bjoernager/rust
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Do not allocate a second "background" alloc id for the main allocation of a static.

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Instead we re-use the static's alloc id within the interpreter for its initializer to refer to the `Allocation` that only exists within the interpreter.
This commit is contained in:
Oli Scherer 2023-10-12 11:27:43 +00:00
parent e2386270df
commit 73b38c661d
19 changed files with 262 additions and 102 deletions
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14
compiler/rustc_const_eval/src/interpret/eval_context.rs
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@ -899,7 +899,19 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
.local_to_op(self.frame(), mir::RETURN_PLACE, None)
.expect("return place should always be live");
let dest = self.frame().return_place.clone();
let err = self.copy_op_allow_transmute(&op, &dest);
let err = if self.stack().len() == 1 {
// The initializer of constants and statics will get validated separately
// after the constant has been fully evaluated. While we could fall back to the default
// code path, that will cause -Zenforce-validity to cycle on static initializers.
// Reading from a static's memory is not allowed during its evaluation, and will always
// trigger a cycle error. Validation must read from the memory of the current item.
// For Miri this means we do not validate the root frame return value,
// but Miri anyway calls `read_target_isize` on that so separate validation
// is not needed.
self.copy_op_no_dest_validation(&op, &dest)
} else {
self.copy_op_allow_transmute(&op, &dest)
};
trace!("return value: {:?}", self.dump_place(&dest));
// We delay actually short-circuiting on this error until *after* the stack frame is
// popped, since we want this error to be attributed to the caller, whose type defines