unify passing of sized and unsized function arguments :-)
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7cdeff266c
commit
f87e91de7d
2 changed files with 36 additions and 32 deletions
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@ -912,6 +912,32 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
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Ok(())
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}
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pub fn storage_live_dyn(
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&mut self,
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local: mir::Local,
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meta: MemPlaceMeta<M::Provenance>,
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) -> InterpResult<'tcx> {
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trace!("{:?} is now live", local);
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let layout = self.layout_of_local(self.frame(), local, None)?;
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let local_val = LocalValue::Live(if layout.is_sized() {
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assert!(matches!(meta, MemPlaceMeta::None)); // we're dropping the metadata
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// Just make this an efficient immediate.
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Operand::Immediate(Immediate::Uninit)
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} else {
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// Need to allocate some memory.
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let dest_place = self.allocate_dyn(layout, MemoryKind::Stack, meta)?;
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Operand::Indirect(*dest_place)
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});
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// StorageLive expects the local to be dead, and marks it live.
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let old = mem::replace(&mut self.frame_mut().locals[local].value, local_val);
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if !matches!(old, LocalValue::Dead) {
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throw_ub_custom!(fluent::const_eval_double_storage_live);
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}
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Ok(())
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}
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/// Mark a storage as live, killing the previous content.
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pub fn storage_live(&mut self, local: mir::Local) -> InterpResult<'tcx> {
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trace!("{:?} is now live", local);
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@ -920,13 +946,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
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throw_unsup!(UnsizedLocal);
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}
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let local_val = LocalValue::Live(Operand::Immediate(Immediate::Uninit));
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// StorageLive expects the local to be dead, and marks it live.
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let old = mem::replace(&mut self.frame_mut().locals[local].value, local_val);
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if !matches!(old, LocalValue::Dead) {
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throw_ub_custom!(fluent::const_eval_double_storage_live);
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}
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Ok(())
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self.storage_live_dyn(local, MemPlaceMeta::None)
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}
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pub fn storage_dead(&mut self, local: mir::Local) -> InterpResult<'tcx> {
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@ -1,5 +1,4 @@
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use std::borrow::Cow;
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use std::mem;
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use either::Either;
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use rustc_ast::ast::InlineAsmOptions;
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@ -15,8 +14,8 @@ use rustc_target::abi::{self, FieldIdx};
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use rustc_target::spec::abi::Abi;
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use super::{
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AllocId, FnVal, ImmTy, InterpCx, InterpResult, LocalValue, MPlaceTy, Machine, MemoryKind, OpTy,
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Operand, PlaceTy, Provenance, Scalar, StackPopCleanup,
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AllocId, FnVal, ImmTy, InterpCx, InterpResult, MPlaceTy, Machine, OpTy, PlaceTy, Projectable,
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Provenance, Scalar, StackPopCleanup,
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};
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use crate::fluent_generated as fluent;
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@ -394,28 +393,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
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// did in-place of by-copy argument passing, except for pointer equality tests.
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let caller_arg_copy = self.copy_fn_arg(&caller_arg)?;
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if !already_live {
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// Special handling for unsized parameters: they are harder to make live.
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if caller_arg_copy.layout.is_unsized() {
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// `check_argument_compat` ensures that both have the same type, so we know they will use the metadata the same way.
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assert_eq!(caller_arg_copy.layout.ty, callee_ty);
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// We have to properly pre-allocate the memory for the callee.
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// So let's tear down some abstractions.
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// This all has to be in memory, there are no immediate unsized values.
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let src = caller_arg_copy.assert_mem_place();
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// The destination cannot be one of these "spread args".
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let dest_local = callee_arg.as_local().expect("unsized arguments cannot be spread");
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// Allocate enough memory to hold `src`.
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let dest_place = self.allocate_dyn(src.layout, MemoryKind::Stack, src.meta)?;
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// Update the local to be that new place. This is essentially a "dyn-sized StorageLive".
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let old = mem::replace(
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&mut self.frame_mut().locals[dest_local].value,
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LocalValue::Live(Operand::Indirect(*dest_place)),
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);
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assert!(matches!(old, LocalValue::Dead));
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} else {
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// Just make the local live.
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self.storage_live(callee_arg.as_local().unwrap())?;
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}
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let local = callee_arg.as_local().unwrap();
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let meta = caller_arg_copy.meta();
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// `check_argument_compat` ensures that if metadata is needed, both have the same type,
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// so we know they will use the metadata the same way.
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assert!(!meta.has_meta() || caller_arg_copy.layout.ty == callee_ty);
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self.storage_live_dyn(local, meta)?;
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}
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// Now we can finally actually evaluate the callee place.
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let callee_arg = self.eval_place(*callee_arg)?;
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