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Ensure nested allocations in statics do not get deduplicated

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This commit is contained in:
Oli Scherer
2024-02-26 18:03:06 +00:00
parent 92414ab25d
commit d3514a036d
21 changed files with 259 additions and 54 deletions
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38
compiler/rustc_const_eval/src/interpret/memory.rs
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@@ -15,6 +15,7 @@ use std::ptr;
use rustc_ast::Mutability;
use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
use rustc_hir::def::DefKind;
use rustc_middle::mir::display_allocation;
use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TyCtxt};
use rustc_target::abi::{Align, HasDataLayout, Size};
@@ -761,19 +762,36 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
// be held throughout the match.
match self.tcx.try_get_global_alloc(id) {
Some(GlobalAlloc::Static(def_id)) => {
assert!(self.tcx.is_static(def_id));
// Thread-local statics do not have a constant address. They *must* be accessed via
// `ThreadLocalRef`; we can never have a pointer to them as a regular constant value.
assert!(!self.tcx.is_thread_local_static(def_id));
// Use size and align of the type.
let ty = self
.tcx
.type_of(def_id)
.no_bound_vars()
.expect("statics should not have generic parameters");
let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
assert!(layout.is_sized());
(layout.size, layout.align.abi, AllocKind::LiveData)
let DefKind::Static { nested, .. } = self.tcx.def_kind(def_id) else {
bug!("GlobalAlloc::Static is not a static")
};
let (size, align) = if nested {
// Nested anonymous statics are untyped, so let's get their
// size and alignment from the allocaiton itself. This always
// succeeds, as the query is fed at DefId creation time, so no
// evaluation actually occurs.
let alloc = self.tcx.eval_static_initializer(def_id).unwrap();
(alloc.0.size(), alloc.0.align)
} else {
// Use size and align of the type for everything else. We need
// to do that to
// * avoid cycle errors in case of self-referential statics,
// * be able to get information on extern statics.
let ty = self
.tcx
.type_of(def_id)
.no_bound_vars()
.expect("statics should not have generic parameters");
let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
assert!(layout.is_sized());
(layout.size, layout.align.abi)
};
(size, align, AllocKind::LiveData)
}
Some(GlobalAlloc::Memory(alloc)) => {
// Need to duplicate the logic here, because the global allocations have