Turn const_caller_location from a query to a hook

Author: oli-obk

compiler/rustc_const_eval/src/lib.rs

@@ -49,7 +49,7 @@ 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.const_caller_location = util::caller_location::const_caller_location_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();
         const_eval::eval_to_valtree(tcx, param_env, raw)

compiler/rustc_const_eval/src/util/caller_location.rs

@@ -1,8 +1,9 @@
 use rustc_hir::LangItem;
 use rustc_middle::mir;
+use rustc_middle::query::TyCtxtAt;
+use rustc_middle::ty;
 use rustc_middle::ty::layout::LayoutOf;
-use rustc_middle::ty::{self, TyCtxt};
-use rustc_span::{source_map::DUMMY_SP, symbol::Symbol};
+use rustc_span::symbol::Symbol;
 use rustc_type_ir::Mutability;
 
 use crate::const_eval::{mk_eval_cx, CanAccessStatics, CompileTimeEvalContext};
@@ -49,11 +50,13 @@ fn alloc_caller_location<'mir, 'tcx>(
 }
 
 pub(crate) fn const_caller_location_provider(
-    tcx: TyCtxt<'_>,
-    (file, line, col): (Symbol, u32, u32),
+    tcx: TyCtxtAt<'_>,
+    file: Symbol,
+    line: u32,
+    col: u32,
 ) -> mir::ConstValue<'_> {
     trace!("const_caller_location: {}:{}:{}", file, line, col);
-    let mut ecx = mk_eval_cx(tcx, DUMMY_SP, ty::ParamEnv::reveal_all(), CanAccessStatics::No);
+    let mut ecx = mk_eval_cx(tcx.tcx, tcx.span, ty::ParamEnv::reveal_all(), CanAccessStatics::No);
 
     let loc_place = alloc_caller_location(&mut ecx, file, line, col);
     if intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &loc_place).is_err() {

compiler/rustc_middle/src/hooks/mod.rs

@@ -67,4 +67,7 @@ declare_hooks! {
     /// Tries to destructure an `mir::Const` ADT or array into its variant index
     /// and its field values. This should only be used for pretty printing.
     hook try_destructure_mir_constant_for_diagnostics(val: mir::ConstValue<'tcx>, ty: Ty<'tcx>) -> Option<mir::DestructuredConstant<'tcx>>;
+
+    /// Getting a &core::panic::Location referring to a span.
+    hook const_caller_location(file: rustc_span::Symbol, line: u32, col: u32) -> mir::ConstValue<'tcx>;
 }

compiler/rustc_middle/src/mir/consts.rs

@@ -590,12 +590,12 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn span_as_caller_location(self, span: Span) -> ConstValue<'tcx> {
         let topmost = span.ctxt().outer_expn().expansion_cause().unwrap_or(span);
         let caller = self.sess.source_map().lookup_char_pos(topmost.lo());
-        self.const_caller_location((
+        self.const_caller_location(
             rustc_span::symbol::Symbol::intern(
                 &caller.file.name.for_codegen(&self.sess).to_string_lossy(),
             ),
             caller.line as u32,
             caller.col_display as u32 + 1,
-        ))
+        )
     }
 }

compiler/rustc_middle/src/query/mod.rs

@@ -1101,10 +1101,6 @@ rustc_queries! {
         desc { "destructuring type level constant"}
     }
 
-    query const_caller_location(key: (rustc_span::Symbol, u32, u32)) -> mir::ConstValue<'tcx> {
-        desc { "getting a &core::panic::Location referring to a span" }
-    }
-
     // FIXME get rid of this with valtrees
     query lit_to_const(
         key: LitToConstInput<'tcx>