llvm/test/Linker/2011-08-18-unique-class-type.ll
Adrian Prantl 4eeaa0da04 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266446 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-15 15:57:41 +00:00

40 lines
2.0 KiB
LLVM

; RUN: llvm-link %s %p/2011-08-18-unique-class-type2.ll -S -o - | FileCheck %s
; CHECK: DW_TAG_class_type
; CHECK-NOT: DW_TAG_class_type
; Test to check there is only one MDNode for class A after linking.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-macosx10.7.0"
%"class.N1::A" = type { i8 }
define void @_Z3fooN2N11AE() nounwind uwtable ssp !dbg !5 {
entry:
%mya = alloca %"class.N1::A", align 1
call void @llvm.dbg.declare(metadata %"class.N1::A"* %mya, metadata !9, metadata !DIExpression()), !dbg !13
ret void, !dbg !14
}
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!18}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.0 (trunk 137954)", isOptimized: true, emissionKind: FullDebug, file: !16, enums: !2, retainedTypes: !2, globals: !2)
!1 = !{!2}
!2 = !{}
!5 = distinct !DISubprogram(name: "foo", linkageName: "_Z3fooN2N11AE", line: 4, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, file: !16, scope: !6, type: !7)
!6 = !DIFile(filename: "n1.c", directory: "/private/tmp")
!7 = !DISubroutineType(types: !8)
!8 = !{null}
!9 = !DILocalVariable(name: "mya", line: 4, arg: 1, scope: !5, file: !6, type: !10)
!10 = !DICompositeType(tag: DW_TAG_class_type, name: "A", line: 3, size: 8, align: 8, file: !17, scope: !11, elements: !2)
!11 = !DINamespace(name: "N1", line: 2, file: !17, scope: null)
!12 = !DIFile(filename: "./n.h", directory: "/private/tmp")
!13 = !DILocation(line: 4, column: 12, scope: !5)
!14 = !DILocation(line: 4, column: 18, scope: !15)
!15 = distinct !DILexicalBlock(line: 4, column: 17, file: !16, scope: !5)
!16 = !DIFile(filename: "n1.c", directory: "/private/tmp")
!17 = !DIFile(filename: "./n.h", directory: "/private/tmp")
!18 = !{i32 1, !"Debug Info Version", i32 3}