llvm/test/DebugInfo/Generic/2010-03-19-DbgDeclare.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

21 lines
870 B
LLVM

; RUN: opt < %s -verify -S | FileCheck %s
; CHECK: DW_LANG_Mips_Assembler
define void @Foo(i32 %a, i32 %b) {
entry:
call void @llvm.dbg.declare(metadata i32* null, metadata !1, metadata !DIExpression()), !dbg !DILocation(scope: !6)
ret void
}
!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!5}
!2 = distinct !DICompileUnit(language: DW_LANG_Mips_Assembler, producer: "clang version 3.3 ", isOptimized: false, emissionKind: FullDebug, file: !4, enums: !3, retainedTypes: !3, globals: !3, imports: !3)
!3 = !{}
!0 = !DILocation(line: 662302, column: 26, scope: !1)
!1 = !DILocalVariable(name: "foo", scope: !6)
!4 = !DIFile(filename: "scratch.cpp", directory: "/usr/local/google/home/blaikie/dev/scratch")
!6 = distinct !DISubprogram(unit: !2)
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
!5 = !{i32 1, !"Debug Info Version", i32 3}