Commit fff6a1b0 authored by Leonard Chan's avatar Leonard Chan
Browse files

[SafeStack][DebugInfo] Insert DW_OP_deref in correct location 

This patch addresses the issue found in https://bugs.llvm.org/show_bug.cgi?id=44585
where a DW_OP_deref was placed at the end of a dwarf expression, resulting in
corrupt symbols when debugging.

Differential Revision: https://reviews.llvm.org/D73526
parent 457a6d49

llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp

+3 −3
Original line number Diff line number Diff line
@@ -754,8 +754,8 @@ InstrEmitter::EmitDbgValue(SDDbgValue *SD, 


  // Indirect addressing is indicated by an Imm as the second parameter.

  if (SD->isIndirect())

    Expr = DIExpression::append(Expr, {dwarf::DW_OP_deref});



    MIB.addImm(0U);

  else

    MIB.addReg(0U, RegState::Debug);



  MIB.addMetadata(Var);

llvm/test/DebugInfo/COFF/types-array-advanced.ll

+20 −31
Original line number Diff line number Diff line
@@ -51,39 +51,28 @@ 
; CHECK:     SizeOf: 0

; CHECK:     Name: 

; CHECK:   }

; CHECK:   Pointer (0x1004) {

; CHECK:     TypeLeafKind: LF_POINTER (0x1002)

; CHECK:     PointeeType: 0x1003

; CHECK:     PtrType: Near32 (0xA)

; CHECK:     PtrMode: LValueReference (0x1)

; CHECK:     IsFlat: 0

; CHECK:     IsConst: 0

; CHECK:     IsVolatile: 0

; CHECK:     IsUnaligned: 0

; CHECK:     SizeOf: 0

; CHECK:   }

; CHECK:   Array (0x1005) {

; CHECK:   Array (0x1004) {

; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)

; CHECK:     ElementType: char (0x70)

; CHECK:     IndexType: unsigned long (0x22)

; CHECK:     SizeOf: 7

; CHECK:     Name: 

; CHECK:   }

; CHECK:   Array (0x1006) {

; CHECK:   Array (0x1005) {

; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)

; CHECK:     ElementType: 0x1005

; CHECK:     ElementType: 0x1004

; CHECK:     IndexType: unsigned long (0x22)

; CHECK:     SizeOf: 35

; CHECK:     Name: 

; CHECK:   }

; CHECK:   Array (0x1007) {

; CHECK:   Array (0x1006) {

; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)

; CHECK:     ElementType: 0x1006

; CHECK:     ElementType: 0x1005

; CHECK:     IndexType: unsigned long (0x22)

; CHECK:     SizeOf: 70

; CHECK:     Name: 

; CHECK:   }

; CHECK:   Struct (0x1008) {

; CHECK:   Struct (0x1007) {

; CHECK:     TypeLeafKind: LF_STRUCTURE (0x1505)

; CHECK:     MemberCount: 0

; CHECK:     Properties [ (0x280)
@@ -97,16 +86,16 @@ 
; CHECK:     Name: incomplete_struct

; CHECK:     LinkageName: .?AUincomplete_struct@@

; CHECK:   }

; CHECK:   Array (0x1009) {

; CHECK:   Array (0x1008) {

; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)

; CHECK:     ElementType: incomplete_struct (0x1008)

; CHECK:     ElementType: incomplete_struct (0x1007)

; CHECK:     IndexType: unsigned long (0x22)

; CHECK:     SizeOf: 12

; CHECK:     Name: 

; CHECK:   }

; CHECK:   Pointer (0x100A) {

; CHECK:   Pointer (0x1009) {

; CHECK:     TypeLeafKind: LF_POINTER (0x1002)

; CHECK:     PointeeType: 0x1009

; CHECK:     PointeeType: 0x1008

; CHECK:     PtrType: Near32 (0xA)

; CHECK:     PtrMode: Pointer (0x0)

; CHECK:     IsFlat: 0
@@ -115,7 +104,7 @@ 
; CHECK:     IsUnaligned: 0

; CHECK:     SizeOf: 4

; CHECK:   }

; CHECK:   FieldList (0x100B) {

; CHECK:   FieldList (0x100A) {

; CHECK:     TypeLeafKind: LF_FIELDLIST (0x1203)

; CHECK:     DataMember {

; CHECK:       TypeLeafKind: LF_MEMBER (0x150D)
@@ -125,31 +114,31 @@ 
; CHECK:       Name: s1

; CHECK:     }

; CHECK:   }

; CHECK:   Struct (0x100C) {

; CHECK:   Struct (0x100B) {

; CHECK:     TypeLeafKind: LF_STRUCTURE (0x1505)

; CHECK:     MemberCount: 1

; CHECK:     Properties [ (0x200)

; CHECK:       HasUniqueName (0x200)

; CHECK:     ]

; CHECK:     FieldList: <field list> (0x100B)

; CHECK:     FieldList: <field list> (0x100A)

; CHECK:     DerivedFrom: 0x0

; CHECK:     VShape: 0x0

; CHECK:     SizeOf: 4

; CHECK:     Name: incomplete_struct

; CHECK:     LinkageName: .?AUincomplete_struct@@

; CHECK:   }

; CHECK:   StringId (0x100D) {

; CHECK:   StringId (0x100C) {

; CHECK:     TypeLeafKind: LF_STRING_ID (0x1605)

; CHECK:     Id: 0x0

; CHECK:     StringData: /t.cpp

; CHECK:   }

; CHECK:   UdtSourceLine (0x100E) {

; CHECK:   UdtSourceLine (0x100D) {

; CHECK:     TypeLeafKind: LF_UDT_SRC_LINE (0x1606)

; CHECK:     UDT: incomplete_struct (0x100C)

; CHECK:     SourceFile: /t.cpp (0x100D)

; CHECK:     UDT: incomplete_struct (0x100B)

; CHECK:     SourceFile: /t.cpp (0x100C)

; CHECK:     LineNumber: 4

; CHECK:   }

; CHECK:   Modifier (0x100F) {

; CHECK:   Modifier (0x100E) {

; CHECK:     TypeLeafKind: LF_MODIFIER (0x1001)

; CHECK:     ModifiedType: int (0x74)

; CHECK:     Modifiers [ (0x3)
@@ -157,9 +146,9 @@ 
; CHECK:       Volatile (0x2)

; CHECK:     ]

; CHECK:   }

; CHECK:   Array (0x1010) {

; CHECK:   Array (0x100F) {

; CHECK:     TypeLeafKind: LF_ARRAY (0x1503)

; CHECK:     ElementType: const volatile int (0x100F)

; CHECK:     ElementType: const volatile int (0x100E)

; CHECK:     IndexType: unsigned long (0x22)

; CHECK:     SizeOf: 16

; CHECK:     Name:

llvm/test/DebugInfo/X86/safestack-byval.ll

+1 −1
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ 
; }



; CHECK: ![[ZZZ:.*]] = !DILocalVariable(name: "zzz",

; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], !DIExpression(DW_OP_constu, 400, DW_OP_minus, DW_OP_deref)

; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], !DIExpression(DW_OP_constu, 400, DW_OP_minus)



%struct.S = type { [100 x i32] }

llvm/test/DebugInfo/X86/safestack-deref.ll

0 → 100644
+42 −0
Original line number Diff line number Diff line 
; This test prevents a regression of PR44585 where the DW_OP_deref is incorrectly placed at the end of the expression chain.



; RUN: llc -O0 -mtriple=x86_64-unknown-linux-gnu -filetype=obj %s -o - | llvm-dwarfdump - --name=value | FileCheck %s

; REQUIRES: object-emission



; CHECK:      DW_TAG_variable

; CHECK-NEXT: DW_AT_location

; CHECK-NEXT: DW_OP_breg{{[0-9]+}} R{{[0-9A-Z]+}}-8

; CHECK-NEXT: DW_OP_breg{{[0-9]+}} R{{[0-9A-Z]+}}+8, DW_OP_deref, DW_OP_lit8, DW_OP_minus

; CHECK-NEXT: DW_AT_name ("value")



define dso_local void @_Z4funcv() safestack !dbg !7 {

  %1 = alloca i8, align 8

  call void @llvm.dbg.declare(metadata i8* %1, metadata !11, metadata !DIExpression()), !dbg !22

  call void @extern_func(i8* %1), !dbg !22

  ret void

}

declare void @llvm.dbg.declare(metadata, metadata, metadata)

declare void @extern_func(i8* %0)



!llvm.dbg.cu = !{!0}

!llvm.module.flags = !{!4}



!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, emissionKind: FullDebug)

!1 = !DIFile(filename: "/tmp/test3.cpp", directory: "")

!4 = !{i32 2, !"Debug Info Version", i32 3}

!7 = distinct !DISubprogram(name: "func", linkageName: "_Z4funcv", scope: !8, file: !8, line: 7, type: !9, scopeLine: 7, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0)

!8 = !DIFile(filename: "/tmp/test3.cpp", directory: "")

!9 = !DISubroutineType(types: !10)

!10 = !{null}

!11 = !DILocalVariable(name: "value", scope: !7, file: !8, line: 8, type: !12)

!12 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "A", file: !8, line: 1, size: 64, flags: DIFlagTypePassByValue | DIFlagNonTrivial, elements: !13, identifier: "_ZTS1A")

!13 = !{!14, !18}

!14 = !DIDerivedType(tag: DW_TAG_member, name: "c", scope: !12, file: !8, line: 4, baseType: !15, size: 64, flags: DIFlagPublic)

!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)

!16 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !17)

!17 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)

!18 = !DISubprogram(name: "A", scope: !12, file: !8, line: 3, type: !19, scopeLine: 3, flags: DIFlagPublic | DIFlagPrototyped, spFlags: 0)

!19 = !DISubroutineType(types: !20)

!20 = !{null, !21, !15}

!21 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)

!22 = !DILocation(line: 8, column: 5, scope: !7)