Return ConstAllocation from eval_static_initializer query directly

Author: oli-obk

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -8,6 +8,7 @@ use rustc_middle::traits::Reveal;
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 use rustc_target::abi::{self, Abi};
 
@@ -249,11 +250,36 @@ pub fn eval_to_const_value_raw_provider<'tcx>(
     tcx.eval_to_allocation_raw(key).map(|val| turn_into_const_value(tcx, val, key))
 }
 
+#[instrument(skip(tcx), level = "debug")]
+pub fn eval_static_initializer_provider<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    def_id: LocalDefId,
+) -> ::rustc_middle::mir::interpret::EvalStaticInitializerRawResult<'tcx> {
+    assert!(tcx.is_static(def_id.to_def_id()));
+
+    let instance = ty::Instance::mono(tcx, def_id.to_def_id());
+    let cid = rustc_middle::mir::interpret::GlobalId { instance, promoted: None };
+    let ecx = InterpCx::new(
+        tcx,
+        tcx.def_span(def_id),
+        ty::ParamEnv::reveal_all(),
+        // Statics (and promoteds inside statics) may access other statics, because unlike consts
+        // they do not have to behave "as if" they were evaluated at runtime.
+        CompileTimeInterpreter::new(CanAccessMutGlobal::Yes, CheckAlignment::Error),
+    );
+    let alloc_id = eval_in_interpreter(ecx, cid, true)?.alloc_id;
+    let alloc = tcx.global_alloc(alloc_id).unwrap_memory();
+    Ok(alloc)
+}
+
 #[instrument(skip(tcx), level = "debug")]
 pub fn eval_to_allocation_raw_provider<'tcx>(
     tcx: TyCtxt<'tcx>,
     key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,
 ) -> ::rustc_middle::mir::interpret::EvalToAllocationRawResult<'tcx> {
+    // This shouldn't be used for statics, since statics are conceptually places,
+    // not values -- so what we do here could break pointer identity.
+    assert!(key.value.promoted.is_some() || !tcx.is_static(key.value.instance.def_id()));
     // Const eval always happens in Reveal::All mode in order to be able to use the hidden types of
     // opaque types. This is needed for trivial things like `size_of`, but also for using associated
     // types that are not specified in the opaque type.

compiler/rustc_const_eval/src/lib.rs

@@ -40,13 +40,7 @@ pub fn provide(providers: &mut Providers) {
     const_eval::provide(providers);
     providers.eval_to_const_value_raw = const_eval::eval_to_const_value_raw_provider;
     providers.eval_to_allocation_raw = const_eval::eval_to_allocation_raw_provider;
-    providers.eval_static_initializer_raw = |tcx, def_id| {
-        assert!(tcx.is_static(def_id.to_def_id()));
-        let instance = ty::Instance::mono(tcx, def_id.to_def_id());
-        let gid = rustc_middle::mir::interpret::GlobalId { instance, promoted: None };
-        let param_env = ty::ParamEnv::reveal_all();
-        Ok(tcx.eval_to_allocation_raw(param_env.and(gid))?.alloc_id)
-    };
+    providers.eval_static_initializer = const_eval::eval_static_initializer_provider;
     providers.hooks.const_caller_location = util::caller_location::const_caller_location_provider;
     providers.eval_to_valtree = |tcx, param_env_and_value| {
         let (param_env, raw) = param_env_and_value.into_parts();

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -250,14 +250,14 @@ provide! { tcx, def_id, other, cdata,
     fn_arg_names => { table }
     coroutine_kind => { table_direct }
     coroutine_for_closure => { table }
-    eval_static_initializer_raw => {
+    eval_static_initializer => {
         Ok(cdata
             .root
             .tables
-            .eval_static_initializer_raw
+            .eval_static_initializer
             .get(cdata, def_id.index)
             .map(|lazy| lazy.decode((cdata, tcx)))
-            .unwrap_or_else(|| panic!("{def_id:?} does not have eval_static_initializer_raw")))
+            .unwrap_or_else(|| panic!("{def_id:?} does not have eval_static_initializer")))
     }
     trait_def => { table }
     deduced_param_attrs => { table }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1454,8 +1454,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
             if let DefKind::Static(_) = def_kind {
                 if !self.tcx.is_foreign_item(def_id) {
-                    let data = self.tcx.eval_static_initializer_raw(def_id).unwrap();
-                    record!(self.tables.eval_static_initializer_raw[def_id] <- data);
+                    let data = self.tcx.eval_static_initializer(def_id).unwrap();
+                    record!(self.tables.eval_static_initializer[def_id] <- data);
                 }
             }
             if let DefKind::Enum | DefKind::Struct | DefKind::Union = def_kind {

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -443,7 +443,7 @@ define_tables! {
     fn_arg_names: Table<DefIndex, LazyArray<Ident>>,
     coroutine_kind: Table<DefIndex, hir::CoroutineKind>,
     coroutine_for_closure: Table<DefIndex, RawDefId>,
-    eval_static_initializer_raw: Table<DefIndex, LazyValue<mir::interpret::AllocId>>,
+    eval_static_initializer: Table<DefIndex, LazyValue<mir::interpret::ConstAllocation<'static>>>,
     trait_def: Table<DefIndex, LazyValue<ty::TraitDef>>,
     trait_item_def_id: Table<DefIndex, RawDefId>,
     expn_that_defined: Table<DefIndex, LazyValue<ExpnId>>,

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -1,4 +1,4 @@
-use super::{AllocId, AllocRange, Pointer, Scalar};
+use super::{AllocId, AllocRange, ConstAllocation, Pointer, Scalar};
 
 use crate::error;
 use crate::mir::{ConstAlloc, ConstValue};
@@ -83,7 +83,7 @@ impl Into<ErrorGuaranteed> for ReportedErrorInfo {
 TrivialTypeTraversalImpls! { ErrorHandled }
 
 pub type EvalToAllocationRawResult<'tcx> = Result<ConstAlloc<'tcx>, ErrorHandled>;
-pub type EvalStaticInitializerRawResult = Result<AllocId, ErrorHandled>;
+pub type EvalStaticInitializerRawResult<'tcx> = Result<ConstAllocation<'tcx>, ErrorHandled>;
 pub type EvalToConstValueResult<'tcx> = Result<ConstValue<'tcx>, ErrorHandled>;
 /// `Ok(None)` indicates the constant was fine, but the valtree couldn't be constructed.
 /// This is needed in `thir::pattern::lower_inline_const`.

compiler/rustc_middle/src/mir/interpret/queries.rs

@@ -1,7 +1,7 @@
 use super::{ErrorHandled, EvalToConstValueResult, EvalToValTreeResult, GlobalId};
 
 use crate::mir;
-use crate::query::{TyCtxtAt, TyCtxtEnsure};
+use crate::query::TyCtxtEnsure;
 use crate::ty::visit::TypeVisitableExt;
 use crate::ty::GenericArgs;
 use crate::ty::{self, TyCtxt};
@@ -173,30 +173,6 @@ impl<'tcx> TyCtxt<'tcx> {
             self.eval_to_valtree(inputs)
         }
     }
-
-    /// Evaluate a static's initializer, returning the allocation of the initializer's memory.
-    #[inline(always)]
-    pub fn eval_static_initializer(
-        self,
-        def_id: DefId,
-    ) -> Result<mir::ConstAllocation<'tcx>, ErrorHandled> {
-        self.at(DUMMY_SP).eval_static_initializer(def_id)
-    }
-}
-
-impl<'tcx> TyCtxtAt<'tcx> {
-    /// Evaluate a static's initializer, returning the allocation of the initializer's memory.
-    ///
-    /// The span is entirely ignored here, but still helpful for better query cycle errors.
-    pub fn eval_static_initializer(
-        self,
-        def_id: DefId,
-    ) -> Result<mir::ConstAllocation<'tcx>, ErrorHandled> {
-        trace!("eval_static_initializer: Need to compute {:?}", def_id);
-        assert!(self.is_static(def_id));
-        let alloc_id = self.eval_static_initializer_raw(def_id)?;
-        Ok(self.global_alloc(alloc_id).unwrap_memory())
-    }
 }
 
 impl<'tcx> TyCtxtEnsure<'tcx> {
@@ -218,11 +194,4 @@ impl<'tcx> TyCtxtEnsure<'tcx> {
         let inputs = self.tcx.erase_regions(param_env.and(cid));
         self.eval_to_const_value_raw(inputs)
     }
-
-    /// Evaluate a static's initializer, returning the allocation of the initializer's memory.
-    pub fn eval_static_initializer(self, def_id: DefId) {
-        trace!("eval_static_initializer: Need to compute {:?}", def_id);
-        assert!(self.tcx.is_static(def_id));
-        self.eval_static_initializer_raw(def_id);
-    }
 }

compiler/rustc_middle/src/mir/mod.rs

@@ -2,7 +2,7 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/mir/index.html
 
-use crate::mir::interpret::{AllocRange, ConstAllocation, Scalar};
+use crate::mir::interpret::{AllocRange, Scalar};
 use crate::mir::visit::MirVisitable;
 use crate::ty::codec::{TyDecoder, TyEncoder};
 use crate::ty::fold::{FallibleTypeFolder, TypeFoldable};

compiler/rustc_middle/src/mir/pretty.rs

@@ -4,6 +4,8 @@ use std::fs;
 use std::io::{self, Write as _};
 use std::path::{Path, PathBuf};
 
+use crate::mir::interpret::ConstAllocation;
+
 use super::graphviz::write_mir_fn_graphviz;
 use rustc_ast::InlineAsmTemplatePiece;
 use rustc_middle::mir::interpret::{

compiler/rustc_middle/src/query/erase.rs

@@ -277,7 +277,6 @@ trivial! {
     rustc_middle::mir::interpret::CtfeProvenance,
     rustc_middle::mir::interpret::ErrorHandled,
     rustc_middle::mir::interpret::LitToConstError,
-    rustc_middle::mir::interpret::EvalStaticInitializerRawResult,
     rustc_middle::thir::ExprId,
     rustc_middle::traits::CodegenObligationError,
     rustc_middle::traits::EvaluationResult,
@@ -338,6 +337,7 @@ tcx_lifetime! {
     rustc_middle::mir::ConstValue,
     rustc_middle::mir::interpret::GlobalId,
     rustc_middle::mir::interpret::LitToConstInput,
+    rustc_middle::mir::interpret::EvalStaticInitializerRawResult,
     rustc_middle::traits::query::MethodAutoderefStepsResult,
     rustc_middle::traits::query::type_op::AscribeUserType,
     rustc_middle::traits::query::type_op::Eq,