# RUN: llc -start-before=livedebugvalues -filetype=obj -o - %s | llvm-dwarfdump - | FileCheck %s

# Based on the following C++ code:
# struct A { A(A &) {} };
# struct B { A a; };
# struct C { C(B); };
# struct D : C { D(B); };
# D::D(B b) : C(b) {}

# Reproducer for PR44275. Ideally we should get an entry value location list
# entry for the reference parameter b, but we are currently not able to do that
# due to limitations in the DWARF emission code, which puts restrictions on the
# DIExpression. For now verify that we don't crash when trying to add such an
# entry value.

# CHECK: DW_AT_location
# CHECK-NEXT: [{{0x[0-9a-f]+}}, {{0x[0-9a-f]+}}): DW_OP_reg5 RDI
# CHECK-NEXT: [{{0x[0-9a-f]+}}, {{0x[0-9a-f]+}}): DW_OP_GNU_entry_value(DW_OP_reg5 RDI), DW_OP_stack_value)
# CHECK-NEXT: DW_AT_name    ("this")

# CHECK: DW_AT_location
# CHECK-NEXT: [0x0000000000000000, 0x0000000000000004): DW_OP_breg4 RSI+0)
# TODO: Here we should ideally get a location list entry using an entry value.
# CHECK-NEXT: DW_AT_name    ("b")

--- |
  target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"

  %struct.D = type { i8 }
  %struct.B = type { %struct.A }
  %struct.A = type { i8 }
  %struct.C = type { i8 }

  @_ZN1DC1E1B = dso_local unnamed_addr alias void (%struct.D*, %struct.B*), void (%struct.D*, %struct.B*)* @_ZN1DC2E1B
  ; Function Attrs: uwtable
  define dso_local void @_ZN1DC2E1B(%struct.D* %this, %struct.B* nocapture readnone %b) unnamed_addr #0 align 2 !dbg !7 {
  entry:
    %agg.tmp = alloca %struct.B, align 1
    call void @llvm.dbg.value(metadata %struct.D* %this, metadata !32, metadata !DIExpression()), !dbg !35
    call void @llvm.dbg.declare(metadata %struct.B* %b, metadata !34, metadata !DIExpression()), !dbg !36
    %0 = bitcast %struct.D* %this to %struct.C*, !dbg !36
    call void @_ZN1CC2E1B(%struct.C* %0, %struct.B* nonnull %agg.tmp), !dbg !36
    ret void, !dbg !36
  }

  ; Function Attrs: nounwind readnone speculatable willreturn
  declare void @llvm.dbg.declare(metadata, metadata, metadata) #1

  declare dso_local void @_ZN1CC2E1B(%struct.C*, %struct.B*) unnamed_addr

  ; Function Attrs: nounwind readnone speculatable willreturn
  declare void @llvm.dbg.value(metadata, metadata, metadata) #1

  attributes #0 = { uwtable }
  attributes #1 = { nounwind readnone speculatable willreturn }

  !llvm.dbg.cu = !{!0}
  !llvm.module.flags = !{!3, !4, !5}
  !llvm.ident = !{!6}

  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 10.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
  !1 = !DIFile(filename: "foo.cpp", directory: "/")
  !2 = !{}
  !3 = !{i32 7, !"Dwarf Version", i32 4}
  !4 = !{i32 2, !"Debug Info Version", i32 3}
  !5 = !{i32 1, !"wchar_size", i32 4}
  !6 = !{!"clang version 10.0.0"}
  !7 = distinct !DISubprogram(name: "D", linkageName: "_ZN1DC2E1B", scope: !8, file: !1, line: 5, type: !28, scopeLine: 5, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, declaration: !27, retainedNodes: !31)
  !8 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "D", file: !1, line: 4, size: 8, flags: DIFlagTypePassByValue | DIFlagNonTrivial, elements: !9, identifier: "_ZTS1D")
  !9 = !{!10, !27}
  !10 = !DIDerivedType(tag: DW_TAG_inheritance, scope: !8, baseType: !11, extraData: i32 0)
  !11 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "C", file: !1, line: 3, size: 8, flags: DIFlagTypePassByValue | DIFlagNonTrivial, elements: !12, identifier: "_ZTS1C")
  !12 = !{!13}
  !13 = !DISubprogram(name: "C", scope: !11, file: !1, line: 3, type: !14, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
  !14 = !DISubroutineType(types: !15)
  !15 = !{null, !16, !17}
  !16 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
  !17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "B", file: !1, line: 2, size: 8, flags: DIFlagTypePassByReference | DIFlagNonTrivial, elements: !18, identifier: "_ZTS1B")
  !18 = !{!19}
  !19 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !17, file: !1, line: 2, baseType: !20, size: 8)
  !20 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "A", file: !1, line: 1, size: 8, flags: DIFlagTypePassByReference | DIFlagNonTrivial, elements: !21, identifier: "_ZTS1A")
  !21 = !{!22}
  !22 = !DISubprogram(name: "A", scope: !20, file: !1, line: 1, type: !23, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
  !23 = !DISubroutineType(types: !24)
  !24 = !{null, !25, !26}
  !25 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !20, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
  !26 = !DIDerivedType(tag: DW_TAG_reference_type, baseType: !20, size: 64)
  !27 = !DISubprogram(name: "D", scope: !8, file: !1, line: 4, type: !28, scopeLine: 4, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
  !28 = !DISubroutineType(types: !29)
  !29 = !{null, !30, !17}
  !30 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
  !31 = !{!32, !34}
  !32 = !DILocalVariable(name: "this", arg: 1, scope: !7, type: !33, flags: DIFlagArtificial | DIFlagObjectPointer)
  !33 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64)
  !34 = !DILocalVariable(name: "b", arg: 2, scope: !7, file: !1, line: 5, type: !17)
  !35 = !DILocation(line: 0, scope: !7)
  !36 = !DILocation(line: 5, scope: !7)

...
---
name:            _ZN1DC2E1B
body:             |
  bb.0.entry:
    liveins: $rdi

    DBG_VALUE $rdi, $noreg, !32, !DIExpression(), debug-location !35
    DBG_VALUE $rsi, $noreg, !34, !DIExpression(DW_OP_deref), debug-location !36
    frame-setup PUSH64r undef $rax, implicit-def $rsp, implicit $rsp
    CFI_INSTRUCTION def_cfa_offset 16
    $rsi = MOV64rr $rsp
    DBG_VALUE $rdi, $noreg, !32, !DIExpression(), debug-location !35
    CALL64pcrel32 @_ZN1CC2E1B, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, implicit $rsi, implicit-def $rsp, implicit-def $ssp, debug-location !36
    $rax = frame-destroy POP64r implicit-def $rsp, implicit $rsp, debug-location !36
    CFI_INSTRUCTION def_cfa_offset 8, debug-location !36
    RETQ debug-location !36

...