From 99cebcf0a3754c0c3a3ce538d3299285e04b73ee Mon Sep 17 00:00:00 2001
From: Richard Smith <richard@metafoo.co.uk>
Date: Wed, 5 Nov 2025 13:18:53 -0800
Subject: [PATCH] Add lowering tests for pointer parameters and return values.
 (#6328)

---
 .../lower/testdata/interop/cpp/pointer.carbon | 331 ++++++++++++++++++
 1 file changed, 331 insertions(+)
 create mode 100644 toolchain/lower/testdata/interop/cpp/pointer.carbon

diff --git a/toolchain/lower/testdata/interop/cpp/pointer.carbon b/toolchain/lower/testdata/interop/cpp/pointer.carbon
new file mode 100644
index 000000000000..34561be3009b
--- /dev/null
+++ b/toolchain/lower/testdata/interop/cpp/pointer.carbon
@@ -0,0 +1,331 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/interop/cpp/pointer.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/interop/cpp/pointer.carbon
+
+// ============================================================================
+// Non-null pointers
+// ============================================================================
+
+// --- nonnull.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp inline '''
+class C {};
+
+auto TakePtr(C* _Nonnull) -> void;
+auto ReturnPtr() -> C* _Nonnull;
+
+auto TakePtrWithThunk(C* _Nonnull, int = 0) -> void;
+auto ReturnPtrWithThunk(int = 0) -> C* _Nonnull;
+''';
+
+fn PassPtr(p: Cpp.C*) {
+  Cpp.TakePtr(p);
+}
+
+fn ReturnPtr() -> Cpp.C* {
+  return Cpp.ReturnPtr();
+}
+
+fn PassPtrWithThunk(p: Cpp.C*) {
+  Cpp.TakePtrWithThunk(p);
+}
+
+fn ReturnPtrWithThunk() -> Cpp.C* {
+  return Cpp.ReturnPtrWithThunk();
+}
+
+// ============================================================================
+// Nullable pointers
+// ============================================================================
+
+// --- nullable.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp inline '''
+class C {};
+
+auto TakePtr(C*) -> void;
+auto ReturnPtr() -> C*;
+
+auto TakePtrWithThunk(C*, int = 0) -> void;
+auto ReturnPtrWithThunk(int = 0) -> C*;
+''';
+
+fn PassPtr(p: Core.Optional(Cpp.C*)) {
+  // TODO: Add support for passing an optional here.
+  // Cpp.TakePtr(p);
+}
+
+fn PassNonnullPtr(p: Cpp.C*) {
+  Cpp.TakePtr(p);
+}
+
+fn ReturnPtr() -> Core.Optional(Cpp.C*) {
+  return Cpp.ReturnPtr();
+}
+
+fn PassPtrWithThunk(p: Core.Optional(Cpp.C*)) {
+  // TODO: Add support for passing an optional here.
+  // Cpp.TakePtrWithThunk(p);
+}
+
+fn PassNonnullPtrWithThunk(p: Cpp.C*) {
+  Cpp.TakePtrWithThunk(p);
+}
+
+fn ReturnPtrWithThunk() -> Core.Optional(Cpp.C*) {
+  return Cpp.ReturnPtrWithThunk();
+}
+
+// CHECK:STDOUT: ; ModuleID = 'nonnull.carbon'
+// CHECK:STDOUT: source_filename = "nonnull.carbon"
+// CHECK:STDOUT: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassPtr.Main(ptr %p) #0 !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   call void @_Z7TakePtrP1C(ptr %p), !dbg !10
+// CHECK:STDOUT:   ret void, !dbg !11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_Z7TakePtrP1C(ptr)
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define ptr @_CReturnPtr.Main() #0 !dbg !12 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %ReturnPtr.call = call ptr @_Z9ReturnPtrv(), !dbg !13
+// CHECK:STDOUT:   ret ptr %ReturnPtr.call, !dbg !14
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare ptr @_Z9ReturnPtrv()
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassPtrWithThunk.Main(ptr %p) #0 !dbg !15 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   call void @_Z16TakePtrWithThunkP1Ci.carbon_thunk1(ptr %p), !dbg !16
+// CHECK:STDOUT:   ret void, !dbg !17
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define ptr @_CReturnPtrWithThunk.Main() #0 !dbg !18 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %ReturnPtrWithThunk__carbon_thunk.call = call ptr @_Z18ReturnPtrWithThunki.carbon_thunk0(), !dbg !19
+// CHECK:STDOUT:   ret ptr %ReturnPtrWithThunk__carbon_thunk.call, !dbg !20
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: alwaysinline mustprogress
+// CHECK:STDOUT: define dso_local void @_Z16TakePtrWithThunkP1Ci.carbon_thunk1(ptr %0) #1 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.addr = alloca ptr, align 8
+// CHECK:STDOUT:   store ptr %0, ptr %.addr, align 8
+// CHECK:STDOUT:   %1 = load ptr, ptr %.addr, align 8
+// CHECK:STDOUT:   call void @_Z16TakePtrWithThunkP1Ci(ptr %1, i32 0)
+// CHECK:STDOUT:   ret void
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_Z16TakePtrWithThunkP1Ci(ptr, i32) #2
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: alwaysinline mustprogress
+// CHECK:STDOUT: define dso_local ptr @_Z18ReturnPtrWithThunki.carbon_thunk0() #1 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %call = call ptr @_Z18ReturnPtrWithThunki(i32 0)
+// CHECK:STDOUT:   ret ptr %call
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare ptr @_Z18ReturnPtrWithThunki(i32) #2
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { alwaysinline mustprogress "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT: attributes #2 = { "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1, !2, !3, !4}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!5}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
+// CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
+// CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "nonnull.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "PassPtr", linkageName: "_CPassPtr.Main", scope: null, file: !6, line: 14, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{}
+// CHECK:STDOUT: !10 = !DILocation(line: 15, column: 3, scope: !7)
+// CHECK:STDOUT: !11 = !DILocation(line: 14, column: 1, scope: !7)
+// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "ReturnPtr", linkageName: "_CReturnPtr.Main", scope: null, file: !6, line: 18, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !13 = !DILocation(line: 19, column: 10, scope: !12)
+// CHECK:STDOUT: !14 = !DILocation(line: 19, column: 3, scope: !12)
+// CHECK:STDOUT: !15 = distinct !DISubprogram(name: "PassPtrWithThunk", linkageName: "_CPassPtrWithThunk.Main", scope: null, file: !6, line: 22, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !16 = !DILocation(line: 23, column: 3, scope: !15)
+// CHECK:STDOUT: !17 = !DILocation(line: 22, column: 1, scope: !15)
+// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "ReturnPtrWithThunk", linkageName: "_CReturnPtrWithThunk.Main", scope: null, file: !6, line: 26, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !19 = !DILocation(line: 27, column: 10, scope: !18)
+// CHECK:STDOUT: !20 = !DILocation(line: 27, column: 3, scope: !18)
+// CHECK:STDOUT: ; ModuleID = 'nullable.carbon'
+// CHECK:STDOUT: source_filename = "nullable.carbon"
+// CHECK:STDOUT: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+// CHECK:STDOUT: target triple = "x86_64-unknown-linux-gnu"
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassPtr.Main(ptr %p) #0 !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !10
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassNonnullPtr.Main(ptr %p) #0 !dbg !11 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc20_15.1.temp = alloca ptr, align 8, !dbg !12
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc20_15.1.temp), !dbg !12
+// CHECK:STDOUT:   call void @"_CConvert.f82b7327366b1770:ImplicitAs.Core.78b0d6e062ff6422"(ptr %.loc20_15.1.temp, ptr %p), !dbg !12
+// CHECK:STDOUT:   call void @_Z7TakePtrP1C(ptr %.loc20_15.1.temp), !dbg !13
+// CHECK:STDOUT:   ret void, !dbg !14
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_Z7TakePtrP1C(ptr)
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CReturnPtr.Main(ptr sret(ptr) %return) #0 !dbg !15 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   call void @_Z9ReturnPtrv(ptr %return), !dbg !16
+// CHECK:STDOUT:   ret void, !dbg !17
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_Z9ReturnPtrv(ptr sret(ptr))
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassPtrWithThunk.Main(ptr %p) #0 !dbg !18 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !19
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CPassNonnullPtrWithThunk.Main(ptr %p) #0 !dbg !20 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc33_24.1.temp = alloca ptr, align 8, !dbg !21
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(ptr %.loc33_24.1.temp), !dbg !21
+// CHECK:STDOUT:   call void @"_CConvert.f82b7327366b1770:ImplicitAs.Core.78b0d6e062ff6422"(ptr %.loc33_24.1.temp, ptr %p), !dbg !21
+// CHECK:STDOUT:   call void @_Z16TakePtrWithThunkP1Ci.carbon_thunk1(ptr %.loc33_24.1.temp), !dbg !22
+// CHECK:STDOUT:   ret void, !dbg !23
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CReturnPtrWithThunk.Main(ptr sret(ptr) %return) #0 !dbg !24 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   call void @_Z18ReturnPtrWithThunki.carbon_thunk0(ptr %return), !dbg !25
+// CHECK:STDOUT:   ret void, !dbg !26
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(ptr captures(none)) #1
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CConvert.f82b7327366b1770:ImplicitAs.Core.78b0d6e062ff6422"(ptr sret(ptr) %return, ptr %self) #0 !dbg !27 {
+// CHECK:STDOUT:   call void @"_CConvert.8d16edc1dfe20a7c:OptionalAs.Core.b5eba8f3f1d9af5a"(ptr %return, ptr %self), !dbg !29
+// CHECK:STDOUT:   ret void, !dbg !30
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CConvert.8d16edc1dfe20a7c:OptionalAs.Core.b5eba8f3f1d9af5a"(ptr sret(ptr) %return, ptr %self) #0 !dbg !31 {
+// CHECK:STDOUT:   call void @_CSome.Optional.Core.b5eba8f3f1d9af5a(ptr %return, ptr %self), !dbg !32
+// CHECK:STDOUT:   ret void, !dbg !33
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @_CSome.Optional.Core.b5eba8f3f1d9af5a(ptr sret(ptr) %return, ptr %value) #0 !dbg !34 {
+// CHECK:STDOUT:   call void @"_CSome.4f0b5cc38af595d2:OptionalStorage.Core.f53db17714b9f655"(ptr %return, ptr %value), !dbg !35
+// CHECK:STDOUT:   ret void, !dbg !36
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define linkonce_odr void @"_CSome.4f0b5cc38af595d2:OptionalStorage.Core.f53db17714b9f655"(ptr sret(ptr) %return, ptr %self) #0 !dbg !37 {
+// CHECK:STDOUT:   store ptr %self, ptr %return, align 8, !dbg !38
+// CHECK:STDOUT:   ret void, !dbg !39
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: alwaysinline mustprogress
+// CHECK:STDOUT: define dso_local void @_Z16TakePtrWithThunkP1Ci.carbon_thunk1(ptr %0) #2 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.addr = alloca ptr, align 8
+// CHECK:STDOUT:   store ptr %0, ptr %.addr, align 8
+// CHECK:STDOUT:   %1 = load ptr, ptr %.addr, align 8
+// CHECK:STDOUT:   call void @_Z16TakePtrWithThunkP1Ci(ptr %1, i32 0)
+// CHECK:STDOUT:   ret void
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_Z16TakePtrWithThunkP1Ci(ptr, i32) #3
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: alwaysinline mustprogress
+// CHECK:STDOUT: define dso_local ptr @_Z18ReturnPtrWithThunki.carbon_thunk0() #2 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %call = call ptr @_Z18ReturnPtrWithThunki(i32 0)
+// CHECK:STDOUT:   ret ptr %call
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare ptr @_Z18ReturnPtrWithThunki(i32) #3
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; uselistorder directives
+// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
+// CHECK:STDOUT: uselistorder ptr @"_CConvert.f82b7327366b1770:ImplicitAs.Core.78b0d6e062ff6422", { 1, 0 }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT: attributes #2 = { alwaysinline mustprogress "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT: attributes #3 = { "no-trapping-math"="true" "stack-protector-buffer-size"="0" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1, !2, !3, !4}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!5}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
+// CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
+// CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "nullable.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "PassPtr", linkageName: "_CPassPtr.Main", scope: null, file: !6, line: 14, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{}
+// CHECK:STDOUT: !10 = !DILocation(line: 14, column: 1, scope: !7)
+// CHECK:STDOUT: !11 = distinct !DISubprogram(name: "PassNonnullPtr", linkageName: "_CPassNonnullPtr.Main", scope: null, file: !6, line: 19, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !12 = !DILocation(line: 20, column: 15, scope: !11)
+// CHECK:STDOUT: !13 = !DILocation(line: 20, column: 3, scope: !11)
+// CHECK:STDOUT: !14 = !DILocation(line: 19, column: 1, scope: !11)
+// CHECK:STDOUT: !15 = distinct !DISubprogram(name: "ReturnPtr", linkageName: "_CReturnPtr.Main", scope: null, file: !6, line: 23, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !16 = !DILocation(line: 24, column: 10, scope: !15)
+// CHECK:STDOUT: !17 = !DILocation(line: 24, column: 3, scope: !15)
+// CHECK:STDOUT: !18 = distinct !DISubprogram(name: "PassPtrWithThunk", linkageName: "_CPassPtrWithThunk.Main", scope: null, file: !6, line: 27, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !19 = !DILocation(line: 27, column: 1, scope: !18)
+// CHECK:STDOUT: !20 = distinct !DISubprogram(name: "PassNonnullPtrWithThunk", linkageName: "_CPassNonnullPtrWithThunk.Main", scope: null, file: !6, line: 32, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !21 = !DILocation(line: 33, column: 24, scope: !20)
+// CHECK:STDOUT: !22 = !DILocation(line: 33, column: 3, scope: !20)
+// CHECK:STDOUT: !23 = !DILocation(line: 32, column: 1, scope: !20)
+// CHECK:STDOUT: !24 = distinct !DISubprogram(name: "ReturnPtrWithThunk", linkageName: "_CReturnPtrWithThunk.Main", scope: null, file: !6, line: 36, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !25 = !DILocation(line: 37, column: 10, scope: !24)
+// CHECK:STDOUT: !26 = !DILocation(line: 37, column: 3, scope: !24)
+// CHECK:STDOUT: !27 = distinct !DISubprogram(name: "Convert", linkageName: "_CConvert.f82b7327366b1770:ImplicitAs.Core.78b0d6e062ff6422", scope: null, file: !28, line: 82, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !28 = !DIFile(filename: "{{.*}}/prelude/types/optional.carbon", directory: "")
+// CHECK:STDOUT: !29 = !DILocation(line: 83, column: 12, scope: !27)
+// CHECK:STDOUT: !30 = !DILocation(line: 83, column: 5, scope: !27)
+// CHECK:STDOUT: !31 = distinct !DISubprogram(name: "Convert", linkageName: "_CConvert.8d16edc1dfe20a7c:OptionalAs.Core.b5eba8f3f1d9af5a", scope: null, file: !28, line: 68, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !32 = !DILocation(line: 69, column: 12, scope: !31)
+// CHECK:STDOUT: !33 = !DILocation(line: 69, column: 5, scope: !31)
+// CHECK:STDOUT: !34 = distinct !DISubprogram(name: "Some", linkageName: "_CSome.Optional.Core.b5eba8f3f1d9af5a", scope: null, file: !28, line: 29, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !35 = !DILocation(line: 30, column: 12, scope: !34)
+// CHECK:STDOUT: !36 = !DILocation(line: 30, column: 5, scope: !34)
+// CHECK:STDOUT: !37 = distinct !DISubprogram(name: "Some", linkageName: "_CSome.4f0b5cc38af595d2:OptionalStorage.Core.f53db17714b9f655", scope: null, file: !28, line: 125, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !38 = !DILocation(line: 127, column: 5, scope: !37)
+// CHECK:STDOUT: !39 = !DILocation(line: 128, column: 5, scope: !37)