Add testing for interop with C++ inline and thread_local variables. (#6568)

Inline variables already work fine; thread_local variables need more
work.

toolchain/lower/testdata/interop/cpp/globals.carbon

@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/destroy.carbon
+// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/int.carbon
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
@@ -29,6 +29,57 @@ fn MyF() {
   let _: Cpp.C = Cpp.global;
 }
 
+// ============================================================================
+// Inline variable
+// ============================================================================
+
+// --- inline.h
+
+struct C {
+  C();
+  ~C();
+  void f();
+};
+inline C inline_global;
+
+// --- import_inline.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "inline.h";
+
+fn CallF() {
+  Cpp.inline_global.f();
+}
+
+// ============================================================================
+// Thread-local variable
+// ============================================================================
+
+// --- thread_local.h
+
+thread_local int thread_local_global;
+
+int init();
+thread_local int thread_local_global_with_init = init();
+
+// --- todo_import_thread_local.carbon
+
+library "[[@TEST_NAME]]";
+
+import Cpp library "thread_local.h";
+
+// TODO: We should call the C++ thread wrapper function here instead of directly
+// accessing the global. We fail to trigger the initialization of the global.
+
+fn ThreadLocalStore() {
+  Cpp.thread_local_global = 42;
+}
+
+fn ThreadLocalTriggerInit() -> i32 {
+  return Cpp.thread_local_global_with_init;
+}
+
 // CHECK:STDOUT: ; ModuleID = 'import_global.carbon'
 // CHECK:STDOUT: source_filename = "import_global.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"
@@ -60,3 +111,207 @@ fn MyF() {
 // CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
 // CHECK:STDOUT: !9 = !{null}
 // CHECK:STDOUT: !10 = !DILocation(line: 6, column: 1, scope: !7)
+// CHECK:STDOUT: ; ModuleID = 'import_inline.carbon'
+// CHECK:STDOUT: source_filename = "import_inline.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: %struct.C = type { i8 }
+// CHECK:STDOUT:
+// CHECK:STDOUT: $inline_global = comdat any
+// CHECK:STDOUT:
+// CHECK:STDOUT: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 65535, ptr @__cxx_global_var_init, ptr @inline_global }]
+// CHECK:STDOUT: @llvm.used = appending global [1 x ptr] [ptr @inline_global], section "llvm.metadata"
+// CHECK:STDOUT: @inline_global = linkonce_odr dso_local global %struct.C zeroinitializer, comdat, align 1
+// CHECK:STDOUT: @_ZGV13inline_global = linkonce_odr dso_local global i64 0, comdat($inline_global), align 8
+// CHECK:STDOUT: @__dso_handle = external hidden global i8
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CCallF.Main() #0 !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   call void @_ZN1C1fEv(ptr @inline_global), !dbg !10
+// CHECK:STDOUT:   ret void, !dbg !11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_ZN1C1fEv(ptr)
+// CHECK:STDOUT:
+// CHECK:STDOUT: define internal void @__cxx_global_var_init() #1 section ".text.startup" comdat($inline_global) personality ptr @__gxx_personality_v0 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %exn.slot = alloca ptr, align 8
+// CHECK:STDOUT:   %ehselector.slot = alloca i32, align 4
+// CHECK:STDOUT:   %0 = load atomic i8, ptr @_ZGV13inline_global acquire, align 8
+// CHECK:STDOUT:   %guard.uninitialized = icmp eq i8 %0, 0
+// CHECK:STDOUT:   br i1 %guard.uninitialized, label %init.check, label %init.end
+// CHECK:STDOUT:
+// CHECK:STDOUT: init.check:                                       ; preds = %entry
+// CHECK:STDOUT:   %1 = call i32 @__cxa_guard_acquire(ptr @_ZGV13inline_global) #0
+// CHECK:STDOUT:   %tobool = icmp ne i32 %1, 0
+// CHECK:STDOUT:   br i1 %tobool, label %init, label %init.end
+// CHECK:STDOUT:
+// CHECK:STDOUT: init:                                             ; preds = %init.check
+// CHECK:STDOUT:   invoke void @_ZN1CC1Ev(ptr nonnull align 1 dereferenceable(1) @inline_global)
+// CHECK:STDOUT:           to label %invoke.cont unwind label %lpad
+// CHECK:STDOUT:
+// CHECK:STDOUT: invoke.cont:                                      ; preds = %init
+// CHECK:STDOUT:   %2 = call i32 @__cxa_atexit(ptr @_ZN1CD1Ev, ptr @inline_global, ptr @__dso_handle) #0
+// CHECK:STDOUT:   call void @__cxa_guard_release(ptr @_ZGV13inline_global) #0
+// CHECK:STDOUT:   br label %init.end
+// CHECK:STDOUT:
+// CHECK:STDOUT: init.end:                                         ; preds = %invoke.cont, %init.check, %entry
+// CHECK:STDOUT:   ret void
+// CHECK:STDOUT:
+// CHECK:STDOUT: lpad:                                             ; preds = %init
+// CHECK:STDOUT:   %3 = landingpad { ptr, i32 }
+// CHECK:STDOUT:           cleanup
+// CHECK:STDOUT:   %4 = extractvalue { ptr, i32 } %3, 0
+// CHECK:STDOUT:   store ptr %4, ptr %exn.slot, align 8
+// CHECK:STDOUT:   %5 = extractvalue { ptr, i32 } %3, 1
+// CHECK:STDOUT:   store i32 %5, ptr %ehselector.slot, align 4
+// CHECK:STDOUT:   call void @__cxa_guard_abort(ptr @_ZGV13inline_global) #0
+// CHECK:STDOUT:   br label %eh.resume
+// CHECK:STDOUT:
+// CHECK:STDOUT: eh.resume:                                        ; preds = %lpad
+// CHECK:STDOUT:   %exn = load ptr, ptr %exn.slot, align 8
+// CHECK:STDOUT:   %sel = load i32, ptr %ehselector.slot, align 4
+// CHECK:STDOUT:   %lpad.val = insertvalue { ptr, i32 } poison, ptr %exn, 0
+// CHECK:STDOUT:   %lpad.val1 = insertvalue { ptr, i32 } %lpad.val, i32 %sel, 1
+// CHECK:STDOUT:   resume { ptr, i32 } %lpad.val1
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @__gxx_personality_v0(...)
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: declare i32 @__cxa_guard_acquire(ptr) #0
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare void @_ZN1CC1Ev(ptr nonnull align 1 dereferenceable(1)) unnamed_addr #2
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: declare void @_ZN1CD1Ev(ptr nonnull align 1 dereferenceable(1)) unnamed_addr #3
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: declare i32 @__cxa_atexit(ptr, ptr, ptr) #0
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: declare void @__cxa_guard_release(ptr) #0
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: declare void @__cxa_guard_abort(ptr) #0
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; uselistorder directives
+// CHECK:STDOUT: uselistorder ptr @inline_global, { 1, 2, 4, 3, 0 }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { "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: attributes #3 = { nounwind "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_plus_plus, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "import_inline.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "CallF", linkageName: "_CCallF.Main", scope: null, file: !6, line: 6, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{null}
+// CHECK:STDOUT: !10 = !DILocation(line: 7, column: 3, scope: !7)
+// CHECK:STDOUT: !11 = !DILocation(line: 6, column: 1, scope: !7)
+// CHECK:STDOUT: ; ModuleID = 'todo_import_thread_local.carbon'
+// CHECK:STDOUT: source_filename = "todo_import_thread_local.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: $_ZTW19thread_local_global = comdat any
+// CHECK:STDOUT:
+// CHECK:STDOUT: $_ZTW29thread_local_global_with_init = comdat any
+// CHECK:STDOUT:
+// CHECK:STDOUT: @thread_local_global = dso_local thread_local global i32 0, align 4
+// CHECK:STDOUT: @thread_local_global_with_init = dso_local thread_local global i32 0, align 4
+// CHECK:STDOUT: @__tls_guard = internal thread_local global i8 0, align 1
+// CHECK:STDOUT:
+// CHECK:STDOUT: @_ZTH29thread_local_global_with_init = dso_local alias void (), ptr @__tls_init
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define void @_CThreadLocalStore.Main() #0 !dbg !7 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   store i32 42, ptr @thread_local_global, align 4, !dbg !10
+// CHECK:STDOUT:   ret void, !dbg !11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nounwind
+// CHECK:STDOUT: define i32 @_CThreadLocalTriggerInit.Main() #0 !dbg !12 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %.loc14 = load i32, ptr @thread_local_global_with_init, align 4, !dbg !16
+// CHECK:STDOUT:   ret i32 %.loc14, !dbg !17
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define weak_odr hidden ptr @_ZTW19thread_local_global() #1 comdat {
+// CHECK:STDOUT:   %1 = call align 4 ptr @llvm.threadlocal.address.p0(ptr align 4 @thread_local_global)
+// CHECK:STDOUT:   ret ptr %1
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
+// CHECK:STDOUT: declare nonnull ptr @llvm.threadlocal.address.p0(ptr nonnull) #2
+// CHECK:STDOUT:
+// CHECK:STDOUT: define weak_odr hidden ptr @_ZTW29thread_local_global_with_init() #1 comdat {
+// CHECK:STDOUT:   call void @_ZTH29thread_local_global_with_init()
+// CHECK:STDOUT:   %1 = call align 4 ptr @llvm.threadlocal.address.p0(ptr align 4 @thread_local_global_with_init)
+// CHECK:STDOUT:   ret ptr %1
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define internal void @__tls_init() #3 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %0 = load i8, ptr @__tls_guard, align 1
+// CHECK:STDOUT:   %guard.uninitialized = icmp eq i8 %0, 0
+// CHECK:STDOUT:   br i1 %guard.uninitialized, label %init, label %exit, !prof !18
+// CHECK:STDOUT:
+// CHECK:STDOUT: init:                                             ; preds = %entry
+// CHECK:STDOUT:   store i8 1, ptr @__tls_guard, align 1
+// CHECK:STDOUT:   call void @__cxx_global_var_init()
+// CHECK:STDOUT:   br label %exit
+// CHECK:STDOUT:
+// CHECK:STDOUT: exit:                                             ; preds = %init, %entry
+// CHECK:STDOUT:   ret void
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define internal void @__cxx_global_var_init() #3 section ".text.startup" {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %call = call i32 @_Z4initv()
+// CHECK:STDOUT:   %0 = call align 4 ptr @llvm.threadlocal.address.p0(ptr align 4 @thread_local_global_with_init)
+// CHECK:STDOUT:   store i32 %call, ptr %0, align 4
+// CHECK:STDOUT:   ret void
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: declare i32 @_Z4initv() #1
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nounwind }
+// CHECK:STDOUT: attributes #1 = { "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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+// CHECK:STDOUT: attributes #3 = { "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:
+// 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_plus_plus, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !6 = !DIFile(filename: "todo_import_thread_local.carbon", directory: "")
+// CHECK:STDOUT: !7 = distinct !DISubprogram(name: "ThreadLocalStore", linkageName: "_CThreadLocalStore.Main", scope: null, file: !6, line: 9, type: !8, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !8 = !DISubroutineType(types: !9)
+// CHECK:STDOUT: !9 = !{null}
+// CHECK:STDOUT: !10 = !DILocation(line: 10, column: 3, scope: !7)
+// CHECK:STDOUT: !11 = !DILocation(line: 9, column: 1, scope: !7)
+// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "ThreadLocalTriggerInit", linkageName: "_CThreadLocalTriggerInit.Main", scope: null, file: !6, line: 13, type: !13, spFlags: DISPFlagDefinition, unit: !5)
+// CHECK:STDOUT: !13 = !DISubroutineType(types: !14)
+// CHECK:STDOUT: !14 = !{!15}
+// CHECK:STDOUT: !15 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+// CHECK:STDOUT: !16 = !DILocation(line: 14, column: 10, scope: !12)
+// CHECK:STDOUT: !17 = !DILocation(line: 14, column: 3, scope: !12)
+// CHECK:STDOUT: !18 = !{!"branch_weights", i32 1, i32 1023}