::TyCtxtAt<'a, 'tcx, 'tcx>,
378 ) -> EvalResult<'tcx, Cow<'tcx, Allocation>> {
383 _: &InterpretCx<'a, 'mir, 'tcx, Self>,
387 ) -> EvalResult<'tcx, (Scalar, bool)> {
391 fn box_alloc(_: &mut InterpretCx<'a, 'mir, 'tcx, Self>, _: PlaceTy<'tcx>) -> EvalResult<'tcx> {
396 _: &InterpretCx<'a, 'mir, 'tcx, Self>,
398 _: Option<::rustc::hir::Mutability>,
399 ) -> EvalResult<'tcx, Scalar> {
403 fn adjust_static_allocation<'alloc>(
404 alloc: &'alloc Allocation,
406 ) -> Cow<'alloc, Allocation> {
410 fn tag_new_allocation(
411 _: &mut InterpretCx<'a, 'mir, 'tcx, Self>,
418 fn stack_push(_: &mut InterpretCx<'a, 'mir, 'tcx, Self>) -> EvalResult<'tcx> {
422 fn stack_pop(_: &mut InterpretCx<'a, 'mir, 'tcx, Self>, _: ()) -> EvalResult<'tcx> {