From 8b847ef734e2bf2d424cf111f671978505c04cf1 Mon Sep 17 00:00:00 2001
From: Moulins <arthur.heuillard@orange.fr>
Date: Fri, 23 Jun 2023 21:05:24 +0200
Subject: [PATCH] add crate-local `-Z reference_niches` unstable flag (does
nothing for now)
---
compiler/rustc_abi/src/lib.rs | 8 +++++
compiler/rustc_interface/src/tests.rs | 2 ++
.../src/rmeta/decoder/cstore_impl.rs | 1 +
compiler/rustc_metadata/src/rmeta/encoder.rs | 1 +
compiler/rustc_metadata/src/rmeta/mod.rs | 3 +-
compiler/rustc_middle/src/query/erase.rs | 1 +
compiler/rustc_middle/src/query/mod.rs | 5 ++++
compiler/rustc_session/src/config.rs | 2 ++
compiler/rustc_session/src/options.rs | 30 +++++++++++++++++++
compiler/rustc_ty_utils/src/layout.rs | 11 +++++--
10 files changed, 61 insertions(+), 3 deletions(-)
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index ef0c763ac20..29b3c44dcd6 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -49,6 +49,14 @@ bitflags! {
}
}
+/// Which niches (beyond the `null` niche) are available on references.
+#[derive(Default, Copy, Clone, Hash, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+pub struct ReferenceNichePolicy {
+ pub size: bool,
+ pub align: bool,
+}
+
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
pub enum IntegerType {
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 5c6c3491b38..49bd7b6aa9c 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -28,6 +28,7 @@ use rustc_span::edition::{Edition, DEFAULT_EDITION};
use rustc_span::symbol::sym;
use rustc_span::FileName;
use rustc_span::SourceFileHashAlgorithm;
+use rustc_target::abi::ReferenceNichePolicy;
use rustc_target::spec::{CodeModel, LinkerFlavorCli, MergeFunctions, PanicStrategy, RelocModel};
use rustc_target::spec::{RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TlsModel};
@@ -819,6 +820,7 @@ fn test_unstable_options_tracking_hash() {
tracked!(profile_emit, Some(PathBuf::from("abc")));
tracked!(profile_sample_use, Some(PathBuf::from("abc")));
tracked!(profiler_runtime, "abc".to_string());
+ tracked!(reference_niches, Some(ReferenceNichePolicy { size: true, align: false }));
tracked!(relax_elf_relocations, Some(true));
tracked!(relro_level, Some(RelroLevel::Full));
tracked!(remap_cwd_prefix, Some(PathBuf::from("abc")));
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index a8815ee0908..77c33336dff 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -301,6 +301,7 @@ provide! { tcx, def_id, other, cdata,
is_profiler_runtime => { cdata.root.profiler_runtime }
required_panic_strategy => { cdata.root.required_panic_strategy }
panic_in_drop_strategy => { cdata.root.panic_in_drop_strategy }
+ reference_niches_policy => { cdata.root.reference_niches_policy }
extern_crate => {
let r = *cdata.extern_crate.lock();
r.map(|c| &*tcx.arena.alloc(c))
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index ac86110f2bd..46571e7796d 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -673,6 +673,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
stable_crate_id: tcx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(),
required_panic_strategy: tcx.required_panic_strategy(LOCAL_CRATE),
panic_in_drop_strategy: tcx.sess.opts.unstable_opts.panic_in_drop,
+ reference_niches_policy: tcx.reference_niches_policy(LOCAL_CRATE),
edition: tcx.sess.edition(),
has_global_allocator: tcx.has_global_allocator(LOCAL_CRATE),
has_alloc_error_handler: tcx.has_alloc_error_handler(LOCAL_CRATE),
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 0bc16fc64ff..8bc2e0aa5a9 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -32,7 +32,7 @@ use rustc_span::edition::Edition;
use rustc_span::hygiene::{ExpnIndex, MacroKind};
use rustc_span::symbol::{Ident, Symbol};
use rustc_span::{self, ExpnData, ExpnHash, ExpnId, Span};
-use rustc_target::abi::{FieldIdx, VariantIdx};
+use rustc_target::abi::{FieldIdx, ReferenceNichePolicy, VariantIdx};
use rustc_target::spec::{PanicStrategy, TargetTriple};
use std::marker::PhantomData;
@@ -251,6 +251,7 @@ pub(crate) struct CrateRoot {
stable_crate_id: StableCrateId,
required_panic_strategy: Option<PanicStrategy>,
panic_in_drop_strategy: PanicStrategy,
+ reference_niches_policy: ReferenceNichePolicy,
edition: Edition,
has_global_allocator: bool,
has_alloc_error_handler: bool,
diff --git a/compiler/rustc_middle/src/query/erase.rs b/compiler/rustc_middle/src/query/erase.rs
index a0cb23b5a4c..9bf02267005 100644
--- a/compiler/rustc_middle/src/query/erase.rs
+++ b/compiler/rustc_middle/src/query/erase.rs
@@ -296,6 +296,7 @@ trivial! {
rustc_span::Symbol,
rustc_span::symbol::Ident,
rustc_target::spec::PanicStrategy,
+ rustc_target::abi::ReferenceNichePolicy,
rustc_type_ir::Variance,
u32,
usize,
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index c728cc0b39f..51409f90843 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1480,6 +1480,11 @@ rustc_queries! {
desc { "getting a crate's configured panic-in-drop strategy" }
separate_provide_extern
}
+ query reference_niches_policy(_: CrateNum) -> abi::ReferenceNichePolicy {
+ fatal_cycle
+ desc { "getting a crate's policy for size and alignment niches of references" }
+ separate_provide_extern
+ }
query is_no_builtins(_: CrateNum) -> bool {
fatal_cycle
desc { "getting whether a crate has `#![no_builtins]`" }
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 593983f117d..43dae9e8de2 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -3076,6 +3076,7 @@ pub(crate) mod dep_tracking {
use rustc_feature::UnstableFeatures;
use rustc_span::edition::Edition;
use rustc_span::RealFileName;
+ use rustc_target::abi::ReferenceNichePolicy;
use rustc_target::spec::{CodeModel, MergeFunctions, PanicStrategy, RelocModel};
use rustc_target::spec::{
RelroLevel, SanitizerSet, SplitDebuginfo, StackProtector, TargetTriple, TlsModel,
@@ -3171,6 +3172,7 @@ pub(crate) mod dep_tracking {
OomStrategy,
LanguageIdentifier,
TraitSolver,
+ ReferenceNichePolicy,
);
impl<T1, T2> DepTrackingHash for (T1, T2)
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 87d67c099ce..0d63db2bfef 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -6,6 +6,7 @@ use crate::{lint, EarlyErrorHandler};
use rustc_data_structures::profiling::TimePassesFormat;
use rustc_errors::ColorConfig;
use rustc_errors::{LanguageIdentifier, TerminalUrl};
+use rustc_target::abi::ReferenceNichePolicy;
use rustc_target::spec::{CodeModel, LinkerFlavorCli, MergeFunctions, PanicStrategy, SanitizerSet};
use rustc_target::spec::{
RelocModel, RelroLevel, SplitDebuginfo, StackProtector, TargetTriple, TlsModel,
@@ -421,6 +422,8 @@ mod desc {
pub const parse_proc_macro_execution_strategy: &str =
"one of supported execution strategies (`same-thread`, or `cross-thread`)";
pub const parse_dump_solver_proof_tree: &str = "one of: `always`, `on-request`, `on-error`";
+ pub const parse_opt_reference_niches: &str =
+ "`null`, or a `,` separated combination of `size` or `align`";
}
mod parse {
@@ -1253,6 +1256,31 @@ mod parse {
};
true
}
+
+ pub(crate) fn parse_opt_reference_niches(
+ slot: &mut Option<ReferenceNichePolicy>,
+ v: Option<&str>,
+ ) -> bool {
+ let Some(s) = v else {
+ return false;
+ };
+
+ let slot = slot.get_or_insert_default();
+
+ if s == "null" {
+ return true;
+ }
+
+ for opt in s.split(",") {
+ match opt {
+ "size" => slot.size = true,
+ "align" => slot.align = true,
+ _ => return false,
+ }
+ }
+
+ true
+ }
}
options! {
@@ -1698,6 +1726,8 @@ options! {
"enable queries of the dependency graph for regression testing (default: no)"),
randomize_layout: bool = (false, parse_bool, [TRACKED],
"randomize the layout of types (default: no)"),
+ reference_niches: Option<ReferenceNichePolicy> = (None, parse_opt_reference_niches, [TRACKED],
+ "override the set of discriminant niches that may be exposed by references"),
relax_elf_relocations: Option<bool> = (None, parse_opt_bool, [TRACKED],
"whether ELF relocations can be relaxed"),
relro_level: Option<RelroLevel> = (None, parse_relro_level, [TRACKED],
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 2afe1cb37bb..19545a1b135 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -3,7 +3,7 @@ use rustc_hir as hir;
use rustc_index::bit_set::BitSet;
use rustc_index::{IndexSlice, IndexVec};
use rustc_middle::mir::{GeneratorLayout, GeneratorSavedLocal};
-use rustc_middle::query::Providers;
+use rustc_middle::query::{LocalCrate, Providers};
use rustc_middle::ty::layout::{
IntegerExt, LayoutCx, LayoutError, LayoutOf, NaiveLayout, TyAndLayout, TyAndNaiveLayout,
MAX_SIMD_LANES,
@@ -25,7 +25,14 @@ use crate::errors::{
use crate::layout_sanity_check::sanity_check_layout;
pub fn provide(providers: &mut Providers) {
- *providers = Providers { layout_of, naive_layout_of, ..*providers };
+ *providers = Providers { layout_of, naive_layout_of, reference_niches_policy, ..*providers };
+}
+
+#[instrument(skip(tcx), level = "debug")]
+fn reference_niches_policy<'tcx>(tcx: TyCtxt<'tcx>, _: LocalCrate) -> ReferenceNichePolicy {
+ const DEFAULT: ReferenceNichePolicy = ReferenceNichePolicy { size: false, align: false };
+
+ tcx.sess.opts.unstable_opts.reference_niches.unwrap_or(DEFAULT)
}
#[instrument(skip(tcx, query), level = "debug")]