diff --git a/src/librustc_mir/interpret/const_eval.rs b/src/librustc_mir/interpret/const_eval.rs index 87219511e6ff3..57977b6201a61 100644 --- a/src/librustc_mir/interpret/const_eval.rs +++ b/src/librustc_mir/interpret/const_eval.rs @@ -5,6 +5,7 @@ use rustc::mir; use rustc::ty::{self, TyCtxt, Ty, Instance}; use rustc::ty::layout::{self, LayoutOf}; use rustc::ty::subst::Subst; +use rustc::util::nodemap::FxHashSet; use syntax::ast::Mutability; use syntax::codemap::Span; @@ -504,7 +505,13 @@ pub fn const_eval_provider<'a, 'tcx>( }; let (res, ecx) = eval_body_and_ecx(tcx, cid, None, key.param_env); - res.map(|(miri_value, _, miri_ty)| { + res.map(|(miri_value, ptr, miri_ty)| { + if tcx.is_static(def_id).is_some() { + if let Ok(ptr) = ptr.primval.to_ptr() { + let mut seen = FxHashSet::default(); + create_depgraph_edges(tcx, ptr.alloc_id, &mut seen); + } + } tcx.mk_const(ty::Const { val: ConstVal::Value(miri_value), ty: miri_ty, @@ -521,3 +528,35 @@ pub fn const_eval_provider<'a, 'tcx>( } }) } + +// This function creates dep graph edges from statics to all referred to statics. +// This is necessary, because the `const_eval` query cannot directly call itself +// for other statics, because we cannot prevent recursion in queries. +// +// see test/incremental/static_refering_to_other_static2/issue.rs for an example +// where not creating those edges would cause static A, which refers to static B +// to point to the old allocation of static B, even though B has changed. +// +// In the future we will want to remove this funcion in favour of a system that +// makes sure that statics don't need to have edges to other statics as long as +// they are only referring by reference and not inspecting the other static's body. +fn create_depgraph_edges<'a, 'tcx>( + tcx: TyCtxt<'a, 'tcx, 'tcx>, + alloc_id: AllocId, + seen: &mut FxHashSet, +) { + trace!("create_depgraph_edges: {:?}, {:?}", alloc_id, seen); + if seen.insert(alloc_id) { + trace!("seen: {:?}, {:?}", alloc_id, seen); + if let Some(alloc) = tcx.interpret_interner.get_alloc(alloc_id) { + trace!("get_alloc: {:?}, {:?}, {:?}", alloc_id, seen, alloc); + for (_, &reloc) in &alloc.relocations { + if let Some(did) = tcx.interpret_interner.get_corresponding_static_def_id(reloc) { + trace!("get_corresponding: {:?}, {:?}, {:?}, {:?}, {:?}", alloc_id, seen, alloc, did, reloc); + let _ = tcx.maybe_optimized_mir(did); + } + create_depgraph_edges(tcx, reloc, seen); + } + } + } +} diff --git a/src/test/incremental/static_refering_to_other_static2/issue.rs b/src/test/incremental/static_refering_to_other_static2/issue.rs new file mode 100644 index 0000000000000..5584786689518 --- /dev/null +++ b/src/test/incremental/static_refering_to_other_static2/issue.rs @@ -0,0 +1,20 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// revisions:rpass1 rpass2 + +#[cfg(rpass1)] +pub static A: i32 = 42; +#[cfg(rpass2)] +pub static A: i32 = 43; + +pub static B: &i32 = &A; + +fn main() {}