Auto merge of #105531 - matthiaskrgr:rollup-7y7zbgl, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #104460 (Migrate parts of `rustc_expand` to session diagnostics)
 - #105192 (Point at LHS on binop type err if relevant)
 - #105234 (Remove unneeded field from `SwitchTargets`)
 - #105239 (Avoid heap allocation when truncating thread names)
 - #105410 (Consider `parent_count` for const param defaults)
 - #105482 (Fix invalid codegen during debuginfo lowering)

Failed merges:

 - #105411 (Introduce `with_forced_trimmed_paths`)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 22 insertions, 0 deletions

diff --git a/src/test/codegen/issue-105386-ub-in-debuginfo.rs b/src/test/codegen/issue-105386-ub-in-debuginfo.rs
new file mode 100644
index 00000000000..d54ac9e33bc
--- /dev/null
+++ b/src/test/codegen/issue-105386-ub-in-debuginfo.rs
@@ -0,0 +1,22 @@
+// compile-flags: --crate-type=lib -O -Cdebuginfo=2 -Cno-prepopulate-passes
+// min-llvm-version: 15.0 # this test uses opaque pointer notation
+#![feature(stmt_expr_attributes)]
+
+pub struct S([usize; 8]);
+
+#[no_mangle]
+pub fn outer_function(x: S, y: S) -> usize {
+    (#[inline(always)]|| {
+        let _z = x;
+        y.0[0]
+    })()
+}
+
+// Check that we do not attempt to load from the spilled arg before it is assigned to
+// when generating debuginfo.
+// CHECK-LABEL: @outer_function
+// CHECK: [[spill:%.*]] = alloca %"[closure@{{.*.rs}}:9:23: 9:25]"
+// CHECK-NOT: [[ptr_tmp:%.*]] = getelementptr inbounds %"[closure@{{.*.rs}}:9:23: 9:25]", ptr [[spill]]
+// CHECK-NOT: [[load:%.*]] = load ptr, ptr
+// CHECK: call void @llvm.lifetime.start{{.*}}({{.*}}, ptr [[spill]])
+// CHECK: call void @llvm.memcpy{{.*}}(ptr {{align .*}} [[spill]], ptr {{align .*}} %x