llvm/test/Verifier/metadata-function-dbg.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

23 lines
591 B
LLVM

; RUN: not llvm-as %s -disable-output 2>&1 | FileCheck %s
define void @foo() !dbg !4 !dbg !4 {
unreachable
}
; CHECK-NOT: !dbg
; CHECK: function !dbg attachment must be a subprogram
; CHECK-NEXT: void ()* @bar
; CHECK-NEXT: !{{[0-9]+}} = !{}
define void @bar() !dbg !6 {
unreachable
}
!llvm.module.flags = !{!0}
!0 = !{i32 2, !"Debug Info Version", i32 3}
!llvm.dbg.cu = !{!1}
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2)
!2 = !DIFile(filename: "t.c", directory: "/path/to/dir")
!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !2, unit: !1)
!6 = !{}