Get rid of special const intrinsic query in favour of const_eval

Author: oli-obk

src/librustc/query/mod.rs

@@ -441,15 +441,6 @@ rustc_queries! {
             no_force
             desc { "extract field of const" }
         }
-
-        /// Produces an absolute path representation of the given type. See also the documentation
-        /// on `std::any::type_name`.
-        query type_name(key: Ty<'tcx>) -> &'tcx ty::Const<'tcx> {
-            eval_always
-            no_force
-            desc { "get absolute path of type" }
-        }
-
     }
 
     TypeChecking {

src/librustc_codegen_llvm/intrinsic.rs

@@ -17,6 +17,7 @@ use rustc_codegen_ssa::glue;
 use rustc_codegen_ssa::base::{to_immediate, wants_msvc_seh, compare_simd_types};
 use rustc::ty::{self, Ty};
 use rustc::ty::layout::{self, LayoutOf, HasTyCtxt, Primitive};
+use rustc::mir::interpret::GlobalId;
 use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
 use rustc::hir;
 use syntax::ast::{self, FloatTy};
@@ -83,13 +84,14 @@ fn get_simple_intrinsic(cx: &CodegenCx<'ll, '_>, name: &str) -> Option<&'ll Valu
 impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
     fn codegen_intrinsic_call(
         &mut self,
-        callee_ty: Ty<'tcx>,
+        instance: ty::Instance<'tcx>,
         fn_ty: &FnType<'tcx, Ty<'tcx>>,
         args: &[OperandRef<'tcx, &'ll Value>],
         llresult: &'ll Value,
         span: Span,
     ) {
         let tcx = self.tcx;
+        let callee_ty = instance.ty(tcx);
 
         let (def_id, substs) = match callee_ty.sty {
             ty::FnDef(def_id, substs) => (def_id, substs),
@@ -208,8 +210,11 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
                 self.const_usize(self.layout_of(tp_ty).align.pref.bytes())
             }
             "type_name" => {
-                let tp_ty = substs.type_at(0);
-                let ty_name = self.tcx.type_name(tp_ty);
+                let gid = GlobalId {
+                    instance,
+                    promoted: None,
+                };
+                let ty_name = self.tcx.const_eval(ty::ParamEnv::reveal_all().and(gid)).unwrap();
                 OperandRef::from_const(self, ty_name).immediate_or_packed_pair(self)
             }
             "type_id" => {

src/librustc_codegen_ssa/mir/block.rs

@@ -662,8 +662,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             }).collect();
 
 
-            let callee_ty = instance.as_ref().unwrap().ty(bx.tcx());
-            bx.codegen_intrinsic_call(callee_ty, &fn_ty, &args, dest,
+            bx.codegen_intrinsic_call(*instance.as_ref().unwrap(), &fn_ty, &args, dest,
                                       terminator.source_info.span);
 
             if let ReturnDest::IndirectOperand(dst, _) = ret_dest {

src/librustc_codegen_ssa/traits/intrinsic.rs

@@ -1,6 +1,6 @@
 use super::BackendTypes;
 use crate::mir::operand::OperandRef;
-use rustc::ty::Ty;
+use rustc::ty::{self, Ty};
 use rustc_target::abi::call::FnType;
 use syntax_pos::Span;
 
@@ -10,7 +10,7 @@ pub trait IntrinsicCallMethods<'tcx>: BackendTypes {
     /// add them to librustc_codegen_llvm/context.rs
     fn codegen_intrinsic_call(
         &mut self,
-        callee_ty: Ty<'tcx>,
+        instance: ty::Instance<'tcx>,
         fn_ty: &FnType<'tcx, Ty<'tcx>>,
         args: &[OperandRef<'tcx, Self::Value>],
         llresult: Self::Value,

src/librustc_mir/const_eval.rs

@@ -13,10 +13,11 @@ use rustc::mir::interpret::{ConstEvalErr, ErrorHandled, ScalarMaybeUndef};
 use rustc::mir;
 use rustc::ty::{self, TyCtxt, query::TyCtxtAt};
 use rustc::ty::layout::{self, LayoutOf, VariantIdx};
-use rustc::ty::subst::Subst;
+use rustc::ty::subst::{Subst, SubstsRef};
 use rustc::traits::Reveal;
 use rustc::util::common::ErrorReported;
 use rustc_data_structures::fx::FxHashMap;
+use crate::interpret::alloc_type_name;
 
 use syntax::source_map::{Span, DUMMY_SP};
 
@@ -588,11 +589,42 @@ pub fn const_eval_provider<'tcx>(
             other => return other,
         }
     }
+
+    if let ty::InstanceDef::Intrinsic(def_id) = key.value.instance.def {
+        let ty = key.value.instance.ty(tcx);
+        let substs = match ty.sty {
+            ty::FnDef(_, substs) => substs,
+            _ => bug!("intrinsic with type {:?}", ty),
+        };
+        return Ok(eval_intrinsic(tcx, def_id, substs));
+    }
+
     tcx.const_eval_raw(key).and_then(|val| {
         validate_and_turn_into_const(tcx, val, key)
     })
 }
 
+fn eval_intrinsic<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    def_id: DefId,
+    substs: SubstsRef<'tcx>,
+) -> &'tcx ty::Const<'tcx> {
+    match &*tcx.item_name(def_id).as_str() {
+        "type_name" => {
+            let alloc = alloc_type_name(tcx, substs.type_at(0));
+            tcx.mk_const(ty::Const {
+                val: ConstValue::Slice {
+                    data: alloc,
+                    start: 0,
+                    end: alloc.bytes.len(),
+                },
+                ty: tcx.mk_static_str(),
+            })
+        },
+        other => bug!("`{}` is not a zero arg intrinsic", other),
+    }
+}
+
 pub fn const_eval_raw_provider<'tcx>(
     tcx: TyCtxt<'tcx>,
     key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>,

src/librustc_mir/interpret/intrinsics.rs

@@ -16,7 +16,7 @@ use super::{
 
 mod type_name;
 
-pub use type_name::*;
+pub(crate) use type_name::alloc_type_name;
 
 fn numeric_intrinsic<'tcx, Tag>(
     name: &str,

src/librustc_mir/interpret/intrinsics/type_name.rs

@@ -7,7 +7,7 @@ use rustc::ty::{
 use rustc::hir::map::{DefPathData, DisambiguatedDefPathData};
 use rustc::hir::def_id::CrateNum;
 use std::fmt::Write;
-use rustc::mir::interpret::{Allocation, ConstValue};
+use rustc::mir::interpret::Allocation;
 
 struct AbsolutePathPrinter<'tcx> {
     tcx: TyCtxt<'tcx>,
@@ -208,22 +208,11 @@ impl Write for AbsolutePathPrinter<'_> {
     }
 }
 
-/// Produces an absolute path representation of the given type. See also the documentation on
-/// `std::any::type_name`
-pub fn type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> &'tcx ty::Const<'tcx> {
-    let alloc = alloc_type_name(tcx, ty);
-    tcx.mk_const(ty::Const {
-        val: ConstValue::Slice {
-            data: alloc,
-            start: 0,
-            end: alloc.bytes.len(),
-        },
-        ty: tcx.mk_static_str(),
-    })
-}
-
 /// Directly returns an `Allocation` containing an absolute path representation of the given type.
-pub(super) fn alloc_type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> &'tcx Allocation {
+pub(crate) fn alloc_type_name<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ty: Ty<'tcx>
+) -> &'tcx Allocation {
     let path = AbsolutePathPrinter { tcx, path: String::new() }.print_type(ty).unwrap().path;
     let alloc = Allocation::from_byte_aligned_bytes(path.into_bytes());
     tcx.intern_const_alloc(alloc)

src/librustc_mir/interpret/mod.rs

@@ -34,6 +34,6 @@ pub use self::visitor::{ValueVisitor, MutValueVisitor};
 
 pub use self::validity::RefTracking;
 
-pub(super) use self::intrinsics::type_name;
-
 pub use self::intern::intern_const_alloc_recursive;
+
+pub(crate) use self::intrinsics::alloc_type_name;

src/librustc_mir/lib.rs

@@ -69,7 +69,6 @@ pub fn provide(providers: &mut Providers<'_>) {
         let (param_env, (value, field)) = param_env_and_value.into_parts();
         const_eval::const_field(tcx, param_env, None, field, value)
     };
-    providers.type_name = interpret::type_name;
 }
 
 __build_diagnostic_array! { librustc_mir, DIAGNOSTICS }