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

3 files changed, 72 insertions, 5 deletions

diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs
index 51e789b1788..928532a1f47 100644
--- a/src/librustc_codegen_llvm/debuginfo/metadata.rs
+++ b/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)
@@ -1205,6 +1208,7 @@ 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);
 
@@ -1212,7 +1216,7 @@ fn prepare_tuple_metadata(
                                          tuple_type,
                                          &tuple_name[..],
                                          unique_type_id,
-                                         NO_SCOPE_METADATA);
+                                         containing_scope);
 
     create_and_register_recursive_type_forward_declaration(
         cx,
diff --git a/src/librustc_codegen_ssa/debuginfo/type_names.rs b/src/librustc_codegen_ssa/debuginfo/type_names.rs
index ea39913d4b9..b7c782528de 100644
--- a/src/librustc_codegen_ssa/debuginfo/type_names.rs
+++ b/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(_) |
diff --git a/src/test/debuginfo/issue-57822.rs b/src/test/debuginfo/issue-57822.rs
new file mode 100644
index 00000000000..ba5e8e0f219
--- /dev/null
+++ b/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() { () }