Give Instance::expect_resolve a span

compiler/rustc_codegen_cranelift/src/abi/mod.rs

@@ -371,9 +371,14 @@ pub(crate) fn codegen_terminator_call<'tcx>(
 
     // Handle special calls like intrinsics and empty drop glue.
     let instance = if let ty::FnDef(def_id, fn_args) = *func.layout().ty.kind() {
-        let instance =
-            ty::Instance::expect_resolve(fx.tcx, ty::ParamEnv::reveal_all(), def_id, fn_args)
-                .polymorphize(fx.tcx);
+        let instance = ty::Instance::expect_resolve(
+            fx.tcx,
+            ty::ParamEnv::reveal_all(),
+            def_id,
+            fn_args,
+            Some(source_info.span),
+        )
+        .polymorphize(fx.tcx);
 
         if is_call_from_compiler_builtins_to_upstream_monomorphization(fx.tcx, instance) {
             if target.is_some() {

compiler/rustc_codegen_cranelift/src/main_shim.rs

@@ -119,6 +119,7 @@ pub(crate) fn maybe_create_entry_wrapper(
                     ParamEnv::reveal_all(),
                     report.def_id,
                     tcx.mk_args(&[GenericArg::from(main_ret_ty)]),
+                    None,
                 )
                 .polymorphize(tcx);
 
@@ -144,6 +145,7 @@ pub(crate) fn maybe_create_entry_wrapper(
                     ParamEnv::reveal_all(),
                     start_def_id,
                     tcx.mk_args(&[main_ret_ty.into()]),
+                    None,
                 )
                 .polymorphize(tcx);
                 let start_func_id = import_function(tcx, m, start_instance);

compiler/rustc_codegen_gcc/src/context.rs

@@ -479,6 +479,7 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
                     ty::ParamEnv::reveal_all(),
                     def_id,
                     ty::List::empty(),
+                    None,
                 );
 
                 let symbol_name = tcx.symbol_name(instance).name;

compiler/rustc_codegen_llvm/src/context.rs

@@ -580,6 +580,7 @@ impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                 ty::ParamEnv::reveal_all(),
                 def_id,
                 ty::List::empty(),
+                None,
             )),
             _ => {
                 let name = name.unwrap_or("rust_eh_personality");

compiler/rustc_codegen_ssa/src/base.rs

@@ -467,6 +467,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
                 ty::ParamEnv::reveal_all(),
                 start_def_id,
                 cx.tcx().mk_args(&[main_ret_ty.into()]),
+                None,
             );
             let start_fn = cx.get_fn_addr(start_instance);
 

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -842,6 +842,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         ty::ParamEnv::reveal_all(),
                         def_id,
                         args,
+                        Some(fn_span),
                     )
                     .polymorphize(bx.tcx()),
                 ),

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -253,6 +253,7 @@ impl<'tcx> CompileTimeInterpCx<'tcx> {
                 ty::ParamEnv::reveal_all(),
                 const_def_id,
                 instance.args,
+                Some(self.find_closest_untracked_caller_location()),
             );
 
             return Ok(Some(new_instance));

compiler/rustc_middle/src/ty/instance.rs

@@ -13,7 +13,7 @@ use rustc_macros::{
 };
 use rustc_middle::ty::normalize_erasing_regions::NormalizationError;
 use rustc_span::def_id::LOCAL_CRATE;
-use rustc_span::Symbol;
+use rustc_span::{Span, Symbol};
 use tracing::{debug, instrument};
 
 use std::assert_matches::assert_matches;
@@ -513,10 +513,12 @@ impl<'tcx> Instance<'tcx> {
         param_env: ty::ParamEnv<'tcx>,
         def_id: DefId,
         args: GenericArgsRef<'tcx>,
+        span: Option<Span>,
     ) -> Instance<'tcx> {
         match ty::Instance::resolve(tcx, param_env, def_id, args) {
             Ok(Some(instance)) => instance,
-            instance => bug!(
+            instance => span_bug!(
+                span.unwrap_or(tcx.def_span(def_id)),
                 "failed to resolve instance for {}: {instance:#?}",
                 tcx.def_path_str_with_args(def_id, args)
             ),
@@ -588,7 +590,7 @@ impl<'tcx> Instance<'tcx> {
             return Instance { def: InstanceKind::VTableShim(def_id), args };
         }
 
-        let mut resolved = Instance::expect_resolve(tcx, param_env, def_id, args);
+        let mut resolved = Instance::expect_resolve(tcx, param_env, def_id, args, None);
 
         let reason = tcx.sess.is_sanitizer_kcfi_enabled().then_some(ReifyReason::Vtable);
         match resolved.def {
@@ -665,13 +667,13 @@ impl<'tcx> Instance<'tcx> {
     pub fn resolve_drop_in_place(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ty::Instance<'tcx> {
         let def_id = tcx.require_lang_item(LangItem::DropInPlace, None);
         let args = tcx.mk_args(&[ty.into()]);
-        Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args)
+        Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args, None)
     }
 
     pub fn resolve_async_drop_in_place(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ty::Instance<'tcx> {
         let def_id = tcx.require_lang_item(LangItem::AsyncDropInPlace, None);
         let args = tcx.mk_args(&[ty.into()]);
-        Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args)
+        Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args, None)
     }
 
     #[instrument(level = "debug", skip(tcx), ret)]

compiler/rustc_monomorphize/src/collector.rs

@@ -916,7 +916,13 @@ fn visit_fn_use<'tcx>(
 ) {
     if let ty::FnDef(def_id, args) = *ty.kind() {
         let instance = if is_direct_call {
-            ty::Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args)
+            ty::Instance::expect_resolve(
+                tcx,
+                ty::ParamEnv::reveal_all(),
+                def_id,
+                args,
+                Some(source),
+            )
         } else {
             match ty::Instance::resolve_for_fn_ptr(tcx, ty::ParamEnv::reveal_all(), def_id, args) {
                 Some(instance) => instance,
@@ -1318,8 +1324,13 @@ fn visit_mentioned_item<'tcx>(
     match *item {
         MentionedItem::Fn(ty) => {
             if let ty::FnDef(def_id, args) = *ty.kind() {
-                let instance =
-                    Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args);
+                let instance = Instance::expect_resolve(
+                    tcx,
+                    ty::ParamEnv::reveal_all(),
+                    def_id,
+                    args,
+                    Some(span),
+                );
                 // `visit_instance_use` was written for "used" item collection but works just as well
                 // for "mentioned" item collection.
                 // We can set `is_direct_call`; that just means we'll skip a bunch of shims that anyway
@@ -1544,6 +1555,7 @@ impl<'v> RootCollector<'_, 'v> {
             ty::ParamEnv::reveal_all(),
             start_def_id,
             self.tcx.mk_args(&[main_ret_ty.into()]),
+            None,
         );
 
         self.output.push(create_fn_mono_item(self.tcx, start_instance, DUMMY_SP));
@@ -1614,7 +1626,7 @@ fn create_mono_items_for_default_impls<'tcx>(
         // As mentioned above, the method is legal to eagerly instantiate if it
         // only has lifetime generic parameters. This is validated by
         let args = trait_ref.args.extend_to(tcx, method.def_id, only_region_params);
-        let instance = ty::Instance::expect_resolve(tcx, param_env, method.def_id, args);
+        let instance = ty::Instance::expect_resolve(tcx, param_env, method.def_id, args, None);
 
         let mono_item = create_fn_mono_item(tcx, instance, DUMMY_SP);
         if mono_item.node.is_instantiable(tcx) && should_codegen_locally(tcx, instance) {