1 files changed, 89 insertions, 0 deletions
diff --git a/tests/codegen/debuginfo-generic-closure-env-names.rs b/tests/codegen/debuginfo-generic-closure-env-names.rs
new file mode 100644
index 000000000..b29f8b4a0
--- /dev/null
+++ b/tests/codegen/debuginfo-generic-closure-env-names.rs
@@ -0,0 +1,89 @@
+// This test checks that we get proper type names for closure environments and
+// async-fn environments in debuginfo, especially making sure that generic arguments
+// of the enclosing functions don't get lost.
+//
+// Unfortunately, the order that debuginfo gets emitted into LLVM IR becomes a bit hard
+// to predict once async fns are involved, so DAG allows any order.
+//
+// Note that the test does not check async-fns when targeting MSVC because debuginfo for
+// those does not follow the enum-fallback encoding yet and thus is incomplete.
+
+// ignore-tidy-linelength
+
+// Use the v0 symbol mangling scheme to codegen order independent of rustc version.
+// Unnamed items like shims are generated in lexicographical order of their symbol name and in the
+// legacy mangling scheme rustc version and generic parameters are both hashed into a single part
+// of the name, thus randomizing item order with respect to rustc version.
+
+// compile-flags: -Cdebuginfo=2 --edition 2021 -Copt-level=0 -Csymbol-mangling-version=v0
+
+// non_generic_closure()
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}", scope: ![[non_generic_closure_NAMESPACE:[0-9]+]],
+// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0", scope: ![[non_generic_closure_NAMESPACE:[0-9]+]],
+// CHECK: ![[non_generic_closure_NAMESPACE]] = !DINamespace(name: "non_generic_closure"
+
+// CHECK: ![[function_containing_closure_NAMESPACE:[0-9]+]] = !DINamespace(name: "function_containing_closure"
+// CHECK: ![[generic_async_function_NAMESPACE:[0-9]+]] = !DINamespace(name: "generic_async_function"
+// CHECK: ![[generic_async_block_NAMESPACE:[0-9]+]] = !DINamespace(name: "generic_async_block"
+
+// function_containing_closure<u32>()
+// NONMSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}<u32>", scope: ![[function_containing_closure_NAMESPACE]]
+// MSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0<u32>", scope: ![[function_containing_closure_NAMESPACE]]
+
+// generic_async_function<Foo>()
+// NONMSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_fn_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: ![[generic_async_function_NAMESPACE]]
+
+// generic_async_function<u32>()
+// NONMSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_fn_env#0}<u32>", scope: ![[generic_async_function_NAMESPACE]]
+
+// generic_async_block<Foo>()
+// NONMSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_block_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: ![[generic_async_block_NAMESPACE]]
+
+// generic_async_block<u32>()
+// NONMSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_block_env#0}<u32>", scope: ![[generic_async_block_NAMESPACE]]
+
+// function_containing_closure<Foo>()
+// NONMSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: ![[function_containing_closure_NAMESPACE]]
+// MSVC-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0<debuginfo_generic_closure_env_names::Foo>", scope: ![[function_containing_closure_NAMESPACE]]
+
+
+#![crate_type = "lib"]
+use std::future::Future;
+
+pub struct Foo;
+
+pub fn non_generic_closure(x: Foo) -> Box<dyn FnOnce() -> Foo> {
+    return Box::new(move || x);
+}
+
+fn function_containing_closure<T: 'static>(x: T) -> impl FnOnce() -> T {
+    // This static only exists to trigger generating the namespace debuginfo for
+    // `function_containing_closure` at a predictable, early point, which makes
+    // writing the FileCheck tests above simpler.
+    static _X: u8 = 0;
+
+    return move || x;
+}
+
+async fn generic_async_function<T: 'static>(x: T) -> T {
+    static _X: u8 = 0; // Same as above
+    x
+}
+
+fn generic_async_block<T: 'static>(x: T) -> impl Future<Output=T> {
+    static _X: u8 = 0; // Same as above
+    async move {
+        x
+    }
+}
+
+pub fn instantiate_generics() {
+    let _closure_u32 = function_containing_closure(7u32);
+    let _closure_foo = function_containing_closure(Foo);
+
+    let _async_fn_u32 = generic_async_function(42u32);
+    let _async_fn_foo = generic_async_function(Foo);
+
+    let _async_block_u32 = generic_async_block(64u32);
+    let _async_block_foo = generic_async_block(Foo);
+}