From fd7557b7ee454058fff84b556892adbef89f7d52 Mon Sep 17 00:00:00 2001
From: Michael Woerister <michaelwoerister@posteo>
Date: Wed, 19 Jan 2022 17:56:53 +0100
Subject: debuginfo: Make sure that type names for closure and generator
 environments are unique in debuginfo.

Before this change, closure/generator environments coming from different
instantiations of the same generic function were all assigned the same
name even though they were distinct types with potentially different data
layout. Now we append the generic arguments of the originating function
to the type name.

This commit also emits '{closure_env#0}' as the name of these types in
order to disambiguate them from the accompanying closure function
'{closure#0}'. Previously both were assigned the same name.
---
 compiler/rustc_codegen_llvm/src/debuginfo/mod.rs | 37 +++++++++++++-----------
 1 file changed, 20 insertions(+), 17 deletions(-)

(limited to 'compiler/rustc_codegen_llvm/src')

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index 61e49fab6ff..833604c533c 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -25,7 +25,7 @@ use rustc_data_structures::sync::Lrc;
 use rustc_hir::def_id::{DefId, DefIdMap};
 use rustc_index::vec::IndexVec;
 use rustc_middle::mir;
-use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
+use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TypeFoldable};
 use rustc_session::config::{self, DebugInfo};
@@ -307,9 +307,11 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
         maybe_definition_llfn: Option<&'ll Value>,
     ) -> &'ll DIScope {
+        let tcx = self.tcx;
+
         let def_id = instance.def_id();
         let containing_scope = get_containing_scope(self, instance);
-        let span = self.tcx.def_span(def_id);
+        let span = tcx.def_span(def_id);
         let loc = self.lookup_debug_loc(span.lo());
         let file_metadata = file_metadata(self, &loc.file);
 
@@ -319,16 +321,24 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         };
 
         let mut name = String::new();
-        type_names::push_item_name(self.tcx(), def_id, false, &mut name);
+        type_names::push_item_name(tcx, def_id, false, &mut name);
 
         // Find the enclosing function, in case this is a closure.
-        let enclosing_fn_def_id = self.tcx().typeck_root_def_id(def_id);
+        let enclosing_fn_def_id = tcx.typeck_root_def_id(def_id);
+
+        // We look up the generics of the enclosing function and truncate the substs
+        // to their length in order to cut off extra stuff that might be in there for
+        // closures or generators.
+        let generics = tcx.generics_of(enclosing_fn_def_id);
+        let substs = instance.substs.truncate_to(tcx, generics);
+
+        type_names::push_generic_params(
+            tcx,
+            tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), substs),
+            &mut name,
+        );
 
-        // Get_template_parameters() will append a `<...>` clause to the function
-        // name if necessary.
-        let generics = self.tcx().generics_of(enclosing_fn_def_id);
-        let substs = instance.substs.truncate_to(self.tcx(), generics);
-        let template_parameters = get_template_parameters(self, generics, substs, &mut name);
+        let template_parameters = get_template_parameters(self, generics, substs);
 
         let linkage_name = &mangled_name_of_instance(self, instance).name;
         // Omit the linkage_name if it is the same as subprogram name.
@@ -350,7 +360,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         if self.sess().opts.optimize != config::OptLevel::No {
             spflags |= DISPFlags::SPFlagOptimized;
         }
-        if let Some((id, _)) = self.tcx.entry_fn(()) {
+        if let Some((id, _)) = tcx.entry_fn(()) {
             if id == def_id {
                 spflags |= DISPFlags::SPFlagMainSubprogram;
             }
@@ -429,14 +439,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             cx: &CodegenCx<'ll, 'tcx>,
             generics: &ty::Generics,
             substs: SubstsRef<'tcx>,
-            name_to_append_suffix_to: &mut String,
         ) -> &'ll DIArray {
-            type_names::push_generic_params(
-                cx.tcx,
-                cx.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), substs),
-                name_to_append_suffix_to,
-            );
-
             if substs.types().next().is_none() {
                 return create_DIArray(DIB(cx), &[]);
             }
-- 
cgit 1.4.1-3-g733a5