Infallible version of fn_sig.

Author: cjgillot

compiler/rustc_incremental/src/persist/dirty_clean.rs

@@ -42,7 +42,7 @@ const BASE_CONST: &[&str] = &[label_strs::try_type_of];
 /// DepNodes for functions + methods
 const BASE_FN: &[&str] = &[
     // Callers will depend on the signature of these items, so we better test
-    label_strs::fn_sig,
+    label_strs::try_fn_sig,
     label_strs::generics_of,
     label_strs::predicates_of,
     label_strs::try_type_of,

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

@@ -123,7 +123,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     mir_abstract_const => { cdata.get_mir_abstract_const(tcx, def_id.index) }
     unused_generic_params => { cdata.get_unused_generic_params(def_id.index) }
     mir_const_qualif => { cdata.mir_const_qualif(def_id.index) }
-    fn_sig => { cdata.fn_sig(def_id.index, tcx) }
+    try_fn_sig => { Ok(cdata.fn_sig(def_id.index, tcx)) }
     inherent_impls => { cdata.get_inherent_implementations_for_type(tcx, def_id.index) }
     is_const_fn_raw => { cdata.is_const_fn_raw(def_id.index) }
     asyncness => { cdata.asyncness(def_id.index) }

compiler/rustc_middle/src/query/mod.rs

@@ -600,7 +600,7 @@ rustc_queries! {
     }
 
     /// The signature of functions.
-    query fn_sig(key: DefId) -> ty::PolyFnSig<'tcx> {
+    query try_fn_sig(key: DefId) -> Result<ty::PolyFnSig<'tcx>, String> {
         desc { |tcx| "computing function signature of `{}`", tcx.def_path_str(key) }
     }
 

compiler/rustc_middle/src/ty/query/mod.rs

@@ -313,6 +313,12 @@ impl TyCtxt<'tcx> {
             .unwrap_or_else(|| bug!("def_kind: unsupported node: {:?}", def_id))
     }
 
+    pub fn fn_sig(self, def_id: impl IntoQueryParam<DefId>) -> ty::PolyFnSig<'tcx> {
+        let def_id = def_id.into_query_param();
+        self.try_fn_sig(def_id)
+            .unwrap_or_else(|s| span_bug!(self.def_span(def_id), "fn_sig: {}", s))
+    }
+
     pub fn type_of(self, def_id: impl IntoQueryParam<DefId>) -> Ty<'tcx> {
         let def_id = def_id.into_query_param();
         self.try_type_of(def_id).unwrap_or_else(|msg| {
@@ -329,6 +335,12 @@ impl TyCtxtAt<'tcx> {
             .unwrap_or_else(|| bug!("def_kind: unsupported node: {:?}", def_id))
     }
 
+    pub fn fn_sig(self, def_id: impl IntoQueryParam<DefId>) -> ty::PolyFnSig<'tcx> {
+        let def_id = def_id.into_query_param();
+        self.try_fn_sig(def_id)
+            .unwrap_or_else(|s| span_bug!(self.def_span(def_id), "fn_sig: {}", s))
+    }
+
     pub fn type_of(self, def_id: impl IntoQueryParam<DefId>) -> Ty<'tcx> {
         let def_id = def_id.into_query_param();
         self.try_type_of(def_id).unwrap_or_else(|msg| {

compiler/rustc_typeck/src/collect.rs

@@ -83,7 +83,7 @@ pub fn provide(providers: &mut Providers) {
         type_param_predicates,
         trait_def,
         adt_def,
-        fn_sig,
+        try_fn_sig,
         impl_trait_ref,
         impl_polarity,
         is_foreign_item,
@@ -730,7 +730,7 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
                 tcx.ensure().try_type_of(item.def_id);
                 tcx.ensure().predicates_of(item.def_id);
                 if let hir::ForeignItemKind::Fn(..) = item.kind {
-                    tcx.ensure().fn_sig(item.def_id);
+                    tcx.ensure().try_fn_sig(item.def_id);
                 }
             }
         }
@@ -793,7 +793,7 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
             tcx.ensure().try_type_of(def_id);
             tcx.ensure().predicates_of(def_id);
             match it.kind {
-                hir::ItemKind::Fn(..) => tcx.ensure().fn_sig(def_id),
+                hir::ItemKind::Fn(..) => tcx.ensure().try_fn_sig(def_id),
                 hir::ItemKind::OpaqueTy(..) => tcx.ensure().item_bounds(def_id),
                 _ => (),
             }
@@ -808,7 +808,7 @@ fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::TraitItemId) {
     match trait_item.kind {
         hir::TraitItemKind::Fn(..) => {
             tcx.ensure().try_type_of(trait_item_id.def_id);
-            tcx.ensure().fn_sig(trait_item_id.def_id);
+            tcx.ensure().try_fn_sig(trait_item_id.def_id);
         }
 
         hir::TraitItemKind::Const(.., Some(_)) => {
@@ -854,7 +854,7 @@ fn convert_impl_item(tcx: TyCtxt<'_>, impl_item_id: hir::ImplItemId) {
     let impl_item = tcx.hir().impl_item(impl_item_id);
     match impl_item.kind {
         hir::ImplItemKind::Fn(..) => {
-            tcx.ensure().fn_sig(def_id);
+            tcx.ensure().try_fn_sig(def_id);
         }
         hir::ImplItemKind::TyAlias(_) => {
             // Account for `type T = _;`
@@ -1631,7 +1631,7 @@ pub fn get_infer_ret_ty(output: &'hir hir::FnRetTy<'hir>) -> Option<&'hir hir::T
     None
 }
 
-fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
+fn try_fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> Result<ty::PolyFnSig<'_>, String> {
     use rustc_hir::Node::*;
     use rustc_hir::*;
 
@@ -1640,7 +1640,8 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
 
     let icx = ItemCtxt::new(tcx, def_id.to_def_id());
 
-    match tcx.hir().get(hir_id) {
+    let node = tcx.hir().find(hir_id).ok_or_else(|| "not found in HIR map".to_owned())?;
+    let sig = match node {
         TraitItem(hir::TraitItem {
             kind: TraitItemKind::Fn(sig, TraitFn::Provided(_)),
             ident,
@@ -1749,15 +1750,17 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: DefId) -> ty::PolyFnSig<'_> {
             // `sig` method on the `ClosureSubsts`:
             //
             //    substs.as_closure().sig(def_id, tcx)
-            bug!(
-                "to get the signature of a closure, use `substs.as_closure().sig()` not `fn_sig()`",
+            return Err(
+                "to get the signature of a closure, use `substs.as_closure().sig()` not `fn_sig()`"
+                    .to_owned(),
             );
         }
 
-        x => {
-            bug!("unexpected sort of node in fn_sig(): {:?}", x);
+        _ => {
+            return Err(format!("unexpected sort of node in fn_sig()"));
         }
-    }
+    };
+    Ok(sig)
 }
 
 fn impl_trait_ref(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::TraitRef<'_>> {

src/test/incremental/hashes/enum_constructors.rs

@@ -139,7 +139,7 @@ pub mod change_constructor_path_indirectly_struct_like {
 
     #[rustc_clean(
         cfg="cfail2",
-        except="fn_sig,hir_owner,hir_owner_nodes,optimized_mir,\
+        except="try_fn_sig,hir_owner,hir_owner_nodes,optimized_mir,\
                 typeck"
     )]
     #[rustc_clean(cfg="cfail3")]
@@ -232,7 +232,7 @@ pub mod change_constructor_path_indirectly_tuple_like {
 
     #[rustc_clean(
         cfg="cfail2",
-        except="fn_sig,hir_owner,hir_owner_nodes,optimized_mir,\
+        except="try_fn_sig,hir_owner,hir_owner_nodes,optimized_mir,\
                 typeck"
     )]
     #[rustc_clean(cfg="cfail3")]
@@ -309,7 +309,7 @@ pub mod change_constructor_path_indirectly_c_like {
 
     #[rustc_clean(
         cfg="cfail2",
-        except="fn_sig,hir_owner,hir_owner_nodes,optimized_mir,\
+        except="try_fn_sig,hir_owner,hir_owner_nodes,optimized_mir,\
                 typeck"
     )]
     #[rustc_clean(cfg="cfail3")]

src/test/incremental/hashes/function_interfaces.rs

@@ -22,7 +22,7 @@ pub fn add_parameter() {}
 #[cfg(not(cfail1))]
 #[rustc_clean(
     cfg = "cfail2",
-    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
 )]
 #[rustc_clean(cfg = "cfail3")]
 pub fn add_parameter(p: i32) {}
@@ -45,7 +45,7 @@ pub fn type_of_parameter(p: i32) {}
 #[cfg(not(cfail1))]
 #[rustc_clean(
     cfg = "cfail2",
-    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
 )]
 #[rustc_clean(cfg = "cfail3")]
 pub fn type_of_parameter(p: i64) {}
@@ -58,7 +58,7 @@ pub fn type_of_parameter_ref(p: &i32) {}
 #[cfg(not(cfail1))]
 #[rustc_clean(
     cfg = "cfail2",
-    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
 )]
 #[rustc_clean(cfg = "cfail3")]
 pub fn type_of_parameter_ref(p: &mut i32) {}
@@ -71,7 +71,7 @@ pub fn order_of_parameters(p1: i32, p2: i64) {}
 #[cfg(not(cfail1))]
 #[rustc_clean(
     cfg = "cfail2",
-    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
 )]
 #[rustc_clean(cfg = "cfail3")]
 pub fn order_of_parameters(p2: i64, p1: i32) {}
@@ -84,7 +84,7 @@ pub fn make_unsafe() {}
 #[cfg(not(cfail1))]
 #[rustc_clean(
     cfg = "cfail2",
-    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+    except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
 )]
 #[rustc_clean(cfg = "cfail3")]
 pub unsafe fn make_unsafe() {}
@@ -95,7 +95,7 @@ pub unsafe fn make_unsafe() {}
 pub fn make_extern() {}
 
 #[cfg(not(cfail1))]
-#[rustc_clean(cfg = "cfail2", except = "hir_owner, hir_owner_nodes, typeck, fn_sig")]
+#[rustc_clean(cfg = "cfail2", except = "hir_owner, hir_owner_nodes, typeck, try_fn_sig")]
 #[rustc_clean(cfg = "cfail3")]
 pub extern "C" fn make_extern() {}
 
@@ -241,7 +241,7 @@ pub fn return_impl_trait() -> i32 {
 }
 
 #[cfg(not(cfail1))]
-#[rustc_clean(cfg = "cfail2", except = "hir_owner, hir_owner_nodes, typeck, fn_sig")]
+#[rustc_clean(cfg = "cfail2", except = "hir_owner, hir_owner_nodes, typeck, try_fn_sig")]
 #[rustc_clean(cfg = "cfail3")]
 pub fn return_impl_trait() -> impl Clone {
     0
@@ -274,7 +274,7 @@ pub mod change_return_type_indirectly {
 
     #[rustc_clean(
         cfg = "cfail2",
-        except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+        except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
     )]
     #[rustc_clean(cfg = "cfail3")]
     pub fn indirect_return_type() -> ReturnType {
@@ -292,7 +292,7 @@ pub mod change_parameter_type_indirectly {
 
     #[rustc_clean(
         cfg = "cfail2",
-        except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, fn_sig"
+        except = "hir_owner, hir_owner_nodes, optimized_mir, typeck, try_fn_sig"
     )]
     #[rustc_clean(cfg = "cfail3")]
     pub fn indirect_parameter_type(p: ParameterType) {}

src/test/incremental/hashes/inherent_impls.rs

@@ -120,7 +120,7 @@ impl Foo {
 impl Foo {
     #[rustc_clean(
         cfg="cfail2",
-        except="hir_owner,hir_owner_nodes,fn_sig,typeck,optimized_mir"
+        except="hir_owner,hir_owner_nodes,try_fn_sig,typeck,optimized_mir"
     )]
     #[rustc_clean(cfg="cfail3")]
     pub fn method_selfmutness(&mut self) { }
@@ -160,7 +160,7 @@ impl Foo {
 impl Foo {
     #[rustc_clean(
         cfg="cfail2",
-        except="hir_owner,hir_owner_nodes,fn_sig,typeck,optimized_mir"
+        except="hir_owner,hir_owner_nodes,try_fn_sig,typeck,optimized_mir"
     )]
     #[rustc_clean(cfg="cfail3")]
     pub fn add_method_parameter(&self, _: i32) { }
@@ -197,7 +197,7 @@ impl Foo {
 impl Foo {
     #[rustc_clean(
         cfg="cfail2",
-        except="hir_owner,hir_owner_nodes,fn_sig,optimized_mir,typeck")]
+        except="hir_owner,hir_owner_nodes,try_fn_sig,optimized_mir,typeck")]
     #[rustc_clean(cfg="cfail3")]
     pub fn change_method_return_type(&self) -> u8 { 0 }
 }
@@ -251,7 +251,7 @@ impl Foo {
 impl Foo {
     #[rustc_clean(
         cfg="cfail2",
-        except="hir_owner,hir_owner_nodes,fn_sig,typeck,optimized_mir"
+        except="hir_owner,hir_owner_nodes,try_fn_sig,typeck,optimized_mir"
     )]
     #[rustc_clean(cfg="cfail3")]
     pub unsafe fn make_method_unsafe(&self) { }
@@ -269,7 +269,7 @@ impl Foo {
 #[rustc_clean(cfg="cfail2")]
 #[rustc_clean(cfg="cfail3")]
 impl Foo {
-    #[rustc_clean(cfg="cfail2", except="hir_owner,hir_owner_nodes,fn_sig,typeck")]
+    #[rustc_clean(cfg="cfail2", except="hir_owner,hir_owner_nodes,try_fn_sig,typeck")]
     #[rustc_clean(cfg="cfail3")]
     pub extern "C" fn make_method_extern(&self) { }
 }
@@ -286,7 +286,7 @@ impl Foo {
 #[rustc_clean(cfg="cfail2")]
 #[rustc_clean(cfg="cfail3")]
 impl Foo {
-    #[rustc_clean(cfg="cfail2", except="hir_owner,hir_owner_nodes,fn_sig,typeck")]
+    #[rustc_clean(cfg="cfail2", except="hir_owner,hir_owner_nodes,try_fn_sig,typeck")]
     #[rustc_clean(cfg="cfail3")]
     pub extern "system" fn change_method_calling_convention(&self) { }
 }
@@ -453,7 +453,7 @@ impl Bar<u32> {
 impl<T> Bar<T> {
     #[rustc_clean(
         cfg="cfail2",
-        except="generics_of,fn_sig,typeck,try_type_of,optimized_mir"
+        except="generics_of,try_fn_sig,typeck,try_type_of,optimized_mir"
     )]
     #[rustc_clean(cfg="cfail3")]
     pub fn add_type_parameter_to_impl(&self) { }
@@ -471,7 +471,7 @@ impl Bar<u32> {
 #[rustc_clean(cfg="cfail2", except="hir_owner,hir_owner_nodes")]
 #[rustc_clean(cfg="cfail3")]
 impl Bar<u64> {
-    #[rustc_clean(cfg="cfail2", except="fn_sig,optimized_mir,typeck")]
+    #[rustc_clean(cfg="cfail2", except="try_fn_sig,optimized_mir,typeck")]
     #[rustc_clean(cfg="cfail3")]
     pub fn change_impl_self_type(&self) { }
 }

src/test/incremental/hashes/struct_constructors.rs

@@ -173,7 +173,7 @@ pub mod change_constructor_path_indirectly_regular_struct {
 
     #[rustc_clean(
         cfg="cfail2",
-        except="fn_sig,hir_owner,hir_owner_nodes,optimized_mir,typeck"
+        except="try_fn_sig,hir_owner,hir_owner_nodes,optimized_mir,typeck"
     )]
     #[rustc_clean(cfg="cfail3")]
     pub fn function() -> Struct {
@@ -230,7 +230,7 @@ pub mod change_constructor_path_indirectly_tuple_struct {
 
     #[rustc_clean(
         cfg="cfail2",
-        except="fn_sig,hir_owner,hir_owner_nodes,optimized_mir,typeck"
+        except="try_fn_sig,hir_owner,hir_owner_nodes,optimized_mir,typeck"
     )]
     #[rustc_clean(cfg="cfail3")]
     pub fn function() -> Struct {

src/test/ui/dep-graph/dep-graph-struct-signature.rs

@@ -28,30 +28,30 @@ mod signatures {
     #[rustc_then_this_would_need(associated_item)] //~ ERROR no path
     #[rustc_then_this_would_need(trait_def)] //~ ERROR no path
     trait Bar {
-        #[rustc_then_this_would_need(fn_sig)] //~ ERROR OK
+        #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR OK
         fn do_something(x: WillChange);
     }
 
-    #[rustc_then_this_would_need(fn_sig)] //~ ERROR OK
+    #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR OK
     #[rustc_then_this_would_need(typeck)] //~ ERROR OK
     fn some_fn(x: WillChange) { }
 
-    #[rustc_then_this_would_need(fn_sig)] //~ ERROR OK
+    #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR OK
     #[rustc_then_this_would_need(typeck)] //~ ERROR OK
     fn new_foo(x: u32, y: u32) -> WillChange {
         WillChange { x: x, y: y }
     }
 
     #[rustc_then_this_would_need(try_type_of)] //~ ERROR OK
     impl WillChange {
-        #[rustc_then_this_would_need(fn_sig)] //~ ERROR OK
+        #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR OK
         #[rustc_then_this_would_need(typeck)] //~ ERROR OK
         fn new(x: u32, y: u32) -> WillChange { loop { } }
     }
 
     #[rustc_then_this_would_need(try_type_of)] //~ ERROR OK
     impl WillChange {
-        #[rustc_then_this_would_need(fn_sig)] //~ ERROR OK
+        #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR OK
         #[rustc_then_this_would_need(typeck)] //~ ERROR OK
         fn method(&self, x: u32) { }
     }
@@ -73,14 +73,14 @@ mod invalid_signatures {
 
     #[rustc_then_this_would_need(try_type_of)] //~ ERROR no path
     trait A {
-        #[rustc_then_this_would_need(fn_sig)] //~ ERROR no path
+        #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR no path
         fn do_something_else_twice(x: WontChange);
     }
 
-    #[rustc_then_this_would_need(fn_sig)] //~ ERROR no path
+    #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR no path
     fn b(x: WontChange) { }
 
-    #[rustc_then_this_would_need(fn_sig)] //~ ERROR no path from `WillChange`
+    #[rustc_then_this_would_need(try_fn_sig)] //~ ERROR no path from `WillChange`
     #[rustc_then_this_would_need(typeck)] //~ ERROR no path from `WillChange`
     fn c(x: u32) { }
 }