llvm/test/Verifier/func-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

25 lines
846 B
LLVM

; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
define i32 @foo() !dbg !4 {
entry:
ret i32 0, !dbg !6
}
define i32 @bar() !dbg !5 {
entry:
; CHECK: !dbg attachment points at wrong subprogram for function
ret i32 0, !dbg !6
}
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!7, !8}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
!1 = !DIFile(filename: "dwarf-test.c", directory: "test")
!2 = !{}
!4 = distinct !DISubprogram(name: "foo", scope: !0, isDefinition: true, unit: !0)
!5 = distinct !DISubprogram(name: "bar", scope: !0, isDefinition: true, unit: !0)
!6 = !DILocation(line: 7, scope: !4)
!7 = !{i32 2, !"Dwarf Version", i32 3}
!8 = !{i32 1, !"Debug Info Version", i32 3}