debuginfo: give unique names to closure and generator types

Closure types have been moved to the namespace where they
are defined, and both closure and generator type names now
include the disambiguator.

This fixes an exception when lldb prints nested closures.

Fixes #57822

Author: philipc

src/librustc_codegen_llvm/debuginfo/metadata.rs

@@ -683,11 +683,13 @@ pub fn type_metadata(
         }
         ty::Closure(def_id, substs) => {
             let upvar_tys : Vec<_> = substs.upvar_tys(def_id, cx.tcx).collect();
+            let containing_scope = get_namespace_for_item(cx, def_id);
             prepare_tuple_metadata(cx,
                                    t,
                                    &upvar_tys,
                                    unique_type_id,
-                                   usage_site_span).finalize(cx)
+                                   usage_site_span,
+                                   Some(containing_scope)).finalize(cx)
         }
         ty::Generator(def_id, substs,  _) => {
             let upvar_tys : Vec<_> = substs.prefix_tys(def_id, cx.tcx).map(|t| {
@@ -728,7 +730,8 @@ pub fn type_metadata(
                                    t,
                                    &tys,
                                    unique_type_id,
-                                   usage_site_span).finalize(cx)
+                                   usage_site_span,
+                                   NO_SCOPE_METADATA).finalize(cx)
         }
         _ => {
             bug!("debuginfo: unexpected type in type_metadata: {:?}", t)
@@ -1205,14 +1208,15 @@ fn prepare_tuple_metadata(
     component_types: &[Ty<'tcx>],
     unique_type_id: UniqueTypeId,
     span: Span,
+    containing_scope: Option<&'ll DIScope>,
 ) -> RecursiveTypeDescription<'ll, 'tcx> {
     let tuple_name = compute_debuginfo_type_name(cx.tcx, tuple_type, false);
 
     let struct_stub = create_struct_stub(cx,
                                          tuple_type,
                                          &tuple_name[..],
                                          unique_type_id,
-                                         NO_SCOPE_METADATA);
+                                         containing_scope);
 
     create_and_register_recursive_type_forward_declaration(
         cx,

src/librustc_codegen_ssa/debuginfo/type_names.rs

@@ -190,11 +190,19 @@ pub fn push_debuginfo_type_name<'tcx>(
             // processing
             visited.remove(t);
         },
-        ty::Closure(..) => {
+        ty::Closure(def_id, ..) => {
             output.push_str("closure");
+            let disambiguator = tcx.def_key(def_id).disambiguated_data.disambiguator;
+            if disambiguator != 0 {
+                output.push_str(&format!("-{}", disambiguator));
+            }
         }
-        ty::Generator(..) => {
+        ty::Generator(def_id, ..) => {
             output.push_str("generator");
+            let disambiguator = tcx.def_key(def_id).disambiguated_data.disambiguator;
+            if disambiguator != 0 {
+                output.push_str(&format!("-{}", disambiguator));
+            }
         }
         ty::Error |
         ty::Infer(_) |

src/test/debuginfo/issue-57822.rs

@@ -0,0 +1,55 @@
+// This test makes sure that the LLDB pretty printer does not throw an exception
+// for nested closures and generators.
+
+// Require LLVM with DW_TAG_variant_part and a gdb that can read it.
+// min-system-llvm-version: 8.0
+// min-gdb-version: 8.2
+// ignore-tidy-linelength
+
+// compile-flags:-g
+
+// === GDB TESTS ===================================================================================
+
+// gdb-command:run
+
+// gdb-command:print g
+// gdb-check:$1 = issue_57822::main::closure-1 (issue_57822::main::closure (1))
+
+// gdb-command:print b
+// gdb-check:$2 = issue_57822::main::generator-3 {__0: issue_57822::main::generator-2 {__0: 2, <<variant>>: {[...]}}, <<variant>>: {[...]}}
+
+// === LLDB TESTS ==================================================================================
+
+// lldb-command:run
+
+// lldb-command:print g
+// lldbg-check:(issue_57822::main::closure-1) $0 = closure-1(closure(1))
+
+// lldb-command:print b
+// lldbg-check:(issue_57822::main::generator-3) $1 = generator-3(generator-2(2))
+
+#![feature(omit_gdb_pretty_printer_section, generators, generator_trait)]
+#![omit_gdb_pretty_printer_section]
+
+use std::ops::Generator;
+use std::pin::Pin;
+
+fn main() {
+    let mut x = 1;
+    let f = move || x;
+    let g = move || f();
+
+    let mut y = 2;
+    let mut a = move || {
+        y += 1;
+        yield;
+    };
+    let mut b = move || {
+        Pin::new(&mut a).resume();
+        yield;
+    };
+
+    zzz(); // #break
+}
+
+fn zzz() { () }